Study On Preparation And Release Of BSA Calcium Alginate Microspheres

Microencapsulation technology can protect core materials and endow them with multi-functions.As a wall material of microencapsulation,sodium alginate is used in the scaffold materials for tissue engineering due to its excellent viscidity,stability,solubility and biocompatibility.Therefore,the objective of this thesis is to develop the novel preparation methods of scaffolds for the living environment of cells in the body.It is a subject about a comprehensive study of influence factors of experimental conditions;aimed to explore the preparation methods of BSA calcium alginate microspheres and research the effects of BSA concentration.This thesis mainly includes the following six chapters.The first chapter introduces microencapsulation technology,physicochemical properties of sodium alginate,main methods of preparation of sodium alginate microsphere and applications of microspheres are reviewed.In second chapter,emulsion gelation method was employed for the preparation of calcium alginate microspheres.The effects of experimental conditions such as the method of agitation,emulsifying speed,concentration of sodium alginate,concentration of calcium chloride,emulsifier concentration,emulsifying time,the volume ration of organic phase to aqueous phase on particle size and morphology were investigated.The optimized conditions are identified.The method of agitation is mechanical agitation.The emulsifying speed is 800rpm.The concentration of sodium alginate is 1.0%(w/v).The concentration of calcium chloride is 12%(w/v).The concentration of emulsifier is 4.0%(w/v).The emulsifying time is 120min.The volume ration of organic phase to aqueous phase is 1:1.The third chapter concerned with the evaluation of calcium alginate microspheres on particle size and morphology.Under optimized conditions,the average particle size of calcium alginate microspheres is 363 nm.The particle size distribution is concentrated.The fourth chapter concerned with the preparation of three concentrations of BSA calcium alginate microspheres,the evaluation of BSA calcium alginate microspheres on particle size and morphology.The particle size of calcium alginate microsphere is smallest.In three concentrations,the particle size of 0.5% BSA calcium alginate microspheres is smallest and 1.0% BSA calcium alginate microspheres is biggest.The particle size distribution of BSA calcium alginate microspheres is reduced with the increase of the concentration of BSA.The fifth chapter concerned with the release in vitro of three concentrations of BSA calcium alginate microspheres,investigating the influence of BSA concentrations.Both the drug-loading rate and trapping efficiency are increased while the concentration of BSA is increased.The influence of the drug-loading rate is not obvious.The curve shapes of release in vitro are equivalent.In the simulated physiological environment of buffer solution(PBS=7.4),different concentrations of BSA calcium alginate microspheres are all quick released.The first hour is quick released.The release of 1~12 h is delayed.The release of 12~48 h is slow.The sixth chapter summarized the whole thesis and looked into the prospect of the further research work.