Tissue engineered tendons and ligaments

Abstract

Connective tissue, including neo-tendons and ligaments, has been constructed using biodegradable synthetic scaffolds seeded with tenocytes. The scaffolds are preferably formed from biodegradable fibers formed of a polymer such as polyglycolic acid-polylactic acid copolymers, and seeded with cells isolated from autologous tendon or ligament by means of enzymatic digestion or direct seeding into tissue culture dishes from explants. The cell polymer constructs are then surgically transplanted to replace missing segments of functioning tendon or ligament.

Description

BACKGROUND OF THE INVENTION [0001] The present invention is generally in the area of forming new tissues by implantation of appropriate cells on a polymer matrix, and is specifically directed towards construction of new tendons and ligaments. [0002] Tissues connecting bones and muscles are collectively referred to herein as “connective tissue”. Tendons are tissues which attach muscles to bones; aponeuroses are sheet-like tendons connecting one muscle with another or with bones; ligaments hold bones together at joints. Tendons and ligaments are elongated, cylindric structures formed of dense connective tissue, adapted for tension in one direction, with fibers having an orderly, parallel arrangement. The most common variety of dense regularly arranged connective tissue has a predominance of collagenous (white) fibers arranged in bundles. Fibroblasts are placed in rows between the bundles. The tissue is silvery white, tough, yet somewhat pliable. The collagen bundles of the tendons agg...

AI Technical Summary

Benefits of technology

The method results in the formation of neo-tendons and ligaments with moderate tensile strength and histological organization similar to natural tissues, demonstrating potential for functional repair without foreign material or immunological issues.

Problems solved by technology

When damaged, the orderly structure which imparts this ability to the connective tissue is disrupted and usually does not heal to yield a fully functional tissue.

Tendon defects, regardless of their origin, often prove to be difficult problems for orthopedic surgery and hand surgery.

Autogenous tendon usage is limited by availability and donor site morbidity.

Homo- or heterografts, though, suffer from a scarcity of supply, increased susceptibility to infection, and concerns about possible transmission of infectious agents.

The original structure of the tendons is not maintained, however, and the repaired tendon lacks strength and flexibility.

Artificial prostheses, although not infectious, are also susceptible to infection, extrusion, and uncertain long-term immunologic interactions with the host.

Moreover, prostheses cannot adapt to environmental stresses as do living tendon tissue and have a high incidence of adhesive breakdown at their interface with the host.

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