U.S. patent application number 16/517788 was filed with the patent office on 2019-11-07 for systems and methods of stimulation and activation of fluids for use with instillation therapy.
The applicant listed for this patent is KCI Licensing, Inc.. Invention is credited to Richard Daniel John COULTHARD, Christopher Brian LOCKE, Timothy Mark ROBINSON.
Application Number | 20190336739 16/517788 |
Document ID | / |
Family ID | 46172966 |
Filed Date | 2019-11-07 |
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United States Patent
Application |
20190336739 |
Kind Code |
A1 |
LOCKE; Christopher Brian ;
et al. |
November 7, 2019 |
SYSTEMS AND METHODS OF STIMULATION AND ACTIVATION OF FLUIDS FOR USE
WITH INSTILLATION THERAPY
Abstract
Systems and methods of stimulating or activating fluids for use
in wound treatment systems.
Inventors: |
LOCKE; Christopher Brian;
(Bournemouth, GB) ; ROBINSON; Timothy Mark;
(Shillingstone, GB) ; COULTHARD; Richard Daniel John;
(Verwood, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KCI Licensing, Inc. |
San Antonio |
TX |
US |
|
|
Family ID: |
46172966 |
Appl. No.: |
16/517788 |
Filed: |
July 22, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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15456886 |
Mar 13, 2017 |
10406337 |
|
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16517788 |
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|
14216522 |
Mar 17, 2014 |
9623224 |
|
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15456886 |
|
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|
13477741 |
May 22, 2012 |
8708981 |
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14216522 |
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61490150 |
May 26, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61K 41/0047 20130101;
A61M 1/0058 20130101; A61F 13/00068 20130101; A61P 31/00 20180101;
A61N 5/062 20130101; A61L 2300/418 20130101; A61L 15/18 20130101;
A61N 5/02 20130101; A61M 1/0088 20130101; A61L 15/64 20130101; A61M
1/0084 20130101; A61M 2202/0468 20130101; A61M 2202/0241 20130101;
A61K 41/00 20130101; A61L 15/44 20130101 |
International
Class: |
A61M 35/00 20060101
A61M035/00; A61N 5/06 20060101 A61N005/06; A61M 1/00 20060101
A61M001/00; A61L 15/64 20060101 A61L015/64; A61F 13/00 20060101
A61F013/00; A61L 15/18 20060101 A61L015/18; A61L 15/44 20060101
A61L015/44; A61N 5/02 20060101 A61N005/02; A61K 41/00 20060101
A61K041/00 |
Claims
1. A system for treating a wound, comprising: a fluid storage
device having a fluid comprising a therapeutic agent; a
negative-pressure source configured to draw the fluid from the
fluid storage device through a wound dressing; and an energy source
configured to direct energy to the fluid to activate the
therapeutic agent.
2. The system of claim 1, wherein the therapeutic agent comprises
molecules having a protective coating prior to exposure to the
energy source.
3. The system of claim 2, wherein the energy source is configured
to degrade the protective coating.
4. The system of claim 2, wherein the energy source is configured
to activate a component of the fluid that degrades the protective
coating.
5. The system of claim 1, wherein the energy source is configured
to direct energy to the fluid proximal to the wound dressing.
6. A system for treating a wound, comprising: a fluid storage
device having a fluid comprising a therapeutic agent; a supply pump
configured to move the fluid from the fluid storage device into a
wound dressing; and an energy source configured to direct energy to
the fluid to activate the therapeutic agent.
7. The system of claim 6, wherein the energy source is configured
to emit ultrasonic energy.
8. The system of claim 6, wherein the energy source is configured
to emit magnetic energy.
9. The system of claim 6, wherein the energy source is configured
to emit radio frequency energy.
10. The system of claim 6, wherein the energy source is configured
to emit ionizing radiation energy.
11. The system of claim 6, wherein the energy source is configured
to emit microwave energy.
12. A method of treating a wound, the method comprising: applying
negative pressure to a wound dressing; drawing fluid through the
wound dressing; and directing energy to the fluid proximal to the
wound dressing and activating a therapeutic property of the
fluid.
13. The method of claim 12, wherein activating a therapeutic
property of the fluid comprises degrading a coating of a molecule
in the fluid.
