(282b) Protein–Polyelectrolyte Nanoparticles Via Flash Nanoprecipitation for Enhanced Irreversible Electroporation

Flash NanoPrecipitation (FNP) is a rapid and scalable method for nanoparticle formulation; however, encapsulating large biologics such as proteins remains a challenge due to low hydrophobicity (logP < 6). We achieved protein encapsulation in a single FNP step via electrostatic stabilization. Using bovine serum albumin (BSA) as a model protein, it was rapidly mixed with tannic acid to form an insoluble anionic complex and stabilized with a cationic polyelectrolyte, polyethylenimine (PEI). The mechanism of particle assembly is dependent on molecular weight of the PEI. For high molecular weight PEI, polyelectrolyte molecules form aggregates that absorb the anionic complex. For low molecular weight PEI, polyelectrolyte molecules self-assemble on the surface of the precipitating anionic complex. Encapsulating proteins with electrostatic stabilization allows for high encapsulation efficiency of 80%. The nanoparticle size is affected by pH and ionic strength used during mixing. The stability of the BSA-PEI nanoparticles as a function of pH and ionic strength will be addressed. Finally, the application of the BSA-PEI nanoparticles for cancer treatment using irreversible electroporation is examined in vitro. The results show that the combination of cationic BSA-PEI nanoparticles and irreversible electroporation produce a larger tumor ablation than irreversible electroporation alone. These findings demonstrate a promising synergistic effect between pulsed electric fields and protein-polyelectrolyte nanoparticles for cancer treatment.