Glycogen as crosslinking agent of collagen and nano-hydroxyapatite to form hydrogels for bMSCs differentiation

Polysaccharides have been considered as the important linker of organics and minerals in the scaffold for bone repair. In this study, we exploited glycogen as the contactor of collagen and hydroxyapatite to form composite hydrogels, since it could provide stereoscopic multiple sites for reacting with other components. Glycogen was modified with guanido followed by oxidization to aldehyde, which subsequently combined with collagen and hydroxyapatite through Schiff-base bond and electrostatic interaction, respectively. The resulting hydrogels could almost maintain their prototypes within 2 weeks, with little degradation. Their Youngu0027s modulus (10 to 70 kPa) and compressive modulus (30 to 432 kPa) were all within the range of properties required for stem cells to differentiate into osteoblasts or cartilage. Additionally, bone mesenchymal stem cells cultured on the composite hydrogels presented desirable cell adhesion, viability and growth. The ratio of collagen/glycogen/hydroxyapatite components could regula...