Supramolecular nanocapsules from the self-assembly of amphiphilic calixarene as a carrier for paclitaxel

The encapsulation of paclitaxel (PTX) using amphiphilic calixarene (SC4-C-6) is an attempt to improve its water solubility. The optimized nanocapsules were successfully prepared by a thin film hydration method where an organic phase containing the mixture of PTX and SC4-C-6 (molar ratio of 1:10) was dispersed by probe sonication for 30 s into an aqueous phase. The optimized formulation of PTX loaded amphiphilic calix[4]arene nanocapsules had an average particle size of 206 +/- 14 nm and an encapsulation efficiency of 82.65 +/- 2.54%. Transmission electron micrographs demonstrated the sphere shape of the PTX loaded amphiphilic calix[4]arene formulation without obvious agglomeration. In vitro drug release experiments clarified the obvious sustained release behaviors of the PTX loaded amphiphilic calix[4]arene formulation compared to commercial Taxol. Furthermore, the PTX loaded SC4-C-6 formulation revealed improved PTX induced cytotoxicity in human cervical cancer cell culture experiments in contrast to Taxol. The nanocapsules assembled from amphiphilic calixarenes obtained in this work displayed a desired narrow size range with acceptable drug loading and sustained release behaviors, which are beneficial for their potential application as an anti-cancer drug delivery vehicle.