Nanocarrier systems assembled from PEGylated hyperbranched poly(arylene oxindole)

Abstract

Nanoparticles (NPs) formed from hyperbranched polymers are highly attractive organized structures in nanomedicine. Herein, we utilize copper-catalyzed azide-alkyne cycloaddition of hyperbranched poly(arylene oxindole) derivatives to prepare amphiphilic conjugates with different degrees of PEGylation that form spherical NPs in water with tunable particle diameters (25 ± 5 nm for PEG0.3-NPs and 120 ± 10 nm for PEG0.1-NPs) and zeta potential (−7 ± 2 mV for PEG0.3-NPs and −23 ± 3 mV for PEG0.1-NPs). Cisplatin and BODIPY derivatives can be loaded into the PEG0.1-NPs, and their release over 5 d depends on the physicochemical properties of the payload. Moreover, changing the time and conditions for self-assembly leads to the formation of polymer vesicles that can encapsulate and release hydrophilic cargo, as shown with fluorescein. In vitro cellular uptake experiments demonstrate that at concentrations ≤10 μg/mL the BODIPY-loaded NPs do not induce morphological differences or cause a reduction in metabolic activity of the cells, confirming their cytocompatibility. They are rapidly taken up by ATDC5 cells and remain stable for 7 d thus highlighting their potential as carrier systems for diagnostic or therapeutic applications.