Revestimento antibiofilme para superfícies de dispositivos médico-hospitalares

Abstract

Device-associated biofilms are responsible for 85% of catheter-related bloodstream infections (CRBSI). The aim of this study was investigate two formulations, as central venous catheters (CVC) coating, which were submitted to in vitro evaluation of antimicrobial and anti-adherent efficacy and in vivo evaluation of efficacy and biocompatibility. The antimicrobial activity was assessed by turbidimetric method and the minimum inhibitory concentration (MIC) was determined. The scanning electron microscopy (SEM) was used to assess the anti-adherent property of CVC coated with formulation 1 (CVC-R1) and formulation 2 (CVC-R2), in comparison to uncoated CVC fragments (CVC-NR). Subcutaneous implants were inserted into the dorsal area of rats. The first assay consisted in hematological and microbiological analysis (hemoculture and CVC surfaces colonization) in order to evaluate the coatings effectiveness. The second assay evaluated the biocompatibility by the observation of inflammatory reactions after 7 and 21 days. Both formulations showed antimicrobial activity against all tested strains. The biofilm disaggregation, with reduction in microbial adherence, was noted in coated catheters. In vivo results showed greater antibiofilm efficacy of CVC-R2 since a reduction of Staphylococcus aureus ATCC 25923 colonization was observed. The tissue reactions of CVC-R1 and CVC-R2 groups were initially more pronounced, however, throughout the experiment, the histological parameters have become statistically similar those found in CVC-NR group. Both formulations were biocompatible and a higher speed of tissue repair in CVC-R2 group was noted. The use of CVC- R1, and especially of CVC-R2, may reduce the development of CRBSI, and thereby, CVC-R2 have potential to be clinically tested.