USE OF ENZYMES FOR SKIN EXPANSION

Abstract: There is disclosed a method for expanding healthy skin, comprising administering to healthy skin an efficacious amount of an enzyme which cleaves elastin fibers, preferably elastase or an elastase derivative. The method may be used in the treatment of skin diseases or disorders occuring in areas adjacent to the healthy skin, including treatment of skin loss after excision of a skin tumor or excision of necrotic skin, trauma, a congenital skin condition, and a condition which has resulted or is likely to result in skin loss. There is also disclosed a method for increasing the yield of leather from an animal, comprising contacting the hide of said animal, or a portion of said hide, with an efficacious amount of an enzyme which cleaves elastin fibers, preferably elastase or an elastase derivative. Also disclosed are the use of an enzyme which cleaves elastin fibers in the preparation of medicaments for expanding healthy skin, for increasing the surface area of a piece of skin to be applied as a skin graft, for imitating in a person with healthy skin the pathological condition of the skin of a person suffering from Cutis Laxa disease, and for decreasing the elastic resistance of skin to pulling.

Description: Use of Enzymes for Skin Expansion FIELD OF THE INVENTION The present invention relates to methods for treating human and animal skins to expand said skins, as well as the preparation of medicaments for effecting such expansion. BACKGROUND OF THE INVENTION The skin is composed of an epidermis and a dermis. The dermis is composed collagen and elastin fibers as well as other components. The elastin fibers act like springs, and thus impart to skin its elastic recoil. Broken or destroyed elastin fibers can be found in the following conditions: (a) The aging process: the skin of aged people is wrinkled because of the high percentage of broken elastin fibers, which prevents the skin from retaining its tautness. (b) Cutis Laxa disease: this is a genetic disease in which elastin fibers are destroyed during adolescence, causing the skin of teenagers to wrinkle and giving them the appearance of old age. U.S. Patent No. 4,645,668 describes a method for the prevention and treatment of scars by repeatedly injecting collagenase into various types of disfiguring lesions (keloid, hypertrophic scars, disfiguring surgical scars, acne scars, and fibrotic bands). Therapy was discontinued when the scar appearance was satisfactory. U.S. Patent No. 4,276,281 describes the use of elastase in the form of an ointment to promote the healing of skin burns in rats. Application of the ointment hastened the removal of the burn eschar. The disclosures of all references mentioned above and throughout the present specification are hereby incorporated herein by reference. SUMMARY OF THE INVENTION The present invention seeks to provide an improved method for expanding skin. There is thus provided in accordance with a preferred embodiment of the present invention a method for expanding healthy skin, comprising administering to healthy skin an efficacious amount of an enzyme which cleaves elastin fibers. In a preferred embodiment of the invention, the enzyme is elastase or an elastase derivative. In one preferred embodiment of the invention, the enzyme is administered by injection. In another preferred embodiment of the invention, the enzyme is administered by topical application. Preferably, the enzyme is administered in an concentration selected from (a) a concentration of at least 1 unit of activity per cm 2 of skin or (b) a concentration of at least 1 mg of enzyme per cm 2 of skin. In a preferred embodiment of the invention, the healthy skin is adjacent to an area of skin which suffers from a condition or deficiency. In on preferred embodiment, the condition or deficiency is selected from the group consisting of: (a) skin loss after excision of a skin tumor or excision of necrotic skin; (b) trauma; (c) a congenital condition; and (d) a condition which has resulted or is likely to result in skin loss. In another preferred embodiment of the present invention, the healthy skin is adjacent to an area of skin which is to undergo reconstructive surgery. There is also provided, in accordance with a preferred embodiment of the invention, a method for increasing the surface area of a piece of skin to be applied as a skin graft, comprising contacting the piece of skin with an efficacious amount of an enzyme which cleaves elastin fibers. In a preferred embodiment of the invention, the enzyme is elastase or an elastase derivative. In one preferred embodiment of the invention, the piece of skin is contacted with the enzyme by injecting the enzyme into the piece of skin In another preferred embodiment of the invention, the piece of skm is contacted with the enzyme by topically applying the enzyme to the piece of skin In yet another preferred embodiment of the invention, the piece of skm is contacted with the enzyme by soaking the piece of skin in a solution containing the enzyme There is also provided, in