Interpenetrating polymer network (IPN) scaffolds of sodium hyaluronate and sodium alginate for chondrocyte culture

In this study, porous sodium hyaluronic acid/sodium alginate (HA/SA) scaffold based on interpenetrating polymeric network (IPN) technique has been fabricated, where HA and SA were cross-linked with poly(ethylene glycol) diglycidyl ether (PEGDG) and calcium chloride, respectively. The mean pore size and the swelling ratio of fabricated scaffolds decreased, and the compressive strength increased as the content of SA increased in HA/SA IPN scaffold. Rabbit chondrocytes were seeded within the HA/SA IPN scaffolds, and then their proliferation as well as chondrogenic differentiation was examined. DNA contents observed from the chondrocytes cultured in the IPN scaffolds increased with time over 21 days, which demonstrated that the rabbit chondrocytes continued to proliferate in HA/SA scaffolds. Results of the 1,9-dimethylmethylene blue (DMMB) and p-dimethylaminobenzaldehyde (DMBA) assays showed that glycosaminoglycan (s-GAG) and collagen contents increased over culture period, indicating the chondrogenic differentiation in the scaffold. Reverse transcription-polymerase chain reaction (RT-PCR) results showed the expression of type II collagen, the main chondrogenic differentiation marker. The bands indicating mRNA expression of type II collagen increased with the culture period. These results demonstrated that the porous HA/SA IPN scaffolds were successfully prepared and could serve as an effective delivery system of the three-dimensional culture of chondrocytes.