On the influence of linear and branched polyethylenimine on properties and drug release ability of nanogels

In the panorama of nanomedicine and controlled release of drugs through the use of proper formulated nanocarriers, nanogels represent for sure one of the most important typologies of devices. Their features, such as biocompatibility, tunability and the great ability to load and release drugs thanks to their high volume to surface ratio, ensure their applications in multiple fields, such as therapeutics and diagnostics. Polyethylene glycol (PEG) - linear polyethylenimine (PEI) nanogels represent the literature baseline for this family of biomaterials and they have been largely discussed in various research works. On the other hand, great interest is nowadays given to the tuning of the formulation of nanogel in order to be able to obtain specific properties of the system and final responsive behavior. Because of this, in this work we have decided to investigate the effect of the use of branched polyethylenimine, instead of linear chain, in term of physical and chemical characterization and properties of the nanogel, such as size, surface potential and polydispersity. Moreover, we performed in vitro drug delivery tests to compare the ability of loading and releasing drugs of PEG-PEI NGs obtained working with linear and branched polyethylenimine.