Method of producing tissue by placing a molding support within a body cavity

Abstract

A method of producing a tissue includes placing a molding support within a body cavity for a time and under conditions sufficient for non-vascularized tissue comprising myofibroblasts to form on the molding support. In some embodiments, the tissue produced by this method is particularly useful as vascular tissue for the treatment or prophylaxis of diseased or damaged blood vessels such as in atherosclerosis.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation application of U.S. Ser. No. 10 / 628,308, filed Jul. 29, 2003, which is a continuation-in-part application of U.S. Ser. No. 09 / 763,359, filed May 15, 2001, now U.S. Pat. No. 6,626,823, which is a 371 of PCT / AU1999 / 00670, filed Aug. 20, 1999, the disclosures of which are hereby incorporated by reference.FIELD OF THE INVENTION[0002]The present invention relates generally to tissue implant material for use in grafting procedures. More particularly, the present invention provides non-vascular tissue for use as vascular graft material. The present invention further contemplates a method of vascular grafting using non-vascular tissue.BACKGROUND OF THE INVENTION[0003]Bibliographic details of the publications referred to by author in this specification are also collected at the end of the description.[0004]Tissue grafting represents a major advance in the medical treatment of diseased or damaged tissue. In some c...

AI Technical Summary

Benefits of technology

[0021]Still another aspect of the present invention provides a prosthetic device which facilitates the provision of a foreign body such as a moulding support to a body cavity. Generally, although not exclusively, the prosthetic device comprises an elongated tubular member adapted to be inserted into a body cavity. The elongated tubular member is further adapted to receive an inner elongated member such as a biodegradable scaffold or a mesh (e.g. polyglycolic acid (DEXON) coated tube of, for example, polyethylene. The preferred form of the prosthetic device is a modified Tenckhoff Acute Peritoneal Dialysis Catheter although any similar device may be employed. The device enables growth of a tissue around all or part of the inner elongated member in a controlled or semi-controlled manner.

Problems solved by technology

Atherosclerosis is responsible for a high rate of mortality and an even higher rate of long term physical impairment of subjects affected by this disease.

However, while the mammary artery seldom develops atherosclerosis, it may not always be the proper size or length, and saphenous vein may have varicose degenerative alterations that can lead to aneurysm formation when transplanted to a high pressure arterial site.

Furthermore, the non-thrombogenic surface of endothelial cells of saphenous veins is often damaged during graft preparation.

Venous and arterial allografts have also been tried but have generally been abandoned clinically as they show a high incidence of rejection, deterioration and complications.

Similarly, the use of dialdehyde starch tanned bovine xenografts has been generally abandoned due to a high incidence of aneurysm formation and poor resistance to infection.

Nylon was found to lose most of its tensile strength after a brief period of implantation leading to aneurysmal dilation and graft rupture.

Although both polyethylene terephthalate (DACRON) and polytetrafluoroethylene (TEFLON) fabric grafts perform reasonably satisfactorily in high flow, low resistance conditions such as in the aorta, iliac and proximal femoral arteries, neither of these two materials is satisfactory for small caliber arterial reconstructions.

Such grafts are compounded by graft failures from stenosis at the anastomic sites and excessive intimal hyperplasia.

These complications are associated with graft thrombogenicity, poor healing and lack of compliance.

However, poor healing characteristics and lack of compliance are major causes for its lack of performance.

Indeed, the major problem with all synthetic vascular prostheses is that they are foreign bodies, so that blood coagulation can occur on their luminal surfaces causing occlusion in prostheses.

While flow through the graft is improved and thrombogenesis reduced, graft failure can still occur due to occlusion by overgrowth of endothelial cells.

This refinement addresses the overgrowth, but retrovirally transduced cells on the graft are not able to withstand the shear stresses encountered by flow of blood and are sheared off.

Also, the procedure for obtaining endothelial cells from the patient is invasive and the cells are hard to propagate in vitro.

Although this prosthetic device has been successfully used, it does suffer the disadvantage of lacking elastin, an important component to prevent aneurysmal and dilatory changes from stretching both the collagen and mesh components.

Furthermore, the prosthetic device uses glutaraldehyde and this has the propensity to induce non-specific calcification of the implanted device.

In summary, despite considerable experimental and clinical research, none of the biological and synthetic grafts produced thus far is an ideal substitute for a blood vessel such as an artery, arterio-venous shunt or an access fistula.

Limited availability, graft deterioration and complications such as thrombosis, aneurysm formation and excessive subintimal hyperplasia at the anastomotic sites are major problems.

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