Infections are the most common cause of biomaterial implant failure representing a constant challenge to the more widespread application of medical implants. This study reports on the preparation and characterization of novel hydrophilic copolymeric systems provided with antibacterial properties coming from eugenol residues anchored to the macromolecular chains. Thus, high conversion copolymers were prepared from the hydrophilic monomer 2-hydroxyethyl methacrylate (HEMA) and different eugenol monomeric derivatives, eugenyl methacrylate (EgMA) and ethoxyeugenyl methacrylate (EEgMA), by bulk polymerization reaction. Thermal evaluation revealed glass transition temperature values in the range 95-58 degrees C following the order HEMA-co-EgMA > PHEMA > HEMA-co-EEgMA and a clear increase in thermal stability with the presence of any eugenyl monomer in the system. In vitro wettability studies showed a reduction of water sorption capacity and surface free energy values with increasing the content of eugenol residues in the copolymer. The antimicrobial activity of copolymeric discs was evaluated by determining their capacity to reduce or inhibit colony formation by different bacterial species. All eugenyl containing materials showed bacteria growth inhibition, this one being higher for the EEgMA derivative copolymers.

Hydrophilic copolymers with high refractive index and bactericide properties based on quaternary ammonium salts monomers and methacrylates bearing benzothiazole moieties have been developed for application as foldable intraocular lenses. Composition of the systems was adjusted to get materials with optimized flexibility, wettability, and refractive properties. All the materials have been characterized in terms of optical properties, glass transition temperature, water content, and wettability. Water contact values oscillated between 37 and 15% and refractive index values in the wet state between 1.49 and 1.53, depending on composition. Glass transition temperature interval was 63-77 degrees C. Values of surface free energy of the solid ranged from 49 to 54 mN/m, characteristic of IOL hydrogel materials. Bactericide properties of the quaternary ammonium salts methacrylates were higher than that of the benzothiazole derivative, showing inhibition halos as high as 23-25 mm in antibiogram tests against S. epidermidis and P. aeruginosa , strains found in the ocular cavity and responsible for most postsurgical endolphthalmitis. Biocompatibility of the systems was evaluated in cell cultures using human fibroblasts. Cellular viability was higher than 90%, and close to 100% in many cases, for the extracts of selected formulations collected at different periods of time.