INVITRO CHARACTERIZATION OF POLY (METHYL-METHACRYLATE) NANOPARTICLES AND CORRELATION TO THEIR INVIVO FATE

The organ distribution of poly (methyl methacrylate) nanoparticles surface-modified by the adsorption of surfactants was related to the physicochemical properties. The nanoparticles were modified by coating with poloxamer, poloxamine, Brij and polysorbate surfactants. They were characterized in terms of coating layer thickness, surface hydrophobicity (hydrophobic interaction chromatography) and interaction with serum components (zeta potential). The liver/spleen uptake of particles coated with low molecular weight surfactants has been related to their hydrophobic coating layer interacting strongly with serum components. The protective effect of poloxamer 338 and poloxamine 908 could be explained by their ability to render the surfaces of the particles hydrophilic, which made a reduction of serum opsonization possible. The in vitro characterization methods proved to be suitable to select surfactants with high potential to reduce the uptake of nanoparticles by liver and spleen macrophages. The affinity of particles to other sites in the body (bone marrow, lungs) could, however, not be explained using the above-mentioned in vitro characterization methods.