Induced production of rabbit articular cartilage-derived chondrocyte collagen II on polyhydroxyalkanoate blends.

Three-dimensional porous scaffolds made from blend polyesters of polyhydroxyalkanoates (PHA) were evaluated with respect to their effects on collagen II production. Semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) was used to assay collagen II mRNA for evaluation of the ability for the blend scaffolds to induce collagen II production. It was found that scaffold of poly-3-hydroxybutyrate (PHB) blended with a copolyester consisting of 3-hydoxybutyrate-co3-hydroxyhexanate (PHBHHx) in a radio of 1:2 had strong ability to induce collagen II production compared with other ratios of PHB/PHBHHx and poly-L-lactic acid (PLA). Collagen II expression level remained approx. 1.5-times higher on the above-mentioned blend compared with that of PLA throughout four weeks cultivation. At the same time, the PHB/PHBHHx blend (1:2) exhibited a similar tendency as PLA to maintain the collagen 11 expression level over the entire culture period. The results showed that the PHB/PHBHHx blend (1:2) reported to improve mechanical properties compared with PHB or PHBHHx improved biocompatibility in comparison with PHB, PHBHHx, PLA and other blending systems consisting of PHB/PHBHHX in ratios of 2:1 and 1:1, respectively.