Efficient Fabrication of Uniform, Injectable, and Shape-Memory Chitosan Microsponges as Cell Carriers for Tissue Engineering br

Uniform and porous chitosan-based microparticles with injectable and shape-memory properties are particularlyattractive due to their promising application potential for tissue engineering and regenerative medicine. However, simple andefficient methods for producing this kind of microparticle are still desirable. In this study, we report that uniform, injectable, andshape-memory chitosan microsponges were efficiently prepared by combining microfluidic emulsion with further freezing and in situthawing processes without using any potentially cytotoxic chemical cross-linker. The produced chitosan microsponges havecontrollable size and could be easily injected with syringe needles. Structural observations confirmed that the chitosan microspongehad an interconnected porous structure with pore size of several micrometers and could withstand a large compressive strain of similar to 93% and then recover similar to 96% of its initial diameter without structural damage. The chitosan microsponges showed a high porosity(similar to 84%) and swelling ratio (similar to 3800%) as well as good antibacterial activity. Additionally, an in vitro cell coculturing investigationrevealed that they also had good biocompatibility and exhibited great superiority to support cell adhesion and proliferation in threedimensions. The kind of chitosan microsponge presented here has great potential to serve as cell carriers for biomedical applications, especially as injectable scaffolds for regeneration and reconstruction of tissue defects