Thermo‐Responsive Chitosan‐graft‐poly(N‐isopropylacrylamide) Injectable Hydrogel for Cultivation of Chondrocytes and Meniscus Cells

Abstract Summary: A thermo‐responsive comb‐like polymer with chitosan as the backbone and pendant poly( N ‐isopropylacrylamide) (PNIPAM) groups has been synthesized by grafting PNIPAM‐COOH with a single carboxy end group onto chitosan through amide bond linkages. The copolymer exhibits reversible temperature‐responsive soluble‐insoluble characteristics with the lower critical solution temperature (LCST) being at around 30 °C. Results from SEM observations confirm a porous 3D hydrogel structure with interconnected pores ranging from 10 to 40 µm at physiological temperature. A preliminary in vitro cell culture study has demonstrated the usefulness of this hydrogel as an injectable cell‐carrier material for entrapping chondrocytes and meniscus cells. The hydrogel not only preserves the viability and phenotypic morphology of the entrapped cells but also stimulates the initial cell‐cell interactions. magnified image