U.S. patent application number 10/534715 was filed with the patent office on 2006-06-15 for trombin-carrying bioabsorbable synthetic nonwoven fabric.
This patent application is currently assigned to JURIDICAL FOUNDATION THE CHEMOSERO-THERAPEUTIC RESEARCH INSTITUTE. Invention is credited to Takayuki Imamura, Hiroshi Kaetsu, Chikateru Nozaki, Noriko Shinya, Takanori Uchida.
Application Number | 20060127460 10/534715 |
Document ID | / |
Family ID | 32310601 |
Filed Date | 2006-06-15 |
United States Patent
Application |
20060127460 |
Kind Code |
A1 |
Uchida; Takanori ; et
al. |
June 15, 2006 |
Trombin-carrying bioabsorbable synthetic nonwoven fabric
Abstract
A safe and effective hemostatic is provided. The invention
relates to a bioabsorbable synthetic nonwoven fabric holding
thrombin as an effective ingredient and a hemostatic comprising
said bioabsorbable synthetic nonwoven fabric. The bioabsorbable
synthetic nonwoven fabric holding thrombin in accordance with the
present invention may be prepared by a process which comprises the
steps of immersing a bioabsorbable synthetic nonwoven fabric into a
solution containing thrombin and of lyophilizing the obtained
nonwoven fabric. The bioabsorbable synthetic nonwoven fabric
holding thrombin in accordance with the present invention allows
for quicker and more effective hemostasis.
Inventors: |
Uchida; Takanori;
(Kumamoto-ken, JP) ; Shinya; Noriko;
(Kumamoto-ken, JP) ; Kaetsu; Hiroshi;
(Kumamoto-ken, JP) ; Imamura; Takayuki;
(Kumamoto-ken, JP) ; Nozaki; Chikateru;
(Kumamoto-ken, JP) |
Correspondence
Address: |
BROWDY AND NEIMARK, P.L.L.C.;624 NINTH STREET, NW
SUITE 300
WASHINGTON
DC
20001-5303
US
|
Assignee: |
JURIDICAL FOUNDATION THE
CHEMOSERO-THERAPEUTIC RESEARCH INSTITUTE
6-1, Okubo 1-chome
Kumamoto-shi
JP
860-8568
|
Family ID: |
32310601 |
Appl. No.: |
10/534715 |
Filed: |
November 12, 2003 |
PCT Filed: |
November 12, 2003 |
PCT NO: |
PCT/JP03/14348 |
371 Date: |
May 12, 2005 |
Current U.S.
Class: |
424/445 ;
442/128 |
Current CPC
Class: |
A61L 15/64 20130101;
A61K 47/6953 20170801; A61P 7/04 20180101; A61L 15/26 20130101;
Y10T 442/2566 20150401; A61L 15/44 20130101; A61L 15/26 20130101;
A61L 33/0041 20130101; A61L 15/32 20130101; A61L 2300/418 20130101;
Y10T 442/2525 20150401; C08L 67/04 20130101; A61L 2400/04
20130101 |
Class at
Publication: |
424/445 ;
442/128 |
International
Class: |
A61L 15/00 20060101
A61L015/00; B32B 27/04 20060101 B32B027/04; B32B 27/12 20060101
B32B027/12 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 14, 2002 |
JP |
2002-330677 |
Claims
1. A bioabsorbable synthetic nonwoven fabric holding thrombin as an
effective ingredient.
2. The bioabsorbable synthetic nonwoven fabric according to claim
1, wherein said bioabsorbable synthetic nonwoven fabric is made of
a material selected from the group consisting of polyglycolic acid,
polylactic acid and a copolymer of glycolic acid and lactic
acid.
3. The bioabsorbable synthetic nonwoven fabric according to claim
2, wherein said material is polyglycolic acid.
4. The bioabsorbable synthetic nonwoven fabric according to claim
1, wherein the thrombin is thrombin derived from human blood or a
recombinant human thrombin produced by a recombinant DNA
technique.
5. A hemostatic that uses the bioabsorbable synthetic nonwoven
fabric as set forth in claim 1.
6. A process for preparing a bioabsorbable synthetic nonwoven
fabric holding thrombin which comprises the steps of immersing a
bioabsorbable synthetic nonwoven fabric into a solution containing
thrombin and of lyophilizing the obtained nonwoven fabric.
7. The process according to claim 6, wherein said bioabsorbable
synthetic nonwoven fabric is made of a material selected from the
group consisting of polyglycolic acid, polylactic acid and a
copolymer of glycolic acid and lactic acid.
