U.S. patent application number 13/890868 was filed with the patent office on 2013-11-28 for subdermal tissue remodeling using myostatin, methods and related systems.
This patent application is currently assigned to MyoScience, Inc.. The applicant listed for this patent is MyoScience, Inc.. Invention is credited to Lisa Elkins, Michael Hsu.
Application Number | 20130315924 13/890868 |
Document ID | / |
Family ID | 41053804 |
Filed Date | 2013-11-28 |
United States Patent
Application |
20130315924 |
Kind Code |
A1 |
Hsu; Michael ; et
al. |
November 28, 2013 |
Subdermal Tissue Remodeling Using Myostatin, Methods and Related
Systems
Abstract
Systems and methods of tissue remodeling or altering a surface
of a skin of a patient are provided. A method includes increasing
myostatin activity in a target tissue. Methods can include
increasing myostatin activity in a target tissue in addition to
various tissue remodeling techniques, including cryogenic cooling
of target tissue for tissue remodeling.
Inventors: |
Hsu; Michael; (Oakland,
CA) ; Elkins; Lisa; (Woodside, CA) |
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Applicant: |
Name |
City |
State |
Country |
Type |
MyoScience, Inc.; |
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US |
|
|
Assignee: |
MyoScience, Inc.
Redwood City
CA
|
Family ID: |
41053804 |
Appl. No.: |
13/890868 |
Filed: |
May 9, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12400698 |
Mar 9, 2009 |
8461108 |
|
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13890868 |
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61034781 |
Mar 7, 2008 |
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Current U.S.
Class: |
424/158.1 ;
514/8.9; 604/113 |
Current CPC
Class: |
A61K 38/1841 20130101;
A61Q 19/08 20130101; A61K 38/4893 20130101; A61B 18/02 20130101;
A61K 2800/244 20130101; A61K 45/06 20130101; A61K 39/3955 20130101;
A61K 31/7088 20130101; A61B 18/12 20130101; A61K 38/1841 20130101;
A61K 8/64 20130101; A61K 2300/00 20130101; A61K 31/7088 20130101;
A61K 38/4893 20130101; A61K 2300/00 20130101; A61K 2300/00
20130101 |
Class at
Publication: |
424/158.1 ;
514/8.9; 604/113 |
International
Class: |
A61K 38/18 20060101
A61K038/18; A61B 18/02 20060101 A61B018/02; A61K 39/395 20060101
A61K039/395 |
Claims
1. A method of treatment, the method comprising: delivering
myostatin protein or a functional fragment thereof to a treatment
site underneath a patient's skin so as to modulate myoblasts,
thereby inhibiting myogenesis at or near the treatment site.
2. The method of claim 1, whereby appearances of wrinkles is
reduced in the skin at or near the treatment site.
3. The method of claim 1, further comprising directing cooling
energy to the treatment site underneath the skin.
4. The method of claim 3, which is a method for reducing muscle
spasms at or near the treatment site.
5. The method of claim 3, which is a method for reducing chronic
pain at or near the treatment site.
6. The method of claim 1, further comprising reducing a blood
supply of the treatment site.
7. A method of augmenting a treatment of a patient, the method
comprising: administering a means for increasing myostatin activity
in a target tissue so as to inhibit myogenesis in the target
tissue.
8. The method of claim 7, wherein the means for increasing
myostatin activity is myostatin protein or a functional fragment
thereof.
9. The method of claim 8, wherein the means for increasing
myostatin activity comprises a follistatin binding agent.
10. The method of claim 9, wherein the follistatin binding agent is
an antibody specific for follistatin.
11. The method of claim 9, wherein the follistatin binding agent is
formulated for delivery, and wherein the method further comprises
applying the follistatin binding agent to a skin surface.
12. The method of claim 7, wherein the means for increasing
myostatin activity in the target tissue is administered by
injection directly to the target tissue.
13. The method of claim 7, wherein the means for increasing
myostatin activity in the target tissue is administered topically
adjacent to the target tissue.
14. A delivery device configured to administer a myostatin
increasing agent in or near a subdermal target tissue of a patient,
the device comprising: a composition comprising the myostatin
increasing agent formulated in a physiologically acceptable
carrier; a tissue engaging surface configured for delivery of the
composition to the skin surface; and wherein the tissue engaging
surface and formulation of the composition are configured to
deliver an amount of the myostatin increasing agent to the
subdermal target tissue that is effective to inhibit
myogenesis.
15. The delivery device of claim 14, wherein the myostatin
increasing agent comprises a myostatin protein or functional
fragment thereof.
16. The delivery device of claim 14, wherein the myostatin
increasing agent comprises a follistatin binding agent.
17. A system for treating a subdermal target tissue of a patient,
comprising: a cooling device configured to therapeutically cool the
subdermal target tissue; a composition comprising a myostatin
increasing agent formulated in a physiologically acceptable
carrier; a tissue penetrating probe configured for delivery of the
composition below the skin surface; and wherein the tissue
penetrating probe and the formulation of the composition are
configured to deliver an amount of the myostatin increasing agent
to a subdermal target tissue that is effective to inhibit
myogenesis.
18. The system of claim 17, wherein the tissue penetrating probe is
coupled to a cooling fluid path.
19. The system of claim 18, wherein the therapeutic cooling is
delivered through the tissue penetrating probe.
20. A method of augmenting cosmetic effects of wrinkle reduction
treatment, the method comprising: administering an agent at a
treatment site on or below the skin, wherein the agent comprises a
follistatin inhibiting agent which anti-follistatin antibody is a
species thereof; and wherein the agent modulates myoblasts so as to
inhibit myogenesis, thereby inhibiting lines or wrinkles and
effectively smoothing the skin at or around the treatment site.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a Continuation of U.S. Ser. No.
12/400,698 filed Mar. 9, 2009 (Allowed); which application claims
the benefit of priority of U.S. Provisional Appln. No. 61/034,781
filed Mar. 7, 2008. The disclosures, each of which are incorporated
herein by reference in their entirety for all purposes.
BACKGROUND OF THE INVENTION
[0002] The present invention is generally directed to medical
devices, systems, and methods, particularly for improving the
appearance of a patient and other applications, including
applications cosmetic in nature. Embodiments of the invention
include devices, systems, and methods for increasing myostatin
activity in subcutaneous tissues so as to selectively remodel one
or more target tissues and alter an exposed surface of the skin,
often inhibiting undesirable and/or unsightly effects on the skin
(such as lines, wrinkles, or cellulite dimples) or on other
surrounding tissue. The remodeling of the target tissue may achieve
a desired change in its behavior or composition, and will often
help alleviate cosmetically undesirable characteristics.
[0003] The desire to reshape various features of the human body to
either correct a deformity or merely to enhance one's appearance is
common. This is evidenced by the growing volume of cosmetic surgery
procedures that are performed annually. Many procedures are
intended to change the surface appearance of the skin by reducing
lines and wrinkles. Some of these procedures involve injecting
fillers or stimulating collagen production.
[0004] More recently, pharmacologically based therapies for wrinkle
alleviation and other cosmetic applications have gained in
popularity. Botulinum toxin type A (BOTOX.RTM.) is an example of a
pharmacologically based therapy used for cosmetic applications. It
is typically injected into the facial muscles to block muscle
contraction, resulting in temporary denervation or paralysis of the
muscle. Once the muscle is disabled, the movement contributing to
the formation of the undesirable wrinkle is temporarily eliminated.
Another example of pharmaceutical cosmetic treatment is
mesotherapy, where a cocktail of homeopathic medication, vitamins,
and/or drugs approved for other indications is injected into the
skin to deliver healing or corrective treatment to a specific area
of the body. Various cocktails are intended to effect body
sculpting and cellulite reduction by dissolving adipose tissue, or
skin resurfacing, e.g., via collagen enhancement; or enhancement
can also be achieved via collagen or other injectable. Development
of non-pharmacologically based cosmetic treatments also continues.
For example, endermology is a mechanical based therapy that
utilizes vacuum suction to stretch or loosen fibrous connective
tissues which are implicated in the dimpled appearance of
cellulite. Other examples include transdermal ultrasound, which is
used to reduce fat mass, and several types of energy (e.g., RF)
used to promote collagen building and skin tightening. While
BOTOX.RTM. and/or mesotherapies may temporarily reduce lines and
wrinkles, reduce fat, or provide other cosmetic benefits they are
not without their drawbacks, particularly the dangers associated
with injection of a known toxic substance into a patient, the
potential dangers of injecting unknown and/or untested cocktails,
and the like.
[0005] In light of the above, it would be desirable to provide
improved medical devices, systems, and methods, particularly for
treatment of wrinkles, fat, cellulite, and other cosmetic defects,
as well as some other effects such as treatment of lesions (e.g.,
malignant, benign, etc.), acute or chronic pain, etc. It would be
particularly desirable if these new techniques provided an
alternative visual appearance improvement and/or treatment
mechanism which could replace and/or compliment known bioactive and
other cosmetic therapies, ideally allowing patients to decrease or
eliminate the injection of toxins and harmful cocktails or
pharmaceuticals while providing similar or improved cosmetic
results. It would also be desirable if such techniques were
performed percutaneously using only local or no anesthetic with
minimal or no cutting of the skin, no need for suturing or other
closure methods, no extensive bandaging, and limited or no bruising
or other factors contributing to extended recovery or patient "down
time".
