Amphiphilic poly(hydroxyethylaspartamide) derivative-based micelles as drug delivery systems for ferulic acid

Self-assembling micelles, potentially useful as drug delivery systems for ferulic acid (FA), were obtained in aqueous media from amphiphilic ?,?-poly(N-2-hydroxyethyl)-dl-aspartamide (PHEA) copolymers bearing at the polyamino acidic backbone both poly(ethyleneglycol) (2000 or 5000 Da) and hexadecylamine (C16) moieties, at a concentration of 7 × 10- 3 and 4 × 10- 3 g/l, respectively, with nanometre size and negative zeta potential. These micelles were able to entrap FA and to release it in a prolonged way in phosphate buffer solution at pH 7.4 and human plasma. These systems were also stable in storage conditions and have no cytotoxic effects on Caco-2, 16 HBE, HuDe and K562 cell lines. Moreover, PHEA-PEG2000-C16 and PHEA-PEG5000-C16 micelles were able to escape from phagocytosis by murine macrophages as a function of the surface PEGylation.