14. The method of claim 12, wherein the therapeutic property
includes an anti-biotic property.
15. The method of claim 12, wherein the therapeutic property
includes an analgesic property.
16. The method of claim 12, wherein the therapeutic property aids
with debridement the wound.
17. A method of treating a wound, the method comprising: pumping
fluid through a wound dressing; and directing energy to the fluid
proximal to the wound dressing and activating a therapeutic
property of the fluid.
18. The method of claim 17, wherein the therapeutic property
comprises molecules with a protective coating and activating the
therapeutic property comprises degrading the protective
coating.
19. The method of claim 17, wherein activating a therapeutic
property of the fluid further comprises reducing biofilm
buildup.
20. The method of claim 17, wherein activating a therapeutic
property further comprises debriding the wound.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/456,886, filed Mar. 13, 2017, which is a
continuation of U.S. patent application Ser. No. 14/216,522, filed
Mar. 17, 2014, now U.S. Pat. No. 9,623,224, which claims priority
to U.S. patent application Ser. No. 13/477,741, filed May 22, 2012,
now U.S. Pat. No. 8,708,981, which claims priority to U.S.
Provisional Patent Application Ser. No. 61/490,150, filed May 26,
2011, the entire contents of which are incorporated herein by
reference.
BACKGROUND
1. Field of the Invention
[0002] The present invention relates generally to healing of wounds
and wound-treatment therapies. More particularly, but not by way of
limitation, the present invention relates to fluid-instillation and
negative-pressure wound therapies.
2. Background Information
[0003] Clinical studies and practice have shown that providing
therapeutic fluids, particularly in conjunction with reduced
pressure, in proximity to a tissue site augments and accelerates
the growth of new tissue at the tissue site. The applications of
this phenomenon are numerous, but application of reduced pressure
has been particularly successful in treating wounds. This treatment
(frequently referred to in the medical community as "negative
pressure wound therapy," "reduced pressure therapy," or "vacuum
therapy") provides a number of benefits, including faster healing
and increased formulation of granulation tissue. Typically, reduced
pressure is applied to tissue through a wound insert (e.g., a
porous pad or other manifold device). The wound insert typically
contains cells or pores that are capable of distributing reduced
pressure to the tissue and channeling fluids that are drawn from
the tissue. The wound insert can be incorporated into a wound
dressing having other components that facilitate treatment, such
as, for example, a drape (e.g., adhesive surgical drape).
Instillation fluids may be delivered to the wound insert and held
in place at the site of the wound, further improving the efficacy
of treatment.
[0004] Wound treatment systems, including for example, instillation
therapy units such as the V.A.C. Ulta Therapy System, available
from Kinetic Concepts, Inc., San Antonio, Tex. U.S.A. may be used
to deliver fluids with a more pronounced therapeutic benefit than
saline, and indeed, may expand in complexity and capability to be
able to deliver a plurality of fluids for different purposes
dependent upon wound conditions. It is believed that fluids will be
able to be used to reduce infection, to aid with debridement, to
improve the dressings removability and to address biofilm buildup
in the wound.
[0005] Certain systems offer fluids with molecules which are
tailored and effective to provide the benefits described the above,
but often are not designed for use with a system which doses the
fluid over time and exposes the fluid to tubing and other plastic
components. For example, wound treatment fluids may contain an
active molecule that reacts with various types of plastic and light
(including, e.g., ultraviolet light), thus weakening the molecules
effectiveness and making its practical delivery to the wound site
more difficult.
[0006] It is therefore desirable in systems with molecules which
may be susceptible to negative impacts of contact with certain
materials or light to protect them or render them immune to these
range of deleterious effects until the system determines they
should be active.
[0007] As described herein, it is possible to provide for control
of the stimulation or activation of fluids used in wound treatment
systems.
SUMMARY
[0008] Systems and methods of stimulating or activating fluids for
use in wound treatment systems are presented.
[0009] Certain embodiments include a wound treatment system
comprising: a wound dressing; a fluid storage device comprising a
fluid, where the fluid storage device is in fluid communication
with the wound dressing; and an energy source configured to direct
energy to the fluid and to activate a therapeutic property of the
fluid. Particular embodiments further comprise a negative pressure
source coupled to the wound dressing. In certain embodiments, the
fluid comprises molecules with a coating prior to exposure to the
energy source. In particular embodiments, the energy source is
configured to degrade the protective coating. In specific
embodiments, the energy source is configured to activate a
component of the fluid that degrades the protective coating.
