Insight into drug encapsulation in polymeric nanoparticles using microfluidic nanoprecipitation

Synthesis of polymeric nanoparticles (NPs) through self-assembly of di-block copolymers have attracted substantial interest in the past decades for drug delivery and controlled release. Microfluidics offers a facile approach for making such NPs and drug encapsulation. However, a fundamental understanding of the drug encapsulation process is lacking. In this paper, we report a combined computational fluid dynamics (CFD) and experimental approach to illustrate the fundamental principle that governs the encapsulation of a drug in polymeric NPs through microfluidic nanoprecipitation. Taking a drug curcumin and a polymer poly (ethylene glycol)-block-poly (D, L-lactide-co-glycolide) (PEG-PLGA) as a model system, we demonstrated the different precipitation times of curcumin and PEG-PLGA as well as their mixing times in the microfluidic device. The big difference in their mixing times led to very low drug loading. This study provides a new perspective in understanding and controlling the formation of drug-loaded polymeric NPs and offers a new design rule for selecting the right combinations of drugs, polymers, solvents, and devices. (C) 2021 Elsevier Ltd. All rights reserved.