Biocompatible Micelles Based on Squalene Portions Linked to PEGylated Polyaspartamide as Potential Colloidal Drug Carriers

In this research, we present the synthesis and the characterization of two novel amphiphilic copolymers based on a pegylated α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA) backbone linked to squalene-derived chains bearing 17 or 27 carbon atoms (SqCHO C17 or SqCHO C27). These copolymers were obtained starting from PHEA-poly(ethylene glycol) derivative (PHEA-PEG2000), which was functionalized with ethylenediamine (EDA) and then with SqCHO C17 or SqCHO C27, to obtain PHEA-PEG2000-EDA-SqC17 and PHEA-PEG2000-EDA-SqC27 copolymers, respectively. 1H-NMR and size exclusion chromatography (SEC) analyses confirmed the occurrence of derivatization. Polymeric micelles from both copolymers were obtained by using the dialysis method and were characterized in terms of mean size, zeta potential and critical aggregation concentration (CAC). Furthermore, the formation of micellar nanosystems was confirmed by TEM analysis. These micelles were stable in physiological conditions; in vitro experiments showed that these systems had no cytotoxic effects on Caco-2 and Neuro2a cell lines and no haemolytic activity. Moreover, both PHEA-PEG2000-EDASqC17 and PHEA-PEG2000-EDA-SqC27 micelles were able to penetrate into Neuro2a and Caco-2 cells and to escape from phagocytosis by the J774 A.1 macrophages.