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention generally provides improved medical
devices, systems, and methods for the treatment of cosmetic and
other defects, including those defects that are due at least
partially to muscle activity or contraction in a tissue. The
current invention is based at least partially on the discovery that
activation of myostatin activity in a target tissue can be used to
inhibit muscle contractility and/or mass in that tissue and
alleviate or treat certain defects associated with muscle activity
and contraction, including certain cosmetic defects such as skin
lines or wrinkles. Embodiments of the present invention include
increasing myostatin activity in a target tissue, such as by
delivering a functionally active myostatin peptide to the tissue,
so as to aid in the reduction of muscle contractility and/or mass,
and alleviating certain defects such as surface cosmetic defects,
lines, wrinkles, or rhytids, and the like on the skin surface.
Increasing myostatin activity according to the present invention
can also be used in conjunction with other treatment techniques and
methodologies, such as applying cooling to a tissue, and in some
cases has been observed to prolong the cosmetic or therapeutic
effects (e.g., muscle contractility/mass reducing effects) of a
separately or co-administered treatment. Thus, embodiments of the
present invention can include applying cooling to a tissue, e.g.,
with at least one probe inserted through an exposed surface of the
skin of a patient. The cooling may remodel one or more target
tissue so as to effect a desired change in a composition of the
target tissue and/or a change in its behavior. Exemplary
embodiments of the cooling treatments will interfere with the
nerve/muscle contractile function chain so as to mitigate wrinkles
of the skin, and related treatments may be used therapeutically for
treatment of back and other muscle spasms, chronic pain, and the
like. Some embodiments may remodel subcutaneous adipose tissue or
fibrous connective tissue so as to alter a shape or appearance of
the skin surface.
[0007] In one embodiment, for example, increasing myostatin
activity according to the present methods can be accomplished in
conjunction with application of cooling to a target tissue, and
increasing of myostatin activity in the target tissue can enhance
or increase the duration of the tissue remodeling effects of the
cooling treatment. Examples of tissue cooling can include applying
a cooling to a target tissue with at least one probe though an
exposed surface of the skin of a patient, with the cooling being
applied to tissue of the target below the skin and in some cases to
the surface/skin itself. The cooling may remodel one or more target
tissues so as to effect a desired change in a composition of the
target tissue (e.g., reduced muscle mass) and/or a change in its
behavior (e.g., altered muscle contractility). Cooling treatments
can interfere with the nerve/muscle contractile function chain and
mitigate lines and wrinkles of the skin, and related treatments can
be used for other treatment endpoints, such as treatment for muscle
spasms, back spasms, chronic pain, and the like. In many cases,
prior to remodeling, the skin surface will undesirable cosmetic
features such as lines or wrinkles. Contraction of muscles in the
target tissue, e.g., sub-dermal muscles, and associated movement of
the skin may contribute to the development and appearance of these
lines or wrinkles, and the remodeling can be performed so as to
reduce or eliminate this contraction and/or movement, effectively
smoothing the lines or wrinkles. The skin surface will often
include a region of the face, with target tissues optionally
comprising muscle, nerve, connective tissue nerve/muscle junction,
and/or the like associated with muscle in a target region. The
line/wrinkle alleviation treatment, such as the cooling described
herein, can inhibit contraction of the muscle and/or reduce muscle
mass so as to improve the appearance of the patient. Further
increasing of myostatin activity in the target tissue as either a
separate step (e.g., delivery of myostatin before or after cooling)
or together with cooling can inhibit myogenesis in the target
tissue, and can increase the effectiveness and duration of the
treatment applied.
[0008] Thus, in one aspect of the present invention, a method is
provided for inhibiting myogenesis in a target tissue, which can
inhibit muscle function (e.g., contractility) and/or mass of the
target tissue and alter a surface of a skin of a patient. The
method can include increasing myostatin activity in the target
tissue so as to inhibit myogenesis in the target tissue and inhibit
contraction of muscle in the target tissue and/or reduction in
muscle mass, and an alteration in the surface of the patient's
skin. Inhibition of muscle contraction by increased myostatin
activity may occur indirectly, e.g., where lack of myofibers in the
muscle following agent delivery could result in at least partially
reduced muscle contraction. In some embodiments, inhibiting
myogenesis according to the present invention can be provided in
addition to or in conjunction with other tissue remodeling
treatments, such as skin smoothing or wrinkle reduction treatments,
such as cryogenic cooling techniques, radiofrequency (RF) energy
delivery, delivery of pharmaceutical agents, botulinum toxin (e.g.,
BOTOX.TM.) treatment, surgical methods, or combinations
thereof.
[0009] In another aspect, the present invention can include a
method of treating (e.g., cosmetically treating) a target tissue of
a patient. Such a method can include cooling the target tissue,
e.g., below the skin surface, such that the cooling of the target
tissue inhibits muscle contractility in the target tissue and/or
alters a shape of the skin surface. The method can further include
delivering to the target tissue myostatin or an agent that
increases myostatin activity in the target tissue. Cooling can be
selected to induce muscle damage or otherwise decrease/inhibit
muscle contractility in the target tissue, with increased myostatin
activity in the target tissue inhibiting myogenesis in the target
tissue and increasing repair time of the muscle and
augmenting/increasing the duration of certain effects of the
cooling treatment (e.g., skin smoothing, wrinkle alleviation,
reduction)
[0010] In another aspect, the present invention can include a
method of increasing a duration of a treatment, such as a skin
smoothing treatment, cosmetic treatment, or wrinkle alleviation
technique, including techniques that include tissue remodeling or
inhibiting muscle contractility in a target tissue so as to effect
a skin surface. Such a method can include providing a first
treatment (e.g., skin smoothing) and delivering a myostatin
activity increasing agent to the target tissue so as to inhibit
myogenesis in the target tissue. The increased myostatin activity
can further augment wrinkle reduction of cosmetic effects of the
treatment or increase the duration of the skin smoothing compared
to delivery of the skin smoothing treatment in the absence of the
increased myostatin activity.
[0011] In yet another aspect, the present invention provides
systems and devices. In one embodiment, a system for altering a
surface of a skin of a patient is provided. The system can include
a tissue cooling unit for delivering cooling to a target tissue and
a myostatin agent delivery unit for delivering myostatin or a
myostatin activity increasing agent to the target tissue.
[0012] In some embodiments, the skin surface may have an uneven
cellulite or other adipose tissue-induced texture and/or shape. The
remodeling may be performed so as to smooth such a texture so as to
improve the appearance of the patient. Optionally, the cooling may
be performed so as to induce a reduction in tissue mass, e.g.,
after removal of the probe from the patient. The reduction in
tissue mass may occur as part of a tissue response to the cooling,
optionally as part of the healing process, and the reduction in
tissue mass may at least help provide a desired change in the shape
of the skin surface. For example, where the tissue comprises an
adipose tissue, a healing response to the cooling may decrease a
mass of the adipose tissue by inducing adipose tissue restoration.
In other embodiments, the cooling may reduce muscle mass,
particularly of muscles of the face which are associated with lines
and wrinkles.
[0013] For embodiments including tissue cooling, in general, the
target tissue may be cooled to a temperature from about 10.degree.
C. to about -40.degree. C., with the target tissue optionally being
cooled to a temperature in a range from about 0.degree. C. to about
-15.degree. C., as well as temperatures below about -15.degree. C.,
including a temperature in a range from about 0.degree. C. to about
-20.degree. C. More moderate treatment temperatures (for example,
warmer than about -5.degree. C.) and briefer treatment times may
provide temporary efficacy, while colder treatment temperatures
(for example, at about -5.degree. C. or cooler) and longer
treatment times may result in permanent changes to the target
tissue and/or skin surface shape. Surprisingly, within some
treatment temperature ranges, warmer treatments may provide more
long-term or even permanent efficacy, while colder treatment
temperatures may result in temporary changes to the target tissue
and skin surface shape. For example, in some embodiments long-term
or permanent efficacy of the treatment may be provided through
apoptosis (sometimes referred to as programmed cell death). In
contrast, necrosis-based effects may be reduced or eliminated with
healing. Apoptosis can reduce muscle mass or disrupt the chain of
contractility without inducing inflammation and triggering of the
satellite cells that may be involved in the skeletal muscle repair
process. Alternative mechanisms may also be involved, including a
temporary and/or permanent loss of elasticity in muscle tissues
through changes in morphology of collagen and/or elastin with ice
formation, necrosis, a loss of elasticity in the fibrous connective
tissue, impairment of signal transmission along the neural
pathways, blocking production of acetylcholine (or other chemicals
pertinent to contractility) or disrupting conductivity, hypoxia
(optionally by cutting-off of the blood supply to a muscle or other
tissue in the contractile chain through apoptosis or some other
mechanism), or the like.
