Significance of Fluorescent Spectroscopy in Screening Oral Potentially Malignant Disorders and Oral Cancer by Characterization of Salivary DNA Using Ethidium Bromide-A Comparative Study.

Sangeetha RamamoorthyBackground Optical diagnosis is one of the upcoming methods in screening and diagnosing oral cancer at the earlier stage. Currently, DNA-based diagnosis is used along with light-based imaging methods to diagnose oral cancer rapidly. Aim The aim of this study was to discriminate oral cancer and oral potentially malignant disorders from normal patient with fluorescence spectroscopic characterization of salivary DNA using ethidium bromide dye. Materials and Methods A total of 40 patients with average age of 20 to 60 years in both the genders were selected and divided into three groups. Group A included clinically proven cases of oral cancer, group B1 included clinically diagnosed cases of leukoplakia, group B2 included clinically diagnosed cases of oral submucous fibrosis, and group C included controls. Salivary DNA fluorescence spectrum obtained after adding ethidium bromide was analyzed using FluoroLog spectrophotometer at 480 nm wavelength. Results The discriminant analysis of fluorescent emission of salivary DNA shows predictive accuracy of 90% between group C and group A, 95% between group C and group B1, and 65% observed between group C and group B2. Conclusion From this study, screening of oral cancer can be done at the earliest with the help of fluorescence spectroscopic characterization of salivary DNA. This method can be done rapidly and noninvasively.

CuO-NiO binary transition metal oxide nanoparticle anchored on rGO nanosheets as high-performance electrocatalyst for the oxygen reduction reaction.

To replace the existing noble-metal-based catalysts, developing highly efficient, stable electrocatalysts for oxygen reduction reactions for the increased current generation with lower overpotential is a demanding undertaking. In the present work, CuO-NiO/rGO nanocomposites were prepared using simple, cost-effective Co-precipitation methods. They act as highly effective electrocatalysts for oxygen reduction reactions in an alkaline medium. The structural characterizations demonstrate that prepared nanoparticles (≈13 nm) are tightly and effectively organized on reduced graphene oxide sheets. The electrochemical properties of the CuO, NiO nanoparticles and CuO-NiO, CuO-NiO/rGO nanocomposites were investigated. The results of the CuO-NiO/rGO nanocomposites revealed the high current density (2.9 × 10-4 mA cm-2), lower Tafel slope (72 mV dec-1) and low hydrogen peroxide yield (15%) when compared to other prepared materials (CuO, NiO, and CuO-NiO). The reduced graphene oxide increases an electron transfer during the ORR process, while the CuO-NiO has variable oxidation states that promote electro-rich features. With the combination of CuO-NiO and rGO, the hybrid electrocatalysts specific surface area and charge transfer rate drastically increase. The investigations of the rotating ring-disk electrodes experiments indicate that the oxygen reduction process takes place on CuO-NiO/rGO through an efficient four-electron pathway. Our results propose a new approach to creating highly efficient and long-lasting electrocatalysts.

Effect of molecular weight of polyethyleneimine on loading of CpG oligodeoxynucleotides onto flake-shell silica nanoparticles for enhanced TLR9-mediated induction of interferon-α.

BACKGROUND: Class B CpG oligodeoxynucleotides primarily interact with Toll-like receptor 9 (TLR9) in B cells and enhance the immune system through induction of various interleukins including interleukin-6 in these immune cells. Although free class B CpG oligodeoxynucleotides do not induce interferon (IFN)-α production, CpG oligodeoxynucleotide molecules have been reported to induce IFN-α when loaded onto nanoparticles. Here, we investigated the in vitro induction of IFN-α by a nanocarrier delivery system for class B CpG oligodeoxynucleotide molecules. METHODS: For improving the capacity to load CpG oligodeoxynucleotide molecules, flake-shell SiO(2) nanoparticles with a specific surface area approximately 83-fold higher than that of smooth-surfaced SiO(2) nanoparticles were prepared by coating SiO(2) nanoparticles with polyethyleneimine (PEI) of three different number-average molecular weights (Mns 600, 1800, and 10,000 Da). RESULTS: The capacity of the flake-shell SiO(2) nanoparticles to load CpG oligodeoxynucleotides was observed to be 5.8-fold to 6.7-fold higher than that of smooth-surfaced SiO(2) nanoparticles and was found to increase with an increase in the Mn of the PEI because the Mn contributed to the positive surface charge density of the nanoparticles. Further, the flake-shell SiO(2) nanoparticles showed much higher levels of IFN-α induction than the smooth-surfaced SiO(2) nanoparticles. The highest IFN-α induction potential was observed for CpG oligodeoxynucleotide molecules loaded onto flake-shell SiO(2) nanoparticles coated with PEI of Mn 600 Da, although the CpG oligodeoxynucleotide density was lower than that on flake-shell SiO(2) nanoparticles coated with PEI of Mns 1800 and 10,000 Da. Even with the same density of CpG oligodeoxynucleotides on flake-shell SiO(2) nanoparticles, PEI with an Mn of 600 Da caused a markedly higher level of IFN-α induction than that with Mns of 1800 Da and 10,000 Da. The higher TLR9-mediated IFN-α induction by CpG oligodeoxynucleotides on flake-shell SiO(2) nanoparticles coated with a PEI of Mn 600 Da is attributed to residence of the CpG oligodeoxynucleotide molecules in endolysosomes.