Preparation Of Functional Hydrogels Based On Pectin

Hydrogel is one kind of polymer material with a three-dimensional network swollen by water,which is widely used in various fields.Especially as biological materials,it has a wide range of applications in artificial organs,controlled drug carriers,biosensors,contact lenses,wound dressings and other fields.In this research,hydrogels were mainly prepared by using saccharide polymer pectin widely existing in nature.Pectin-based hydrogels have good biocompatibility and degradability,and have potential medical value in the field of biomedicine,so they have been favored by scientific researchers.In this paper,hydrogels with different functionalities were prepared from modifying copolymers of pectin and different functionalized polymers.The research content of this paper is mainly divided into the following three parts:1、 Fluorescent polymers are used as biomaterials for molecular diagnostics and cell imaging,and fluorescent self-healing hydrogels also have important applications as biomaterials.In this study,Tetraphenylethylene(TPE)with aggregation-induced luminescence(AIE)groups was introduced into the copolymer.The copolymer and biocompatible pectin prepared self-healing hydrogel through acylhydrazone bonds.Its luminescence,self-healing and rheology were studied.2、 The degradability of biomedical materials has always attracted the attention of scientific researchers.In this study,alkali-degradable phenolic ester bonds wereintroduced into the copolymer and reacted with modified biocompatible pectin to prepare hydrogel through acylhydrazone bonds.As a result,degradable,biocompatible,self-healing hydrogel was prepared.By changing the ratio of aldehyde groups to acylhydrazide group in the copolymer to regulate the mechanical strength and swelling ratio of the hydrogel,the injectable hydrogel was prepared and the drug loaded hydrogel was injected into the mice and the drug was released in vivo.The biotoxicity and drug release of this hydrogel have also been studied.3、 Temperature response is an important property as indicator in living organisms,and temperature-sensitive hydrogels are intelligent biological materials that show phase changes with changes in temperature.This part also studies the thermo-sensitive hydrogel based on N-isopropylacrylamide(NIPAM)copolymers and modified biocompatible pectin through acylhydrazone bonds.The mechanical strength of the hydrogel is adjusted by changing the ratio of pectin and NIPAM copolymer,so that the hydrogel can reach the mechanical strength fit for injection,and the biotoxicity of the hydrogel is studied.The hydrogel also showed enhanced anti-tumor effecacy with DOX and CA4 loading through controlled release profile.In this paper,the biocompatible polymer pectin is modified to prepare biodegradable self-healing hydrogels through dynamic acylhydrazone bonds with a light-emitting copolymer,an alkali-degradable copolymer,and a temperature-sensitive copolymer.Results showed the biodegradable pectin based hydrogels have great potential applications in diagnostics,drug loading and controlled release,and tumor treatments,which endowed them great potential application properties as biomedical materials.