Study On The Properties Of Methacrylated Gelatin(GelMA) And Microfluidic Preparation Of Composite Fiber

Objective:Methacrylated gelatin(GelMA)plays an important role in tissue engineering because of its tunable physical and chemical properties and good biocompatibility,especially its high similarity with natural extracellular matrix,which can provide simulation conditions for in vitro cell culture.However,due to the poor mechanical properties and low viscosity of GelMA hydrogel,its application may be limited.This thesis attempts to systematically study the morphology and properties of GelMA hydrogel,respectively in three parts.The first part:the influence of frozen temperature and time on the GelMA hydrogel synthesis,the second part:one-step preparation of calsium alginate hydrogel composite fiber encapsulating GelMA hydrogel precursor microsphere(GelMA_s@Ca-A_f),the third part:impacts of additives on the mechanical properties of GelMA.Methods:In the first part of this thesis,three kinds of frozen temperature-20C,-40C and-80C,and four kinds of frozen time 2 days,7 days,12 days,17 days were employed,and 12 groups of samples were prepared.Then fourier transform infrared spectroscopy(FTIR)characterization,scanning electron microscopy(SEM)characterization,swelling properties characterization,mechanical properties characterization were carried out.The second part was based on the principle of coaxial flow and a microfluidic coaxial capillary device was fabricated to analyze the factors that may affect the formation of the structure.In the third part,literature retrieval was carried out in the electronic database,and then literature screening was performed to extract the research data included in the Meta-analysis,and Meta-analysis was performed with Review Manager software.Results:The results of the first part showed that at frozen temperature of-80C,frozen time of 2 days,GelMA hydrogel was found to possess comprehensive properties,especially the aperture of the GelMA hydrogel samples was the largest under these conditions,which provides a reference for the preparation conditions of GelMA hydrogel used in tissue engineering.In the second part of this study,a microfluidic experimental device was fabricated and the factors that may potentially affect the experimental results were analyzed.Finally,a new structure GelMA_s@Ca-A_f was generated in a one-step method,which has potential applications as an implantable tissue repair material.In the third part,the Meta-analysis showed that additives could improve the mechanical properties of GelMA hydrogel.Meanwhile,the concentration of GelMA hydrogel in the control group,the types of photoinitiator,the exposure time,the exposure intensity,and the concentration of the photoinitiator Irgacure2959 are all sources of heterogeneity.This result provides a reference for construction of GelMA hydrogel composites.Conclusions:1.The frozen temperature and frozen time will affect the pore size of GelMA hydrogel;2.The new structure GelMA_s@Ca-A_f can be prepared by one-step microfluidic method;3.The additives can improve the mechanical properties of GelMA hydrogel,and five factors are the sources of heterogeneity.