[0010] In certain embodiments, the protective coating comprises a
polymer shell. In particular embodiments, the protective coating
comprises a bioabsorbable glass. In specific embodiments, the
protective coating comprises a ceramic.
[0011] In particular embodiments, the energy source emits
ultrasonic energy. In certain embodiments, the energy source emits
magnetic energy. In specific embodiments, the energy source emits
radio frequency energy. In particular embodiments, the energy
source emits ionizing radiation energy. In certain embodiments, the
energy source emits microwave energy. In certain embodiments, the
energy source emits light energy. In particular embodiments, the
energy source is configured to direct energy to the fluid proximal
to the wound dressing.
[0012] Specific embodiments comprise a conduit in fluid
communication with the fluid storage device and the wound dressing.
In certain embodiments, the energy source is configured to direct
energy to the fluid in the conduit. Particular embodiments comprise
a coupling member coupling the conduit to the wound dressing. In
certain embodiments, the energy source is configured to direct
energy to the coupling member. In specific embodiments, the
therapeutic property includes an anti-biotic property. In certain
embodiments, the therapeutic property includes an analgesic
property. In particular embodiments, the therapeutic property aids
with debridement of tissue. In certain embodiments, the therapeutic
property improves the ability to remove the wound dressing from a
wound. In specific embodiments, the therapeutic property reduces
biofilm buildup in a wound.
[0013] Particular embodiments include a method of treating a wound,
where the method comprises: applying a wound dressing to a wound;
transporting fluid to the wound dressing; and directing energy to
the fluid and activating a therapeutic property of the fluid. In
certain embodiments, the energy is directed to the fluid proximal
to the wound dressing. Specific embodiments also include applying a
negative pressure to the wound dressing. Particular embodiments
also include providing a fluid storage device and a conduit in
fluid communication with the wound dressing. In certain
embodiments, the energy is directed to the fluid when the fluid is
in the conduit. Particular embodiments also include a coupling
member coupling the conduit to the wound dressing. In specific
embodiments, the energy is directed to the fluid at the coupling
member. In certain embodiments, the fluid comprises molecules
having a coating and an active agent, and directing energy to the
fluid breaks down the protective coating.
[0014] Particular embodiments include a wound treatment system
comprising: a wound dressing; a negative pressure source coupled to
the wound dressing; a fluid storage device comprising a fluid with
molecules having a coating, wherein the fluid storage device is
configured for fluid communication with the wound dressing; and an
energy source configured to direct energy to the fluid and degrade
the coating.
[0015] In specific embodiments, the energy source directs light
energy to the fluid. In certain embodiments, the energy source
directs ultrasonic energy to the fluid. In certain embodiments, the
energy source directs magnetic energy to the fluid. In particular
embodiments, the energy source directs radio frequency energy to
the fluid. In certain embodiments, the energy source directs
ionizing radiation energy to the fluid. In particular embodiments,
a therapeutic property of the fluid is activated when the coating
is degraded.
[0016] Certain embodiments include a method of treating a wound,
where the method comprises: applying a wound dressing to a wound;
transporting fluid to the wound dressing, where the fluid comprises
molecules having a coating; and directing energy to the fluid and
degrading the coating. In specific embodiments, degrading the
coating activates a therapeutic property of the fluid. In
particular embodiments, the therapeutic property includes an
anti-biotic property. In certain embodiments, the therapeutic
property includes an analgesic property. In particular embodiments,
the therapeutic property aids with debridement of tissue. In
certain embodiments, the therapeutic property improves the ability
to remove the wound dressing from a wound. In particular
embodiments, the therapeutic property reduces biofilm buildup in a
wound.
[0017] The following drawings illustrate by way of example and not
limitation. For the sake of brevity and clarity, every feature of a
given structure is not always labeled in every figure in which that
structure appears. Identical reference numbers do not necessarily
indicate an identical structure. Rather, the same reference number
may be used to indicate a similar feature or a feature with similar
functionality, as may non-identical reference numbers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 illustrates a schematic diagram of an embodiment of a
wound treatment system.
