Aqueous nanoprecipitation for programmable fabrication of versatile biopolymer nanoparticles

Abstract

Biopolymer nanoparticles have become highly important nanomaterials with great utility in the pharmaceutical and food fields. However, the excessive use of organic solvents in common fabrication approaches can cause potential risks to the environment and health. Herein, we report on the one-pot fabrication of pectin-based biopolymer nanoparticles through aqueous nanoprecipitation. An organic solvent-free citric acid solution (solvent)/water (or NaOH solution, non-solvent) shift can significantly switch the solubility of pectin by adjusting the citric acid content in the solution, triggering its supersaturation and subsequent phase separation from the water, allowing robust and scalable production of biopolymer nanoparticles with tunable sizes. The straightforward aqueous nanoprecipitation can be adapted to batch and continuous processes for the direct fabrication of pectin-based biopolymer nanoparticles. The nanoparticles show good colloidal stability in various aqueous environments. The particle size and solid content of the colloidal dispersion can be regulated by the feed concentration, target pH and solvent-shifting process. The versatility of this approach can lead to a high loading capacity (up to ∼52 wt%) of hydrophobic drugs or hydrophilic enzymes in the nanoparticles and on-demand engineering of multicomponent hybrid nanoparticles with tunable compositions, sizes and surface charges, showing great potential for the programmable fabrication of versatile biopolymer nanomaterials.