Shilan Chen

Preparation of oxidized sodium alginate-graft-poly((2-dimethylamino) ethyl methacrylate) gel beads and in vitro controlled release behavior of BSA

Graft copolymerization of amino group-terminated poly((2-dimethylamino) ethyl methacrylate) (PDMAEMA-NH2) onto oxidized sodium alginate (OSA) was reacted without using a catalyst. The structure of the graft was investigated by Fourier transform infrared (FT-IR) spectroscopy. The OSA-g-PDMAEMA gel beads were prepared by dropping the aqueous solution of the graft copolymer into CaCl2 aqueous solution. The effects of pH and ionic strength on the swelling behaviors of the gel beads were studied. The results indicate that the gel beads have pH and ionic strength sensitivity. Bovine serum albumin (BSA) was entrapped in the beads and the in vitro drug release profiles were established in buffer solution with pH 1.8 (HCl), pH 7.4 (KH2PO4-NaOH), and 0.9% (w/v) NaCl at 37 degrees C. The results showed that the oral delivery of proteins can be controlled by adjusting the graft percentage (G, %), pH and ionic strength. According to this study, the OSA-g-PDMAEMA gel beads could be suitable for the oral delivery of proteins.

MMTCA Recognition by Molecular Imprinting in Interpenetrating Polymer Network Hydrogels Based on Poly(acrylic acid) and Poly(vinyl alcohol)

A novel IPN hydrogel designed to recognize MMTCA is prepared by applying the molecular-imprinting method. The IPN is characterized by FT-IR, DSC, and SEM. Langmuir analysis shows that an equal class of adsorption is formed in the hydrogel. The adsorption equilibrium constant and the maximum adsorption capacity are evaluated, and the effect of the pH on MMTCA adsorption is discussed. The selectivity of the imprinted polymer for MMTCA is studied in aqueous solutions of MMTCA/aspirin/riboflavin. The results suggest that the MMTCA-imprinted polymer shows superior selectivity for MMTCA as compared to riboflavin and aspirin. The reproducibility of the imprinted polymer to MMTCA is also studied.