GB2284606A

GB2284606A - Polymerised collagen-based anti-fibroid composition

Info

Publication number: GB2284606A
Application number: GB9324120A
Authority: GB
Inventors: De Leal Nantzin Mart Fleischer
Original assignee: Aspid SA de CV
Current assignee: Aspid SA de CV
Priority date: 1993-11-24
Filing date: 1993-11-24
Publication date: 1995-06-14
Also published as: CA2109989A1; JPH07196530A; FR2713488B1; FR2713488A1; GB9324120D0; BR9305098A

Abstract

An anti-fibroid composition comprises collagen and a vinyl polymer. The vinyl polymer provides a controlled cross-linking of the collagen, determining the anti-fibroid activity.

Description

POLYMERIZED COLLAGEN-BASED ANTI-FIBROID COMPOSITION This invention relates to a polymerised collagenbased anti-fibroid composition.

Medicine has not been able to resolve satisfactorily the problems caused by ailments such as scleroderma, keloid and/or hypertrophic cicatrization, pulmonary emphysema, cirrhosis of the liver, valvulopathy, diabetic ulcers, tendinous sclerosis, consolidation of fractures and other similar ailments which have as a common denominator the presence of fibrosis. As known, fibrosis is the aging of organs and the reparative processes in the tissues originating the hardening of collagen and causing disfunction or death of the organ or tissue involved.

It is generally considered that the fibrosant ailments are characterized by the excessive accumulation of collagen in the extracellular matrix.

The situation becomes serious since fibrosis is not detected generally until it has been established and is progressing, producing organic insufficiency. For example, see Selman, M.; Montana, M.: Ramos, C.: Chapela, R., "Concentration, biosynthesis and degradation of collagen in idiopathic pulmonary fibrosis", Thorax 41:355, 1986.

Medicine has not treated fibrosis with success since there is no specific treatment capable of reversing the process and allowing the normal restitution of the cellular parenchymya.

The increasingly profound knowledge of the metabolism of collagen - the main protein involved in its pathogenesis - as well as of the factors which regulate its biosynthesis and degradation, has suggested the use of collagen in the control of fibrosis. Unfortunately, most of therapeutical studies which have been carried out in experimental models have produced not very conclusive results.

Thus, for example, in animal models of fibrosis or in vitro studies with fibroblasts betaaminopropionitrile, analogs of proline and lysine and the amino-terminal peptide of procollagen to avoid its synthesis in pathological states have been used. See for greater reference Riley, DJ; Kerr, JS; Berg, RA et al., 'Beta-aminopropionitrile prevents bleomycininduced pulmonary fibrosis in the hamster", Am. Rev.

Respir. Dis., 125:67, 1982; Perlish, J; Timpl, R; Fleischmajer, R., "Collagen synthesis regulation by the aminopropeptide of procollagen I in normal and scleroderma fibroblasts", Arthritis Rheum. 28:647, 1985, to quote only two important studies.

The present inventor considers that collagen is found in a high proportion as a protein of the extracellular matrix and given its low antigenicity when found in natural form, has decided to explore the use of collagen in an effort to control and revert fibrosis. Therefore, mention must be made that the collagen are a family of extracellular proteins having diverse functions, from support of organs (together with other proteins and components of the extracellular matrix) to material for the restructuring in case of wounds where the cellular surroundings by themselves cannot regenerate the tissue; in these cases there is a high production of collagen on the part of the regional cells for repairing the damage, wherefore collagen is considered as a structural protein.

To date fourteen types of genetically-different collagen have been identified, all of them closely related, but their distribution in the tissues varies.

There is a pattern of repetition in the primary structure of the molecule, every third aminoacid is glycine and a good proportion is proline or hydroxyproline (approximately 13 to 15% of the latter) and also presents an uncommon aminoacid such as hydroxylisine. These aminoacids are responsible for the collagen to have a tertiary structure of "triple helix" which is a region typical of the different types of this protein. The more abundant types are I, II and III as primary structures, IV as a component of basal membranes and V in interstices. The other types are found in relatively low proportions and present globular non-collagenic regions.

The biosynthesis of collagen varies quantitatively during the development of the response to some trauma and in certain studies of ailments. For the majority of the collagen and specifically in types I to V, the components of the chains are synthesized as great precursors, known as pro-chains, each translated from a different messenger ribonucleic acid (mRNA).

The pro-alfa chains, as known, undergo diverse post-translational changes which include: a) Hydroxylation of proline and lysine residues.

b) Glucosylation of hydroxylysine residues.

c) Formation of interchain disulphuric bridges.

d) Secretion of the precursor to the medium.

e) Elimination of the amino-peptides and carboxyl terminals due to action of the extracellular enzymes.

f) Forming of fibrils and later fibers of the collagen due to intermolecular linking.

The amino-peptide and carboxy terminal extensions have at least two functions: being a peptide signal and control in the production of collagen.

On the other hand, the catabolyc process of collagen is carried out mainly by enzymatic means and is defined as the rupture of peptidical unions in the helicoidal portions of the molecules of natural collagen. The identification of the remaining peptides indicates the type of enzyme and/or the process whereby the molecule was degraded.