[0019] FIG. 2 illustrates a schematic view of the embodiment of
FIG. 1.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0020] The term "coupled" is defined as connected, although not
necessarily directly, and not necessarily mechanically; two items
that are "coupled" may be integral with each other. The terms "a"
and "an" are defined as one or more unless this disclosure
explicitly requires otherwise. The terms "substantially,"
"approximately," and "about" are defined as largely but not
necessarily wholly what is specified, as understood by a person of
ordinary skill in the art.
[0021] The terms "comprise" (and any form of comprise, such as
"comprises" and "comprising"), "have" (and any form of have, such
as "has" and "having"), "include" (and any form of include, such as
"includes" and "including") and "contain" (and any form of contain,
such as "contains" and "containing") are open-ended linking verbs.
As a result, a wound-treatment method that "comprises," "has,"
"includes" or "contains" one or more steps possesses those one or
more steps, but is not limited to possessing only those one or more
steps. Likewise, a wound dressing that "comprises," "has,"
"includes" or "contains" one or more elements possesses those one
or more elements, but is not limited to possessing only those
elements. For example, in a wound dressing that comprises one of
the present wound inserts and a drape, the wound dressing includes
the specified elements but is not limited to having only those
elements. For example, such a wound dressing could also include a
connection pad configured to be coupled to a negative pressure
wound therapy (NPWT) apparatus (e.g., including a vacuum source
and/or a fluid source).
[0022] Further, a device or structure that is configured in a
certain way is configured in at least that way, but it can also be
configured in other ways than those specifically described.
[0023] Turning now to the figures, FIG. 1 depicts a schematic
diagram of a wound treatment system 100 comprising a wound dressing
110, a fluid storage device 120, an energy source 130, and a
negative pressure source 140. An overview of the operation of wound
treatment system 100 will be provided initially, followed by a more
detailed discussion of an exemplary embodiment.
[0024] In the exemplary embodiment shown in FIG. 1, fluid storage
device 120 is in fluid communication with wound dressing 110 via a
conduit 150. In addition, energy source 130 is coupled to a
coupling member 160, which is in turn coupled to wound dressing
110.
[0025] In this exemplary embodiment, fluid storage device 120
comprises a fluid 170 with molecules 175 having a protective
coating 176 around an active agent 177. During operation, fluid 170
is transported from fluid storage device 120, through conduit 150
and coupling member 160 to wound dressing 110. In the embodiment
shown, energy source 130 can be activated to direct energy towards
fluid 170 at coupling member 160. The exposure of fluid 170 to
energy emitted from energy source 130 can degrade or break down
protective coating 176 and allow active agent 177 to be exposed,
thereby activating a therapeutic property of fluid 170. Negative
pressure source 140 can then draw fluid 170 from wound dressing 110
into a suitable storage container (not shown).
[0026] Referring now to FIG. 2, a more detailed view and discussion
of wound treatment system 100 is provided. In this embodiment,
fluid storage device 120 and energy source 130 are housed in wound
treatment apparatus 180, along with a supply pump 126 and a control
system 127. As previously explained, fluid storage device comprises
fluid 170 having molecules 175 with protective coating 176 around
active agent 177. In this embodiment, control system 127 is used to
control supply pump 126, which pumps fluid 170 to wound dressing
110. It is understood that in other exemplary embodiments, negative
pressure source 140 may be used to draw fluid from fluid storage
device 120 without the use of supply pump 126.
[0027] In this embodiment wound dressing 110 comprises a wound
insert 112, which is shown placed in wound 116 of a patient (not
shown). A drape 114 is placed over wound 116 and wound insert 112
such that wound insert 112 is between drape 114 and wound 116. In
the illustrated embodiment, drape 114 is coupled to the skin 118 of
the patient. In this exemplary embodiment, wound insert 112 is
coupled to a fluid storage device 120 by conduit 150. Wound
treatment apparatus 180 may also comprise negative pressure source
140 configured to apply negative pressure to wound insert 112
through a conduit 145 or conduit 150 (if the conduit is a
multi-lumen conduit as further explained below).
