The in vitro biocompatibility of D-(+) raffinose modified chitosan: Two-dimensional and three-dimensional systems for culturing of horse articular chondrocytes

The present study investigated the biocompatibility of chitosan films and scaffolds modified with D-(+)raffinose and their capability to support the growth and maintenance of the differentiation of articular chondrocytes in vitro. Primary equine articular chondrocytes were cultured on films and scaffolds of modified D-(+) raffinose chitosan. Their behavior was compared to that of chondrocytes grown in conventional bi- and three-dimensional culture systems, such as micromasses and alginate beads. Chitosan films maintained the phenotype of differentiated chondrocytes (typical round morphology) and sustained the synthesis of cartilaginous extracellular matrix (ECM), even at 4 weeks of culture. Indeed, starting from 2 weeks of culture, chondrocytes seeded on chitosan scaffolds were able to penetrate the surface pores and to colonize the internal matrix. Moreover they produced ECM expressing the genes of typical chondrocytes differentiation markers such as collagen II and aggrecan. In conclusion, chitosan modified with D-raffinose represents an ideal support for chondrocyte adhesion, proliferation and for the maintenance of cellular phenotypic and genotypic differentiation. This novel biomaterial could potentially be a reliable support for the re-differentiation of dedifferentiated chondrocytes.