(252a) Robust Size Control of Soy Protein Nanoparticles by Speedy Coacervation Method

Soy Protein (SP) Nanoparticles are recently considered as alternative nanocarriers in drug, gene, nutrient and nutraceutical delivery because of its biocompatibility, biodegradability with low toxicity, and the abundant protein resources in the world. To prepare protein nanoparticles, coacervation/desolvation is the most common method which is based on the differential solubility of the protein in different solvents, leading to phase seperation.  Adding desolvating agent causes conformational change of proteins and then coacervation/precipitation at the instant.  For large-scale soy protein nanoparticle manufacturing, a robust and scalable process is on demand. In addition, the size effect of SP nanoparticles in various drug and food applications is crucial for improving bioavailability and lowering toxicity. Therefore, a robust size control of protein nanoparticles at high-yield rate is important to ensure the product quality.

     Herein, we presented a scalable “speedy coacervation method” (SCM) for preparing SP nanoparticles at high-yield rates. In SCM, three high-speed streams of a desolvating agent (ethanol) fast impinged to a stream of soy protein suspension. While four streams rapidly mix together, the sharp change of solvent polarity induces self-assembly of SP nanoparticles. In this study, the effect of the preparation parameters on particle size and stability was investigated. The average particle sizes of SP nanoparticles were ranging from approximately 50~230 nm. The SP nanoparticle size depends on the degree of denaturation and the percentage of ethanol. The formation mechanism under vortex mixing was studied to understand the factors on particle sizes, surface charge and hydrophobicity. The results showed that SCM was superior to conventional dropwise method in producing more stable SP nanoparticles at extremely high-yield rate (> 100 mL/min).