Osteoblast: Osteoclast co-cultures on silk fibroin, chitosan and PLLA films

This study investigates the growth of a co-culture of osteoblasts and osteoclasts on four different types of degradable biomaterials with bone tissue engineering potential. Single or co-cultures of osteoblasts and osteoclasts (used at a ratio of 1:100 osteoblast:osteoclasts) were cultured on vapour stabilised silk fibroin, methanol stabilised silk fibroin, chitosan and poly (l lactic acid) (PLLA) films for 10 days. Osteoclast differentiation was determined by tartrate resistant acid phosphatase (TRAP) staining, total cell number by a picogreen DNA assay, cell morphology by scanning electron microscopy (SEM) and the material topography by atomic force microscopy (AFM). Samples were also monitored for degradation by differential scanning calorimetry (DSC) and fourier transform infrared (FTIR). Results demonstrated that vapour stabilised silk fibroin, methanol stabilised silk fibroin and chitosan all support the growth of osteoblasts and osteoclasts in both single and co-cultures. PLLA showed poor osteoclast differentiation in both single and co-cultures but supported osteoblast attachment and proliferation. Both silk fibroin materials showed sign of early degradation in the ten-day period, but very little change was seen in chitosan and PLLA samples. This study indicates that this novel co-culture approach for bone tissue engineering may be possible if scaffolds are created from silk fibroin or chitosan.