accordance with a preferred embodiment of the invention, a method for increasing the yield of leather from an animal comprising contacting the hide of the animal or a portion thereof with an efficacious amount of an enzyme which cleaves elastm fibers In a preferred embodiment of the invention, the enzyme is elastase or an elastase deπvative In one preferred embodiment of the invention, the hide or portion thereof is on a live animal In another preferred embodiment of the invention, the hide or portion thereof has been removed from the animal but has not yet been cured or tanned In one preferred embodiment of the invention, the hide or portion thereof is contacted with the enzyme by injecting the enzyme into the hide or portion thereof In another preferred embodiment of the invention, the hide or portion thereof is contacted with the enzyme by topically applying the enzyme to the hide or portion thereof In yet another preferred embodiment of the invention, the hide or portion thereof is contacted with the enzyme by soaking the hide or portion thereof m a solution containing the enzyme There is also provided, in accordance with a preferred embodiment of the invention, an animal hide or portion thereof which has been expanded by contacting said hide or portion thereof with an efficacious amount of an enzyme which cleaves elastin fibers There is also provided, in accordance with a preferred embodiment of the invention, a method for imitating m a person with healthy skin the pathological condition of the skin of a person suffering from Cutis Laxa disease, compπsing administering to a region of healthy skin of said person in which region it is desired to imitate said pathological condition an efficacious amount of an enzyme which cleaves elastin fibers There is also provided, in accordance with a preferred embodiment of the invention, a method for decreasing the elastic resistance of skin to pulling, compπsing administering to said skin an efficacious amount of an enzyme which cleaves elastm fibers There is also provided, in accordance with a preferred embodiment of the invention, the use of an enzyme which cleaves elastin fibers in the preparation of a medicament for expanding healthy skin In a preferred embodiment of the invention, the enzyme is elastase or an elastase derivative In one preferred embodiment of the invention, the medicament is administrable by injection In another preferred embodiment of the invention, the medicament is administrable by topical application In a preferred embodiment of the invention, the medicament is administrable in a concentration selected from (a) a concentration of at least 1 unit of activity per cm " of skm, or (b) a concentration of at least 1 mg of enzyme per cm 2 of skin In a preferred embodiment of the invention, the healthy skm is adjacent to an area of skm which suffers from a condition or deficiency In a preferred embodiment of the invention, the condition or deficiency is selected from the group consisting of (a) skin loss after excision of a skin tumor or excision of necrotic skm, (b) trauma, (c) a congenital condition, and (d) a condition which has resulted or is likely to result in skin loss In a preferred embodiment of the invention, the healthy skm is adjacent to an area of skin which is to undergo reconstructive surgery There is also provided in a prefeπed embodiment of the invention the use of an enzyme which cleaves elastm fibers in the preparation of a medicament for increasing the surface area of a piece of skin to be applied as a skm graft In a preferred embodiment of the invention, the enzyme is elastase or an elastase deπvative In one preferred embodiment of the invention, the medicament is administrable by injection to said piece of skin In another preferred embodiment of the invention, the medicament is administrable by topical application to said piece of skin In another preferred embodiment of the invention, the medicament is administrable by soaking said piece of skm m said medicament or in a solution containing said enzyme There is also provided m accordance with a preferred embodiment of the invention the use of an enzyme which cleaves elastin fibers in the preparation of a medicament for imitating in a person with healthy skin the pathological condition of the skin of a person suffeπng from Cutis Laxa disease There is also provided in a preferred embodiment of the invention the use of an enzyme which cleaves elastin fibers in the preparation of a medicament for decreasing the elastic resistance of skin to pulling There is also provided in a preferred embodiment of the invention an enzyme which cleaves elastin fibers for use as a medicament for expanding healthy skin In a preferred embodiment of the invention, the enzyme is elastase or an elastase deπvative In one preferred embodiment of the invention, the medicament is administrable by injection In another preferred embodiment of the invention, the medicament is administrable by topical application In a preferred embodiment of the invention, the medicament is administrable in a