Preparation And Application Research In Bone Tissue Repair Of Jade Powder/PLGA Composite Microspheres

Bone defect is a common clinical disease and a difficult problem in orthopedics and plastic surgery.Bone repair materials play an important role in the whole bone repair process.Poly(lactic-co-glycolic acid)(PLGA),a biodegradable polymer compound,has been widely used as drug delivery carriers or tissue engineering scaffolds in biomedical engineering such as bone tissue repair due to its good biocompatibility and degradation rate controllability.With the further research,some defects of PLGA in the field of bone repair have emerged,mainly manifested as poor hydrophilicity,which is not conducive to cell adhesion and growth;at the same time,PLGA degradation products are acidic,interfering with the microenvironment in vivo and causing inflammation;moreover,PLGA by itself does not promote osteogenic differentiation.Hetian jade powder is a kind of hydrated calcium magnesium silicate with good hydrophilicity,and its rich calcium,magnesium and silicon elements can promote osteogenic differentiation.In this study,jade powder/PLGA composite microspheres were prepared to study whether the addition of jade powder could make up for the deficiency of PLGA,improve the hydrophilicity and biological activity of microspheres,and explore new ideas for bone repair materials.In this study,the phase structure,surface morphology,element content and material properties were characterized and analyzed by XRD,SEM,XPS,ICP and contact angle test,and the toxicity and antibacterial properties of jade powder were tested by in vitro cells and colony experiments.Then the preparation conditions of jade powder/PLGA composite microsphere with different mass ratio were explored and optimized by emulsion solvent evaporation method.And the physical structure of the composite microspheres was characterized by SEM,EDS,FT-IR and contact angle tests.Through in vitro simulation and cell experiments,the ability of jade stone powder/PLGA composite microsphere to stabilize body fluid p H and induce osteogenic differentiation of adipose stem cells was investigated.The results show that:(1)Jade powder particles have irregular morphology and the concentrated particle size distribution,containing stable crystal structure,have good hydrophilic and the content of trace elements is ppm level,no inhibitory cell proliferation and growth of E.coli and S.aureus.(2)Jade powder is successfully combined with PLGA,and the surface roughness and hydrophilic of the composite microsphere are better than that of pure PLGA microsphere,which has the potential to promote cell adhesion and growth.(3)The higher the content of jade powder in the composite microsphere,the stronger the ability to buffer p H,can improve the acidic environment produced by PLGA degradation,and the jade powder/PLGA composite microsphere does not affect the proliferation and growth of cells,and has the ability to induce osteogenic differentiation of adipostem cells.In conclusion,the composite of jade powder can enhance the hydrophilicity of PLGA material and improve its degradation to cause acidic defects to the environment,and enhance the ability of cell osteogenic differentiation.This study provides new ideas for improving the performance of bone tissue repair materials,and provides a research basis for expanding the application of PLGA materials.