Methods NVP-HSP990 price Biofilm Growth Strain C. albicans SC5314 was used in this study . Yeast from frozen stocks were maintained on YPD agar plates. For experimentation, yeast were inoculated into YPD broth supplemented with 2% dextrose and grown overnight at 24°C with shaking. Biofilms were grown by seeding C. albicans blastoconidia in flat bottom well plates (Becton Dickinson, Franklin Lakes, N.J.) and incubating at 37°C from 3 h to 48 h. In preliminary Selleck AZD9291 work, five different seeding media (YNB-0.5% glucose,
DMEM, DMEM-5%FBS, DMEM-10%FBS and RPMI-10%FBS) were tested. Microscopic observations showed that the best attachment of biofilms to plastic was achieved in DMEM-10%FBS. Thus we used DMEM-10%FBS (Biowest/USA Scientific) in all experiments that followed. To grow biofilms under conditions resembling in vivo mucosal biofilm
development a three dimensional model of the human oral mucosa, developed in our laboratory, selleck chemical was used which faithfully mimics the oral mucosal tissue architecture in vivo . Briefly, this model system is composed of 3T3 fibroblasts embedded in a biomatrix of collagen type I, overlaid by a multilayer of well-differentiated oral epithelial cells (OKF6/TERT-1). C. albicans cells (1 × 106 yeast cells) were added to the cultures apically in 100 μl of Clomifene airlift medium without FBS and antibiotics and incubated for 24 h. To assess mucosal tissue damage and invasion tissues were formalin-fixed, embedded in paraffin and 5 μm sections were stained with the Periodic Acid Schiff (PAS) stain. XTT Assay The XTT assay was performed as we described
earlier . Briefly, media were aspirated from biofilms and were replaced with 100 μl/well of XTT solution (Sigma Chemical Co., St. Louis, MO) containing Coenzyme Q0 (CoQ, Sigma Chemical Co., St. Louis, MO). Fresh mixtures of XTT and CoQ [1 mg/ml and 40 μg/ml (or 220 μM), respectively, unless otherwise indicated] were prepared for each experiment. Plates were incubated at 37°C for up to 3 hours, after which supernatants were transferred into new plates, and optical densities (OD) were measured by an Opsys Microplate Reader (Thermo Labsystems, Franklin, MA) at 450-490 nm, with a 630 nm reference filter. When optical densities were higher than the limits of the microplate reader, dilutions of the supernatants in water were made. Quantitative Real-Time RT-PCR Assay To quantify changes in viable biofilms using an alternative approach, we measured mRNA expression of the translation elongation factor-1β (EF-1β), encoded by the EFB1 gene in C. albicans, by real-time quantitative RT-PCR.