The use of novel PLGA-g-PVP amphiphilic copolymers for fabrication of nanostructured materials

The aim of this work is to present a one-pot synthetic process leading to poly(lactide-co-glycolide)-g-poly(vinylpyrrolidone) (PLGA-g-PVP)copolymers consisting of high molecular weight PLGA carryingoligomericPVPside chains. The title copolymers were prepared by chain transfer radical polymerization of N-vinylpyrrolidone in the presence of 50:50 PLGA, acting as polymeric chain transfer agent in the absence of solvents. All copolymers were characterized by1H-NMR (400 MHz), FT-IR, SEC, MALDI-TOF, DSC, TGAand DLS techniques. PLGA is a lipophilic biodegradable polymer, whereas PVP is hydrophilic, biocompatible and also bioeliminablefor molecular weights< 40.000.1,2Both polymers have beenapproved for human use by the U.S. Food and Drug Administration, therefore thePLGA-g-PVPcopolymers are eligible for medical applications.The water-soluble PVPportionimpartsamphiphilicity tothe otherwise hydrophobic PLGA, thus modifying its behavior in aqueous systems. In particular, PLGA-g-PVP samples spontaneously form nanoparticles when dispersed in water. These nanoparticles, besides dissolving hydrophobic drugs,for instance antimalarial drugs, in the inner core, are expected to show higher compatibility than native PLGA towards many drugsknown to interact with PVP.In addition, PLGA-g-PVP samples,whenused as additives,dramatically improved wettability of hydrophobic materials, as forinstance polyesters, processed asnanofibers andintended forapplications involvingcontact with the body fluids.