[0014] In yet another method aspect, the invention provides a
method for treating a patient. The patient has a skin surface and a
muscle therebelow. The method comprises directing sufficient tissue
remodeling energy or cooling below the skin surface so that
contraction of the muscle is inhibited or a loss of elasticity is
induced. Related methods may comprise applying chemicals, and/or a
means of cutting-off the tissue's blood supply.
[0015] Along with directing of cooling to (for example) a component
of the contractile chain of a muscle, embodiments of the invention
may rely at least in part on any of a variety of forms of energy
transmissions to these or other tissues so as to inhibit muscle
contraction, decrease muscle (or other tissue) mass, and the like.
Suitable energy forms that may be used in place of or in
conjunction with cooling may include ultrasound energy, radio
frequency electrosurgical energy, microwave energy, laser energy,
electromagnetic or particle radiation, and the like. Optionally,
any of these treatment modalities may be combined with the use of
bioactive agents, chemicals, or varied method of cutting off the
tissue's blood supply.
[0016] Methods of the present invention can be directed to a
variety of target tissues and are not limited to any particular
tissue. Target tissues can typically include dermatological tissues
and/or subcutaneous tissues. For example, a target tissue can
include a patient's skin and/or tissue below the skin, or below an
exterior surface of the skin. As set forth above, target tissues
can include muscles or muscle containing tissues, nerves, blood
vessels, as well as adipose tissues. Target tissues can also
include various types of lesions, wounds, and the like, including,
for example, various malignant (e.g., cancerous) or benign lesions,
acne, warts, scar tissue, and the like.
[0017] In another embodiment, the cooling can be selected so as to
induce a reduction in tissue mass, for example, during or proximate
to the time of energy delivery or after removal of the probe from
the patient. Reduction of tissue mass can include mass reduction of
any type of tissue amenable to treatment according to the inventive
methods described herein, including, for example, adipose tissue
(e.g., macrosculpting/microsulpting fat), muscle tissue, skin
tissue, tissue of a wound or lesion (e.g., benign lesion, malignant
lesion, wart, scar tissue, acne, etc.), and the like. In yet
another embodiment, delivery of the cooling energy can promote
healing of the target tissue (e.g., lesion, wound, etc.).
[0018] In yet another aspect of the present invention, a method for
treating a target tissue of a patient is provided. The method
includes inserting a needle probe distally to penetrate into a
target tissue of the patient, and directing a cooling energy into
the target tissue through the probe so as to inhibit contraction of
a muscle of the target tissue and remodel the target tissue. In
some instances, delivery of the cooling energy to the target tissue
can be accomplished using a non-penetrating probe. Thus, in another
aspect, a method of treating a target tissue of a patient is
provided, the method including positioning a non-penetrating probe
in contact with a skin surface of the target tissue, and directing
a cooling energy through the probe and into the target tissue so as
to remodel the target tissue. Target tissues can include, for
example, a lesion, such as an acne lesion.
[0019] For a fuller understanding of the nature and advantages of
the present invention, reference should be made to the ensuing
detailed description and accompanying drawings. Other aspects,
objects and advantages of the invention will be apparent from the
drawings and detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a signaling pathway graphic illustrating certain
aspects of myostatin signaling.
[0021] FIG. 2 is a flowchart schematically illustrating a method
for cosmetically treating a target tissue, according to an
embodiment of the present invention.
[0022] FIG. 3 is a block diagram graphically illustrating
components of a system according to one embodiment of the present
invention.
[0023] FIG. 4A is a perspective view of a self-contained subdermal
cryogenic remodeling probe and system, according to an embodiment
of the invention.
[0024] FIG. 4B is a partially transparent perspective view of the
self-contained probe of FIG. 4A, showing internal components of the
cryogenic remodeling system.
[0025] FIG. 5 and FIGS. 5A-5L illustrates target tissues for
treatment in some embodiments of the present invention, along with
associated lines or wrinkles and treatment patterns.
[0026] FIG. 5M is a functional block diagram graphically
illustrating tissue components included in a contractile chain.
[0027] FIG. 6 is a flowchart schematically illustrating a method
for cosmetically treating a target tissue disposed below a skin
surface using both cryogenic cooling and increasing of myostatin
activity so as to reshape the skin surface.
DETAILED DESCRIPTION OF THE INVENTION
[0028] As set forth above, the present invention is based at least
partially on the discovery that increasing myostatin activity in a
target tissue can inhibit muscle contractility and/or mass in that
tissue and alleviate or treat certain skin features, e.g., cosmetic
features or defects, or defects associated with muscle activity and
contraction, including certain skin surface alterations, lines or
wrinkles. As such, embodiments of the present invention include
increasing myostatin activity in a target tissue so as to inhibit
the process of myogenesis in the target tissue. Increasing
myostatin activity can be accomplished by various methods, such as
by delivering a functionally active myostatin peptide to the
tissue, which will aid in the reduction of muscle contractility
and/or mass. Such increased myostatin activity, according to the
present invention, can alleviate certain defects such as surface
cosmetic defects, lines, wrinkles, or rhytids, and the like on the
skin surface. Increasing myostatin activity according to the
present invention can be used in conjunction with other treatment
techniques and methodologies, and in some cases has been observed
to prolong the cosmetic or therapeutic effects (e.g., muscle
contractility/mass reducing effects) of a separately or
co-administered treatment.
[0029] Among the most immediate applications of the present
invention may be the amelioration of lines and wrinkles,
particularly by inhibiting muscular contractions which are
associated with these cosmetic defects so as so improve an
appearance of the patient. Rather than relying entirely on a
pharmacological toxin or the like to disable muscles so as to
induce temporary paralysis, many embodiments of the invention will
at least in part employ cold to immobilize muscles in combination
with increasing myostatin activity, as described further
herein.
[0030] Myostatin (also known as "Growth and Differentiation Factor
8", or GDF-8) is a muscle specific factor that inhibits the process
of myogenesis and is associated with reduced muscle mass and
various muscle wasting diseases. Myostatin is fairly well
characterized in terms of activity, functionality, signaling
pathways and mechanisms, associated phenotypes (e.g., reduced
muscle mass, muscle wasting, etc.). However, the vast majority of
research focus and development efforts for myostatin related
therapies or treatments focus on inhibiting myostatin activity in
order to increase muscle mass, reduce muscle wasting, and/or
stimulate myogenesis. Few, if any, known techniques focus on
actually increasing myostatin activity or deliberately inhibiting
the process of myogenesis.
[0031] Myostatin is part of the transforming growth factor-.beta.
(TGF-.beta.) superfamily, which is known to play an important role
in proliferation, differentiation, and various other functions in
most cell types during embryonic development and adult homeostasis.
Like other TGF-.beta. family members, myostatin is naturally
synthesized in vivo as a precursor protein that undergoes
proteolytic processing at a dibasic site to generate an N-terminal
propeptide and a disulfide linked C-terminal dimer, which is the
biologically active molecule. The circulating form of myostatin
includes a latent complex of the myostatin C-terminal dimer and
other proteins, including the myostatin propeptide, which inhibit
the biological activity of the C-terminal dimer. (Lee S J and
McPherron A C. Proc. Natl. Acad. Sci. U.S.A. 98: 9306-11
(2001)).
[0032] Myostatin decreases myogenesis, thereby decreasing muscle
mass. Various muscle wasting ailments or diseases have been found
to be related to increased levels of Myostatin. (Carlson C J, Booth
F W, Gordon S E. Am. J. Physiol. 277: R601-6 (1999);
Gonzalez-Cadavid N F, Taylor W E, Yarasheski K, et al. Proc. Natl.
Acad. Sci. U.S.A. 95: 14938-43 (1998); Wehling M, Cai B, Tidball J
G., Faseb J. 14: 103-10 (2000)). Additionally, a distinct role of
myostatin in muscle growth has been observed, including
observations that increased myostatin activity decreases muscle
mass and muscle fiber maintenance. A null mutation in the myostatin
gene found in the cattle population was directly linked to a double
muscling phenotype. (McPherron A C and Lee S J. Proc. Natl. Acad.
Sci. U.S.A. 94: 12457-61 (1997)). Muscle section analysis found
that not only is there an increase in the number of muscle fibers,
but also an increase in the size of the fibers. Recently a group
has shown that ectopic expression of Myostatin can induce muscle
reduced muscle mass. (Durieux A C, Amirouche A, Banzet S, et al.
Endocrinology 148: 3140-3147 (2007)). Myostatin mechanisms of
action are still being elucidated and may include inhibition of
satellite cell activation, satellite cell renewal, myoblast
proliferation, myoblast differentiation, and/or maintenance of
muscle fiber. Numerous studies have shown that myostatin seems to
cause muscle reduction at every step of myogenesis, including the
maintenance of muscle fibers (Thomas M, Langley B, Berry C, et al.
J. Biol. Chem. 275: 40235-43 (2000); Durieux A C, Amirouche A,
Banzet S, et al. Endocrinology 148: 3140-3147 (2007); McCroskery S,
Thomas M, Maxwell L, Sharma M, Kambadur R. J. Cell. Biol. 162:
1135-47 (2003)). It has also been shown that myostatin has a
specific impact on skeletal muscle while leaving other muscle
types, such as cardiac muscle unaffected (Cohn R D, Liang H Y,
Shetty R, Abraham T, Wagner K R. Neuromuscul. Disord. 17: 290-6
(2007)).
