Study On Macromolecularly Imprinted Polyvinylpyrrolidone-based/alginate Polymer Microspheres

Calcium polyvinylpyrrolidone/alginate polymer microspheres (PVP/CA MIPMs) and calcium hydrolyzed polyvinylpyrrolidone/alginate polymer microspheres (PVP/CA MIPMs) macromolecularly imprinted hybrid polymer microspheres were firstly designed and prepared with sodium alginate (SA) and polyvinylpyrrolidone (PVP) by using CaCl2 as gelling agent in inverse-phase suspension. Morphology of BSA imprinted PVP-based hybrid polymer microspheres was observed by optical microscopy. The effect of the kind and quantity of the stabilizers, the ratio between the continuous phase and the disperse phase, the stiring speed, the percent of hydrolyzed PVP on the size, size distribution and morphology of the hybrid polymer microspheres. The rebinding capacity of the imprinted and non-imprinded microspheres is determined by UV spectrophotometry and conductivity meter. The processing methods such as eluting progress and time are inspected as impacting factors towards rebinding quantity and imprinting efficiency. The effects of extra stimulation like concentration of crosslinking agent (CaCl2), pH of the BSA solution and the ionic strength of Na+ and Ca2+ are also studied.Rebinding dynamic and thermodynamic behaviors of the two imprinted microspheres were evaluated, resulting in a higher affinity for imprinted microspheres relative to non-imprinted ones. CHPVP/CA MIPMs possess an interpenetrating network (IPNs) that is more stable and compact than the semi-IPNs of the PVP/CA due to the difference in their crosslinking manners. The cavities and functional sites of CHPVP/CA MIPMs are more facilitate in the specific rebinding process. Higher stability and imprinting efficiency are found in CHPVP/CA MIPMs rather than in the PVP/CA MIPMs, however the rebinding quantity is lower than the latter. Meanwhile, the rebinding behavior of the CHPVP/CA MIPMs is more sensitive to ionic strength than PVP/CA MIPMs.