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[摘要]：Although high efficacy has been showed, Paclitaxel and Docetaxel cause serious side effects due to the adjuvant used in their clinical formulation Taxol (R) and Taxotere (R). We developed a micelle system with a newly synthesized TPGS(2k) polymer, which shows lower CMC of 0.0219 mg/ml compared with 0.2 mg/ml for traditional micelles with TPGS involved, to achieve sustained and controlled drug delivery with Docetaxel used as a model anti-cancer drug. The TPGS(2k) micelles were further conjugated to folic acid (FA) for targeted drug delivery. The Docetaxel-loaded TPGS(2k) micelles with and without FA conjugation were found of desired size and size distribution, high drug encapsulation efficiency and favorable drug release. In vitro studies using MCF-7 cancer cells demonstrated significantly the higher cellular uptake of the formulated drug for TPGS(2k) micelle formulation than that for Taxotere (R). The targeting effects for the FA conjugated TPGS(2k) micelles are also demonstrated. The IC(50) value, which is the drug concentration needed for 50% cell viability in the designated time period, is 103.4, 1.280 and 0.1480 mu g/ml for MCF-7 cancer cells after 24, 48, and 72 h treatment respectively, which is greatly decreased to be 0.526, 0.251 and 0.233 mu g/ml, i.e. a 99.5%, 80.4% decrease and 57.5% increase for the TPGS(2k) micelle formulation, and further decreased to be 0.1780, 0.1520 and 0.1140 mu g/ml, i.e. a 99.8%, 88.1% and 23.0% decrease for the folic acid conjugated micelles, respectively. A synergistic effect between TPGS(2k) and Docetaxel is also achieved. The present work represents a new concept in the design of drug delivery systems - the carrier materials of the drug delivery system can also have therapeutic effects, which either modulate the side effects of, or promote a synergistic interaction with the formulated drug. (C) 2011 Elsevier Ltd. All rights reserved. |
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