FILIPPO PINELLI, FILIPPO ROSSI*
* Corresponding author
Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Italy

Abstract

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.

INTRODUCTION

In the last decade the discipline of drug delivery has faced great expansion driven by the important achievements obtained in the field of polymer science (1-5). Novel polymeric chains and new responsive formulations have guaranteed the possibility to synthetize innovative devices useful for various applications (6). In this context, nanogels represent for sure one of the most important families of materials employed in the field, thanks to the advantages related to their formulation (7, 8).

Nanogels are commonly identified as nano- three-dimensional framework obtained by the physical or chemical cross linking between polymeric chains (9, 10). They present important properties in term of stability, biocompatibility, hydrophilicity, swelling behavior and ability in loading and releasing drugs (11). Moreover, compared to conventional treatments, nanogels allow to overcome many limitations, thanks to the possibility to localize the effects of the drug release through proper tuning of the formulation and the functionalization of the system (12, 13). This makes clear why these devices have found large application as drug de ...