The specific enzyme to carry out this process is collagenase which is found in animal tissue and fluids.

The enzyme is present in at least four forms: latent, free, attached to collagen and attached to inhibitors.

Prior research has proven that all types of animal collagenase "divided from soluble natural collagen or reconstituted fibrils, in a peptidical and simple attachment along the helicoidal portion of the molecule when incubation is performed under certain conditions.

These studies seem to indicate that the kinetics of the collagenolytical reaction depends greatly on the degree of aggregation and cross-linking of the substrate.

(For example, see Perez-Tamayo, R., "Pathology of collagen degradation (a review)", American Journal of Pathology, 1978).

When a skin wound is present and the same does not heal normally, a pathological process known as fibrosis or hypertrophical cicatrization occurs. A hypertrophical and/or keloid cicatrization is present as an uncontrolled proliferation of the fibrous tissue, specially the collagen. The difference between a hypertrophical cicatrization and a keloid cicatrization is based on the specificity. Thus, the keloid cicatrization is a generic anomaly which is predisposed in certain races or mixing of the same, while a hypertophic cicatrization is an "unspecified" defect in the repair of a wound by diverse chemical, physical or physiological agents.

Type I collagen is the most abundant in the skin and bones, wherefore it is used greatly as a material of implantation, since the characteristics of the collagen in the different species are very similar, thus allowing performing grafts with an ample margin of safety.

Presently, the implants of collagen in wounds are well known in the field and also in the market, specially when due to the disposition of the injury it is difficult for the body to repair itself the damage or may do so within a brief period of time. Also known are the bioimplants in reconstructive surgery where the heterologous collagen (from swine and sheep) is grafted in bone, with good results, and the regeneration is much more accelerated than when the implant is carried out with alloplastics which also show the disadvantage of not transforming into bone or be eliminated within short periods of time, as is the case with tricalcium phosphate. However, collagen has always been used in the cosmetic filed, in situations of plastic surgery or reconstructive surgery.

The purpose of suggesting studies with type I collagen is due to the fact that its high content in tissues of easy access such as the skin, produces a greater amount of purified collagen than in other tissues and its availability in the market makes it easily available for the medical-surgical area.

The immunological characteristics of collagen have been well studied. Known studies show that it is lowly immunogenic specially in its natural state, less than when denaturalized, due to the fact that the antigenic regions of the molecule (in natural state) are "hidden" due to the disposition of the triple helix (see, for example the implant of the "Zyderm" collagen of Collagen Corporation). Therefore, it may be concluded that the main antigens of collagen are in the primary structure.

Also known is its infiltration in skin, although unfortunately to date there is no known case where collagen has remained for periods of time relatively long, since after 3 to 4 weeks the collagen was reabsorbed. This led to look for the combination of collagen with other components, to obtain permanency and thus control the fibrosis in affected tissue or organs due to the diseases mentioned above.

According to the present invention, there is provided an anti-fibroid composition based on polymerized collagen, comprising collagen and a vinyl polymer, combined in such a manner that the collagen is cross-linked and polymerized by action of the polymer.

Embodiments in accordance with the present invention aim to provide a composition with anti-fibroid activity, based on collagen, which: does not present rejection or collateral effects; provokes an anti-fibroid activity by means of minor modifications to the collagen molecule which may be recognized by the physiological mechanisms of repair; and competes advantageously with non-combined collagen compositions.

The present invention shall now be described, by way of example only, with reference to a presently-preferred embodiment. Considering the known benefits of collagen, an effort was made to combine collagen with another component thus providing a controlled cross-linking and providing permanency in the tissue. This research was due to fact that previously the low effect of collagen was known due to rejection problems and reabsorption within a few weeks.

After testing numerous components, it was found that the use of vinyl polymers improved greatly the activity of the collagen, developing an anti-fibroid composition based on soluble type I collagen and a vinyl polymer.

The vinyl polymer polymerizes and cross-links the collagen in a controlled manner so that the resulting composition identifies the sites of disorder in the structure of the affected tissue or organ and thanks to a mechanism still unknown acts to order these sites and regenerate the injured tissue or organ or that affected with fibrosis. Not wishing to be bound by theory, it is believed that this action of reordering depends mainly on the cross-linking obtained in the collagen by the action of the vinyl polymer.

This activity of the composition of the present invention has been so unusual that it reorders the structure of the tissue and organs not only in the site where applied but also in other places of the body, without there existing a conclusive explanation of the phenomena.

In a currently preferred embodiment of the invention, the composition comprises 1 of a "natural" type I collagen in a buffer solution and a vinyl polymer in a saline buffer solution, at a relatively acid pH. Advantageously, the pH is found between 2.5 and 5.5. The vinyl polymer is selected from the group consisting of polyvinyl alcohol, polyvinyl chloride or any other vinyl polymer pharmaceutically acceptable.

It is considered that the composition of the present invention may be formulated suitably using from 5 to 30 mg of collagen and from 5 to 50% of the vinyl polymer in the composition. However, other more amply ranges are possible, with diverse results but still above the results with alternate products.

