CELL PROLIFERATION MATRIX AND USE THEREOF

Abstract: A cell proliferation matrix consisting of an aqueous gel of hyaluronic acid or a pharmaceutically acceptable salt thereof which is free from production-related animal DNA and RNA and which is in a dissolved state, is disclosed. Further, the use of hyaluronic acid or a pharmaceutically acceptable salt thereof for the preparation of a cell proliferation matrix according to the invention, for the treatment of at least one of bone fractures, Ulcus Varicosum Cruris, and ulcera caused by Diabetes Mellitus and other diseases (e.g. Decubitus) with impaired arterial blood flow, is described. Also, a method of treating at least one of bone fractures, Ulcus Varicosum Cruris, and ulcera caused by Diabetes Mellitus and other diseases with impaired arterial blood flow is disclosed.

Description: Cell proliferation matrix and use thereof The present invention relates to a cell proliferatio matrix which consists of an aqueous gel of hyaluronic acid o a pharmaceutically acceptable salt thereof, which is in a dissolved state. It also relates to the use of hyaluronic acid or a pharmaceutically acceptable salt thereof for the preparation of a cell proliferation matrix. Further, it rela tee to a method of treating at least one of bone fractures, Ulcus Varicosum Cruris, and ulcera caused by Diabetes Melli¬ tus and other diseases with impaired arterial blood flow, wherein the cell proliferation matrix according to the inven tion is used. BACKGROUND Ulcus Varicosum Cruris and ulcera caused by Diabetes Mellitus and other diseases with impaired arterial blood flow, such as Decubitus, are ulcera which are very slow-hea- ling due to defective nutrition of the cells. Such ulcera ma not heal in years, and the patients often repeatedly suffer from infections. These are normally treated with antibiotics but such treatment is not always successful. Obviously there is a great need of medical aid for th treatment of such slow-healing ulcera. In EP-312208-A there is discloβed a gel for topical and incisional wound healing comprising a polypeptide growth factor (PGF) having human mitogenic or angiogenic activity and a water soluble or swellable polymer, which i.a. may be hyaluronic acid. The gel is to be applied to gauze to form a wound healing bandage which stimulates cell growth and in¬ creases the rate of healing. DESCRIPTION OF THE INVENTION It was surprisingly found that an aqueous gel of hya¬ luronic acid or a pharmaceutically acceptable salt thereof, in a dissolved state, alone functions as a cell proliferatio matrix. Since the cell proliferation matrix according to the invention does not only promote epithelial but also endothβ- lial cell growth, it is expected that it will promote oβ- teoblast growth as well. Thus it can be used in the treatmen of bone fractures, Ulcus Varicosum Cruris and ulcera caused by Diabetes Mellitus and other diseases with impaired arte¬ rial blood flow, such as Decubitus. Hyaluronic acid is widely distributed in connective tissues in mammals, but only in small quantities, and it is also known to be present in microorganisms. Hitherto hyaluro nic acid has mostly been extracted from rooster combs, bovin joints and whale cartilages. However, it forms in the animal tissues complexes with proteins and other mucopolysacchari- des, and therefore it is complicated to purify, and thus there is always a risk of contamination by animal DNA and RNA, which may carry DNA and RNA viruses, such as hepatite B virus and HIV virus. Therefore the hyaluronic acid or pharma ceutically acceptable salt thereof which is to be used in th present invention should be free from animal DNA and RNA. Such hyaluronic acid can be produced by microorganisms, and one disclosure of the production of such hyaluronic acid has been published in EP-A-0 266 578. The sodium hyaluronate used in the clinical trials below has been produced by continuous fermentation of Streptococcus equi by FERMENTECH Ltd., Re- search Avenue South, Riccarton Campus, Edinburgh EH14 4AP, Scotland. In a preferred embodiment of the cell proliferation matrix according to the invention the aqueous gel is made of 99.9 to 98.0 percent by weight of water or of phosphate buf¬ fered saline solution and 0.1 to 2.0 percent by weight of sodium hyaluronate having an average molecular weight of at least 25 000 Da. It is believed that the average molecular weight of sodium hyaluronate is not critical as long as it is at least 25 000 Da and as long as it is in a dissolved state. The average