Rapid, Room-Temperature Nanoparticle Drying and Low Energy Reconstitution Via Electrospinning

Polymeric nanoparticle drug formulations can increase drug bioavailability and lower toxicity when compared to the free drug. However, nanoparticle formulations often require drying for long-term size stability. Traditional drying techniques, e.i. freeze-drying and spray-drying, require sonication and large amounts of cryoprotectants to avoid irreversible aggregation so the resulting dispersions can be hypertonic. We propose to convert nanoparticles to a dry, stable form via electrospinning and use polyethylene glycol (PEG)-stabilized nanoparticles and polyvinyl alcohol (PVA) for electrospinning to demonstrate proof-of-concept. For drying, polymer nanoparticles were blended with PVA and electrospun. The nanoparticles were redispersed by dissolving the fibers in aqueous media without sonication. Following electrospinning into ~300 nm fibers, nanoparticles could be stored for at least seven months and redispersed with no change in nanoparticle size upon reconstitution. In order to maintain nanoparticle size upon redispersion, composition of the nanoparticle core, nanoparticle size, and nanoparticle to nanofiber diameter (NP:NF) ratio were important considerations. Size of the nanoparticles upon redispersion were maintained when the fiber diameter and nanoparticle diameter are comparable (NP:NF ratio ~ 1). Nanoparticles with liquid cores and larger particles better maintained their size when compared to nanoparticles with solid core and smaller particles, respectively.