Characterization of polylactic acid-polyglycolic acid composites for cartilage tissue engineering.

The objective of this study was to determine the effects of scaffold composition on the physical properties, adhesion, and growth of bovine articular chondrocytes on polylactic acid (PLA)/polyglycolic acid (PGA) composites. Nonwoven meshes of PGA were coated with PLA, using a solvent evaporation technique that resulted in composites with fractional PLA contents ranging from 0 to 68%. The compressive modulus of scaffolds increased linearly with the addition of PLA, ranging from less than 1 kPa for PGA to approximately 20 kPa for scaffolds with 68% PLA content. The characteristic degradation time of these scaffolds also increased from approximately 5 days for 0% PLA to 45 days for 68% PLA. Addition of PLA decreased cell seeding efficiency from 48% for 0% PLA scaffolds to 27% for 68% PLA scaffolds. Cells seeded onto 27% PLA scaffolds increased 3-fold in number over 4 weeks in culture, whereas cells seeded onto 68% PLA increased only 2-fold in number. Scanning electron microscopy indicated that cells attached to PGA appeared flat with many small processes, whereas those attached to PLA were more rounded. These studies provide important information for the design of scaffolds for cartilage tissue engineering.