The collagen used in the composition of the present invention is advantageously a collagen of mammals, purified in a grade higher than 80%. This collagen is admixed with the vinyl polymer, preferably of low molecular weight (i.e.

5,000 to 60,000) and the resulting composition is sterilized preferably using suitable sterilization procedures for thermolabile materials.

After clinical tests carried out by the inventors, it is considered that due to its anti-fibroid action the composition of the present invention is indicated for hypertrophic cicatrization, keloid cicatrization, acne sequel, post-surgical prophylaxis, varicose ulcers and various ethiologia, wounds, burns and as a coadjuvant to topical antibiotic therapy. Also, in collagenopathies such as scleroderma, lupus and other collagen diseases. In tendinous fibrosis and other types of subcutaneous hydratation in the lines of expression.

Also at a level of geriatrics in unvoluntary ailments.

Other indications are intralesional posology, local subcutaneous application in lupus, scleroderma, scars, localized fibrosis, etc. Also, in topical post-surgical irrigation, in ulcers, wounds.

It has been determined that the frequency of the application in these cases is conditioned to the evolution of the ailment.

It must be stated that no secondary effects of the composition of the present invention are known at this time.

The composition of the present invention is advantageously compared with alternatives in dressing or curing of wounds. As a reference, in Table 1 below some of the ailments and the alternatives of curing, the time and the results, together with an estimate of the possibilities. In contrast, Table 2 identifies the same ailments treated with the composition of the present invention. It may be seen by comparing both tables, that the composition of the present invention provides greater results even in the case of ailments where the possibilities of success were thought to have no expectations.

Table 1

Ailment Grade Possi- Alternatives Time Outcome bilities Curing Keloid HI No Ex Cortisone lM-3Y B Ferrule 3M-2Y R Others 3M-2Y R Surgery iM B Scars I-v + Dressing 1-3M G,R,B I-V ~ Dressing MTM Cirrhosis ofliver II.V */- Surgery 1M ? I-5M ? No Em DMS (I) Achilles Tendon I-V No Em Rehabiliration MTM IZB I-V + Rehabilitationl IA -MTM B Surgery Pulomonary I-T/ No Ex Hospitalizarion MTM B Emphysema (2) - mbulat. MTM IZB Ambulat. MTM B Scleroderma (2) Cortisone MTM B Colchine DMS (1) (1) DMS us a commercial anti-fibroid.

(2) In genetic ailments, the treatment is cyclic.

In the possibilities column, No Ex. = no expectations. + = good possibilities, - = few possibilities.

In the time column, M=Months, Y=Years, MTM=Maintenance.

In the outcome column, E=Excellent, G=Good, R=Regular, B=Bad.

Grades I-V are in order of increasing tissue damage.

Table 2

I 1 Keloid III No Exb 3-6M E,G,R Scars I-V ~ 3-M G,R Liver Cirrhosis Il-V + IM-IY G Achilles Tendon I-V No Ex. 2-6M, MTM Pulmomary I-V No Et 3-6M G,R,B Emphysema 2-4M G,R,B Scleroderma (1) I-V No Ex. MTM G,R,B (1) In genetic ailments, the treatment is cyclic.

In the possibilities column, No Ex. = no expectations.

+ = good possibilities, - = few possibilities In the time column, M = Months, Y = Years, MTM = Maintenance.

In the outcome column, E = Excellent, G = Good, R = Regular, B = Bad Grades I-V are in order of increasing tissue damage.

It is apparent that the composition of the present invention provides for the biological memory of the damaged tissues; therefore, in the case of genetic ailments its application must be made with certain periodicity to "refreshen" the biological memory of the injured tissue. The behaviour of the composition of the present invention seems to be of the immunological type, activating the enzymatic mechanisms.

Claims

CLAIMS:

1. An anti-fibroid composition based on polymerized collagen, comprising collagen and a vinyl polymer, combined in such a manner that the collagen is cross-linked and polymerized by action of the polymer.

2. An anti-fibroid composition based on polymerized collagen as claimed in Claim 1, wherein the collagen is a soluble type I collagen.

3. An anti-fibroid composition based on polymerized collagen as claimed in Claim 1 or Claim 2, wherein the vinyl polymer is selected from the group consisting of polyvinyl alcohol, polyvinyl chloride or any other vinyl polymer pharmaceutically acceptable.

4. An anti-fibroid composition based on polymerized collagen as claimed in Claim 1, 2 or 3, wherein the collagen is found in an amount from 5 to 30 mg and the vinyl polymer is found in an amount from 5 to 50% of the composition.

5. An anti-fibroid composition based on polymerized collagen as claimed in any preceding claim, wherein the collagen is an extract of 1% in a buffer solution.

6. An anti-fibroid composition based on polymerized collagen as claimed in any preceding claim, wherein the vinyl polymer is found in a saline buffer solution.

7. An anti-fibroid composition based on polymerized collagen as claimed in any preceding claim, wherein the vinyl polymer is of low molecular weight.

8. An anti-fibroid composition based on polymerised collagen as claimed in claim 1 substantially as hereinbefore described.