Engineered cartilage with internal porous high-density polyethylene support from bone marrow stromal cells: A preliminary study in nude mice.

Tissue-engineered cartilage may have potential for the construction of clinical implants for the treatment of congenital deformities or post-traumatic defects. However, the lack of seed cells is a challenge, as is the maintenance of ideal shape and size. We have used bone marrow stromal cells (BMSCs) and a pre-shaped polyglycolic acid (PGA)-porous high-density polyethylene composite scaffold to solve these problems. High-density polyethylene was carved into cylindrical rods and encircled with PGA fibres to form scaffolds. Porcine BMSC were seeded into the scaffold and cultured in chondrogenic medium (high-glucose Dulbecco's modified Eagle's medium with 10% (v/v) fetal bovine serum, dexamethasone 40 ng/ml, transforming growth factor-beta1 10 ng/ml, and insulin-like growth factor 50 ng/ml) for 3 weeks in vitro before the cell-scaffold constructs were implanted subcutaneously into nude mice. After 8 weeks of implantation, all specimens in the experimental group had formed mature cartilage around the polyethylene, and the prefabricated shapes and sizes were well maintained. The neoformed cartilage also grew into the pores of the scaffold with a fine interface between them; this gave the whole regenerated composite tissue characteristics similar to those of native cartilage. These results show that it is feasible to construct cartilage using BMSC and PGA-high-density polypropylene scaffolds. This may remove some of the obstacles that have prevented the clinical use of cartilage engineering such as limited volume, deformation, and a limited number of seed cells.