Galactose Decorated Acid-Labile Nanoparticles Encapsulating Quantum Dots for Enhanced Cellular Uptake and Subcellular Localization

Biodegradable polymers containing acid-labile segments and galactose grafts were formulated into nanoparticles in current study, and enhanced cellular uptake and subcellular distribution were clarified. Quantum dots (QDs) was utilized as an imaging agent and a model of bioactive substances, and entrapped into nanoparticles of around 200 nm through a nanoprecipitation process. The acid-labile characteristics of QDs-loaded nanoparticles were approved by the hemolysis capability, the degradation behaviors of matrix polymers, and the fluorescence decay of entrapped QDs after incubation into buffer solutions of different pH values. The galactose grafts increased the acid-lability, due to the hydrophilic moieties on the acid-labile segments, and enhanced uptake efficiency of over 50 % was found after 4 h incubation with HepG2 cells, due to the galactose-receptor mediated endocytosis. The acid-lability led to an efficient endosomal escape of QDs-loaded nanoparticles into cytoplasm. The integration of acid-lability, targeting effect, and full biodegradable backbone into nanoparticle matrices constitutes a promising platform for intracellular delivery of bioactive substances for disease diagnosis, imaging and treatment.