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Objective To develop paclitaxel-loaded polymeric micelles from poly (ε-caprolactone)-poly (ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL),and to evaluate in vitro cytotoxicity as well as in vivo antitumor activity against EMT-6 tumor breast cell.Methods Paclitaxel-loaded polymeric micelles were prepared by thin-film hydration and ultrasonic method.The physical status of paclitaxel inside the polymeric micelles was investigated by differential scanning calorimetry (DSC).In vitro cytotoxicity of paclitaxel-loaded polymeric micelles against EMT-6 cell line was assessed by MTT assay.In vivo anticancer activity was evaluated against EMT-6 tumorbearing mice,with commercially available Taxol injection as control.Results Paclitaxel-loaded polymeric micelles exhibited homogeneous spherical shapes with apparent core-shell morphology.The average diameter of paclitaxelloaded polymeric micelles was 93 nm.DSC study indicated that paclitaxel was in solid amorphous state after being encapsulated in the polymeric micelles.In vitro cytotoxicity demonstrated that the cytotoxic effect of paclitaxelloaded polymeric micelles was lower than that of Taxol injection at the same paclitaxel content.Paclitaxel-loaded polymeric micelles showed greater tumor growth-inhibition effect in vivo on EMT-6 breast tumor in comparison with that of Taxol injection,with tumor growth inhibition of 85.79％ and 63.37％,respectively (P＜0.05).Conculsions The prepared paclitaxel-loaded polymeric micelles showed high anti-tumoral efficacy and low toxicity,and might have the potential to be developed as an effective anticancer drug-delivery system for cancer chemotherapy.
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Aim:To prepare vinblastine-loaded PCL-PEG_(6000)-PCL nanoparticles,and to study their physicochemi-cal properties and in vitro antitumor activity.Methods: PCL-PEG_(6000)-PCL triblock copolymer was prepared by ring-opening polymerization,and vinblastine-loaded PCL-PEG_(6000)-PCL nanoparticles was prepared by coprecipita-tion.The morphous,particle size,polydisperse index,particle yield,the drag-loading content,the encapsulation ef-ficiency and in vitro release rate of these vinblastine-loaded nanoparticles were determined.The cytotoxicity of vinblastine-loaded nanoparticles to K562/A02 leukimia cell line was determined by MTT assay.Results: It was found using transmission electron microscopy(TEM)that the nanoparticles exhibited a spherical shape with core-shell structure.The particle sizes of the nanoparticles obtained by dynamic light scattering were(185 ± 2.7)nm.The drug loading content and the encapsulation efficiency were determined to be 28.83% and 86.52%,re-spectively.In vitro release study revealed that more than 70% of accumulative release of entrapped vinblastine was reached in 9 hr and that nearly complete release was achieved in 24 hr.The inhibition of vinblastine-loaded nanoparticles to K562/A02 cell line was significantly increased as compared with that of the same dose of sulfate vinblastine solution.Conclusions: PCL-PEG-PCL nanoparticles could be used as a carrier of vinblastine,and the prepared nanoparticles exhibited a spherical shape,high encapsulation efficiency,relevant stablity and sustained-release properties.The eytotoxicity of vinblastine to K562/A02 cell line was significantly increased when it was encapsulated in PCL-PEG-PCL nanoparticles.