Two kinds of paclitaxel（PTX） conjugate micelles,of which one contained 25%（mass fraction） PTX [M（PTX）] and the other contained 22.5%（mass fraction） of PTX and 1.4%（mass fraction） of folate（FA）[FA-M（PTX）],were prepared for cell apoptosis and anti-tumor activity evaluation on U14 cervical cancer mouse models in comparison with 0.9%（mass fraction） saline（control） and equivalent Taxol.Seven days after tail intravenous injection of the drugs,the mice were sacrificed to measure the tumor masses.The average tumor masses were 4.26,2.89,2.63,and 2.17 g for the control,Taxol,M（PTX） and FA-M（PTX） groups,respectively.The inhibition rates of tumor growth calculated for the three drug groups were 32%,38% and 49%,respectively.Flow cytometry（FC） analysis and terminal deoxynucleotidyl transferase（TdT）-mediated deoxyuridine triphosphate（dUTP） nick end labeling（TUNEL） assay were conducted on the cancer tissues.The cell apoptosis rates based on the FC data and the TUNEL data were 20%,31%,37%,42%,and 10%,22%,26%,34%,respectively,both showing statistically significant differences（P〈0.05） between three drug groups and the control group,and between the FA-M（PTX） group and the other two drug groups.In conclusion,the composite FA-M（PTX） micelles can be used for U14 cervical cancer treatment.
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
