Preparation And Performance Research Of New Hydroxyapatite Composite Bone Tissue Scaffold Materials

With the advancement and development of science and technology,facing the international problems caused by bone defect diseases,medical researchers have developed bone tissue engineering scaffold materials to be used in the field of bone repair,and have initiated continuous in-depth research.This article chooses to simulate the composition and structure of natural bone,and intends to prepare an ideal new hydroxyapatite(HA)composite bone scaffold material with good mechanical properties,suitable degradation rate and certain antibacterial effects.In this paper,firstly,hydroxypropyl chitosan hydrogel(SG)was prepared as a new type of hydroxyapatite(SHA)modified by surfactants by the hydrothermal precipitation method,and the influence of SG content on the structure of SHA was studied;secondly,The hydroxypropyl chitosan(HPCS)/regenerated silk fibroin(SF)/SHA composite scaffold material is prepared by the combination of blending method,freeze-drying technology and genipin cross-linking method through simple molding,which is divided into different components according to different components.70%HPCS/20%SF/10%SHA,65%HPCS/25%SF/10%SHA and 60%HPCS/30%SF/10%SHA,abbreviated as HSA₁,HSA₂and HSA₃composite scaffold,respectively.Different The influence of the components on the structure of the composite scaffold reveals the composite mechanism of the HPCS/SF/SHA composite scaffold and the effect of component changes on the properties of the HPCS/SF/SHA composite scaffold.SG modified HA obtained SHA rod-shaped particles with high purity,high crystallinity,and good dispersion.The rod-shaped length is approximately between 120 nm and 200 nm,and the diameter is between 20 nm and 40 nm.At this time,the crystal is along the c axis.Growth,sample Ca/P=1.657.The preparation of HPCS/SF/SHA composite scaffolds found that all scaffolds have irregular porous structures on the surface,and such structures are composed of a large number of nano-spherical particles and rod-shaped particles.As the composition changes,the porosity and water absorption of the three groups of scaffolds all show a trend of first increasing and then decreasing.The average porosity is 53.33%,61.27%,and 57.17%,respectively.The porosity of HSA₂is higher.The HSA₂composite scaffold also has a maximum water absorption rate of 68.48%.Such porosity and water absorption rate are conducive to cell adhesion,growth and proliferation.The compressive strengths of the HSA₁,HSA₂,and HSA₃stents are 16.235 MPa,31.759 MPa and 24.190 MPa,respectively,and the corresponding elastic moduli are 0.476 GPa,0.523 GPa,and 0.512 GPa.The degradation rate of HSA₁,HSA₂and HSA₃composite scaffolds gradually increased with the increase of the number of degradation days.After 28 days of degradation,the degradation rates of the three scaffolds were 75.47%,63.24%and 64.28%,respectively.A layer of bone-like apatite nanoparticles was deposited on the surface of the three groups of scaffolds,indicating that the scaffold material has a certain in vitro mineralization ability.The three groups of stents all showed excellent antibacterial ability.As the amount of SF increased,the antibacterial effect of the composite stent decreased.The antibacterial ability of HSA₁against Escherichia coli and Staphylococcus aureus reached 75.6%and 68.7%,respectively.The three groups of composite bone tissue scaffold materials all have certain biological activity,while the biological activity of HSA₁is relatively weak.The rate of viable cells at the beginning of all scaffolds was above 90%,and the rates of viable cells on 7 day were:MC3T3-E1 cells 88.6%,HSA₁scaffold-cells 75.8%,HSA₂scaffold-cells 85.7%and HSA₃scaffold-cells 84.1%,Indicating that the HSA₁scaffold material has certain cytotoxicity,while the HSA₂scaffold and HSA₃scaffold have almost no cytotoxicity.