Background: Currently synthetic polymers have been widely studied in the field of tissue engineering. Poly-L-lactic acid (PLLA), a kind of homopolymers in poly-hydroxy group, can be hydrolyzed without enzymes and then metabolized by the body. The degradation rate of PLLA is mediated by the size of molecular weight, chemical composition, crystallinity and porosity. In clinical periodontics, porous PLLA has been developed as membranes for tissue regeneration. Moreover, PLLA is potentially capable of acting as protein delivery carrier. Objectives: To evaluate the biocompatibility of porous PLLA for a future use as protein or cell carrier for tissue engineering. Methods: A self-made porous scaffold of PLLA polymers was made. Physical properties such as compression strength, proportion of porosity and pore size were studied. The protein dissolution methods were also examined by BSA solution. The PLLA implants were inserted into Wistar rat intramuscularly and miniature pig subcutaneously, and were observed for 2, 4, 6, 10 weeks respectively. Degradation of scaffold, tissue reaction were explored by histologic examination at different experimental periods. Results: All PLLA scaffold implants showed a homeogenous porosity with a mean pore size of 100 um. A minimal inflammatory cell infiltration was observed at early stage of wound healing in recipient animal tissues. Multinuclear giant cells and histiocytes were prominent cell types present at 2-6 weeks after implantation. This phenomenon diminished at later period of observation. Vascular invasion and capillary proliferation at 4-6 weeks were also noted. Conclusions: The self-made PLLA scaffold exhibited a good structure porosity and tissue biocompatibility in animals. The efficacy of using as a carrier needs to be further investigated.

Back to the Pharmacology, Therapeutics, & Toxicology Program
Back to the IADR/AADR/CADR 80th General Session (March 6-9, 2002)

Top Level Search