Micelle formation from hydrophobically end-capped poly(ethylene oxide) and its application for delivery of poorly water-soluble drug

The formation of micelle self-assembled from hydrophobically end-capped poly(ethylene oxide) (PEO) and its application for drug delivery have been investigated. As an important ABA-type associative triblock copolymer, a series of hydrophobically end-capped poly(ethylene oxide) [H(CH 2 ) n O(CH 2 CH 2 O) m (CH 2 ) n H], consisting of PEO (B) as hydrophilic segment and alkyl groups as hydrophobic block, are synthesized successfully according to 1 H NMR, Fourier transform infrared (FTIR), and differential scanning calorimetry (DSC) measurements. The triblock polymer is easy to form aggregates (micelles) under the appropriate conditions. The morphologies of micelles are found to be spherical confirmed by atomic force microscopy (AFM) measurement. Then, the polymeric micelles self-assembled from the triblock copolymer are used as a nanocarrier to solubilize poorly water-soluble drug spironolactone (a typical hydrophobicity drug). In vitro release behavior of spironolactone from triblock copolymer micelle is investigated carefully. It indicates interestingly that the drug can be released from triblock copolymer micelle stably and the release rate can be modulated by the variation of copolymer composition.