[0033] Investigations of the mechanism of how myostatin inhibits
muscle growth have elucidated certain aspects of the myostatin
signaling pathway and signaling mechanisms. For example, studies
have shown that increasing levels of Follistatin can inhibit
myostatin and increase myogenesis. Follistatin-related protein
(FLRP) and follistatin are known to directly bind and inhibit
myostatin and its receptor. (Zhu J, Li Y, Shen W, et al. J. Biol.
Chem. 282: 25852-25863 (2007)). Also, myostatin has been show to
inhibit cellular progression through the cell cycle and into the S
phase of the cell cycle, particularly through upregulation of p21
expression (Cdk inhibitor) (Thomas M, Langley B, Berry C, et al. J.
Biol. Chem. 275: 40235-43 (2000)). However, some details of the
exact molecular mechanism that myostatin plays in myogenesis has
yet to be elucidated.
[0034] In myostatin signaling, myostatin interacts with the ActR2A
and ActR2B receptors (activin type II receptors) which leads to an
overall inhibition of myogenesis of the cell (see FIG. 1). (Lee S
J, Reed L A, Davies M V, et al. Proc. Natl. Acad. Sci. U.S.A. 102:
18117-22 (2005)). The main genes known to be affected by myostatin
signaling are the myogenic regulatory factors (MRF), such as, for
example, myogenin, MyoD, and MyfS. Additionally, there are at least
29 ligands that can signal 5 type II and 7 type I receptors in the
TGF-.beta. superfamily. Each ligand can recruit a unique
combination of receptors that will signal a specific set of SMAD
proteins in the cell. The effector SMAD proteins can then change
gene expression via recognition of the SMAD binding element of the
DNA. (Derynck R, Zhang Y E. Nature 425: 577-84 (2003)).
[0035] As mentioned above, there are various muscle wasting are
related to increased myostatin activity. Such muscle wasting
diseases include, e.g., muscular dystrophy, AIDS wasting syndrome,
and some types of cancer. There are reported clinical trials on
increasing the muscle mass of people who are suffering through a
muscular dystrophy disease. Efforts to reduce muscle wasting
include inhibiting the myostatin activity or signaling of
myostatin. One method of inhibiting myostatin activity is by use
myostatin blocking compounds, such as recombinant human antibodies
that specifically bind to myostatin and inhibit the protein from
signaling its receptor (Wyeth). Another reported approach is the
use of a soluble form of the activin type II receptor (ACVR2B/Fc)
to bind available myostatin in the environment. This is designed to
effectively reduce the availability of myostatin to signal through
the endogenously available activin type II receptor present on the
cell membrane.
[0036] FIG. 1 illustrates certain basic aspects of myostatin
signaling. Referring to FIG. 1, myostatin interacts with activin
type II receptors at the cell surface. Once activated, the activin
type II receptors will initiate the SMAD phosphorylation cascade.
The final effector SMAD will result in a change in gene expression
at the transcription level; therefore, leading to an inhibition of
myogenesis. Follistatin or a follis regulates the amount of
available myostatin for signaling by directly binding to myostatin.
Increasing myostatin activity according to the present methods can
include addressing and effecting myostatin signaling at any step
along the myostatin signaling pathway.
[0037] Thus, the term "myostatin" refers to a specific growth and
differentiation factor-8, as well known and described throughout
the art, that is part of the TGF-.beta. superfamily. A myostatin
protein or peptide refers to the full-length unprocessed precursor
form of myostatin, as well as any mature peptides or propeptides,
or any peptide forms resulting from post-translational processing
(e.g., cleavage), or any combinations thereof. Unless otherwise
specified as inactive, a myostatin protein or peptide as described
herein will retain one or more myostatin biological activities. The
term also refers to any fragments and variants of a myostatin
protein that maintain at least one biological activity associated
with mature myostatin (e.g., myogenesis inhibiting activity), as
discussed herein, including sequences that have been modified in
any way. The present invention will most typically include human
forms of myostatin, or variants thereof, but can include myostatin
from any vertebrate species, including, but not limited to, human,
bovine, chicken, mouse, rat, porcine, ovine, turkey, baboon, and
fish. For non-limiting, exemplary peptide and nucleic acid sequence
information, see, e.g., McPherron et al., Proc. Nat. Acad. Sci.
U.S.A. 94:12457-12461 (1997); U.S. Pat. No. 7,179,884; each of
which is herein incorporated by reference.
[0038] Myostatin activity refers to one or more physiologically
growth-regulatory or morphogenetic activities associated with
active myostatin protein. For example, active myostatin is a
negative regulator of skeletal muscle mass and inhibitor of the
process of myogenesis. Active myostatin can also modulate the
production of muscle-specific enzymes (e.g., creatine kinase),
stimulate myoblast proliferation, and modulate preadipocyte
differentiation to adipocytes. Myostatin activity includes
myostatin binding activity or one or more binding properties of a
functionally active myostatin protein. For example, mature
myostatin specifically binds to the propeptide portion of
myostatin, to ActRIIB, to a myostatin receptor, to activin, to
follistatin, to follistatin-domain-containing proteins, to GASP-1,
and to other proteins. A myostatin activity increasing agent, such
as an antibody or portion thereof, may reduce one or more of these
binding activities that would otherwise cause a decrease in
myostatin activity. Thus, a myostatin activity increasing agent, in
one embodiment, can include an agent that inhibits an inhibitor of
myostatin activity. Exemplary procedures for measuring myostatin
activity in vivo and in vitro are known in the are and
described--see, e.g., U.S. patent application Ser. No.
11/387,643.
[0039] A myostatin modulating agent includes any agent capable of
modulating myostatin activity in a target tissue. Myostatin
activity is as described above, and modulation can include, without
limitation, effecting signaling, expression, processing, or
secretion of myostatin, or a pharmaceutically acceptable derivative
thereof. Agents that either increase or decrease one or more
myostatin activities are encompassed by the term. Typically, for
purposes of the present invention, agents that increase myostatin
activity in a target tissue will be selected for use as described
herein. In certain embodiments, a myostatin activity increasing
agent will affect binding of myostatin to one or more of its
physiological binding partners, including, but not limited to a
receptor (e.g. ActRIIB), a follistatin-domain containing protein
(e.g. follistatin, FLRG, GASP-1, GASP-2), or a myostatin protein
such as the myostatin propeptide and mutants and derivatives
thereof. Such myostatin activity increasing agents can include, for
example, antibodies that specifically bind to an inhibitor of
myostatin activity or bind to other proteins that specifically bind
to myostatin (such as the myostatin propeptide, mutants and
derivatives of the myostatin propeptide, follistatin,
follistatin-domain containing proteins, and Fc fusions of these
proteins). Myostatin activity increasing agents can include
proteins, antibodies, peptides, peptidomimetics, ribozymes, nucleic
acids, anti-sense oligonucleotides, double-stranded RNA, siRNA
(e.g. for RNAi), small molecules, and various compounds or
molecules which specifically increase myostatin activity in a
target tissue. Such agents are said to increase or enhance
myostatin activity in a target tissue, with the term increased
myostatin activity being used in reference to a baseline level of
the specified activity (e.g., myogenesis, muscle mass or
contractility, etc.), which can include a measurable difference
compared to the level of the specified activity in the absence of
the agent having the modulating effect.
[0040] Thus, in one embodiment, the present invention includes
delivering a composition comprising myostatin peptide, or
functional fragment thereof, to the target tissue. In such an
embodiment, the myostatin peptide or active fragment is considered
a myostatin activity increasing agent. The myostatin protein
composition can be delivered (e.g., injected, syringe delivered,
etc.) directly into the target tissue in order to increase
myostatin activity and inhibit myogenesis in the target tissue.
Compositions can make use of one or more carriers, stabilizers,
physiologically acceptable carriers, suspension media,
formulations, and the like and can be delivered to the target
tissue by any suitable method (see below).
[0041] In yet another embodiment of the present invention,
increasing myostatin activity in a target tissue can be
accomplished by delivering to the target tissue a polynucleotide
encoding a myostatin protein. For example, a myostatin protein or
functional fragment can be encoded in a polynucleotide or an
expressible polynucleotide, wherein the polynucleotide is contacted
with a cell of the target tissue under conditions suitable for
introduction of the polynucleotide into the cell and expression of
the encoded myostatin protein. The cell into which the expressible
polynucleotide is introduced can, but need not be, the target cell
(i.e., muscle cell of the target tissue), provided that when the
cell is not the target cell, the expressed myostatin protein is
secreted, actively or passively, from the cell such that it can
contact the target cell and effect its action.