[0028] Wound insert 112 may be a foam member, which may be
open-celled and/or reticulated. In specific embodiments, the wound
insert comprises an open-celled reticulated foam. An open-celled
reticulated foam has a netlike microstructure, with few if any
closed cells. In certain embodiments, the porosity can range from
95%-98%, though less porous or more porous foams may be used.
[0029] In certain embodiments, wound insert 112 may comprise a
polyurethane, such as polyurethane-polyester or
polyurethane-polyether; polyolefins, such as polypropylenes (PP) or
polyethylenes (PE); silicone polymers; polyvinylchloride;
polyamides; polyesters; acrylics; thermoplastic elastomers such as
styrene-butene-styrene (SBS) or styrene-ethylene-butene-styrene
(SEBS); polyether-amide block copolymers (PEBAX); elastomers such
as styrene butadiene rubber (SBR); ethylene propylene rubber (EPR);
ethylene propylene diene modified rubber (EPDM); natural rubber
(NR); ethylene vinyl acetate (EVA); polyvinyl alcohol (PVOH);
polyvinyl acetal; or polyvinyl butyral (PVB). Additionally, wound
insert 20 may comprise a bioabsorbable polymer, examples of which
include polylactic acid, polylactide (PLA), polyglycolic acid,
polyglycolide (PGA), and polycaprolactone (PCL). Methods of
manufacturing open-celled reticulated foam are well known.
Open-celled reticulated foam is commercially available from a
variety of sources, including Kinetic Concepts, Inc., San Antonio,
Tex., U.S.A. (www.kcil.com).
[0030] Wound insert 112 may be of any suitable shape having a depth
dimension, including a sheet, a rectangular prism, a cone, a
cylinder, a sphere, or any other suitable shape.
[0031] In the exemplary embodiment shown, wound treatment apparatus
180 comprises a fluid storage device 120 configured to deliver
fluid 170 through conduit 150 to wound dressing 110. In certain
exemplary embodiments, fluid 170 may comprise medicinal fluids,
antibacterial fluids, or irrigation fluids.
[0032] In specific exemplary embodiments, conduit 150 may comprise
a single lumen conduit (e.g., switched between a vacuum source
and/or a fluid source) or can comprise multiple single-lumen
conduits or a multi-lumen conduit such that, for example, fluid can
be delivered and/or negative pressure can be applied to wound
dressing 110 individually or simultaneously. In other exemplary
embodiments conduit 150 can comprise multiple lumens, for example,
as in a single conduit with a central lumen for application of
negative pressure and/or fluid delivery and one or more peripheral
lumens disposed adjacent or around the central lumen such that the
peripheral lumens can be coupled to a pressure sensor to sense
and/or detect a pressure or negative pressure between drape 114 and
a wound surface. In the embodiment shown, system 100 further
comprises a coupling member 160 configured to be coupled to conduit
150. One example of a suitable coupling member 160 is the "V.A.C.
T.R.A.C..RTM. Pad," commercially available from KCI USA, Inc. of
San Antonio, Tex., U.S.A. One example of a suitable drape 114
includes the "V.A.C..RTM. Drape" commercially available from
Kinetic Concepts, Inc., San Antonio, Tex., U.S.A (www.kcil.com).
Various wound therapy systems and components are commercially
available through Kinetic Concepts, Inc. and its affiliates.
[0033] In the embodiment shown in FIG. 2, wound treatment apparatus
180 may be configured to deliver instillation fluid to wound 116,
to remove fluid from wound 116, and to apply negative pressure to
wound 116 through drape 114 and wound insert 112.
[0034] Wound treatment apparatus 180 may be activated to deliver
fluid 170 from fluid storage device 120 to wound 116 through
conduit 150 coupled to wound insert 112 through coupling member
160. Negative pressure source 140 may also be actuated to provide
negative pressure to wound 116 through drape 114 and wound insert
112.
[0035] Example of fluids 170 that may be delivered to wound 116
include hypochlorous acid (HOCl) and hypochlorite ion (ClO.sup.-,
which is also commonly referred to, generally understood to be
synonymous with, and may be referred to interchangeably in this
disclosure as, OCl.sup.-), which are examples of effective
antimicrobial agents for biocidal action. For example, HOCl is
typically capable of killing a broad spectrum of microbes (e.g.,
fungus, bacteria, viruses, fungus, yeast, and the like); often in a
relatively short period of time (e.g., is capable of killing
greater than 99% of microbes within a period of less than 10
seconds).
