Design of biocompatible surface-modified polyurethane and polyurea nanoparticles

This study is focused to design systems of polyurethane and polyurea nanoparticles prepared via interfacial polycondensation in O/W nano-emulsions with biocompatible components suitable for drug delivery systems. Polyurethane and polyurea nanoparticles with a small diameter (50-90 nm) and high kinetic stability were developed from O/W nano-emulsions in aqueous solution/polysorbate 80/oil systems. The influence of several factors on the particle size and polydispersity index was studied. The monomer concentration, oil/surfactant weight (O/S) ratio, polymerisation temperature and components that can be located in the droplet interface and the dispersed phase of nano-emulsion played a key role in the formation of these nanoparticle systems. The biocompatibility of these nanoparticles was assessed using haemolysis and cell viability assays. No significant haemolysis and low effects on human endothelial cell viability were obtained after incubation with nanoparticles. Therefore, herein we provide useful information for the development of biocompatible drug carriers using polyurethanes and polyureas.