[0042] The term "polynucleotide" is used broadly herein to mean a
sequence of two or more deoxyribonucleotides or ribonucleotides
that are linked together by a phosphodiester bond. As such, the
term "polynucleotide" includes RNA and DNA, which can be a gene or
a portion thereof, a cDNA, a synthetic polydeoxyribonucleic acid
sequence, or the like, and can be single stranded or double
stranded, as well as a DNA/RNA hybrid. Furthermore, the term
"polynucleotide" as used herein includes naturally occurring
nucleic acid molecules, which can be isolated from a cell, as well
as synthetic molecules, which can be prepared, for example, by
methods of chemical synthesis or by enzymatic methods such as by
the polymerase chain reaction (PCR). In various embodiments, the
polynucleotide can contain nucleoside or nucleotide analogs, or a
backbone bond other than a phosphodiester bond. A polynucleotide
comprising naturally occurring nucleotides and phosphodiester bonds
can be chemically synthesized or can be produced using recombinant
DNA methods, using an appropriate polynucleotide as a template. In
comparison, a polynucleotide comprising nucleotide analogs or
covalent bonds other than phosphodiester bonds generally will be
chemically synthesized, although an enzyme such as T7 polymerase
can incorporate certain types of nucleotide analogs into a
polynucleotide and, therefore, can be used to produce such a
polynucleotide recombinantly from an appropriate template (Jellinek
et al., supra, 1995).
[0043] Where the polynucleotide encodes a peptide (e.g., myostatin
peptide), the coding sequence can be contained in a vector and
operatively linked to appropriate regulatory elements, including,
if desired, a tissue specific promoter or enhancer, or an peptide
tag, expression marker, or any number of other elements. As used
herein, the term "operatively linked" or "operatively associated"
means that two or more molecules are positioned with respect to
each other such that they act as a single unit and effect a
function attributable to one or both molecules or a combination
thereof. For example, a polynucleotide sequence encoding a
myostatin polypeptide can be operatively linked to a regulatory
element, in which case the regulatory element confers its
regulatory effect on the polynucleotide similarly to the way in
which the regulatory element would effect a polynucleotide sequence
with which it normally is associated with in a cell. A first
polynucleotide coding sequence also can be operatively linked to a
second (or more) coding sequence such that a chimeric polypeptide
can be expressed from the operatively linked coding sequences.
[0044] A polynucleotide useful in performing a method of the
invention, can be contained in a vector, which can facilitate
manipulation of the polynucleotide, including introduction of the
polynucleotide into a target cell. The vector can be a cloning
vector, which is useful for maintaining the polynucleotide, or can
be an expression vector, which contains, in addition to the
polynucleotide, regulatory elements useful for expressing the
polynucleotide and, where the polynucleotide encodes a polypeptide,
for expressing the encoded peptide in a particular cell. An
expression vector can contain the expression elements necessary to
achieve, for example, sustained transcription of the encoding
polynucleotide, or the regulatory elements can be operatively
linked to the polynucleotide prior to its being cloned into the
vector.
[0045] An expression vector (or the polynucleotide) generally
contains or encodes a promoter sequence, which can provide
constitutive or, if desired, inducible or tissue specific or
developmental stage specific expression of the encoding
polynucleotide, a poly-A recognition sequence, and a ribosome
recognition site or internal ribosome entry site, or other
regulatory elements such as an enhancer, which can be tissue
specific. The vector also can contain elements required for
replication in a prokaryotic or eukaryotic host system or both, as
desired. Such vectors, which include plasmid vectors and viral
vectors such as bacteriophage, baculovirus, retrovirus, lentivirus,
adenovirus, vaccinia virus, semliki forest virus and
adeno-associated virus vectors, are well known and can be purchased
from a commercial source (Promega, Madison Wis.; Stratagene, La
Jolla Calif.; GIBCO/BRL, Gaithersburg Md.) or can be constructed by
one skilled in the art (see, for example, Meth. Enzymol., Vol. 185,
Goeddel, ed. (Academic Press, Inc., 1990); Jolly, Canc. Gene Ther.
1: 51-64, 1994; Flotte, J. Bioenerg. Biomemb. 25: 37-42, 1993;
Kirshenbaum et al., J. Clin. Invest. 92: 381-387, 1993; each of
which is incorporated herein by reference). A tetracycline (tet)
inducible promoter is an example of a promoter that can be useful
for driving expression of a polynucleotide, wherein, upon
administration of tetracycline, or a tetracycline analog, to a
subject containing a polynucleotide operatively linked to a tet
inducible promoter, expression of the encoded polypeptide is
induced.
[0046] The polynucleotide also can be operatively linked to tissue
specific regulatory element, for example, a muscle cell specific
regulatory element, such that expression of an encoded peptide is
restricted to muscle cells in target tissue or tissue region of an
individual, or a mixed population of cells.
[0047] Viral expression vectors can be particularly useful for
introducing a polynucleotide into a cell, particularly a target
tissue cell in a subject. Viral vectors provide the advantage that
they can infect host cells with relatively high efficiency and can
infect specific cell types. For example, a polynucleotide encoding
a myostatin polypeptide can be cloned into a baculovirus vector,
which then can be used to infect an insect host cell, thereby
providing a means to produce large amounts of the myostatin. The
viral vector also can be derived from a virus that infects cells of
an organism of interest, for example, vertebrate host cells such as
mammalian, avian or piscine host cells. Viral vectors can be
particularly useful for introducing a polynucleotide useful in
performing a method of the invention into a target cell. Viral
vectors have been developed for use in particular host systems,
particularly mammalian systems and include, for example, retroviral
vectors, other lentivirus vectors such as those based on the human
immunodeficiency virus (HIV), adenovirus vectors, adeno-associated
virus vectors, herpesvirus vectors, vaccinia virus vectors, and the
like (see Miller and Rosman, BioTechniques 7: 980-990, 1992;
Anderson et al., Nature 392: 25-30 Suppl., 1998; Verma and Somia,
Nature 389: 239-242, 1997; Wilson, New Engl. J. Med. 334: 1185-1187
(1996), each of which is incorporated herein by reference).
[0048] A polynucleotide, which can be contained in a vector, can be
introduced into a cell by any of a variety of methods known in the
art (Sambrook et al., Molecular Cloning: A laboratory manual (Cold
Spring Harbor Laboratory Press 1989); Ausubel et al., Current
Protocols in Molecular Biology, John Wiley and Sons, Baltimore, Md.
(1987, and supplements through 1995), each of which is incorporated
herein by reference). Such methods include, for example,
transfection, lipofection, microinjection, electroporation and,
with viral vectors, infection/transduction; and can include the use
of liposomes, microemulsions or the like, which can facilitate
introduction of the polynucleotide into the cell and can protect
the polynucleotide from degradation prior to its introduction into
the cell. The selection of a particular method will depend, for
example, on the cell into which the polynucleotide is to be
introduced, as well as other conditions and desired effects,
delivery means, tissue localization, and the like.
[0049] A composition of the invention can be prepared for
administration to a subject by mixing the myostatin protein or
agent with a physiologically acceptable carrier, which is nontoxic
in the amount employed. Preparation of such a composition can
include combining the myostatin agent with saline, buffers,
carriers, stabilizers and the like. Compositions can be maintained,
for example, as a suspension or an emulsion, or can be lyophilized,
then formulated as desired under conditions such that they are
suitably prepared for use in the desired application. As such, the
compositions are useful in treating a disorder (e.g., cosmetic
disorder, wrinkle, etc.) or for a purpose as disclosed herein. A
physiologically acceptable carrier can be any material that, when
combined with an a myostatin agent allows the ingredient to retain
the desired activity (e.g., biological activity). Examples of such
carriers include any of the standard physiologically acceptable
carriers such as a phosphate buffered saline solution, water,
emulsions such as oil/water emulsion, and various types of wetting
agents. Compositions comprising such carriers are formulated by
well known conventional methods (see, for example, Remington's
Pharmaceutical Sciences, Chapter 43, 14th Ed., Mack Publishing Co.,
Easton Pa. 18042, USA).
[0050] It will be recognized to the skilled clinician that the
choice of a carrier, including a physiologically acceptable
compound, depends, for example, on the manner in which the compound
is to be administered, as well as on the route of administration of
the composition. A composition can be administered, for example,
intramuscularly, intradermally, or subcutaneously, and also can be
administered by injection, topical administration, or other such
method known in the art. A composition comprising a peptide or
polynucleotide, for example, can be incorporated within an
encapsulating material such as into an oil-in-water emulsion, a
microemulsion, micelle, mixed micelle, liposome, microsphere or
other polymer matrix (see, for example, Gregoriadis, Liposome
Technology, Vol. 1 (CRC Press, Boca Raton, Fla. 1984); Fraley, et
al., Trends Biochem. Sci., 6: 77, 1981, each of which is
incorporated herein by reference).
[0051] In another embodiment of the present invention, increasing
myostatin activity in a target tissue, according to methods of the
invention, can be used in conjunction with other treatment
techniques and methodologies. For example, methods of increasing
myostatin activity in a target tissue can be utilized in
conjunction with other cosmetic treatments, such as wrinkle
alleviation treatments.
[0052] FIG. 2 provides a flowchart illustrating a method 10 of
treating a target tissue of a patient, according to an embodiment
of the present invention. A first treatment (e.g., wrinkle
alleviation treatment) can be provided to the patient (Step 12).