8. The process according to claim 7, wherein said material is
polyglycolic acid.
9. The process according to claim 6, wherein the thrombin is
thrombin derived from human blood or a recombinant human thrombin
produced by a recombinant DNA technique.
Description
TECHNICAL FIELD
[0001] The present invention relates to a bioabsorbable synthetic
nonwoven fabric characterized in that thrombin as an effective
ingredient is held therein, a process for preparing the same and a
hemostatic comprising said nonwoven fabric.
BACKGROUND ART
[0002] In the medical field, hemostatic management is very
important. When the blood vessel in a living body is damaged,
various coagulation factors are activated at that local area and
fibrin is ultimately formed to thereby lead to hemostasis. In this
process, thrombin is the most important enzyme that acts on
fibrinogen so as to convert it into fibrin. Fibrinogen per se,
though it is present in blood, has no hemostatic activity. It is
upon the action of thrombin that the hemostatic activity is
exerted. Namely, thrombin plays the most important role in a
hemostatic reaction in a living body.
DISCLOSURE OF THE INVENTION
Technical Problem to be Solved by the Invention
[0003] Conventional thrombin preparations are in the form of liquid
or powder and hence are often washed away when applied to the
bleeding area, resulting in insufficient hemostatic effect of
thrombin. For obviating this disadvantage, there have been various
reports concerning sheets in which thrombin is held on
bioabsorbable material (e.g. WO 90/13320 and Japanese Patent
Publication No. 61/59737). One of these sheets is such that
thrombin derived from blood is fixed on a sheet material made of
gelatin. This sheet, however, as indicated in the Examples below,
failed to show a sufficient hemostatic effect and is far from
practical usage due to difficulty in its manufacture and problems
when actually used. There is a hemostatic in the form of gel
wherein bovine gelatin is mixed with bovine thrombin but this type
of a hemostatic is also disadvantageous in that it has a risk for
infection such as BSE and is not easy for compression procedure
when used.
[0004] Another type of hemostatic is a fibrin adhesive in which
thrombin is combined with other coagulation factors. A fibrin
adhesive, mainly consisting of thrombin and fibrinogen, is a
biological tissue adhesive that exploits conversion of fibrinogen
to fibrin by the action of thrombin and has been widely used in the
clinical field for the purpose of adhesion, hemostasis and sealing.
However, for use in e.g. surgical operation, preparing a thrombin
solution and a fibrinogen solution by dissolution takes time and
hence it is very inconvenient for use especially in case of
emergency.
[0005] In consideration of such inconvenience, a fibrin adhesive
which is used by directly pressing to the bleeding area with a
sheet is also in a practical usage. However, the currently
available sheet type adhesive is not ideal since it consists of
equine collagen as a basic material together with thrombin derived
from bovine, i.e. material derived from non-human animal species,
and hence there is a possibility that an antibody against
heterologous proteins is elicited and a risk of zoonotic infections
such as prion disease. Thus, the currently available topical
hemostatics are not satisfactorily easy in handling and safe.
[0006] In order to solve the problems mentioned above, there is a
need for a hemostatic comprising a coagulation factor that is
derived from human and is free from an infectious agent, said
hemostatic being in the form of a sheet made of a material that is
strictly selected and devised for full achievement of a hemostatic
effect and is safe to a living body.
Means for Solving the Problems
[0007] In view of the above-mentioned various problems, the present
inventors have carried out intensive investigation and completed
the present invention concerning a topical hemostatic. Thus,
selecting a bioabsorbable synthetic material processed in the form
of a nonwoven fabric among various bioabsorbable material, the
present invention relates to a bioabsorbable synthetic nonwoven
fabric holding thrombin as an effective ingredient for hemostasis,
a process for preparation thereof, and a hemostatic comprising said
nonwoven fabric.
More Efficacious Effects than Prior Art
[0008] The bioabsorbable synthetic nonwoven fabric holding thrombin
in accordance with the present invention has excellent properties
as listed below and hence is an ideal topical hemostatic. [0009]
(1) It has an excellent hemostatic effect; [0010] (2) It can be
handled with ease upon emergency; [0011] (3) It is highly safe;
[0012] (4) It is absorbed with a lapse of time; [0013] (5) It shows
an excellent elasticity and flexibility; [0014] (6) It enables for
hemostasis at a broad area; [0015] (7) It induces a slight or no
inflammation reaction.
