Polymeric Nanogels: Nanocarriers For Drug Delivery Application.

The application of nanotechnology to medicine has enabled the development of functionalised nanoparticles that, acting as carriers, can be loaded with drugs or genetic material to be released with a controlled mechanism in specific districts of the organism. Even though nanomedicine is a relative new branch of science, many type of nanocarriers for drug delivery have been developed over the past 30 years, such as liposomes, dendrimers, quantum dots, solid lipid nanoparticles, viruses and virus-like nanoparticles as well as a wide var iety of polymeric nanoparticles. Among these last, in our opinion, nanogels deserve a special attention. Nanogels are nanoscalar polymer networks, with a tendency to imbibe water when placed in an aqueous environment. Their affinity to aqueous solutions, superior colloidal stability, inertness in the blood stream and the internal aqueous environment, suitable for bulky drugs incorporation, make them ideal candidates for uptake and delivery of proteins, peptides, and other biological compounds. We have synthesised different variants of poly(N-vinyl-pyrrolidone)-based nanogels and demonstrated the absence of cell toxicity, which encourage further development of these materials as smart delivery systems. In particular, in this work we demonstrate the capability of these nanogels to bypass the cell plasma membrane by following their localization in cell cultures as function of the time. We have analyzed this process by both confocal microscopy and a spectrofluorimetric approach. Results show nanoparticles preferential localization on cell surface, inside the cell and again back in the cell culture medium at different times. Ongoing experimentation is now aimed to the loading of nanocarries with biomolecules involved in a specific substrate recognition function. This approach, if proved successful, may have a real impact in nanomedicine.