The treatment will be selected to at least partially remodel the
target tissue so as to alter the surface of the skin, and treatment
can include inhibiting contraction or contractility of muscles
(e.g., subdermal muscles) that cause a irregularity or wrinkle in
the surface of the skin (Step 14). Next, an agent is delivered to
the target tissue so as to increase myostatin activity in the
target tissue (Step 16). Myostatin activity in the target tissue is
increased, which can inhibit myogenesis in the cells (muscle cells)
of the target tissue (Step 18). The increased myostatin activity
can further remodel the target tissue, e.g., further inhibiting
muscle contractility, reducing muscle mass, and/or increase the
duration of the effects of the first treatment of Step 12 (Step
20). The process can optionally be repeated at any point (Step 22).
In one embodiment, as illustrated, myostatin agent can be delivered
following an initial (e.g., "first") treatment, though order can
optionally be reversed, or delivered substantially at the same
time.
[0053] One such method that can be used in conjunction with
myostatin activity increasing techniques described herein is
application or delivery of cryogenic cooling to a target tissue.
Thus, many embodiments of the invention will at least in part
employ cold to immobilize muscles. Advantageously, nerves, muscles,
and associated tissues may be temporarily immobilized using
moderately cold temperatures of 10.degree. C. to -5.degree. C.
without permanently disabling the tissue structures. Using an
approach similar to that employed for identifying structures
associated with atrial fibrillation, a needle probe or other
treatment device can be used to identify a target tissue structure
in a diagnostic mode with these moderate temperatures, and the same
probe (or a different probe) can also be used to provide a longer
term or permanent treatment, optionally by ablating the target
tissue zone and/or inducing apoptosis at temperatures from about
-5.degree. C. to about -50.degree. C. In some embodiments,
apoptosis may be induced using treatment temperatures from about
-1.degree. C. to about -15.degree. C., optionally so as to provide
a permanent treatment that limits or avoids inflammation and
mobilization of skeletal muscle satellite repair cells. Apoptosis
also may be induced using treatment temperatures below about
-15.degree. C., including temperatures from about -1.degree. C. to
about -20.degree. C. Hence, the duration of the treatment efficacy
of such subdermal cryogenic treatments may be selected and
controlled, with colder temperatures, longer treatment times,
and/or larger volumes or selected patterns of target tissue
determining the longevity of the treatment. Non-limiting exemplary
systems and techniques for cryogenic cooling of target tissues that
can be employed in the present invention are further described, for
example, in commonly owned, co-pending applications U.S.
application Ser. No. 11/295,204 (now U.S. Pat. No. 7,713,266); U.S.
application Ser. No. 11/770,185 (now U.S. Pat. No. 7,850,683); U.S.
application Ser. No. 11/614,887 (Attorney Docket No.
90064-000300US-717076); U.S. application Ser. No. 11/675,886 (now
U.S. Pat. No. 8,409,185), the full disclosures of which are
incorporated herein by reference.
[0054] Referring to FIG. 3, a system 30 for providing treatment to
a patient with a combination of tissue cooling and increasing
myostatin activity in a target tissue is described. The system
includes a target tissue cooling unit 32 and a myostatin agent
delivery unit 34. The cooling unit 32 will typically include a
cooling fluid source 36 that can be coupled to a delivery means 38
for delivering cooling to the target tissue. Various cooling
delivery structures can be utilized according to the present
invention, e.g., as described further herein, and, in one
embodiment, can include a probe, such as a needle-like probe with a
tissue piercing portion (e.g., tissue piercing distal end). Such a
probe can be coupled to the source 36 such that the probe is in
thermal communication with the source. The myostatin agent delivery
unit 34 can include a source 40 for a myostatin activity increasing
agent (e.g., see above) and a means 42 for delivering the agent or
myostatin composition to the target tissue. Delivery of a myostatin
agent or composition can include a variety of methodologies and/or
structures, as described further herein, including, for example,
injection of a composition into the target tissue, topical
administration, vector compositions, and the like.
[0055] Referring now to FIGS. 4A and 4B, an exemplary system for
subdermal cryogenic remodeling that can be employed for use in the
present invention is described. The system 50 comprises a
self-contained probe handpiece generally having a proximal end 52
and a distal end 54. A handpiece housing 56 has a size and shape
suitable for supporting in a hand of a surgeon or other system
operator. As can be seen most clearly in FIG. 4B, a cryogenic
cooling fluid supply 58 and electrical power source 60 are found
within housing 56, along with a circuit 62 having a processor for
controlling cooling applied by self-contained system 10 in response
to actuation of an input 64.
[0056] Extending distally from distal end 54 of housing 56 is a
tissue-penetrating cryogenic cooling probe 66. Probe 66 is
thermally coupled to a cooling fluid path extending from cooling
fluid source 58, with the exemplary probe comprising a tubular body
receiving at least a portion of the cooling fluid from the cooling
fluid source therein. The exemplary probe 66 comprises a 30 g
needle having a sharpened distal end that is axially sealed.
Needles of various sizes can be included in the present invention
and can include needles smaller than 20 g needles, as well as
embodiments with needles sized from 14 g to 32 g. Probe 66 may have
an axial length between distal end 54 of housing 56 and the distal
end of the needle of between about 1/2 mm and 5 cm, preferably
having a length from about 1 mm to about 3 mm, and from about 1 cm
to about 3 cm. Such needles may comprise a stainless steel tube
with an inner diameter of about 0.006 inches and an outer diameter
of about 0.012 inches, while alternative probes may comprise
structures having outer diameters (or other lateral cross-sectional
dimensions) from about 0.006 inches to about 0.100 inches.
[0057] Additionally, while needles are generally illustrated herein
as being straight or substantially linear, needles suitable for use
in the present invention can include a variety of shapes and
configurations. For example, needles can be curved or comprise a
curved portion, including pre-bent or curve-shaped needles, and the
like. Also, while a needle or probe 66 will generally extend
distally from the distal end 54 of the housing, the positioning of
the probe is not limited to any particular orientation and can, for
example, extend substantially along a long axis of the housing 56,
or the probe 66 can be at an angle relative to the long axis.
Particular shape and/or configuration or orientation of the probe
66 may depend at least partially on the intended use of the device,
as certain probe shapes, configurations, and/or orientations may be
desired for particular treatments or probe positioning within a
target tissue.
[0058] Addressing some of the components within housing 56, the
exemplary cooling fluid supply 58 comprises a cartridge containing
a liquid under pressure, with the liquid preferably having a
boiling temperature of the less than 37.degree. C. When the fluid
is thermally coupled to the tissue-penetrating probe 66, and the
probe is positioned within the patient so that an outer surface of
the probe is adjacent to a target tissue, the heat from the target
tissue evaporates at least a portion of the liquid and the enthalpy
of vaporization cools the target tissue. A valve (not shown) may be
disposed along the cooling fluid flow path between cartridge 58 and
probe 66, or along the cooling fluid path after the probe so as to
limit the temperature, time, rate of temperature change, or other
cooling characteristics. The valve will often be powered
electrically via power source 60, per the direction of processor
62. The exemplary power source 60 comprises a rechargeable or
single-use battery.
[0059] The exemplary cooling fluid supply 58 comprises a single-use
cartridge. Advantageously, the cartridge and cooling fluid therein
may be stored and/or used at (or even above) room temperature. The
cartridges may have a frangible seal or may be refillable, with the
exemplary cartridge containing liquid N.sub.2O. A variety of
alternative cooling fluids might also be used, with exemplary
cooling fluids including fluorocarbon refrigerants and/or carbon
dioxide. The quantity of cooling fluid contained by cartridge 58
will typically be sufficient to treat at least a significant region
of a patient, but will often be less than sufficient to treat two
or more patients. An exemplary liquid N.sub.2O cartridge might
contain, for example, a quantity in a range from about 7 g to about
30 g of liquid. Other embodiments can include liquid N.sub.2O
cartridge in a quantity less than about 7 g, including embodiments
designed for a smaller limited amount of use or even single
use.
[0060] Processor 62 will typically comprise a programmable
electronic microprocessor embodying machine readable computer code
or programming instructions for implementing one or more of the
treatment methods described herein. The microprocessor will
typically include or be coupled to a memory (such as a non-volatile
memory, a flash memory, a read-only memory ("ROM"), a random access
memory ("RAM"), or the like) storing the computer code and data to
be used thereby, and/or a recording media (including a magnetic
recording media such as a hard disk, a floppy disk, or the like; or
an optical recording media such as a CD or DVD) may be provided.
Suitable interface devices (such as digital-to-analog or
analog-to-digital converters, or the like) and input/output devices
(such as USB or serial I/O ports, wireless communication cards,
graphical display cards, and the like) may also be provided. A wide
variety of commercially available or specialized processor
structures may be used in different embodiments, and suitable
processors may make use of a wide variety of combinations of
hardware and/or hardware/software combinations. For example,
processor 62 may be integrated on a single processor board and may
run a single program or may make use of a plurality of boards
running a number of different program modules in a wide variety of
alternative distributed data processing or code architectures.