[0016] Accordingly, the present invention provides for a hemostatic
comprising a bioabsorbable synthetic nonwoven fabric which allows
for hemostasis with safe in such a surgical operation that requires
for sealing of tissues in various fields of the operation.
BEST MODE FOR CARRYING OUT THE INVENTION
[0017] The bioabsorbable synthetic nonwoven fabric used in the
present invention may be any nonwoven fabric made of a
bioabsorbable synthetic fiber. The nonwoven fabric of the present
invention has preferably appropriate flexibility to ensure that it
may surely coat any affected area. For example, a synthetic fiber
that may form such a nonwoven fabric includes polyglycolic acid,
polylactic acid, or a copolymer of glycolic acid with lactic acid,
etc., which may be used after processing into a nonwoven fabric.
Among these, a bioabsorbable synthetic nonwoven fabric which is
prepared from polyglycolic acid by processing into a nonwoven
fabric is the most preferable material for the purpose of the
present invention.
[0018] The nonwoven fabric of the present invention may be in any
shape but preferably in the form of a sheet in view of versatility
to various applications.
[0019] For thrombin, both thrombin derived from human blood and a
recombinant thrombin obtained by the recombinant DNA technique may
be used. In addition to thrombin, a pharmaceutically acceptable
stabilizer and additive may also be added. Examples of such
stabilizer and additive include, for instance, albumin,
polyethylene glycol, arginine, sodium hyaluronate, glycerol,
mannitol and calcium chloride etc.
[0020] The bioabsorbable synthetic nonwoven fabric holding thrombin
in accordance with the present invention may be manufactured, for
instance, as described below.
[0021] Thrombin is dissolved in a saline or a buffer and thereto is
further added optionally albumin, polyethylene glycol, arginine,
hyaluronic acid, glycerol, mannitol, or calcium chloride etc. as a
stabilizer or an additive. A bioabsorbable synthetic nonwoven
fabric is then immersed into the solution, frozen at -80.degree. C.
for 2 hours and lyophilized to give a desired product.
[0022] The bioabsorbable nonwoven fabric holding thrombin according
to the present invention may be pressed onto a bleeding area to
prevent outflow of blood through pressure and besides thrombin
contained in the sheet instantly reacts with fibrinogen in the
blood to render fibrinogen be converted to fibrin to thereby
achieve a hemostatic effect at the local area. The formed fibrin
may adhere to the surrounding tissues.
[0023] A bioabsorbable nonwoven fabric made of polyglycolic acid
has already been used for a medical purpose and its safety has been
proved as being absorbed into the living body and being decomposed
into water and carbon dioxide.
INDUSTRIAL APPLICABILITY
[0024] As such, the bioabsorbable nonwoven fabric holding thrombin
according to the present invention may easily and quickly be
applied to topical bleeding and allows for efficient hemostasis
through both pressure and a blood coagulation reaction. Besides,
since every material used in said bioabsorbable nonwoven fabric is
safe to the living body, it may be used in a clinical situation
without care.
[0025] The present invention is explained in more detail by means
of the following Examples but should not be construed to be limited
thereto.
EXAMPLE 1
Preparation of Recombinant Thrombin
[0026] A recombinant thrombin was prepared as described in Japanese
Patent Application No. 2001/206,919. Briefly, animal cells to which
a human prethrombin gene is introduced are cultured and prethrombin
is then purified from the resulting culture medium. On the other
hand, ecarin is purified from a culture medium of animal cells into
which ecarin gene is introduced. Prethrombin is activated by ecarin
as obtained to thereby provide thrombin that may be purified.
EXAMPLE 2
Preparation of Sheet Holding Thrombin
[0027] A sheet holding thrombin in accordance with the present
invention was prepared by the process as described below.
[0028] To a solution containing 0.001 to 0.01% sodium hyaluronate
(nacalai tesque; 18237-41) or 0.5 to 2% glycerol (nacalai tesque;
17018) are added mannitol (nacalai tesque; 21303) at a final
concentration of 0.5 to 1.5% and 40 mM calcium chloride and
subsequently the recombinant thrombin at a final concentration of
1000 U/mL. The solution is added dropwise to a bioabsorbable
synthetic nonwoven fabric made of polyglycolic acid (3 cm.times.3
cm; Neoveil, Gunze Limited, thickness 0.15 mm) at 0.05 mL/cm.sup.2.
The sheet, after being frozen at -80.degree. C. for 2 hours and
lyophilized, is used as a sample of a sheet holding recombinant
thrombin. Similarly, a sheet holding thrombin derived from blood is
prepared using thrombin derived from human blood instead of the
recombinant thrombin.
