A molecular picture of diffusion controlled reaction: role of microviscosity and hydration on hydrolysis of benzoyl chloride at a polymer hydration region

A Mechanoelastic Glimpse on Hyaluronan-Coated Extracellular Vesicles

Cancer cells secrete extracellular vesicles (EVs) covered with a carbohydrate polymer, hyaluronan (HA), linked to tumor malignancy. Herein, we have unravelled the contour lengths of HA on a single cancer cell-derived EV surface using single-molecule force spectroscopy (SMFS), which divulges the presence of low molecular weight HA (LMW-HA < 200 kDa). We also discovered that these LMW-HA-EVs are significantly more elastic than the normal cell-derived EVs. This intrinsic elasticity of cancer EVs could be directly allied to the LMW-HA abundance and associated labile water network on EV surface as revealed by correlative SMFS, hydration dynamics with fluorescence spectroscopy, and molecular dynamics simulations. This method emerges as a molecular biosensor of the cancer microenvironment.

Spectroscopic Studies on the Biomolecular Recognition of Toluidine Blue: Key Information Towards Development of a Non-Contact, Non-Invasive Device for Oral Cancer Detection

Molecular interaction of aromatic dyes with biological macromolecules are important for the development of minimally invasive disease diagnostic biotechnologies. In the present work, we have used Toluidine Blue (TB) as a model dye, which is a well-known staining agent for the diagnosis of oral cancer and have studied the interaction of various biological macromolecules (protein and DNA) with the dye at different pH. Our spectroscopic studies confirm that TB interacts with Human Serum Albumin (HSA), a model protein at very high pH conditions which is very hard to achieve physiologically. On the other hand, TB significantly interacts with the DNA at physiological pH value (7.4). Our molecular studies strengthen the understanding of the Toluidine Blue staining of cancer cells, where the relative ratio of the nucleic acids is higher than the normal intracellular content. We have also developed a non-invasive, non-contact spectroscopic technique to explore the possibility of quantitatively detecting oral cancer by exploiting the interaction of TB with DNA. We have also reported development of a prototype named "Oral-O-Scope" for the detection of Oral cancer and have carried out human studies using the prototype.

Investigation of Local Hydration Structures of Alkanethiol Self-Assembled Monolayers with Different Molecular Structures by FM-AFM

Hydration structures play crucial roles in a wide variety of chemical and biological phenomena. However, the key factors that determine a hydration structure remain an open question. Most recent studies have focused on the electrostatic interactions between the surface charges and dipoles of water molecules, which are determined by the atomic/ionic species of the outermost solid surface, as the dominating factor. The number of studies on the correlation between the hydration structure and the atomic-scale surface corrugation has been limited. In this study, we investigated the hydration structures of alkanethiol self-assembled monolayers terminated with a hydroxyl group using frequency-modulated atomic force microscopy. We observed two molecular structures, namely, the (√3 × √3) R30° structure and the c(4 × 2) superlattice structure, and found that their hydration structures are different mainly because of the slight differences in their molecular arrangements. This result suggests that a slight difference in the molecular/atomic arrangements as well as the atomic/ionic species in the outermost solid surface strongly influences the local hydration structures.

Different mechanisms of ultrafast excited state deactivation of coumarin 500 in dioxane and methanol solvents: experimental and theoretical study

The effect of hydrogen bonding on the intermolecular photoinduced ICT and TICT processes for coumarin 500 has been demonstrated, and a reliable mechanism has been revealed to explain the unusual behavior of C500 in dioxane and methanol.

Synthesis and characterization of a novel fish scale-immobilized chitosan adsorbent--preliminary features of dichlorophenol sorption by solution calorimetry

Brazilian Corvina fish scales were cross linked with polyglutaraldehyde and chemically modified with chitosan gel. Characterization has pointed that chitosan has good and stable adhesion on the fish scales. The sorption of dichlorophenol-2,6-indophenol (DPI) on the novel material was studied by isothermal solution calorimetry. The non-symmetric shapes of the calorimetric plots indicate that the DPI sorption sites of the adsorbent are not energetically uniform. The enthalpies of the DPI sorption processes were highly exothermic (from -536.7 to -50.9 kJ mol(-1)). The analysis of both the characterization of the materials and the calorimetric results has suggested that the interactions at the fish scales/DPI interface are due to surface reactions. The present work underlines the excellent features of the new fish scale-based adsorbent for use in phenol sorption applications at solid/solution interfaces.