Coating of nanoparticles bearing amino groups on the surface with hydrophilic HPMA-based polymers

Two hydrophilic polymer systems, multivalent N-(2-hydroxypropyl)methacrylamide-based copolymers bearing thiazolidine-2-thione (TT) reactive groups randomly distributed along the polymer chain and monovalent semitelechelic pHPMA with the TT end group, were designed for surface modification of gene delivery vectors, namely, DNA polyelectrolyte complexes (PECs) and adenoviruses. In this study, the amino group-modified polystyrene latex nanoparticles were selected as a suitable model of a nanoparticulate delivery system bearing NH₂ groups on the surface. The coating process was monitored by changes in molecular weight and hydrodynamic parameters of the nanoparticles by light scattering methods. It was shown that for study of the coating process the model latex particles are more suitable than the original PEC vectors due to better chemical and physical stability of latexes. The results obtained in the model study (reaction conditions, methods of evaluation) suggest an optimal polymer structure and a method of efficient and complete coating of nanoparticle surface well applicable to the real gene delivery vectors.