Recent attempts to prevent device-related infections included several strategies among which catheter coating with antibiotics resulted to be one of the most promising. However, so far only sporadic studies were designed to prevent fungal colonization of devices presumably because of the only recently described ability of Candida species to form biofilms. In this study we report in vitro experiments on the efficacy of coating of newly synthesized polyurethanes with the antifungal drug fluconazole in preventing polymer colonization and biofilm formation by Candida albicans. Polymers used in this study are three synthesized urethane polymers having different functional groups in the side-chain: hydroxyl groups, primary amino groups and tertiary amino groups. Fluconazole was adsorbed on round shaped disks made of the above described polyurethanes. The kinetics of fluconazole release from polymers, either containing or not albumin as pore forming agent, was studied by keeping fluconazole-loaded polymeric disks in water for increasing times up to 8 days. The antifungal activity of polymers was studied by the Kirby Bauer test and scanning electron microscopy. Among the tested polymers, the most hydrophilic ones were able to adsorb higher drug amounts by establishing “hydrogen bond” and “van der Waals” interactions. The kinetics of fluconazole release from polymers was influenced by the degree of polymer swelling in water and resulted significantly improved by the albumin incorporation in polyurethanes which increased polymer porosity. In our best experimental in vitro model consisting of an hydrophilic polymeric disk (average weight 250 mg) impregnated with 62.5mg albumin and 62.5mg fluconazole, the Candida albicans growth was inhibited as evidenced by the Kirby Bauer test and biofilm formation on polymeric surface was not observed up to 8 days as evidenced by scanning electron microscopy. Overall, data obtained from our newly synthesized functionalized polyurethanes loaded with fluconazole seem to be very promising in the perspective to develop medical devices refractory to Candida colonization.
Inhibition of Candida growth and biofilm formation on polyurethanes by fluconazole adsorption / G., Donelli; Francolini, Iolanda; Ruggeri, Valeria; E., Guaglianone; Piozzi, Antonella. - In: CLINICAL MICROBIOLOGY AND INFECTION. - ISSN 1198-743X. - STAMPA. - 11(S2):(2005), pp. 543-543. (Intervento presentato al convegno 15th European Congress of Clinical Microbiology and Infectious tenutosi a Copenhagen, Denmark nel 2-5 April) [10.1111/j.1469-0691.2005.clm_1134_03.x].
Inhibition of Candida growth and biofilm formation on polyurethanes by fluconazole adsorption.
FRANCOLINI, IOLANDA;RUGGERI, VALERIA;PIOZZI, Antonella
2005
Abstract
Recent attempts to prevent device-related infections included several strategies among which catheter coating with antibiotics resulted to be one of the most promising. However, so far only sporadic studies were designed to prevent fungal colonization of devices presumably because of the only recently described ability of Candida species to form biofilms. In this study we report in vitro experiments on the efficacy of coating of newly synthesized polyurethanes with the antifungal drug fluconazole in preventing polymer colonization and biofilm formation by Candida albicans. Polymers used in this study are three synthesized urethane polymers having different functional groups in the side-chain: hydroxyl groups, primary amino groups and tertiary amino groups. Fluconazole was adsorbed on round shaped disks made of the above described polyurethanes. The kinetics of fluconazole release from polymers, either containing or not albumin as pore forming agent, was studied by keeping fluconazole-loaded polymeric disks in water for increasing times up to 8 days. The antifungal activity of polymers was studied by the Kirby Bauer test and scanning electron microscopy. Among the tested polymers, the most hydrophilic ones were able to adsorb higher drug amounts by establishing “hydrogen bond” and “van der Waals” interactions. The kinetics of fluconazole release from polymers was influenced by the degree of polymer swelling in water and resulted significantly improved by the albumin incorporation in polyurethanes which increased polymer porosity. In our best experimental in vitro model consisting of an hydrophilic polymeric disk (average weight 250 mg) impregnated with 62.5mg albumin and 62.5mg fluconazole, the Candida albicans growth was inhibited as evidenced by the Kirby Bauer test and biofilm formation on polymeric surface was not observed up to 8 days as evidenced by scanning electron microscopy. Overall, data obtained from our newly synthesized functionalized polyurethanes loaded with fluconazole seem to be very promising in the perspective to develop medical devices refractory to Candida colonization.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
