Self-assembled micelles of the (lipo) glycopeptides, teicoplanin, as taxane nanocarriers

Abstract

The use of nanoparticles is one of the strategies currently studied to minimize the toxicity and lack of tissue specificity of many cancer drugs used in chemotherapy. In this research the physicochemical and biological behavior of a novel self-assembled nanostructure of the antibiotic Teicoplanin (Teico) was characterized as a nanocarrier system for solubilizing highly hydrophobic drugs like Paclitaxel (Ptx) in aqueous media. The Teico micelles were loaded with Ptx in DMSO or PEG-400. The interaction between the loaded micelles and Albumin human serum albumin (HSA) was then studied by size exclusion chromatography. Transmission electron microscopy, dynamic light scattering and high-resolution liquid chromatography were also used to characterize the physicochemical and structural properties of the micelles to form the Teico/Ptx and Teico/Ptx/HSA micelles. Cellular uptake of Ptx was evaluated by fluorescent microscopy. The in vitro cytotoxicity of the complexes was studied on Hep-2 tumor cells, by a Crystal Violet assay. Teico cosolvent-free micelles can solubilize up to 20 mg.ml-1 of Ptx dissolved in PEG, increasing four times the solubility of Ptx in water compared to Abraxane, and 20 000 times the intrinsic solubility of Ptx in water. In addition, Teico/Ptx micelles binds spontaneously HSA through hydrophobic interaction. Teico and Teico/HSA micelles as a Ptx transporter does not affect its release or biological activity. Therefore, Teico/Ptx or Teico/Ptx/HSA complexes appear as new alternatives for transporting larger amounts of hydrophobic drugs that offer advantages, turning it an interesting option for further study.