[0061] It will be noted that systems and devices of the present
invention can make use of a variety of power sources including, for
example, an on-board power sources, such as a battery that can
provide for a more portable and/or maneuverable, as well as
self-contained, system or device. In one embodiment, for example, a
power source 60 (e.g., battery) can be positioned in and/or affixed
to the handpiece housing 16 or otherwise coupled with the housing
56 in a manner such that the probe device, including the needle
probe 66, battery or power source 60, as well as other components,
can be manipulated and positioned my manipulation of the handpiece
housing 56.
[0062] Besides cryogenic tissue cooling techniques, including those
described above, other wrinkle alleviation and/or cosmetic
treatment methods will find use in the present inventive methods.
One such treatment that can be provided according to the current
methods, which is commonly used for cosmetic treatment of skin
surface alterations and wrinkles, includes BOTOX.TM. (botulinum
neurotoxin A) treatment techniques. Currently, BOTOX.TM. is a
popularly used neurotoxin is used to temporarily eliminate muscle
movement in the face for cosmetic aesthetics. Botox has also been
used off label for therapeutic treatments which has led to serious
adverse events which include death (Cote T R, Mohan A K, Polder J
A, Walton M K, Braun M M. J. Am. Acad. Dermatol. 53: 407-15
(2005)). Other non-limiting examples of cosmetic treatment methods
and/or wrinkle alleviation techniques include application of other
forms of energy delivery, including radiofrequency (e.g., RF
ablation), ultrasound energy, and the like, as well as various
surgical treatments and methodologies.
[0063] As indicated above, among the most immediate applications of
the present invention may be the amelioration of lines and
wrinkles, particularly by inhibiting muscular contractions which
are associated with these cosmetic defects so as to improve an
appearance of the patient. Referring now to FIGS. 5 through 5M,
subdermal remodeling of tissues for alleviation of lines and
wrinkles will find particular applications for skin surface regions
of the face and neck, with procedures optionally being performed so
as to alter contractile function of muscles A-I in the upper
one-third of the face as shown in FIG. 5. Treatments may be
performed so as to alleviate frown lines, lines or wrinkles between
the eyes, crow's feet, horizontal lines in the forehead, neck,
wrinkles around the mouth, chin, and the like. Many of these
cosmetic defects may be treated by targeting and/or inactivating
tissues such as the corrugator and/or procerus muscles. More
specifically, as seen in FIGS. 5A and 5B, movement of the facial
muscles can cause the skin to crease, for example, with contraction
of corrugator muscle J and/or procerus muscle K leading to creases
between the brows L, which may be clinically referred to as
glabellar lines. Additional treatment locations, muscles M-Q whose
contractile function may be targeted, related lines or wrinkles,
and treatment patterns R are illustrated in FIGS. 5C-5L.
[0064] Regarding the specific muscles and tissue structures
identified in FIG. 5, treatments may be directed towards one or
more of levator palpebrae superioris A, orbicularis oculi B,
frontalis C, levator labii D, corrugator E, zygomaticus minor F,
zygomaticus major G, buccinator H, and/or temporalis I. Treatments
targeting contraction of oticularis M of FIG. 5C may help decrease
crow's feet wrinkles of FIG. 5H, optionally using a treatment
pattern R. Treatments altering the function of Frontalis N of FIG.
5D may alleviate the wrinkles of FIG. 5I, while altering
functioning of Orbicularis O of FIG. 5E may alleviate the wrinkles
shown in FIG. 5J. Wrinkles of the chin as shown in FIG. 5K may be
mitigated by treatment of Mentalis P and neck wrinkles such as
those of FIG. 5L may be improved by treatments of platysma Q, as
seen in FIG. 5G. Treatment patterns R for improvement of these and
other cosmetic defects may correspond to or be derived from known
treatments (such as patterns for injections of BOTOX.RTM. or the
like), may be determined by anatomical analysis using the desired
physiological effects, by animal or clinical studies, or the
like.
[0065] Target muscles for contraction inhibition so as to alleviate
wrinkles and the like may often include the glabellar and procerus
complex including, but not limited to, the corrugator procerus,
orbicularis oculi, depressor, supercilli, and frontalis. Other
muscle groups of the facial region may also be
contraction-inhibited, such as the nasalis, orbicularis oris,
buccinator, depressor anguli oris, quadratus labii superioris and
inferioris, zygomaticus, maxillae, platysma, and mentalis.
Contraction of these and/or other muscles may be inhibited by
targeting associated nerve tissues, connective tissues,
nerve/muscle interface, blood supply, and/or at least a portion of
tissues of one or more of these muscles themselves. Preferred
wrinkle alleviation treatments may alter functioning of muscles
including one or more of, but not limited to, frontalis pars
medialis, frontalis pars lateralis, corrugator supercilii,
procerus, depressor supercilii, levator palpebrae superioris,
orbicularis oculi pars orbitalis, orbicularis oculi pars
palpebralis, levator labii superioris alaquae nasi, levator labii
superioris, zygomaticus minor, zygomaticus major, levator anguli
oris (a.k.a. caninus), buccinator, depressor anguli oris (a.k.a.
triangularis), depressor labii inferioris, mentalis, incisivii
labii superioris, incisivii labii inferioris, risorius, platysma,
orbicularis oris, masseter, temporalis, internal pterygoid,
digastric, nasalis, maxillae, quadratus labii superioris and
inferioris.
[0066] In many embodiments, remodeling a tissue included in a
contractile function chain 70 will effect a desired change in a
composition of the treated tissue and/or a change in its behavior
which is sufficient to mitigate wrinkles of the skin associated
with contraction of a muscle 72, as illustrated in FIG. 5M. While
this may involve a treatment of the tissues of muscle 72 directly,
treatments may also target nerve tissues 74, neuromuscular junction
tissues 76, connective tissues 78, and the like. Still further
tissues may directly receive the treatment, for example, with
treatments being directed to tissues of selected blood vessels so
as to induce hypoxia in muscle 72 or the like. Regardless of the
specific component of contractile chain 70 which is treated, the
treatment will preferably inhibit contraction of the muscle 72
which would otherwise form wrinkles or lines in the exposed skin
surface overlying that muscle.
[0067] A variety of specific tissue remodeling treatments
mechanisms targeting of one or more components of contractile chain
70 may be employed so as to inhibit lines or wrinkles. For example,
ablation of muscle cells/tissues, or the associated nerves
(optionally being a component thereof integral to nerve function
such as a myelin sheath or the like), or the nerve endings or
neuromuscular junction (which generally forms the interface between
the nerves and the muscles) may be sufficient to inhibit muscular
contraction. Such ablation may result in a short-term, long-term or
permanent inactivation of the muscle. Other long-lasting or
permanent treatments may involve inducing apoptosis, typically at
temperatures which are not as severe as ablation temperatures, but
which remodel the tissue behavior with long term changes in the
cellular life and/or proliferation cycles. Specific remodeling
mechanisms so as to change the function of the muscle in a desired
way or for a desired time may be induced by appropriate therapeutic
dosages of the treatment modalities described herein, for example
so as to induce cell death (apoptotic or necrotic), embolization of
blood supply, or the like. Alternative remodeling mechanisms which
may be shorter in effect may include stunning of one or more
component of contractile chain 70, inactivation of one or more
component, or the like. Remodeling treatments which effectively
block the release of or response to chemicals (such as but not
limited to acetylcholine) along the contractile chain 70 may be
sufficient to inhibit muscular contraction in response to signals
transmitted along the neural pathways, either temporarily or
permanently, and may also be employed.
[0068] Muscular movement is generally controlled by stimulation of
a nerve. The motor unit of the neuromuscular system contains three
components: motor neuron (spine), axon (spine to motor endplate),
and innervated muscle fibers (endplate to muscle). Treatments
directed to one or more of these tissues may be employed.
[0069] When treatments are intended to inhibit muscle contraction,
the treatment may be determined at least in part by the type of
muscle being treated (skeletal (striated) or smooth (not
striated)). For example, skeletal muscle may have muscle fibers
that are innervated by motor neuron, with a single neuromuscular
junction lying along a midpoint of muscle fibers, and a single
muscle fiber within a motor unit supplied by a single motor neuron
and its axon. Each muscle receives one or more nerves of supply,
and the nerve generally enters deep into the muscle surface near
its origin where the muscle is relatively immobile. Blood vessels
typically accompany the nerve to enter the muscle at the
neurovascular hilum. Each nerve contains motor and sensory fibers,
motor endplates, vascular smooth muscle cells, and various sensory
endings and endings in fascia. When the nerve enters the muscle, it
breaks off into a plexus running into the various layers of
muscle-epimysium, perimysium, endomysium--each terminating in
several branches joining a muscle fiber at the motor endplate.
Remodeling of one or more of these tissues may be sufficient to
temporarily or permanently inhibit muscle contraction.
[0070] Embodiments of the invention may interrupt or disable nerve
impulses by disrupting conductivity by eliminating or decreasing
charge differences across plasma membranes, either mechanically or
chemically; by destroying Schwann cells that insulate the axonal
processes speeding up impulse conduction; and/or by repeated
injury/healing cycles timed to limited capacity for neuron
regeneration.
