A three-dimensional structure with osteoconductive function made of O-carboxymethyl chitosan using aspirin as a cross-linker

Hydrogels have a structure similar to the extracellular matrix and have wide applications in tissue engineering. Most hydrogels need to be composited with different substances to enhance mechanical and cell compatibility. In this study, aspirin (ASP) as a cross-linker improved the three-dimensional synthesis of chitosan-based hydrogels. Porous hydrogels in different concentrations of O-carboxymethyl chitosan (O-CMC) with aspirin were prepared by freeze drying. The reaction between (-COOH) of aspirin with (-NH2) of chitosan created the formation of crosslinks in O-CMC/ASP hydrogels. The SEM images showed these hydrogels have great morphological characteristics with high porosity and favorable pore size. The O-CMC/ASP scaffold showed appropriate swelling ability. Cell culture experiments demonstrated that using human adipose mesenchyme stem cells (hADMSC) improved cell viability, alkaline phosphatase activity (ALP), and bone-specific genes on the O-CMC/ASP scaffold compared to the O-CMC scaffold. As a result, the O-CMC/ASP scaffold has high osteogenesis induction and can be used as a biocompatible implant in bone tissue engineering.