Functionalized aliphatic polyesters, especially those with pendent hydroxyl, carboxyl and amino groups, have attracted much research interest in recent years due to their perfect biocompatibility, biodegra-dability and reactivity. Copolymerization of lactide with functionalized cyclic carbonate monomers proved to be an efficient way to functionalize aliphatic polyesters. However, random co-polyesters with pendent amino groups were seldom reported. This article reported a facile way to prepare aliphatic polyesters with random pendant azido and amino groups via Click reaction.
The copolymer poly(L-lactic acid)-b-poly(L-cysteine) (PLA-b-PCys) was co-electrospun with PLGA into ultrafine fibers. The reduced glutathione (GSH) was conjugated to the fiber surfaces via disulfide bonds. The glutathione S-transferase (GST) was captured onto the GSH fibers via specific substrate-enzyme interaction between the bound GSH and GST. The captured GST was eluted with free GSH aqueous solution and lyophilized to get pure GST powders. The results show that the GSH moieties on the fiber surface retain the bioactivity of the free GSH and thus they can bind specifically with GST and the GST in solution is captured onto the fiber surface. In addition, the bound GSH is not as active as free GSH so that the captured GST can be eluted off from the fiber by free GSH aqueous solution. Based on this principle, GST itself or its fused proteins can be separated and purified very easily. The preliminary purification efficiency is 6.5 mg·(gPCys)-1. Further improvements are undertaken.
LU TianChengSUN JingDONG XiaoQingCHEN XueSiWANG YuJING XiaBin