[0029] As a control, a bioabsorbable synthetic nonwoven fabric not
treated with thrombin, a hemostatic sponge made of gelatin prepared
as described in Examples of WO 90/13320 and a commercially
available fibrin adhesive in sheet were used.
Group 1: Sheet Holding Thrombin Derived from Blood
[0030] A sheet was used where thrombin derived from human blood was
held in a nonwoven fabric made of polyglycolic acid at 50
U/cm2.
Group 2: Sheet Holding Recombinant Thrombin A sheet was used where
a recombinant thrombin was held in a nonwoven fabric made of
polyglycolic acid at 50 U/cm.sup.2.
Group 3: Sheet with no Thrombin
[0031] A sheet was used where a nonwoven fabric made of
polyglycolic acid was treated as in Group 1 with no thrombin.
Group 4: Hemostatic Sponge with Fixed Thrombin
[0032] A hemostatic sponge made of gelatin containing thrombin
derived from human blood was used that was prepared as described in
Examples of WO 90/13320 (Spongostan, Johnson & Johnson K.
K.).
Group 5: Fibrin Adhesive in Sheet
[0033] A fibrin adhesive in sheet where components of a fibrin
adhesive are fixed on a collagen sheet (TachoComb, Torii
Pharmaceutical Co., Ltd.) was used wherein components such as
fibrinogen and thrombin were fixed by lyophilization on one side of
a sponge sheet made of equine collagen.
EXAMPLE 3: Test for Hemostasis in Exudative Bleeding
[0034] Rabbit was used as an animal model for assessing hemostasis.
Rabbit was subject to abdominal section and a part of the liver was
excised, to which bleeding area each hemostatic of the groups as
prepared in Example 2 was applied for a whole area of the wound and
was pressed for a minute. Assessment used was as indicated
below.
[0035] (1) Rabbit was subject to abdominal section under anesthesia
with Nembutal.
[0036] (2) Heparin was intravenously administered at 300 U/kg.
[0037] (3) The surface of the right lobe, the inner left lobe or
the outer left lobe of the liver was excised in a shape of circle
of 1.5 cm diameter with thickness of 4 mm.
[0038] (4) Bleeding from the excised wound was absorbed with gauze
for 10 seconds and weighed. An amount of bleeding after generation
of the excised wound was about 0.50 g.
[0039] (5) Attempt to cease bleeding was done with various
hemostatic means as mentioned above. Each treatment was conducted
without avascularization but with blood flowing out.
[0040] (6) Bleeding for 5 minutes, including the time required for
the hemostatic treatment, was absorbed with gauze and weighed. When
bleeding from the wound surface was observed after 5 minutes, the
hemostatic treatment and the weighing of bleeding were
repeated.
[0041] (7) The hemostatic treatment was repeated for at most four
times and assessment was made with a frequency of the hemostatic
treatment needed for hemostasis and a total weight of bleeding from
the initiation of the hemostatic treatment up till hemostasis
(Table 1). TABLE-US-00001 TABLE 1 No. of cases in which hemostasis
was achieved with Total bleeding each of hemostatic treatment after
hemostatic Group 1st 2nd 3rd 4th treatments/g 1 7 1 0 0 0.51 .+-.
0.31 2 7 1 0 0 0.34 .+-. 0.15 3 2 3 3 0 2.03 .+-. 0.95 4 0 2 4 2*
6.28 .+-. 1.67 5 0 4 1 3* 6.70 .+-. 2.64 *Even after the fourth
hemostatic treatment, cases were observed where hemostasis was not
possible.
[0042] As shown in Table 1, the sheet holding thrombin of the
present invention was found to exhibit a more excellent hemostatic
effect in both thrombin derived from blood (Group 1) and a
recombinant thrombin (Group 2) than that of the control sheets.
With a nonwoven fabric alone with no thrombin treatment (Group 3),
a hemostatic effect was scarcely observed but was even higher than
that of the hemostatic sponge made of gelatin with fixed thrombin
(Group 4) as described in WO 90/13320. This indicates that, among
the known bioabsorbable material, a bioabsorbable nonwoven fabric
used in the present invention as a substrate is the most suitable
material for use in hemostasis. It was further revealed that
holding thrombin in this nonwoven fabric allowed for quicker and
more effective hemostasis. Besides, as is clear from the results of
the comparative test, the fibrin adhesive in sheet where collagen
is used as a substrate (Group 5) showed far less hemostatic effect
as compared to the sheet holding thrombin of the present
invention.
* * * * *