[The experimental study of tissue engineered mandible condyle in the shape of human]

This study evaluates the feasibility of creating a tissue engineered adult human mandible condyle composite of bone and cartilage.

A polymer template formed in the shape of the human mandible condyle using a scaffold composed of polyglycolic acid (PGA) and polylactic acid (PLA) was seeded with osteoblasts isolated from a bovine periosteum suspended in calcium alginate. Chondrocytes isolated from the same calf suspended in 30% pluronic were then "painted" onto the articular surface of the scaffold and implanted into subcutaneous pockets on the dorsa of athymic mice. Animals were divided into three groups: Group I (n=6) received PGA/PLA scaffold saturated with hydrogels not containing cells. Group II (n=6) received scaffolds seeded with both cell types suspended in saline rather than hydrogels. Group III (n=6) received scaffolds seeded with both cell types suspended in hydrogel composites. Constructs were harvested after 12 weeks, and evaluated grossly and microscopically using histologic stains.

In group I, constructs formed a small mass without evidence of new bone or cartilage. In group II, constructs were small and irregular in shape. Microscopically they contained scattered islands of bone and cartilage. All specimens in group III retained their original condylar shapes and were quite firm in consistency. Microscopic evaluation revealed trabecular bone interfacing with hyaline cartilage on its articulating surface.

These findings demonstrate that the composites of bone and cartilage can be engineered to serve as mandibular condylar substitutes. The interdigitation of bone and cartilage at their interface is similar to the normal interface of these composite tissues seen in articulating joints.