(692e) Engineered Biodegradable Janus Particles for Drug Delivery

Recent advances in the field of nanotechnology have generated interest in the creation of “Janus” particles, whose dual surface chemistries and unique properties set them apart from spherical isotropic particles. Janus particles present two distinct faces with different shapes, compositions, chemistries, and polarities. Polymeric and hybrid polymer-lipid Janus particles have applications as compartmentalized drug carriers, biological sensors, surfactants, or display materials for electronics. However, biodegradable Janus particles have yet to make their debut in the pharmaceutical industry because current synthesis methods rely on microfluidic devices capable of producing just one single particle at a time. Furthermore, lipid-based materials do not meet the low viscosity requirements of microfluidic devices. Here, we describe a modified emulsion-solvent evaporation template for the large-scale production of biodegradable Janus micro- and nanoparticles from GRAS materials. Biodegradable anisotropic particles are produced through emulsification of the oil phase containing the two GRAS components and the aqueous phase containing stabilizers, followed b homogenization and solvent evaporation. During the slow 6-hour evaporation process, the two immiscible components segregate to an entropically favorable state of separation. However, the immiscible polymer and/or lipid components are forced to co-precipitate within the same oil droplet “microreactor” during evaporation, leading to the formation of an interpenetrating network connecting the two components. Polymeric Janus particles have been formed from 50/50 combinations of GRAS polymers such as PLGA, polycaprolactone, polyvinylpyrrolidone, and poly(4-vinylpyrrolidone). Polymer-lipid “ice cream cone” particles have been formed from 75/25 combinations of GRAS polymers listed above and GRAS lipids such as precirol and compritol. Drug loading is achieved by co-dissolving the API with the polymer and/or lipid components in the dispersed phase prior to emulsification. In some cases, drug loading tremendously alters the phase separation and self-assembly of polymeric Janus particles. Spherical particles with surface pox marks were produced when 5% w/w griseofulvin, omeprazole, or acetaminophen was co-dissolved with the 50/50 polymer mixture in the dispersed phase. However, a Janus-like morphology is still obtained when 5% w/w curcumin or quercetin is introduced into the system. It is hypothesized that certain APIs form interactions with both polymers, thus acting as block copolymer compatibilizers that reduce the interfacial tension between two immiscible polymers. No APIs were found to disrupt the phase separation behavior of the polymer-lipid hybrid particles, presumably because the polymer and lipid are highly dissimilar in structure and chemistry.