Synthesis And Properties Of A Novel Functingally Modified Chitosan Derivatized Hydrogel

The chitosan-based hydrogel is highly similar to the biological tissue of the body.It can be used to support the regeneration of cells and tissues in the body.The development of new functional hydrogels by modern biochemical methods can effectively cope with and solve the practical problems that the mechanical strength and dynamic self-recovery ability of hydrogels are insufficient.In this study,a variety of superior cross-linking methods were jointly applied to obtain self-healing single/multi-bridge network functionalized hydrogel.The gel forming factor module and natural polymer were integrated to obtain photothermal nanocomposite functionalized hydrogel.This study provides a theoretical basis for the development of functionalized chitosan hydrogels with new structural,and provides new ideas for the preparation of functionalized bio-titanium hydrogels with both mechanical properties and special characteristics.The main research contents are as follows:1)a variety of functional groups such as carboxyl groups,cyclodextrins,and sulfhydryl groups are introduced into the chitosan molecular.The new gum-forming unit were obtained,including CMCS/CD-CMCS/Thiolated-CMCS/Thiolated-CD-CMCS.2)Ferrocene was introduced into polyacrylamide structure and gel-forming modular polyacrylamide-ferrocene（APM-Fc）was obtained.The host-guest interaction,disulfide bond,intermolecular hydrogen bond are collaboratively assembled and integrated into the hydrogel preparation to obtain single/multi-bridge network hydrogel with strong mechanical properties and self-healing properties:CD-CMCS-PAM-Fc/Thiolated-CMCS-PAM-Fc/Thiolated-CD-CMCS-PAM-Fc.The photothermal nanocomposite hydrogel（CMCS-Fe₃O₄-AM）was obtained by assembling Fe₃O₄ nanoparticles,amide bonds and intermolecular hydrogen bonding.FT-IR,¹H NMR,XRD,DSC,TG,SEM are used to characterize the gel-forming unit,module and gel structure,and study its cross-linking mode,thermal degradation and micro-morphology.The self-healing,photothermal function characteristics and basic performance were researched.The effect of cross-linking method and raw material composition on the hydrogel material texture and targeting function was found.The tightness of cross-linking is positively correlated with the water holding capacity and mechanical strength of the gel,and negatively correlated with the degradation rate.In addition,the multi-bridge synergy can give Thiolated-CD-CMCS-PAM-Fc self-healing properties and enhance its mechanical properties.The composition significantly affects the mark performance of CMCS-Fe₃O₄-AM,and it is confirmed that Fe₃O₄ nanoparticles give the target gel photothermal function.In this paper,multi-bridge/nano-composite functionalized hydrogels obtained by different gel-forming strategies have achieved self-healing recovery,photothermal and other advantageous properties.They can be used as biomacromolecule medical materials in the body.The compatibility need to be further studied in the future.