molecular weight of the sodium hyaluronate to be used in the invention is suitably in the range of 1.2xl0 6 - 2.5x10^ Da. In a preferred embodiment of the invention the cell proliferation matrix consists of an aqueous gel contai ning 1.0 percent by weight of sodium hyaluronate having an average molecular weight of 1.2x10^ Da. It should be understood that the aqueous gel accordi to the invention should have a viscosity which allows the hyaluronic acid or a pharmaceutically acceptable salt there to be in a dissolved state, so that the molecules can readi function as cell proliferation matrix. If the concentration of the sodium hyaluronate exceeds 2.0 percent by weight of the aqueous gel, then the viscosity of the gel is probably too high. On the other hand, if the concentration of the so dium hyaluronate is less than 0.1 percent by weight of the aqueous gel, then the gel will probably be too diluted for the gel to stay in place when it is applied to an ulcus or bone fracture. Thus, one aspect of the invention is directed to a cell proliferation matrix, which consists of an aqueous gel of hyaluronic acid or a pharmaceutically acceptable salt thereof which is free from production-related animal DNA an RNA and which is in a dissolved state. In one embodiment of this aspect of the invention the aqueous gel is made of 99. to 98.0 percent by weight of water or of phosphate buffered saline solution and 0.1 to 2.0 percent by weight of sodium hyaluronate having an average molecular weight of at least 25000 Da. Suitably the average molecular weight of the sodi hyaluronate is in the range of 1.2xl0 6 to 2.5xl0 6 Da. In a preferred embodiment of the cell proliferation matrix ac- cording to the invention the aqueous gel contains 1.0 perce by weight of sodium hyaluronate having an average molecular weight of 1.2xl0 6 Da. Another aspect of the invention is directed to the us of hyaluronic acid or a pharmaceutically acceptable salt thereof which is free from production-related animal DNA and RNA for the preparation of an aqueous cell proliferation matrix for the treatment of at least one of bone fractures-, Ulcus Varicosum Cruris, and ulcera caused by Diabetes Mellitus and other diseases with impaired arterial blood flow, such as Decubitus. The aquous cell proliferation matrix is preferably in the form of an aqueous gel in which said hyaluronic acid o pharmaceutically acceptable salt thereof is in a dissolved state. The embodiments of this aspect of the invention corre¬ spond to the embodiments and preferred embodiments of the cel proliferation matrix according to the invention. Yet another aspect of the invention is directed to a method of treating at least one of bone fractures, Ulcus Va¬ ricosum Cruris, and ulcera caused by Diabetes Mellitus and other diseases with impaired arterial blood flow (e.g. Decu¬ bitus), which comprises topically administering to a patient in need of such treatment.s) a therapeutically effective a- mount of a cell proliferation matrix consisting of an aqueous gel of hyaluronic acid or a pharmaceutically acceptable salt thereof, which is free from production-related animal DNA and RNA and which is in a dissolved state. In an embodiment of this aspect of the invention said cell proliferation matrix consists of an aqueous gel which is made of 99.9 to 98.0 percent by weight of water or a phosphate buffered saline solution and 0.1 to 2.0 percent by weight of sodium hyaluronate having an average molecular weight of at least 25000 Da. A therapeutically effective amount of a cell prolife¬ ration matrix according to the invention is an amount which promotes healing compared to a blank. Examples of pharmaceutically acceptable salts of hya- luronic acid are the potassium and the sodium salts. The aqueous gel according to the invention should be sterile when used. The aqueous gel can be sterilized in an autoclave or by irradiation with gamma rays, or an appropri- ate amount of sodium hyarulonate may be sterilized in solid form and reconstituted in sterile water before use. The cell proliferation matrix according to the inven¬ tion, in the form of an aqueous gel of hyaluronic acid or a pharmaceutically acceptable salt thereof, is applied directl to the ulcus and/or the bone fracture to be treated, where- upon the ulcus is covered with a dry bandage. The applicatio of the cell proliferation matrix according to the invention is suitably effected once or twice a day. CLINICAL TRIALS The cell proliferation matrix according to the inven¬ tion has been used in clinical