Development of reinforced chitosan/pectin scaffold by using the cellulose nanocrystals as nanofillers: An injectable hydrogel for tissue engineering

Injectable hydrogels based on chitosan (CS), cellulose nanocrystals (CNCs) and pectin were designed with the well internal structure that are significant for tissue engineering. Pectin and CS-based hydrogels that mimic the extracellular matrix (ECM) are widely used to maintain the balance between biofunctional and physical properties. While, these hydrogels display low mechanical strength limits their uses in cartilage repair. So, CNCs were employed as nanofillers to reinforce the hydrogels based on the natural polysaccharides. In this regard, the aim of this study was to improve the mechanical property of CS/pectin injectable hydrogels by introducing CNCs into the CS/pectin hydrogels. By varying their weight ratios, physicochemical properties of CS/pectin hydrogels with or without CNCs were characterized. The results indicated that with increasing the CNCs content, more compact network structure, lower equilibrium swelling ratios and better the resistance to degradation of composite hydrogels were observed. Furthermore, the incorporation of CNCs in CS/pectin hydrogels increased the proliferation of chondrocytes, demonstrating cell supportive properties of CNCs. This result was due to the higher potential interaction of cells with sulphate groups of CNC. These findings suggested that the novel multicomponent hydrogel can be a useful scaffold for cartilage tissue regeneration.