concentration selected from (a) a concentration of at least 1 unit of activity per cm" of skin, or (b) a concentration of at least 1 mg of enzyme per cm " of skm In a preferred embodiment of the invention, the healthy skm is adjacent to an area of skin which suffers from a condition or deficiency In a preferred embodiment of the invention, the condition or deficiency is selected from the group consisting of (a) skm loss after excision of a skin tumor or excision of necrotic skin, (b) trauma, (c) a congenital condition, and (d) a condition which has resulted or is likely to result in skin loss In a preferred embodiment of the invention, the healthy skin is adjacent to an area of skin which is to undergo reconstructive surgery There is also provided in accordance with a preferred embodiment of the invention an enzyme which cleaves elastin fibers for use as a medicament for increasing the surface area of a piece of skin to be applied as a skin graft In a prefeπed embodiment of the invention, the enzyme is elastase or an elastase deπvative In one preferred embodiment of the invention, the medicament is administrable by injection to said piece of skin In another prefeπed embodiment of the invention, the medicament is administrable by topical application to said piece of skm In another preferred embodiment of the invention, the medicament is administrable by soaking said piece of skin in said medicament or in a solution containing said enzyme There is also provided m accordance with a prefeπed embodiment of the invention an enzyme which cleaves elastm fibers for use as a medicament for imitating in a person with healthy skin the pathological condition of the skm of a person suffeπng from Cutis Laxa disease There is also provided in accordance with a preferred embodiment of the invention an enzyme which cleaves elastin fibers for use as a medicament for decreasing the elastic resistance of skm to pulling DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Without wishing to be bound by any particular theory, it is believed that the present invention is based on the ability of certain enzymes, particularly elastase or elastase deπvatives, to cleave the elastin fibers in the skin of humans and other animals It is believed that contacting such skin with such an enzyme results in the loss of the elastic recoil of the skin so contacted, "loosening" the skin and causing its expansion Such contacting can be effected by any suitable means, including by injection, by topical administration, and in cases of skin which has been removed from the person or animal on which it grew, by soaking in an enzyme-contaimng solution Throughout this descnption and the claims that follow, the term "elastase or elastase derivatives' * will be understood to refer to elastase fiom various animal sources, as well as elastases which have been modified by genetic engineering to contain point mutations, ammo acid insertions or deletions, as well as elastases which have been conjugated, bonded, coupled or otherwise linked to other molecules, or which have been chemically modified, but which still substantially maintain their enzymic activity The term "healthy skm" will be understood to mean skin which is relatively healthy for a patient or animal of that age Skm expanded by the method of the present invention has uses in several areas Surgery The enzyme, e g elastase, can be injected or be applied topically to healthy skin, particularly in proximity to areas of skin loss, before, duπng or after surgery Such areas of skin loss can be seen after excision of skin tumors or necrotic skin (e g from burns or wounds), after trauma, as a result of congenital conditions such as aplasia cutis congenita, after mastectomy, and in other skin deficiency conditions The expanded healthy skm can be used to help cover the area of skin loss, e g in breast reconstruction Skm grafts Applying the enzyme to pieces of skin to be used for skin grafts, or contacting said pieces with the enzyme by soaking or topical application, either during or after surgery or while the skm to be grafted is in a skin bank, can increase the amount of skm surface available for grafting Leather industry contacting animal hides or portions thereof with enzyme, either while the ammal is alive or after the hide has been removed from the carcass but before cuπng or tanning, can increase the yield of leather from a single animal Although the ability of elastase to cleave elastin is well-known in the art, prior to the present invention it was not known to utilize elastase to expand healthy human skin, whether of live patients or in a skm bank, nor was it known to utilize elastase or other enzymes to expand the skin available from animals whereby to increase the yield of leather from an animal The invention will be better understood from the following detailed description of a prefeπed embodiment thereof Ten fresh samples of healthy skin 5 5 cm in length and 0 6 cm in width which had been removed from the legs of patients were incubated in Tπs HC1 buffer (Sigma Product No T-l 503) at