[0036] Such antimicrobial agents can be generated or formed by a
combination of the present reactive agents and fluid (e.g., water
and/or aqueous solution, such as, for example, saline solution) and
may be more effective and/or more versatile than antibiotics and
other commonly used antimicrobial agents used in wound treatment in
the past. For example, antibiotics may be bacteria-specific such
that testing may be required to determine a suitable antibiotic to
use for a specific wound or infection; and/or such that antibiotics
may have only limited effectiveness for individual wounds and/or
infections (e.g., where testing is not performed and/or where a
wound is infected with a plurality of different bacteria).
[0037] Such testing may take as long as several days to determine
an appropriate antibiotic, delaying treatment or selection of an
effective antibiotic. Additionally, bacteria may develop resistance
to antibiotics, such that antibiotics may have reduced
effectiveness after an amount of time. Further, antibiotics are
typically administered intravenously (systemically) such that
antibiotics may kill beneficial bacteria (e.g., in a patient's
digestive system) and/or may cause organ damage (e.g., to a
patient's liver).
[0038] Further, wound treatment apparatus 180 may be configured to
remove spent instillation fluids, secretions, and/or infected
tissue from wound 116. Undesirable effluent may be removed by
actuating the negative pressure source 140; effluent may flow into
wound insert, through conduit 145, and into a waste chamber coupled
to wound treatment apparatus 180.
[0039] As previously described, in this exemplary embodiment, fluid
170 comprises molecules 175 having a protective coating 176
surrounding an active agent 177. In certain embodiments, protective
coating 176 may be constructed using a layer-by-layer technique
(LbL) where polyallylamine hydrochloride (PAH)/polysodium
4-styrenesulfonate (PSS) may be the layers used to form
coating.
[0040] During operation, as fluid 170 is initially transported from
fluid storage device 120 and through conduit 150, protective
coating 176 surrounds active agent 177 of molecules 175. Upon
reaching coupling member 160, energy source 130 directs energy to
fluid 170 and degrades or breaks down protective coating 176. It is
understood that in other embodiments, energy source 130 may direct
energy to fluid 150 at other locations within wound treatment
system 100. For example energy source 130 may direct energy to
fluid 170 at a location within wound treatment apparatus 180, along
conduit 150, or directly in wound dressing 110.
[0041] In certain embodiments, it may be beneficial to have energy
source 130 direct energy to fluid 170 in a location proximal to
wound dressing 110. Such a configuration can allow protective
coating 176 to remain in place as fluid 170 is transported to wound
dressing 110. This can minimize the effects of exposure of fluid
170 to materials or environmental conditions (e.g., light,
temperature, etc.) that may affect active agent 177 of fluid
170.
[0042] In certain embodiments, energy source 130 may direct
ultrasonic, magnetic, radio, ionizing radiation, microwave or light
energy to fluid 170. In specific embodiments, energy source 130 may
direct ultraviolet, infrared or visible light waves to fluid 170.
In certain embodiments, energy source 130 may emit light with a
wavelength in the range of approximately 400 nm-450 nm. In
particular embodiments, energy source 130 may emit ionizing
radiation in the form of gamma rays, x-rays, or electron-beams.
[0043] In particular embodiments, energy source 130 may activate a
component of fluid 170 that in turn degrades or breaks down
protective coating 176. For example, fluid 170 may comprise a
component that does not degrade protective coating under particular
temperature or light conditions. However, when energy source 130
directs energy to fluid 170, the environmental conditions are
changed sufficiently that the component degrades protective coating
176. In other embodiments, energy source 130 may be configured to
directly degrade protective coating 176 without the use of an
additional component in fluid 170.
[0044] After protective coating 176 is degraded, active agent 177
can provide a therapeutic benefit to the patient. Non-limiting
examples of the therapeutic benefits that may be provided to a
patient include antibiotic and analgesic properties. Therapeutic
properties may also aid with debridement, improve the ability to
remove the wound dressing, and reduce biofilm buildup in the
wound.
