Nanomicelles,self-assembling nanosized particles with a hydrophobic core and hydrophilic shell,are currently successfully used as carriers for targeted drug delivery systems via the enhanced permeability and retention...Nanomicelles,self-assembling nanosized particles with a hydrophobic core and hydrophilic shell,are currently successfully used as carriers for targeted drug delivery systems via the enhanced permeability and retention（EPR） effect at the tumor sites.In this study,a near-infrared fluorescent cyanine dye（Cy7-NHS） was conjugated to poly（ethylene glycol）-block-poly（ε-caprolactone）（NH 2-PEG-b-PCL）,and the resulting Cy7-PEG-PCL was further mixed with mPEG-b-PCL to form nanomicelles as carriers for paclitaxel（PTX） delivery.Our results showed that the selected mPEG 4000-b-PCL 2500 copolymers self-assembled to form stable micelles with an average size of 30 nm in diameter and a zeta potential of approximately-3 mV.The micelles also exhibited more than 95% encapsulation efficiency of PTX when the molar ratio between paclitaxel and copolymers was 1/4.In vitro cytotoxicity study showed that the PTX-loaded nanomicelles had a similar cell growth inhibition efficacy to that of Taxol against human breast cancer MCF-7 cells.In vivo imaging showed that the Cy7-labeled nanomicelles could be passively targeted to tumor sites effectively after intravenous injection via the tail vein.Also,a strong anti-tumor activity was observed in the nude mice xenografted MCF-7 breast tumor after treatment with PTX-loaded micelles,similar to that of Taxol.As a result,the micelle drug delivery system designed in this paper has great potential in targeted imaging of tumors and chemotherapy.展开更多
基金National Basic Research Program of China (973Program,Grant No. 2007CB935800 and 2009CB930300)Program forNew Drug R&D (Grant No. 2009ZX09310-001)+2 种基金NSFC projects(Grant No. 81072597)Beijing NSF project (Grant No. 7112089)Programs from Ministry of Education (Grant No. BMU20110268and BMU20110263)
文摘Nanomicelles,self-assembling nanosized particles with a hydrophobic core and hydrophilic shell,are currently successfully used as carriers for targeted drug delivery systems via the enhanced permeability and retention（EPR） effect at the tumor sites.In this study,a near-infrared fluorescent cyanine dye（Cy7-NHS） was conjugated to poly（ethylene glycol）-block-poly（ε-caprolactone）（NH 2-PEG-b-PCL）,and the resulting Cy7-PEG-PCL was further mixed with mPEG-b-PCL to form nanomicelles as carriers for paclitaxel（PTX） delivery.Our results showed that the selected mPEG 4000-b-PCL 2500 copolymers self-assembled to form stable micelles with an average size of 30 nm in diameter and a zeta potential of approximately-3 mV.The micelles also exhibited more than 95% encapsulation efficiency of PTX when the molar ratio between paclitaxel and copolymers was 1/4.In vitro cytotoxicity study showed that the PTX-loaded nanomicelles had a similar cell growth inhibition efficacy to that of Taxol against human breast cancer MCF-7 cells.In vivo imaging showed that the Cy7-labeled nanomicelles could be passively targeted to tumor sites effectively after intravenous injection via the tail vein.Also,a strong anti-tumor activity was observed in the nude mice xenografted MCF-7 breast tumor after treatment with PTX-loaded micelles,similar to that of Taxol.As a result,the micelle drug delivery system designed in this paper has great potential in targeted imaging of tumors and chemotherapy.
