Polymeric Micelles in Anticancer Therapy: Targeting, Imaging and Triggered Release

Abstract

Micelles are colloidal particles with a size around 5–100 nm which are currently under investigation as carriers for hydrophobic drugs in anticancer therapy. Currently, five micellar formulations for anticancer therapy are under clinical evaluation, of which Genexol-PM has been FDA approved for use in patients with breast cancer. Micelle-based drug delivery, however, can be improved in different ways. Targeting ligands can be attached to the micelles which specifically recognize and bind to receptors overexpressed in tumor cells, and chelation or incorporation of imaging moieties enables tracking micelles in vivo for biodistribution studies. Moreover, pH-, thermo-, ultrasound-, or light-sensitive block copolymers allow for controlled micelle dissociation and triggered drug release. The combination of these approaches will further improve specificity and efficacy of micelle-based drug delivery and brings the development of a ‘magic bullet’ a major step forward.

Peptide-Based Polymer Therapeutics

“…This dual-imaging approach allowed an accurate mapping of the intratumoral distribution of the conjugate. In this area, polypeptide-based micellar MRI contrast agents are under current development ensuring the validity of these constructs for imaging purposes [182,183].…”

The Development of Targeted Drug Delivery Systems for Rheumatoid Arthritis Treatment

“…Micelles are typically smaller than liposomes (20-50 nm) and the hydrophobic cores are used to entrap drugs that possess low aqueous solubility (Haag & Kratz, 2006). The CMC provides an indicator of stability, where systems with low CMCs are not easily disrupted or disintegrated (Oerlemans et al, 2010). Only a handful of investigators have used micelle-based drug delivery systems to improve the efficacy of DMARDs that have historically suffered from unpredictable pharmacokinetics resultant from poor solubility (Bader et al, 2011;Koo et al, 2011;Zhang et al, 2007).…”

Formulation Development and Evaluation of Doxorubicin Hydrochloride Liposomes

“…The restricted distribution of the parent drug to the non-target site(s) with effective accessibility to the target site(s) could maximize the benefits of targeted drug delivery. [1][2][3][4][5] …”