trials at the Department of Endocrinology, Karolinska Sjukhuset, Stockholm, Sweden. The cell proliferation matrix used in the treatment of the below specified ulcera consisted of a sterile aqueous gel of 1.0 percent by weight of sodium hyaluronate having an average molecular weight of 1.2xl0 6 , and of 99.0 percent by weight o phosphate buffered saline solution. Said sodium hyaluronate was from FERMENTECH, Scotland. CASE 1> A man, 58 years of age, with insulin treated diabetes type 2 since 10 years. In the anamnesis angina pectoris, claudicatio intermittens and hypotalamus infarctus 1986 with recurrent transitory ischemic attacks during the last year. Surgery July 1989 with righthand-sided nephrectomi and adre- nalectomi due to renal cancer engaging capβula and surroun¬ ding glandula βuprarenalis without sign of spreading to the liver. In conjunction with the nephrectomi the patient deve¬ loped decubitus on the left heel. First appearance as bliste with a diameter of approximately one inch. Investigation shows general macroangiopathy with weak ened peripheral pulses in the left and right leg. Further sign of neuropathy with lowered sensibility bilaterally in the feet. The blister developed to necrosis with some infec- tion and was treated with antibiotics during the autumn 1989 The patient was treated until spring 1989 with the effort to normalize the blood sugar, repeated treatment with antibio¬ tics due to recurrence of infections in the heel ulcus which did not heal. Vascular surgery was refused despite stenotic changes due to multiple stenosis from A. femoralis down to the feet. The local treatment was changed June 1 to a cell pro¬ liferation matrix consisting of an aqueous gel containing 1. percent by weight of a sodium hyarulonate. In other respects the peroral treatment with Solvezink, Vitamineral, Apresolin Albyl Minor and Persantin was unchanged. During the earlier treatment for 3 months the size of the ulcus is reduced app¬ roximately 50% from 1.80 cm 2 (March 2, 1990) to 0.96 cm 2 (Ma 30, 1990). Following hyaluronic acid treatment the ulcus-are was reduced by 90% from 0.96 cm 2 to 0.08 cm 2 (September 5, 1990). The metabolic control was unchanged during the period of observation. CASE 2) A man, 67 years of age, with Diabetes Mellitus of type 1 known since 1940, insulin-treated and with complications in the form of retinopathy, cataract, neuropathy, macroangiopa- thy with angina pectoris, suspected heart attack 1989 and hypertonia since 1964, and also nephropathy with proteinuria and impaired renal function with increased S-creatinine, ap- proximately 140 μmol/1. May 1989 amputated right big toe af¬ ter cronic ulcus which was infected. The ulcus after amputa¬ tion was very slow-healing, and the patient was remitted to the Department of Endocrinology, Karolinska Sjukhuset, Stock¬ holm, Sweden, in September 1989. The slow-healing of the ul- cus was partly due to recurrent infections, impaired circula¬ tion, loss of peripheral pulses, neuropathy with nasty edema in the ulcus-area. The patient was treated with antibiotics perorally and locally by revification with Jodosorb, sodium chloride compresses and fibrinolytic treatment. The size of the ulcus: September, 1989 30 x 20 mm depth 18 mm January 30, 1990 15 x 24 mm " 11 mm March 21, 1990 16 x 10 mm " 5 mm May 30, 1990 12 x 7 mm " 7 mm On May 30 local treatment with a cell proliferation matrix consisting of a 1.0 percent by weight aqueous gel of sodium hyaluronate starts, accelerating the healing and on August 8, 1990, the ulcus is 3 x 7 mm, depth 3.5 mm. On Oct ber 3, 1990, the ulcus has healed, despite impaired circula tion, which failed to be treated. CASE 3) A man, 43 years of age, with Diabetes Mellitus since 1958 and with multiple complications in the form of grave retinopathy (blind), neuropathy, nephropathy, kidney-trans¬ planted in 1987 and amputated, in connection with a traffic accident, of left lower part of the leg 1975, has since 198 a cronic ulcus which has not healed on the right heel. Ear- lier in the 1980-ieβ he has had recurrent ulcera in the sam area and gangrenously infected ulcus on the same foot dig I which has caused several periods of treatment in the Depa¬ rtment of Endocrinology at Karolinska Sjukhuset and in the diabetes infection clinic. The patient has also had recurre problems with ulcus and osteitis in the left amputated stum which has also led to hospitalization and intensified thera with antibiotics. Since the kidney transplantation in 1987 the patient has been treated with