Covalently Crosslinked Chitosan-Poly(ethylene glycol) Hybrid Hydrogels to Deliver Insulin for Adipose-Derived Stem Cells Encapsulation

Biodegradable hydrogels carrying adipose-derived stem cells (ASCs) have been highlighted with promising potential regarding adipose tissue engineering. In this study, covalently crosslinked natural/synthetic hybrid hydrogels were prepared from methacrylated water soluble chitosan (N-succinyl-chitosan, SCS) and poly(ethylene glycol) (PEG) by photoinitiaing polymerization under the existence of Irgacure 2959 and the irradiation of UV light. The effect of the incorporated PEG on the in vitro morphologies, equilibrium swelling, weight loss and compressive modulus of SCS/PEG hybrid hydrogels in phosphate buffered saline (PBS) at 37 degrees C were studied. In order to evaluate the ability of hydrogels to effectively deliver the adipogenic factor, insulin was entrapped within hydrogels by copolymerizing methacrylated SCS/PEG. The insulin would be released from the hydrogels into the local microenvironment via the controlled weight ratio of SCS/PEG. Results demonstrated that the hybrid hydrogel with 10 wt% PEG showed a higher efficiency of insulin delivery compared to the control hydrogels. ASCs were seeded into the insulin-loaded SCS/PEG hydrogels in vitro to assess the biological performance and applicability of hydrogels as cell carriers. These characteristics provide potential opportunities for the hybrid SCS/PEG hydrogels as injectable scaffolds in soft tissue engineering applications.