The Effects of Perichondrium on Cartilage Tissue Engineering

ABSTRACT

Despite many successful reports of cartilage tissue engineering, actual clinical application has not been performed due to several critical problems in this new pioneering field of tissue restoration. The problems of progressive absorption and distortion of engineered cartilage are one of those problems preventing clinical application. Distortion of tissue engineered cartilaginous tissue may be induced by internal and external factors such as gradual absorption of biomaterials, inappropriate production of matrix and contractile force in the process of wound healing. Naturally, cartilage tissue is completely enveloped by a layer of connective tissue, the perichondrium, and it continually provides chondrocytes and cartilage matrix. The author's speculation is that we may need the perichondrial layer in cartilage tissue engineering. Perichondrium may be another important element of cartilage tissue engineering. After harvesting a cartilaginous tissue from ear of 12 rabbits, we cultured rabbit ear chondrocytes. Polylactide-co-polyglycolide(PLGA) and fibrin glue were used as chondrogenic scaffold to compare the effect of different biomaterials in cartilage tissue engineering. Tissue engineered construct (TEC) were incubated for 4 weeks and autogenous implantation was performed. During the implantation procedure, some of the TEC were wrapped with perichondrial graft to find out the effect of perichondrium on cartilage tissue engineering. Four weeks after implantation, gross and histologic examinations were performed.With this experiment, we could obtain perichondrium covered cartilage tissue similar to natural cartilage. It was observed that there was less distortion or absorption in TEC with perichondrial graft than TEC without perichondrial graft. As far as the biomaterials are concerned, PLGA group showed less distortion or absorption than fibrin glue group after 4 weeks of in vivo implantation. In conclusion, we could find out the positive effect of perichondrium in cartilage tissue engineering with simple perichondrial graft on TEC. Also, less absorbable biomaterial such as PLGA, seems to provide more reliable results than fibrin glue which is quite easily degraded.