Preparation, characterization, and in vitro evaluation of amphiphilic peptide P12 and P12-DOX nanomicelles as antitumor drug carriers

Polymerized polypeptide nanomicelles have attracted much attention as novel drug carriers because of their good biocompatibility and degradability. To prepare doxorubicin (DOX)-loaded nanomicelles, an amphiphilic peptide, FFHFFH-KKGRGD (P12), was synthesized by solid-phase synthesis, and the physicochemical and drug-release properties, as well as the cytotoxicity of the nanomicelles, were evaluated in vitro. The P12-DOX polymer micelles were prepared by dialysis. The morphology and particle size were characterized by transmission electron microscopy and dynamic light scattering. The critical micelle concentration (CMC) of the polymer was determined by the probe method, and the drug-release characteristics of the micelles were studied by dynamic dialysis. The cytotoxicity and uptake of the P12-DOX micelles were evaluated against mouse breast cancer cells (4T1) and human umbilical vein endothelial cells. The peptide polymer micelles containing DOX were uniformly sized and had a spherical core–shell structure with an average particle size of 128.6 nm. The CMC of the polymer was low (0.0357 mg/mL). The in vitro release of DOX from the micelles is slow and is consistent with first-order kinetics. The copolymer micelles of the P12 polypeptide and DOX can be used as nanoscale spherical carriers of hydrophobic drugs and have broad applicability.