Anti-biofilm Activity of Dendrons

The anti-biofilm activity of dendron 1 and dendron 2 was carried out as previously described [7 (link)]. An inoculum of C. glabrata was adjusted to 0.5 McFarland standard in RPMI 1640 medium (Sigma-Aldrich) with morpholine-propane-sulfonic acid (Sigma-Aldrich) and 2% glucose (RPMI + MOPS + GLU). Then, 50 μL of the suspension were inoculated in 96-well microtiter plates containing two-fold serial dilutions of the dendrons. Plates were incubated for 48 h at 37 °C. Candida controls free of compound, control of compound without inoculum, and control of medium free of compound and inoculum were included. The minimum biofilm inhibitory concentration (MBIC) was determined with resazurin colorimetric assay and has been previously defined as the lowest concentration in which no reduction in resazurin was observed (no growth, nor absorbance signal detected) in biofilm in formation [7 (link),8 (link),14 (link),15 (link)]. The minimum fungicidal concentration in biofilm (MFCB) was determined using the drop plate method and was defined as the lowest concentration capable of inducing the total death of the yeast population, avoiding the generation of the biofilm (0% cell viability) [7 (link),8 (link),14 (link),15 (link)]. These MFCB values were obtained by scraping the biofilm and plating 5 μL suspension of each well (drop plate method) [7 (link),8 (link)].