动态席夫碱交联的壳聚糖基水凝胶的合成与性能研究OA北大核心CSTPCD

The mechanical performance of chitosan hydrogel is often undesirable,and glutaraldehyde cross-linking is widely carried out to improve their mechanical performance.Unfortunately,glutaraldehyde affects the biosafety of hydrogel.In order to improve the mechanical performance of chitosan hydrogel and ensure their biosafety,a hydrogel and its derivatives were prepared entirely from chitosan in this study.Carboxymethyl chitosan(CMC)and dialdehyde chitosan(DACS)were covalently crosslinked through Schiff base bonding to form a chitosan-based hydrogel(CBH).The self-healing and mechanical property of CBH were evaluated through rheological,tensile and adhesion experiments.In addition,the antibacterial function,biocompatibility and anti-inflammatory function of CBH were comprehensively evaluated via antibacterial,live/dead and anti-inflammatory assays,and cytotoxicity and haemolysis tests.It was found that CBH has a healing efficiency of 72%after 4 h and can be stretched to double its original length.Our results demonstrated that Schiff base bond cross-linking endows CBH with a good self-healing performance and improves its mechanical property.CBH has an equilibrium swelling rate of up to 4 500%and is p H responsive.The inhibition efficiency against E.coli and S.aureus was 80.95%and 79.79%,respectively.Cells co-cultured with CBH proliferated normally over time without a significant cell death,and the hemolysis rate was only 3%,proving that CBH has an excellent biocompatibility.Meanwhile,CBH also inhibited the secretion of pro-inflammatory factors such as nitric oxide and TNF-α,IL-1β,IL-6,and increased the secretion of anti-inflammatory factors such as IL-10.Our results showed that CBH prepared by CMC and DACS have good self-healing,mechanical,antibacterial and anti-inflammatory properties,and are highly biocompatible.CBH holds broad potentials for being applied in biomedical fields.