[0045] By protecting active agent 177 in protective coating 176
until fluid 170 is proximal to wound dressing 110, it is believed
that more accurate dosing of active agent 177 can be achieved. For
example, in certain prior art wound treatment systems that do not
provide for protection of an active ingredient, it may be necessary
to increase the dosage or concentrations levels of the active
ingredient in a fluid container to account for degradation during
delivery. Wound treatment system 100 can reduce the amount of
degradation of active agent 177 during transport of fluid 170
throughout.
[0046] The various illustrative embodiments of devices, systems,
and methods described herein are not intended to be limited to the
particular forms disclosed. Rather, they include all modifications
and alternatives falling within the scope of the claims. For
example, in certain exemplary embodiments, the protective coating
may comprise an ultraviolet-activated protective cover which is
partially activated to break down by ambient light while traveling
through the conduit to the wound dressing (or during storage in the
fluid storage device). The breakdown of the protective coating can
then be completed by an energy source proximal to the wound
dressing.
[0047] In certain exemplary embodiments, rather than a protective
coating, the fluid may comprise molecules constructed so that the
active agent is inhibited by a light sensitive branch. In such
embodiments, for example, exposure to ultraviolet light could be
used to break the branch and activate the compound. Such
configurations could be of use with active agents that have a short
active life due to a spontaneous reaction or from interaction with
the surrounding environment. In particular embodiments,
photoinhibition could also be used to control the behavior of the
active agents.
[0048] Certain exemplary embodiments may also comprise a clotting
agent, e.g. fibrin, chitosan, and trivalent salts, such as
Fe.sup.+++ & Al.sup.+++. In particular embodiments, a Fe+++
compound (such as ferric chloride) can be encapsulated in a glucose
sensitive microcapsule (e.g., glutaraldehyde cross-linked
hemoglobin and glucose oxidase). On encountering glucose (which may
be present in wound fluid or instilled by the user), the
permeability of the microcapsule increases allowing for the release
of the Fe+++ agent. The wound fluid may also enter the microcapsule
and initiate the clotting reaction. In specific embodiments, the
clotting agent may be applied to the wound dressing. The clotting
agent may be protected by an active layer capable of being
activated by haemoglobin and releasing the clotting agent locally.
In certain embodiments, the clotting agent is the active agent in a
molecule with a protective coating, and may be activated as
described in previous exemplary embodiments.
[0049] In particular embodiments, thrombin may be utilized in the
clotting mechanism, for example, in combination with fibrinogen. In
specific embodiments, thrombin may be inhibited or `blocked` by
p-Amidinophenyl-(E)-4-diethylamino-2-hydroxy-alpha-methylcinnamate
hydrochloride through covalent bonding. By exposing the blocked
thrombin to light (e.g., at approximately 366 nm) the thrombin may
unblocked and clotting can occur.
[0050] In other exemplary embodiments, the fluid may comprise
multiple molecules, particles or agents in the fluid which are
activated by different wavelengths of light or frequencies of
energy, which could be delivered at the point of entry to the wound
or once in the wound to activate them. For example, in certain
embodiments a light-activated group (e.g. the thrombin-fibrinogen
group described above) could be grafted onto a molecule at one
location. At another location on the molecule, a group could be
grafted that would liberate cations when exposed to light at a
wavelength other than 366 nm. Non-limiting examples of such
chemical groups that could be used to liberate cations include
(photoacid generators [PAGs]) in the 150 nm-350 nm UV light range
are carboranes, and diphenyliodonium nitrate (activated at about
226 nm). A simple alternative, avoiding grafting, would be to mix
the two sensitive materials (clotting agent and cationic agent).
The cationic agent would be acidic and could aid in debriding
[0051] In particular exemplary embodiments, local activation of the
energy source may be utilized in the wound by either a coating on
the wound insert local to a targeted issue such as necrotic tissue
or by localised external stimulation. In certain exemplary
embodiments, multiple molecules in the wound fluid may be utilized
which activate based upon reaction with biomarkers in the wound
(e.g., inflammatory response markers).
[0052] The claims are not intended to include, and should not be
interpreted to include, means-plus- or step-plus-function
limitations, unless such a limitation is explicitly recited in a
given claim using the phrase(s) "means for" or "step for,"
respectively.
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