pH 8 8 and 37°C for 24 hours Five of the skin samples were designated control samples and five were designated test samples Immediately pπor to incubation, each control sample was intradermally injected with 2 5 ml of the aforementioned Tπs HC1 buffer Immediately prior to incubation, each test sample was injected with 2 5 ml of this same buffer, but which contained addition 3 5 mg of elastase (porcine pancreas elastase, Sigma product no E6883, 1-3 units of activity per mg) diluted therein Following the 24-hour incubation, one end of each sample was fixed with a nail and the other end of each sample was weighted with a 10 g weight The length of each sample was measured, and the following results were obtained Control Samples | Test Samples It will be appreciated that since the use of elastase or other enzymes to achieve the expansion of healthy skin was unknown pnor to the present invention, there was no pπor work available to guide the present inventor m determining the concentrations of enzyme and contact times required to effect the present invention It will also be appreciated that the enzyme used in the above example was not of a pharmaceutical standard, and that the purer the enzyme used in accordance with the invention, the lower the concentration of the enzyme necessary to effect the invention It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and descπbed hereinabove Rather the scope of the present invention includes both combinations and subcombinations of the features descπbed hereinabove as well as modifications and variations thereof which would occur to a person of skill in the art upon reading the foregoing descπption and which are not in the prior art

Claims: Claims 1 A method for expanding healthy skin compπsing administeπng to healthy skin an efficacious amount of an enzyme which cleaves elastin fibers 2 A method according to claim 1 wherein said enzyme is elastase or an elastase deπvative 3 A method according to claim 1 wherein said enzyme is administered by injection 4 A method according to claim 1 wherein said enzyme is administered by topical application 5 A method according to claim 1 wherein said enzyme is administered in an concentration selected from (a) a concentration of at least 1 unit of activity per cm 2 of skm, or (b) a concentration of at least 1 mg of enzyme per cm 2 of skin 6 A method according to claim 1 wherein said healthy skm is adjacent to an area of skin which suffers from a condition or deficiency 7 A method according to claim 6 wherein said condition or deficiency is selected from the group consisting of (a) skin loss after excision of a skin tumor or excision of necrotic skin, (b) trauma, (c) a congenital condition, and (d) a condition which has resulted or is likely to result in skin loss 8 A method according to claim 1 wherein said healthy skm is adjacent to an area of skm which is to undergo reconstructive surgery 9 A method for increasing the surface area of a piece of skm to be applied as a skin graft, comprising contacting said piece of skm with an efficacious amount of an enzyme which cleaves elastin fibers 10 A method according to claim 9 wherein said enzyme is elastase or an elastase derivative 11 A method according to claim 9 wherein said piece of skm is contacted with said enzyme by injecting said enzyme into said piece of skm 12 A method according to claim 9 wherein said piece of skin is contacted with said enzyme by topically applying said enzyme to said piece of skin 13 A method according to claim 9 wherein said piece of skin is contacted with said enzyme by soaking said piece of skin in a solution containing said enzyme 14 A method for increasing the yield of leather from an animal, compπsing contacting the hide of said animal, or a portion of said hide, with an efficacious amount of an enzyme which cleaves elastm fibers 15 A method according to claim 14 wherein said enzyme is elastase or an elastase deπvative 16 A method according to claim 14 wherein said hide or portion thereof is on a live animal 17 A method according to claim 14 wherein said hide or portion thereof has been removed from the animal but has not yet been cured or tanned 18 A method according to claim 14 wherein said hide or portion thereof is contacted with said enzyme by injecting said enzyme into said hide or portion thereof 19 A method according to claim 14 wherein said hide or portion thereof is contacted with said enzyme by topically applying said enzyme to said hide or portion thereof 20 A method according to claim 14 wherein said hide or portion thereof is contacted with said enzyme by soaking said hide or portion thereof in a solution containing said enzyme 21 An animal hide or portion thereof which has been expanded by contacting said hide or portion thereof with an efficacious amount of an enzyme which cleaves elastin fibers 22 A method for imitating in a person with healthy skin the pathological condition of the skin of a person suffeπng from Cutis Laxa disease, comprising administering to a region of healthy sk of said person in which region it is desired to imitate said pathological condition an efficacious amount of an enzyme which cleaves elastin fibers 23 A method for decreasing the elastic resistance of skin to pulling, compnsing admimsteπng to said skin an efficacious amount of an enzyme which cleaves elastin fibers 24 Use of an enzyme which cleaves elastin fibers in the preparation of a medicament for expanding healthy skin 25. Use according to claim 24 wherein said enzyme is elastase or an elastase derivative. 