The Investigation On The PLGA Microspheres Composite With A New Type Of Mesoporous Bioactive Glass For Drug Release And Bone Repair

At present,the main clinical treatments for bone defects are autogenous bone,allogeneic or allogeneic bone and artificial bone replacement materials.However,healing of bone defects is particularly difficult in people with pre-existing chronic conditions such as diabetes,hypothyroidism,chronic bone infections,malignancy,calcium and phosphorus metabolism disorders,and osteoporosis.Therefore,it is necessary to research and develop bone prostheses that can be loaded with relevant drugs to meet the clinical needs.Considering the biological safety of material,good performance of development,as well as local drug release for a long time,this study first using sol-gel method combined with template method and secondary calcination technology using soaking calcium nitrate solution preparation of the calcium content of controllable mesoporous bioactive glass(MBG),and the composite microspheres with good drug loading and slow-release performance were prepared by combining MBG and PLGA.On this basis,by loading drugs with different hydrophilicity,the drug-loading composite microspheres were finally obtained,and their physical and chemical properties and biological properties were further explored.The main research contents are as follows:1)A series of bioactive glass(MBG)with high specific surface area,large pore size and pore volume and good dispersion were prepared by changing the dosage of template agent(CTAB)combined with sol-gel method,and the calcium content of MBG was stable and controllable by soaking calcium nitrate alcohol solution and then calcining.2)By adjusting the dosage of the preparation of MBG,using microemulsion technology to the preparation of different mass fraction(0 wt%/10 wt%/20 wt%/30 wt%)of MBG/PLGA composite microspheres,through its degradation experiment,ion dissolution experiment and ALP,alizarin red staining observed,mesoporous bioactive glass composite can counteract the PLGA degradation of acid,helps to reduce inflammation,and improve the performance of the osteogenesis.3)The hydrophilic drug berberine(BBR)and hydrophobic drug icariin(ICA)were used as drug model to prepare drug-carrying composite microspheres.It was found that,compared with MBG loading alone,the drug-loading composite microspheres had a significant sustained release effect and a sustained release time of more than 60 days.In addition,both the drugloaded MBG and the drug-loaded composite microspheres have good biocompatibility and can promote osteogenic differentiation of m BMSCs.In this study,a bone repair material based on MBG / PLGA composite microspheres was successfully prepared.Through a large number of experiments,it was proved that it had good biocompatibility,osteogenic ability,drug loading and sustained-release ability.For patients with underlying diseases or bone defects that are difficult to heal,it is expected to achieve local long-term drug release and promote bone healing.