Prednisolon, 10 mg daily, Imurβl 50 m daily, Sandimmun 250 mg daily and Azatioprin 10 mg daily. D to recurrent infection with septic influence the patient ha been treated from March 26 to July 2 in the Department of Endocrinology at Karolinska Sjukhuβet. Before that the pa¬ tient has been treated in the diabetes infection clinic at the beginning of March 1989 under the same diagnosis. Despite intensified treatment with antibiotics, local treatment and unloading, previously with patβllar tendon bea ring-ortosis and finally attempts with a plaster treatment, the heel ulcus did not heal, which was assessed to partly be due to a cronic osteomyelitis. A treatment with Gentamycin locally for several months gave effect on infection parame¬ ters in the blood with normalization of reactive protein, improvement of the blood status (Hb, LPK) . The patient was sent home from hospital for a stay in the countryside on Jul 3, 1990, and at the same time the treatment with a cell proliferation matrix consisting of a 1.0 percent by weight aqueous sodium hyaluronate gel was started locally for in¬ stallation directly into the ulcus cavity. The size of the ulcus was prior to the treatment ap- proximately 30x25x27 mm with an ulcus depth of 50 mm. On Au¬ gust 15, 1990, it was observed that the ulcus had healed wit the exception of a little retained fistula hole which was 4x mm with a retained fistel of 50 mm. On September 5 further shrinking of the fistula passway was observed, despite rai- sing signs of local osteomyelitis in the metatarβal bone. Throughout the period of observation the patient has been treated with antibiotics; Flagyl and Cloxacillin or Cip roxin.

Claims: CLAIMS 1. Cell proliferation matrix, characterized in that consists of an aqueous gel of hyaluronic acid or a pharmace tically acceptable salt thereof which is free from produc- tion-related animal DNA and RNA and which is in a dissolved state . 2. Cell proliferation matrix according to claim 1, wherein said aqueous gel is made of 99.9 to 98.0 percent by weight of water or of phosphate buffered saline solution an 0.1 to 2.0 percent by weight of sodium hyaluronate having a average molecular weight of at least 25 000 Da. 3. Cell proliferation matrix according to claim 2 , wherein said sodium hyaluronate has an average molecular weight of 1.2 x 10 6 to 2.5 x 10 6 Da. 4. Cell proliferation matrix according to claim 3, wherein said aqueous gel contains 1.0 percent by weight of sodium hyaluronate having an average molecular weight of 1. x 10 6 Da. 5. Use of hyaluronic acid or a pharmaceutically accep salt thereof which is free from production-related animal and RNA for the preparation of an aqueous cell proliferati matrix for the treatment of at least one of bone fractures Ulcus Varicosum Cruris , and ulcera caused by Diabetes Mell and other diseases with impaired arterial blood flow, such Decubitus. 6. Use according to claim 5, wherein said aqueous cel proliferation matrix consists of a gel which is made of 99 to 98.0 percent by weight of water or of phosphate buffere saline solution and 0.1 to 2.0 percent by weight of sodium hyaluronate having an average molecular weigth of at least 25 000 Da dissolved therein. 7. Use according to claim 6, wherein said sodium hyaluronate has an average molecular weight of 1.2 x 10 to 2.5 x 10 6 Da. 8. Use according to claim 7, wherein said aqueous ge contains 1.0 percent by weight of sodium hyaluronate having an average molecular weight of 1.2 x 10 6 Da. 9. A method of treating at least one of bone fractu- res, Ulcus Varicosum Cruris, and ulcera caused by Diabetes Mellitus and other diseases with impaired arterial blood flow, such as Decubitus, which comprises topically administe ring to a patient in need of such treatment(e) a therapeuti¬ cally effective amount of a cell proliferation matrix consis ting of an aqueous gel of hyaluronic acid or a pharmaceuti¬ cally acceptable salt thereof, which is free from production -related animal DNA and RNA and which is in a dissolved state. 10. A method according to claim 9, wherein said cell proliferation matrix consists of an aqueous gel which is mad of 99.9 to 98.0 percent by weight of water or of phosphate buffered saline solution and 0.1 to 2.0 percent by weight of sodium hyaluronate having an average molecular weight of at least 25 000 Da.

Inventors: AABERG BERTIL, BRISMAR KERSTIN, AABERG, BERTIL, BRISMAR, KERSTIN
Applicants: SKANDIGEN AB
Application year: 1991
Main classification: A61K31
IPC codes: A61K9, A61K31, A61L26, A61L27, A61P43