Preparation, Structure And Properties Of BSA Imprinted PHB Based Microspheres Via Multiple Emulsion

In this dissertation water in oil in water (w1/o/w2) multiple emulsion method was selected to prepare bovine serum albumin (BSA) imprinted Poly(3-hydroxybutyrate) (PHB) microspheres with average diameter from 101μm to 102μm. Optical microscope was used for observation the course of solvent evaporation and solidification of multiple emulsion microdroplets. On the basis of the study BSA molecular imprinted PHB microspheres and PHB/Poly(ethylene glycol) (PEG) microspheres were prepared with embedding technique. The preparation, structure, characteristic and properties of the microspheres were detailedly discussed too.The result of research showed that structure of the multiple emulsion, especially the microdroplets'diameter and morphology of initial emulsion and multiple emulsion was a crucial factor to influence the structure of microspheres, which would form different structures such as deflated, closed, hollow or honeycomb at last. Participation of Poly(ethylene glycol) (PEG) strengthened the emulsification effect, improved the hydrophilic properties, played a role of pores-maker as templates and had an important influence on the structure of microspheres, The structure of microspheres had close relatively with the crystallizing behavior of PHB during the course of forming microspheres.The factors that worked on the diameter, surface morphology and porosity of the microspheres were systematically studied, including stirring speed of the second emulsion, volume ratio of W1/O and (W1/O)/W2, concentration of PHB, PEG, polyvinyl alcohol (PVA), BSA and mass ratio of PHB/PEG. Also the relationship between the structure of microspheres and entrapment rate and the property of dissolving out was discussed. The optimized processes parameters were fixed after that.The research of adsorption behavior showed that molecular imprinted PHB based microspheres had good specific adsorption, recognition and regeneration of the template. Greater absorption capacity could be achieved at equilibrium for the template at the preparation conditions of moderate template adding, lower molecular weight of PHB and the addition of PEG. The principle of PHB as a new molecularly imprinted material was discussed.