| The hydrogel has an adjustable three-dimensional network structure,and can simulate the extracellular matrix(ECM),has good biocompatibility,and is a mature bone tissue engineering scaffold material.However,the general hydrogel has poor mechanical properties and it is difficult to provide the mechanical support required for bone repair.On the other hand,mesoporous silicon(MSN)is used in the biomedical field due to its high specific surface area,non-toxicity,and good biocompatibility,but it has a highly stable network due to its Si-O-Si bonding Structure,which makes MSN more difficult to degrade.In view of the current problems of hydrogels as bone repair scaffold materials and the difficulty of MSN degradation,this paper prepared alginic acid-polyethylene glycol diacrylate-polydopamine by ultraviolet free radical polymerization and in-situ release-zinc-doped mesoporous silicon(SA-PEGDA-PDA-MSN-Zn)hydrogel-mesoporous silicon composite scaffold material,used as a scaffold material for the treatment of bone repair,and the hydrogel-mesoporous silicon composite scaffold The material has been studied by systematic mechanical testing and swelling rate.The main research contents are as follows:First,the alginic acid-polyethylene glycol diacrylate(SA-PEGDA)double network(DN)hydrogel was prepared by UV polymerization and in-situ release method,and the optimal concentration ratio was: the concentration of SA was 1 wt%,the concentration of PEGDA is 10wt%,the mechanical properties are optimized,the compressive strength is increased to 0.79 MPa,the mechanical properties are significantly improved,the microscopic morphology test shows that the pores of DN hydrogel are more uniform,and the rheological test shows that the system It can quickly form gel,shorten the gel time to 16 s,and form a three-dimensional network structure with perfect cross-link density.Second,in this study,mesoporous silica(MSN)was modified to improve its degradation,and the metal elements strontium(Sr),zinc(Zn),and calcium(Ca)were respectively doped into MSN through a one-pot method.Preparation of dendritic mesoporous silicon spheres MSN-Sr,MSN-Zn,MSN-Ca,SEM,TEM,particle size test analysis showed that MSN-Sr,MSN-Zn,MSN-Ca are uniform size,dendritic mesoporous silicon spheres,but the internal structure of MSN-Sr,MSN-Zn,and MSN-Ca is different from that of MSN dendrites,indicating that thedoping of Sr,Zn,and Ca changes the internal structure of MSN;BET and XPS tests show that MSN-Sr,MSN-Zn,and MSN-Ca is suitable for the choice of bone repair materials.The comparison of the three silicon balls shows that MSN-Zn is more suitable as a bone repair material than MSN-Sr and MSN-Ca.The degradation test found that the degradation rates of MSN-Sr,MSN-Zn,and MSN-Ca are higher than MSN,indicating that the doping of metal elements can accelerate the degradation of MSN.Finally,MSN-Zn was coated with polydopamine(PDA)to prepare polydopamine-zinc-doped mesoporous silicon(PDA-MSN-Zn).PDA-MSN-Zn and SA-PEGDA were prepared through hydrogen bonding to produce SA-PEGDA-PDA-MSN-Zn hydrogel-mesoporous silicon composite scaffold material,and the optimal concentration ratio is:SA concentration is 1 wt%,PEGDA concentration is 10 wt%,PDA-MSN-Zn concentration is 0.2wt%,its compressive strength can reach 0.83 MPa,which is higher than that of SA-PEGDA DN hydrogel,and its mechanical properties are significantly improved.Cyclic compression characterization of the composite scaffold material showed that the self-recovery of the composite scaffold material was higher than that of SA-PEGDA DN hydrogel,indicating that the addition of the inorganic phase PDA-MSN-Zn made the composite scaffold material physico-chemical The three network structures of cross-linking and hydrogen bonding make the cross-linking density more perfect.This makes the SA-PEGDA-PDA-MSN-Zn hydrogel-mesoporous silicon composite scaffold material not only provide mechanical support in the field of bone repair,but also has the potential to effectively control drug release and active ion release. |
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