In this work a synthetic protocol for the functionalization of hyaluronic acid with diethylenetriamine (DETA) was standardized. HA-DETA derivatives were characterized by NMR and proton carbon correlation analysis HSQC and HMBC to confirm chemical structure. A selected derivative was used to set up a green fabrication procedure for HA-DETA capped silver nanoparticles with the aim to achieve a polymeric based coating with potential application in the treatment of medical devices associated infections. Data from UV-visible spectroscopy, electron scanning and transmission microscope (STEM), photoelectric spectroscopy (XPS) and rheological characterization were combined to characterize the HA-DETA/Ag nanocomposites. HA-DETA stabilized Ag nanoparticles (10-30 nm) were obtained through an UV accelerated production. The viability of MC3T3-E1 was analyzed with the aim of designing a cytocompatible antimicrobial coating. Antibacterial and antibiofilm activity of HA-DETA/Ag nanocomposites have been tested in vitro against Staphylococcus aureus and Pseudomonas aeruginosa both in culture plates than on titanium specimens.