Application of tris-(4,7-Diphenyl-1,10 phenanthroline)ruthenium(II) Dichloride to Detection of Microorganisms in Pharmaceutical Products

Abstract

tris-[(4,7-diphenyl-1,10-phenanthroline)ruthenium(II)] dichloride (Ru(DPP)3Cl2), a fluorescent sensor which is sensitive to the amount of oxygen in the sample, was applied using the fluorescent optical respirometry (FOR) technique. The oxygen in the samples quenches the fluorescence. The fluorescence intensity depends on the metabolic rate of the viable microorganisms. The effect of DMSO and plant extracts on bacteria was determined by FOR. It was shown that the MIC values obtained by FOR were consistent with the results of the MIC determinations using the method of serial dilutions; at the same time, the effects of concentrations lower than the growth-inhibitory concentrations on microbial cells were demonstrated. The FOR method enables the detection of multiplying bacteria in sterile and non-sterile pharmaceutical preparations in real time, which significantly shortens the time required to obtain results and allows the introduction of repair processes in the production. This method also allows for quick, unambiguous detection and the counting of the viable cells of aerobic microorganisms in non-sterile pharmaceuticals.

A 0D-2D Heterojunction Bismuth Molybdate-Anchored Multifunctional Hydrogel for Highly Efficient Eradication of Drug-Resistant Bacteria

“…Therefore, scavenging oxidative stress and ameliorating hypoxia for converting macrophages from the M1 phenotype to M2 phenotype would be key to wound healing in bacterial infections. Intracellular oxidative stress and O 2 levels were assessed by DCFH-DA (2′,7′-dichlorodihydrofluorescein diacetate) and [Ru­(dpp) 3 ]­Cl 2 (tris­(4,7-diphenyl-1,10-phenanthroline) ruthenium (II) dichloride), respectively. , ROS could oxidize DCFH-DA to DCF accompanied by green fluorescence, whereas the red fluorescence of [Ru­(dpp) 3 ]­Cl 2 can be quenched to [Ru­(dpp) 3 ] 2+ by O 2 . Lipopolysaccharide (LPS)-induced M1 macrophages showed distinct green and red fluorescence, suggesting oxidative stress and hypoxia in bacterial infection .…”

“…Intracellular oxidative stress and O 2 levels were assessed by DCFH-DA (2′,7′-dichlorodihydrofluorescein diacetate) and [Ru(dpp) 3 ]Cl 2 (tris(4,7-diphenyl-1,10-phenanthroline) ruthenium (II) dichloride), respectively. 64,65 66 The fluorescence intensity of the LPS +CPTB@pMBO group showed distinctly weaker than that of the LPS group, indicating the potential ability of CPTB@ pMBO to scavenge ROS and supply O 2 (Figure 8d,e). This result should be attributed to CPTB@pMBO-mediated ROSscavenging and O 2 -supplying, consistent with the results in Figure 4m,n.…”