The cytotoxicity assessment of the novel latex urinary catheter with prolonged antimicrobial activity

The purpose of this study was to evaluate the in vitro biocompatibility of the novel Sparfoxacin (SPA)-treated latex catheter with previously performed prolonged antimicrobial activity. Rectangular-shaped test samples of silicone latex catheter were fabricated according to patented procedure permitting the immobilization of SPA on heparin (HP)-coated catheter by means of mixed, covalent and non-covalent bonds. Samples subjected to cytotoxicity assay were divided into four groups: (1) the untreated catheter, (2) HP-coated catheter, (3) HP-coated catheter with SPA immobilized in low SPA concentration solution (SPA-L treated sample), and (4) high SPA concentration solution (SPA-H treated sample). Then the samples were placed directly into green monkey kidney (GMK) cell monolayer for 24 h. After the incubation period, cytotoxicity was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The degree of cytotoxicity of each sample was evaluated according to the reference value represented by the control cells cultured without catheter sample. Statistical significance was determined by repeated t-test (P < 0.05). The cytotoxic effect of treated and untreated catheters was also estimated by microscopic observations of GMK cells morphological changes. SPA-treated catheters demonstrated high survival rates in MTT assay (>93%) on the contrary to the untreated catheters (6.13%) and HP-coated catheters (80.90%). Moreover, microscopic observation of GMK cells exposed to SPA-treated samples revealed no morphological changes and no cell growth reduction. We suggest that SPA-treated latex catheters are biofilm formation resistant (as we revealed in our previous work), considerably less toxic than untreated ones, and can be undoubtedly used in urological practice.