BIOABSORBABLE SYNTHETIC POLYESTERS AND TI SSUE REGENERATION - A STUDYON THE 3-DIMENSIONAL PROLIFERATION OF OVINE CHONDROCYTES AND OSTEOBLASTS

The tissue engineering area henceforth calls more and more for bioabso rbable substrata made of biopolymers (collagen, laminin...) or polymer s (PLA, PLGA, PGA...) to realize the three-dimensional culture of tiss ue equivalents. The poly (beta-hydroxybutyrate-beta-hydroxyvalerate), a biopolymer considered as being biodegradable and biocompatible, has been recently introduced for orthopaedic biomaterials and regeneration pur poses. In our study, a PHB/9% HV polymer was transformed into 3D foams, then applied to the culture 3D of ovine chondrocytes (fibrous r ings & growth plates) and osteoblasts (periostum). Sponges made ofbovi ne type I collagen were used as references. Orthopaedic cells were iso lated, prepared and sown by simple injection to the geometrical center of the substrata, then incubated from 0 to 35 days by changing the cu lture medium all 4 days. Maximal densities were reached after 21 days: 18-24.10(6) cells/g for the chondrocytes, 8-10.10(6) cells/g for the osteoblasts. The cellular proliferation was more marked, with highest cell densities, for the collagen sponges. Laser confocal microscopy sh ows that the cellular diffusion take place throughout the entire volum e of the porous artificial substrata. Future studies will allow to app ly the porous bioabsorbable substrata to high-density cell cultures, t o the tissue engineering and regeneration, for example for orthopaedic tissues: cartilage, fibrocartilage and bone.