Dextran-Based Nanoparticles to Formulate pH-Responsive Pickering Emulsions: A Fully Degradable Vector at a Day Scale
Valentin Maingret, Clémence Courrégelongue, Véronique Schmitt, Valérie Héroguez
Abstract
Biosourced Pickering emulsion stabilizers with stimuli responsiveness are mostly designed for recycling and do not offer fast degradability as required for drug-delivery applications. Herein, dextran-a hydrophilic and biofriendly polysaccharide obtainable from biomass recovery-was used for the first time as a brick material for the formulation of (bio)degradable pH-sensitive Pickering emulsions. It was first modified with hydrophobic acetal moieties to provide pH-sensitive acetalated dextran. Under acidic conditions, it degrades into three biocompatible (macro)molecules: dextran, ethanol, and acetone. Nanoparticles of acetalated dextran were obtained using the nanoprecipitation process and could be similarly fully hydrolyzed under acidic conditions within 6 h. Then, O/W Pickering emulsions of dodecane (model oil) and medium-chain triglyceride (biocompatible oil) were successfully stabilized using these nanoparticles. pH-induced destabilization of these Pickering emulsions (including nanoparticles degradation) took less than 24 h. Finally, neither accumulation of nanoparticles nor harmful component release happened during the process, making this stimuli-responsive vector safe and environmentally friendly.