Preparation of a drug carrier through α-cyclodextrin-induced micellization of poly(ε-caprolactone-block-4-vinylpyridine) for controlled delivery of doxorubicin

Abstract

A novel method has been used to prepare the selfassembled supramolecular micelles which aid in the delivery of anticancer drugs. α-Cyclodextrin (α-CD) induces a micellization process of poly(ε-caprolactone-block-4-vinylpyridine) (PCL-b-P4VP) copolymers through selective inclusion of PCL segments into the cavity of α-CD, resulting in the formation of pseudopolyrotaxane-b-P4VP. Compound pseudopolyrotaxane-b-P4VP forms supramolecular micelles in aqueous medium through self-assembly, which has been characterized using various analytical techniques. The resultant complex micelles consist of pseudopolyrotaxane as the core and P4VP chains in the outer shell, and the micelles possess a well-defined spherical morphology. The selfassembly process can easily be tailor-made by varying the number of PCL and P4VP segments in the PCL x -b-P4VP y copolymer. The arrangement of pseudopolyrotaxane-b-P4VP in the form of Bchannel-type^crystallites (derived from the supramolecular columns) is confirmed from the wide-angle X-ray diffraction (WAXD) patterns as well as by the composition of the inclusion complexes (ICs) calculated via proton nuclear magnetic resonance ( 1 H NMR) spectral data. The biocompatibility of the micelles was evaluated by a cell viability test and the results revealed excellent cytocompatibility. The prepared micelles were used as carriers for the model anticancer drug doxorubicin (DOX) and successful drug release was observed with a loading content of 14.4 % (w/w) and a loading efficiency of 28.9 %. In vitro drug delivery was evaluated in phosphate-buffered saline (PBS) solution. DOX release from the micelles was considerably faster at pH 5.0 in comparison to a physiological pH of 7.4. The development of supramolecular self-assembled micelles based on partial IC formation between α-CD and compatible block copolymers opens a new, facile and attractive approach for designing novel drug carriers for future pharmaceutical applications.

Synthesis and characterization of mesoporous magnetic nanocomposites wrapped with chitosan gatekeepers for pH-sensitive controlled release of doxorubicin

“…The drug loading content and loading efficiency are calculated to be 29.3% and 93.6%, respectively. The DOX loading amount in our work was found to be much higher than those in earlier reports [44][45][46]. The in vitro release experiment of Fe 3 O 4 @mSiO 2 -DOX and CS/Fe 3 O 4 @mSiO 2 -DOX was performed under pH 7.5, 5.8 and 4.0 at 37℃.…”