26. Use according to claim 24 wherein said medicament is administrable by injection. 27. Use according to claim 24 wherein said medicament is administrable by topical application. 28. Use according to claim 24 wherein said medicament is administrable in a concentration selected from: (a) a concentration of at least 1 unit of activity per cm" of skin; or (b) a concentration of at least 1 mg of enzyme per cm 2 of skin. 29. Use according to claim 24 wherein said healthy skin is adjacent to an area of skin which suffers from a condition or deficiency. 30. Use according to claim 29 wherein said condition or deficiency is selected from the group consisting of: (a) skin loss after excision of a skin tumor or excision of necrotic skin; (b) trauma; (c) a congenital condition; and (d) a condition which has resulted or is likely to result in skin loss. 31. Use according to claim 24 wherein said healthy skin is adjacent to an area of skin which is to undergo reconstructive surgery. 32. Use of an enzyme which cleaves elastin fibers in the preparation of a medicament for increasing the surface area of a piece of skin to be applied as a skin graft. 33 Use according to claim 32 wherein said enzyme is elastase or an elastase deπvative 34 Use according to claim 32 wherein said medicament is administrable by injection to said piece of skin 35 Use according to claim 32 wherein said medicament is administrable by topical application to said piece of skin 36 Use according to claim 32 wherein said medicament is administrable by soaking said piece of skin in said medicament or in a solution containing said enzyme 37 Use of an enzyme which cleaves elastm fibers in the preparation of a medicament for imitating in a person with healthy skin the pathological condition of the skin of a person suffeπng from Cutis Laxa disease 38 Use of an enzyme which cleaves elastin fibers in the preparation of a medicament for decreasing the elastic resistance of skin to pulling 39 An enzyme which cleaves elastin fibers for use as a medicament for expanding healthy skin 40 An enzyme for use as a medicament according to claim 39 wherein said enzyme is elastase or an elastase deπvative 41 An enzyme for use as a medicament according to claim 39 wherein said medicament is administrable by injection 42. An enzyme for use as a medicament according to claim 39 wherein said medicament is administrable by topical application. 43. An enzyme for use as a medicament according to claim 39 wherein said medicament is administrable in a concentration selected from: (a) a concentration of at least 1 unit of activity per cm" of skin; or (b) a concentration of at least 1 mg of enzyme per cm 2 of skin. 44. An enzyme for use as a medicament according to claim 39 wherein said healthy skin is adjacent to an area of skin which suffers from a condition or deficiency. 45. An enzyme for use as a medicament according to claim 44 wherein said condition or deficiency is selected from the group consisting of: (a) skin loss after excision of a skin tumor or excision of necrotic skin; (b) trauma; (c) a congenital condition; and (d) a condition which has resulted or is likely to result in skin loss. 46. An enzyme for use as a medicament according to claim 39 wherein said healthy skin is adjacent to an area of skin which is to undergo reconstructive surgery. 47. An enzyme which cleaves elastin fibers for use as a medicament for increasing the surface area of a piece of skin to be applied as a skin graft. 48. An enzyme for use as a medicament according to claim 47 wherein said enzyme is elastase or an elastase derivative. 49. An enzyme for use as a medicament according to claim 47 wherein said medicament is administrable by injection to said piece of skin. 50. An enzyme for use as a medicament according to claim 47 wherein said medicament is administrable by topical application to said piece of skin. 51. An enzyme for use as a medicament according to claim 47 wherein said medicament is administrable by soaking said piece of skin in said medicament or in a solution containing said enzyme. 52. An enzyme which cleaves elastin fibers for use as a medicament for imitating in a person with healthy skin the pathological condition of the skin of a person suffering from Cutis Laxa disease. 53. An enzyme which cleaves elastin fibers for use as a medicament for decreasing the elastic resistance of skin to pulling.

Inventors: AMIR ABRAHAM, AMIR REVA, AMIR, ABRAHAM, AMIR, REVA
Applicants: AMIR ABRAHAM, AMIR REVA, AMIR, ABRAHAM, AMIR, REVA
Application year: 2000
Main classification: A61K
IPC codes: A61F2, A61K38, A61P17, A61P43