Stealth Properties to Improve Therapeutic Efficacy of Drug Nanocarriers

TLDR

Nanocarriers promise improved anticancer drug efficacy, but their small size causes rapid clearance by the mononuclear phagocyte system, limiting site specificity and increasing systemic side effects. The authors aim to endow nanosystems with long circulation properties through surface modification technologies. Stealth nanocarriers are achieved by polymeric coating, with the study detailing how coating parameters, materials, and interactions with opsonins and macrophages influence performance.

Abstract

Over the last few decades, nanocarriers for drug delivery have emerged as powerful tools with unquestionable potential to improve the therapeutic efficacy of anticancer drugs. Many colloidal drug delivery systems are underdevelopment to ameliorate the site specificity of drug action and reduce the systemic side effects. By virtue of their small size they can be injected intravenously and disposed into the target tissues where they release the drug. Nanocarriers interact massively with the surrounding environment, namely, endothelium vessels as well as cells and blood proteins. Consequently, they are rapidly removed from the circulation mostly by the mononuclear phagocyte system. In order to endow nanosystems with long circulation properties, new technologies aimed at the surface modification of their physicochemical features have been developed. In particular, stealth nanocarriers can be obtained by polymeric coating. In this paper, the basic concept underlining the “stealth” properties of drug nanocarriers, the parameters influencing the polymer coating performance in terms of opsonins/macrophages interaction with the colloid surface, the most commonly used materials for the coating process and the outcomes of this peculiar procedure are thoroughly discussed.