Synthesis And Application Research On Mesoporous Bioactive Glass Microspheres

Mesoporous bioactive glasses(MBGs),with well-ordered mesoporous channel structure,high specific surface area,great bioactivity and biodegradability,have been widely concerned in the field of drug delivery.By adjusting the formation conditions of MBGs microspheres,different morphologies of MBGs microspheres can be synthesized.These microspheres have great potential for application as drug-loading carriers and modifier of sodium alginate(SA).Firstly,polystyrene and phenolic resin(PF)were used to replicate the three-dimensional ordered silica colloidal crystal template.After etched by hydrofluoric acid,the three-dimensional ordered macroporous polystyrene template(OMP)was obtained;Three-dimensional ordered macroporous carbon template(OMC)was obtained by carbonization of PF at 800 C;MBGs microspheres with special morphology were synthesized by silica sol gel process:The core-shell bioglasses(CSBG),the ordered mesoporous bioglasses(OMBGs),the disordered macroporous bioglasses(DMBG)and the homogeneous bioglasses(HBG).The influence of calcinate temperature and the inner surface hydrophobicity of macroporous templates were discussed in detail.The morphological features and microstructures of MBGs powders were studied by transmission electron microscope(TEM),X-ray diffractometer(XRD)and BET patterns.The particle size was investigated by dynamic light scattering(DLS).The degradation behavior of MBGs in human body simulated fluid(SBF)solution was evaluated through inductively coupled plasma atomic emission spectrometry(ICP).Secondly,we compounded OMBGs with polymer to abtain a drug carrier.The drug loading and releasing behavior of amides in compound microspheres were studied.An amide narcotic drug ropivacaine hydrochloride was loaded into the OMBGs through soaking combined with a wet-impregnated method;OMBGs were modified with PLA-PEG and PEG,the vitro release behavior of ropivacaine hydrochloride in OMBGs@PLA-PEG and OMBGs@PLA-PEG&PEG was investigated.The morphological features and microstructures of the compound system were characterized with SEM,TEM and SXRD;the quantity of PLA-PEG and PEG modified onto the surface of OMBGs and drug loading capacity were detected by thermal gravimetric analysis(TGA);the process of drug release in vitro was detected by ultraviolet spectrum(UV).The results indicated that OMBGs could load ropivacaine hydrochloride efficiently,PLA-PEG could evidently control drug release.Finally,in order to expand the application of MBGs,we incorporated the HBGs in sodium alginate(SA)to obtain HBGs/SA composite porous materials.The surface morphology of the composites was characterized by SEM and TEM.The compressive stress-strain,modulus of elasticity and hardness of the composites were characterized by nanoindentation and universal mechanical testing machine.The mechanical properties of SA materials were greatly improved by adding HBGs microspheres.Further more,the method we used in preparing composite materials had effectively solved the problems in SA modification by nanomaterials,such as difficult dispersion,easy aggregation and affecting the homogeneity of products.It provided an affective reference method for nanomaterials to modify SA.The mechanical properties of SA materials were improved by adding OMBGs.