Zarrin
Haris1*, Asad U Khan2
1Research scholar, Interdisciplinary
Biotechnology Unit, Aligarh Muslim University, Aligarh, India
2Professor, Interdisciplinary Biotechnology
Unit, Aligarh Muslim University, Aligarh, India
*Address for Correspondence: Ms. Zarrin
Haris, Research scholar, Interdisciplinary Biotechnology Unit, Aligarh
Muslim University, Aligarh, India
ABSTRACT- Present
work explores the novel selenium nanoparticle-enhanced photodynamic therapy of
toluidine blue O against Streptococcus
mutans biofilm. Physiochemical (Ultraviolet-visible absorption, FTIR, and
fluorescence spectroscopy) and Electron microscopy techniques were used to
characterize selenium nanoparticles. The UV spectrum of different concentrations
of SeNP were showed distinct peak at ~288 nm, which confirmed the successful
synthesis of SeNP in this study. The synthesized Selenium nanoparticles were
uniform and spherical in shape with average size ~100 nm. In FTIR spectra of
SeNPs there were strong absorption band around 3425cm-1, 2928 cm-1
and 1647 cm-1. TBO showed MIC
and MBC of 62.5 μg/mL and 125 μg/mL respectively whereas in presence of SeNPs
showed MIC and MBC of 31.25 μg/mL and MBC of 62.5 μg/mL. SeNPs–TBO conjugate showed twofold higher activities against S
mutans than TBO alone. A 630 nm diode laser was applied for activation of
SeNP- Toluidine blue O (TBO) combination and TBO against S. mutans biofilm and cells. The UV-vis
absorption result suggests that TBO is not present on the surface of SeNP. In
fluorescence emission spectra, there is
enhancement of fluorescence of TBO fluorescence in the presence of nanoparticle.
This showed that SeNP are enhancing the photodynamic therapy.
Antibiofilm assays and microscopic studies showed significant reduction of
biofilm presence of conjugate. A crystal violet assay revealed a maximum
percent inhibition of S. mutans biofilm formation after 24 hours’
incubation, recorded as 20% and 60% by TBO (31.25 μg/mL) and SeNP–TBO (31.25
μg/mL; TBO) conjugate, respectively. XTT biofilm reduction assay were showed
32% loss in viability in presence of SeNP-TBO conjugate whereas in presence of
only TBO there was 22% loss in viability of cells. Fluorescence spectroscopic
study confirmed type I photo toxicity against biofilm. Selenium nanoparticle
conjugate–mediated photodynamic therapy may be used against recalcitrant biofilm
based infections and can be helpful in dentistry.
Key-words- S. mutans, SeNP, TBO, UV absorption,
FTIR, fluorescence spectroscopy