[0071] Immobilization of muscle by disabling any one or a specified
combination of components of the connective tissue matrix, either
temporarily or permanently, may also be employed. Treatments
targeting connective tissues, such as the fibroblasts,
myofibroblasts (which may be responsible for contractility of
granulation tissue in healing), collagen, reticulin, elastin, or
the like of aponeurotic or tendinous attachment of muscles to bone,
fascia, ligaments, or the like may also be advantageous, and the
remodeling form and/or treatment dosage may be selected in response
to the condition being treated (for example, when primarily
treating cellulite dimples rather than primarily treating
contraction-induced lines or wrinkles). Treatments of the
superficial fascia just beneath the skin may also be employed. To
achieve a loss of elasticity in fibrous connective tissue during
treatment of cellulite, temperature may be varied to achieve
temporary or permanent changes to the morphology of the collagen
and elastin matrix contained within that tissue.
[0072] In addition to cosmetic treatments of lines, wrinkles, and
the like, embodiments of the invention may also find applications
for treatments of subdermal adipose tissues. Embodiments of the
invention may also find applications for alleviation of pain,
including those associated with muscle spasms. Still further
embodiments may rely on application of energy (with or without
cooling) for remodeling of target tissues and producing a desired
cosmetic effect, with the energy optionally comprising focused or
unfocused ultrasound energy, radio frequency energy, laser energy
microwave energy, other electromagnetic or particle radiation,
alternative methods of applying heat, chemicals, vascular
embolization, and the like. Hence, a variety of embodiments may be
provided. In one embodiment, for example, delivery of energy, such
as radio frequency energy, can be used to target and disable muscle
tissue of the target tissue as opposed to targeting nerve ablation
to block competition.
[0073] Referring now to FIG. 6, an embodiment of a method 100 for
effecting a cosmetic treatment 100 includes identifying a cosmetic
defect 102 such as lines, wrinkles, cellulite, fat, or the like. A
desired skin surface reshaping is determined 104 which may include
the elimination of lines or wrinkles, smoothing of cellulite
dimples, reduction of fat, or the like. In many embodiments, it may
be desirable to avoid permanently altering a color of the skin
surface in effecting such treatments.
[0074] An appropriate target tissue is identified 106, such as
identifying a nerve, muscle, neuromuscular junction, connective
tissue, adipose tissue layer, or the like below the cosmetic
defect. A remodeling effect duration 108 may be selected, and the
treatment probe positioned 110. Positioning of the treatment probe
may, for example, comprise inserting one or more tissue-penetrating
probe needles into the target tissue, engaging the skin surface
with a skin-engaging surface of a handpiece, and/or the like.
Injury to the skin may be inhibited 112, such as by warming the
skin surface, infusing a warmed biocompatible fluid such as saline,
applying a cryoprotectant such as DMSO, or the like.
[0075] Cooling and/or energy (or chemical or vascular embolization)
is applied to the target tissue 114 so as to effect the desired
remodeling of that tissue. The tissue response and healing 116 may
follow immediately after cooling and/or energy (or chemical or
vascular embolization) is applied, or may take place over a
considerable time (such as when efficacy is achieved through
apoptosis or the like). Furthermore, a step is included where
myostatin activity in the target tissue in increased 115, e.g., by
delivery of a myostatin agent (e.g., myostatin protein) to the
target tissue. The increased myostatin activity can act to further
remodel the target tissue in the desired manner, and/or can extend
the duration of the cosmetic defect correction actions of the
tissue cooling compared to cooling alone. The increased myostatin
activity, for example, can effectively inhibit certain aspects of
the healing response, such as myogenesis. Delivery of the myostatin
agent can be accomplished before, after or concurrently with
application of the tissue cooling. Generally, for certain myostatin
agents, such as myostatin protein, delivery of the agent will occur
before, and typically after, application of tissue cooling, as
cooling can in some instances effect biological activity of the
agent. In some instances, e.g., if a short duration or trial
treatment was performed to verify the target tissue and treatment
effect, retreatment 118 may optionally be performed.
[0076] Permanent and/or temporary muscular function inhibition may
be employed. A temporary effect can be used on a trial basis to
avoid long term injuries or undesirable outcomes. A permanent
effect may be desirable to minimize cost and avoid repeated
treatments. Desired temperature ranges to temporarily and/or
permanently disable muscle, as well as protect the skin and
surrounding tissues, may be indicated by Table 1 as follows:
TABLE-US-00001 TABLE 1 Temperature Skin Muscle/Fat 37.degree. C.
baseline baseline 25.degree. C. cold sensation 18.degree. C. reflex
vasodilation of deep blood vessels 15.degree. C. cold pain
sensation 12.degree. C. reduction of spasticity 10.degree. C. very
cold sensation reduction of chronic oedema Hunting response
5.degree. C. pain sensation 0.degree. C. freezing point -1.degree.
C. Phase transition begins -2.degree. C. minimal apoptosis
-3.degree. C. Peak phase transition -5.degree. C. tissue damage
moderate apoptosis -8.degree. C. Completion of phase transition
-10.degree. C. mild apoptosis; considerable apoptosis -15.degree.
C. moderate apoptosis; extensive apoptosis mild-moderate necrosis
-40.degree. C. extensive necrosis
[0077] It will be recognized that the methods of the present
invention can be directed to a variety of target tissues and are
not limited to any particular tissue. Target tissues amenable to
treatment according to the present invention can include without
limitation, for example, tissues that have been subjected to
cryogenic or cryosurgical treatments using previously known
techniques for delivering cooling energy to tissues (e.g., open
spray, touch probe). See, e.g., Cutaneous Cryosurgery: Principles
and Clinical Practice (3rd Edition); Jackson et al., CRC Press,
2005. Target tissues can typically include dermatological tissues
and/or subcutaneous tissues. For example, a target tissue can
include a patient's skin, including an outer surface of the
patient's skin as well as tissues of the skin located below the
skin surface. In one embodiment, for example, a needle probe can be
advanced distally so as to penetrate into the patients skin, e.g.,
through a surface of the skin and cooling energy directed to the
skin surface and/or to tissue below the skin, including tissues at
various depths of penetration into or through the skin surface and
into or through the skin tissue itself.
[0078] As set forth above, target tissues can include skin, muscles
or muscle containing tissues, nerves, connective tissue, as well as
adipose tissues. Target tissues can also include various types of
lesions, wounds, and the like. Target tissues can include cancerous
lesions, malignant or premalignant lesions, or tissues having cells
either exhibiting or predisposed to exhibiting unregulated growth.
Target tissues can additionally include benign lesion. Non-limiting
examples of benign lesions amenable to treatment according to the
present invention can include the following: acne; adenoma
sebaceum; alopecia greata; angiokeratoma; angiolymphoid
hyperplasia; cherry angioma; chondrodermatitis nodularis helices;
clear cell acanthoma; cutaneous horn; dermatofibroma; dermatosis
papulosa nigrans; disseminated superficial actinic keratosis;
elastosis perforans serpiginosa; epidermal naevus; granuloma
annulare; granuloma faciale; haemangioma; herpes labialis,
recurrent; hidradenitis suppurativa; hyperhidrosis, axillary;
hypertrophic scar; idiopathic guttate melanosis; ingrowing toenail;
keloid; kyrle's disease; leishmaniasis; lentigines; lentigo
simplex; lichen planus, hypertrophic; lichen sclerosus, vulva;
lichen simplex; lichenoid keratosis, benign; lupus erythematosus,
discoid; lymphangioma; lymphocytoma cutis; melasma; milia;
molluscum contagiosum; mucocoele, mouth; myxoid cyst, digital; orf;
pigmented naevi; porokeratosis; prurigo nodularis; pruritus ani;
psoriasis, lichenified; pyogenic granuloma; rhinophyma; rosacea;
sarcoid, granuloma; sebaceous hyperplasia; seborrhoeic keratosis;
skin tags; solar atropy, keratosis, or lentigo; spider naevus;
steatocystoma multiplex; syringoma; tattoos; trichiasis;
trichoepithelioma; venous lakes; warts; or xanthoma.
[0079] In some instances it may be desired to cool the target
tissue, as described above, but without penetrating the target
tissue with a cooling probe. As such, according to another
embodiment, delivery of the cooling energy to the target tissue can
be accomplished using a non-penetrating probe. Rather than
penetrating into the target tissue as with a needle electrode, the
non-penetrating probe is positioned in contact with a portion of
the target tissue (e.g., skin surface), and cooling is directed
through the probe and the cooling transferred to the target tissue.
The probe includes at least one tissue engaging surface that is
positioned in contact with the target tissue for tissue cooling.
Systems and devices of the present invention having the
non-penetrating probe configuration can be used, for example, for
treating a target tissue comprising a lesion, such as an acne
lesion. Similar to the above, tissue cooling in this manner can be
used for treating and remodeling the acne lesion target tissue, for
example, by stimulating apoptosis, reducing or eliminating
infection or inflammation, reduction in scarring, and the like.
[0080] It is understood that the examples and embodiments described
herein are for illustrative purposes and that various modifications
or changes in light thereof may be suggested to persons skilled in
the art and are to be included within the spirit and purview of
this application and the scope of the appended claims. Numerous
different combinations are possible, and such combinations are
considered to be part of the present invention.
* * * * *