pH/温度双响应壳聚糖基可注射水凝胶的制备及性能OA

Stimuli-responsive injectable hydrogel,a kind of polymer material that can respond to changes in the external environment,is injected in solution form,and forms gel with three-dimen-sional network structure after phase transition at the site of action.It has the characteristics of biocompatibility and similarity with natural tissue,which is widely used in medicine fields such as drug delivery and tissue engineering.To realize the synergistic function of"in-situ gelation-precise response-on-demand drug release",two injectable hydrogels with pH/temperature dual response were constructed by using polycationic chitosan(CS)as the matrix,temperature-sensitive anionic polymer(PNAM),and sodium bicarbonate(SHC)/sodium glycerophosphate(GP)as crosslink-ing agents through the dual-ion crosslinking method.The influence of single factors(concentra-tion,ratio,etc.)on the gelation time was investigated,and their structures and morphologies were characterized by using infrared spectroscopy and scanning electron microscopy.The swelling property and biocompatibility were explored in detail.The results showed that when the concen-tration of chitosan(CS)was 20 mg/mL,temperature-sensitive polymer(PNAM)was 4.0 mg/mL,and the ratio was 10∶2∶5,the gelation time of CS-PNAM-SHC hydrogel was 180 s at 37℃.The hydrogel presents a porous surface and a high swelling rate,which can realize the con-trolled and sustain release of drugs.When the concentration of CS was 20 mg/mL,the concentra-tion of PNAM was 3.0 mg/mL,and the ratio was 10∶13∶1,the formation time of CS-PNAM-GP hydrogel was 90 s,and the hydrogel showed a stratified structure with slow swelling speed,which can be used in the preparation of scaffold materials.Both hydrogels have good biocompati-bility,and both can respond intelligently at 37℃,which are expected to have wide application prospect in the biomedical field.