Microbial dysbiosis has been implicated in the pathogenesis of oral cancer. We analyzed the compositional and metabolic profile of the bacteriome in three specific niches in oral cancer patients along with controls using 16SrRNA sequencing (Illumina Miseq) and DADA2 software. We found major differences between patients and control subjects. Bacterial communities associated with the tumor surface and deep paired tumor tissue differed significantly. Tumor surfaces carried elevated abundances of taxa belonging to genera Porphyromonas, Enterobacteriae, Neisseria, Streptococcus and Fusobacteria, whereas Prevotella, Treponema, Sphingomonas, Meiothermus and Mycoplasma genera were significantly more abundant in deep tissue. The most abundant microbial metabolic pathways were those related to fatty-acid biosynthesis, carbon metabolism and amino-acid metabolism on the tumor surface: carbohydrate metabolism and organic polymer degradation were elevated in tumor tissues. The bacteriome of saliva from patients with oral cancer differed significantly from paired tumor tissue in terms of community structure, however remained similar at taxonomic and metabolic levels except for elevated abundances of Streptococcus, Lactobacillus and Bacteroides, and acetoin-biosynthesis, respectively. These shifts to a pro-inflammatory profile are consistent with other studies suggesting oncogenic properties. Importantly, selection of the principal source of microbial DNA is key to ensure reliable, reproducible and comparable results in microbiome studies.

Objective : While some oral carcinomas appear to arise de novo , others develop within long-standing conditions of the oral cavity that have malignant potential, now known as oral potentially malignant disorders (OPMDs). The oral bacteriome associated with OPMD has been studied to a lesser extent than that associated with oral cancer. To characterize the association in detail we compared the bacteriome in whole mouth fluid (WMF) in patients with oral leukoplakia, oral cancer and healthy controls. Methods : WMF bacteriome from 20 leukoplakia patients, 31 patients with oral cancer and 23 healthy controls were profiled using the Illumina MiSeq platform. Sequencing reads were processed using DADA2, and taxonomical classification was performed using the phylogenetic placement method. Sparse Partial Least Squares Regression Discriminant Analysis model was used to identify bacterial taxa that best discriminate the studied groups. Results : We found considerable overlap between the WMF bacteriome of leukoplakia and oral cancer while a clearer separation between healthy controls and the former two disorders was observed. Specifically, the separation was attributed to 14 taxa belonging to the genera Megaspheara, unclassified enterobacteria, Prevotella, Porphyromonas, Rothia and Salmonella, Streptococcus, and Fusobacterium . The most discriminative bacterial genera between leukoplakia and oral cancer were Megasphaera, unclassified Enterobacteriae, Salmonella and Prevotella. Conclusion : Oral bacteria may play a role in the early stages of oral carcinogenesis as a dysbiotic bacteriome is associated with oral leukoplakia and this resembles that of oral cancer more than healthy controls. Our findings may have implications for developing oral cancer prevention strategies targeting early microbial drivers of oral carcinogenesis.

A series of electron deficient perylene bisimides (PBIs) bearing 3,4,5-tridecylphenyl substituents on the imide N-atoms and bay-annulated with the hetero atoms like N, S, Se in the bay positions of...

Highly electron‐deficient heteroatom (N, S, Se) bay‐annulated PBIs exhibiting ordered columnar phase over a wide mesomorphic range including ambient temperature are reported in this manuscript. These compounds with six peripheral n‐decyloxy chains exhibited absorption spectra with high molar extinction coefficients, electron‐deficient nature and self‐assembling behaviour. A detailed comparison with the PBIs bearing six peripheral n‐decyl chains was also carried out to get the valuable insights on the structure‐property relations in this important class of organic semiconductors. Both of the PBI series were tested for their charge carrier mobility by space charge limited current method and found that they exhibit ambipolar conductivity. This is in contrary to the vast body of literature, where most of the PBI based semiconductors exhibit electron transport behaviour. In general, PBIs derived from tri‐n‐alkyl anilines exhibit higher mobility values than the PBIs derived from tri‐n‐alkoxy anilines. Especially, the ambipolar S‐annulated PBI derived from tri‐n‐alkyl aniline exhibited highest hole (8.39×10−3 cm2/V.s) and electron (1.5×10−2 cm2/V.s) mobility values and promising for the application in organic electronics.

A self-assembled ambipolar organic semiconductor based on naphthalene diimide with low clearing temperature, solution processability, high molar extinction coefficient, exhibiting room temperature columnar hexagonal liquid crystalline phase is reported.