Fibrillar deposits of the human islet amyloid polypeptide (hIAPP) are considered as a root of Type II diabetes mellitus. Fluorinated graphene quantum dots (FGQDs) are new carbon nanomaterials with unique physicochemical properties containing highly electronegative F atoms. Herein we report a single step synthesis method of FGQDs with an inhibitory effect on aggregation and cytotoxicity of hIAPP in vitro. Highly fluorescent and water dispersible FGQDs, less than 3 nm in size, were synthesized by the microwave-assisted hydrothermal method. Efficient inhibition capability of FGQDs to amyloid aggregation was demonstrated. The morphologies of hIAPP aggregates were observed to change from the entangled long fibrils to short thin fibrils and amorphous aggregates in the presence of FGQDs. In thioflavin T fluorescence analysis, inhibited aggregation with prolonged lag time and reduced fluorescence intensity at equilibrium were observed when hIAPP was incubated together with FGQDs. Circular dichroism spectrum results reveal that FGQDs could inhibit conformational transition of the peptide from native structure to β-sheets. FGQDs could also rescue the cytotoxicity of INS-1 cells induced by hIAPP in a dose dependent manner. This study could be beneficial for design and preparation of inhibitors for amyloids, which is important for prevention and treatment of amyloidosis.

Early detection of peptide aggregate intermediates is quite challenging because of their variable and complex nature as well as due to lack of reliable sensors for diagnosis. Herein, we report the detection of monomers and oligomers using specified fluorescence and a magnetic resonance imaging (MRI) multimodal probe based on bovine-serum-albumin-capped fluorine functionalized graphene quantum dots (BSA@FGQDs). This probe enables in vitro fluorescence-based monitoring of human islet amyloid polypeptide (hIAPP), insulin, and amyloid β(1–42) (Aβ42) monomers and oligomers during the fibrillogenesis dynamic. Up to 90% fluorescence quenching of BSA@FGQDs probe upon addition of amyloid monomers/oligomers was observed due to static quenching and nonradiative energy transfer. Moreover, the BSA@FGQDs probe shows 10 times higher signals in detecting amyloid intermediates and fibrils than that of conventional thioflavin dye. A negative ΔG° value (−36.21 kJ/mol) indicates spontaneous interaction of probe with the peptide. These interactions are hydrogen bonding and hydrophobic as proved by thermodynamic parameters. Visual binding clues of BSA@FGQDs with different morphological states of amyloid protein was achieved through electron microscopy. Furthermore, intravenous and intracranial injection of BSA@FGQDs probe in Alzheimer model mice brain enabled in vivo detection of amyloid plaques in live mice brain by 19F MRI through contrast enhancement. Our proposed probe not only effectively monitors in vitro fibrillation kinetics of number of amyloid proteins with higher sensitivity and specificity than thioflavin dye, but also, the presence of a 19F center makes BSA@FGQDs an effective probe as a noninvasive and nonradiative in vivo detection probe for amyloid plaques.

The effective treatment of industrial wastewater to protect freshwater reserves for the survival of life is a primary focus of current research. Herein, a multicomponent Eleocharis-manganese peroxidase enzyme (Eleocharis@ MnPE) layered hybrid with high surface area (1200 m 2 /m 3 ), with a strong synergistic adsorption and catalytic biodegradation (SACB), has been developed through a facile method. A combination of outer porous (Eleocharis) and inner catalytically active (MnPE) components of the hybrid resulted in highly efficient SACB system, evidenced by high removal rate of 15 kg m −3 day −1 (100%) and complete degradation of toxic Orange II (OR) azo dye into nontoxic products (gases and weak acids). The Eleocharis@MnPE layered hybrid efficiently degraded both OR in synthetic wastewater and also other azo dyes (red, pink, and yellow dyes) present in three different textile industrial effluents. For the industrial effluents, these were evidenced by the color disappearance and reduction in biological oxygen demand (BOD), chemical oxygen demand (COD), and total organic carbon (TOC) of up to 97%, 92%, and 76%, respectively. Furthermore, reduced toxicity of treated wastewater was confirmed by decreased cell toxicity to 0.1%−1% and increased cell viability to 90%. We believe that designing a hybrid system with strong ability of SACB could be highly effective for industrial-scale treatment of wastewater.

Loureirin B (LB) is the most radioactive compound of dragon's blood, but its poor pharmacokinetics due to its hydrophobic nature limits its clinical applications. Owing to the excellent biocompatibility of liposomes with body fluid, here phospholipids and cholesterol-based nanoliposomes (NLs) were synthesized using the thin-film evaporation technique as a nanocarrier for LB to overcome associated clinical issues. The NLs exhibited overall vesicular shape, which is favorable for enhanced drug uptake (up to 74.5%), while the particle size of NLs was found to be strongly dependent on lipid concentration that ranges from 58 to 94 nm. Further, a high ζ-potential of −51.2 mV shown by the LBloaded NLs confirms their high stability and better dispersion in designated solvents/cell plasma as well as proves their ability for homogeneous drug delivery. In vitro flow cytometry results revealed that LB-loaded NLs recover the radiation injury in viable cell from 79.4 to 89.9%, early apoptosis from 3.5 to 0.2%, necrosis from 14.8 to 9.8%, and late apoptosis from 2.3 to 0.0%. In vivo assay showed that LB-loaded NLs successfully improved the pharmacokinetic parameters such as maximum concentration of LB-loaded NLs formulation, elimination rate half-life, area under the curve, and plasma clearance to 3.247 ± 0.631 ng/mL h, 14.765 ± 10.780 min, 2.957 ± 0.201 ng/mL h, and 0.132 ± 0.901 ng/mL h, respectively. Thus, we believe that designing such unique LB-loaded NLs composite not only improved the antiradiation characteristics of LB but also make it suitable for other biomedical applications like drug delivery by enhancing its solubility and dispersion.

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Hydrogen production via water dissociation under exposure to sunlight has emanated as an environmentally friendly, highly productive and expedient process to overcome the energy production and consumption gap, while evading the challenges of fossil fuel depletion and ecological contamination. Various classes of materials are being explored as viable photocatalysts to achieve this purpose, among which, the two-dimensional materials have emerged as prominent candidates, having the intrinsic advantages of visible light sensitivity; structural and chemical tuneability; extensively exposed surface area; and flexibility to form composites and heterostructures. In an abridged manner, the common types of 2D photocatalysts, their position as potential contenders in photocatalytic processes, their derivatives and their modifications are described herein, as it all applies to achieving the coveted chemical and physical properties by fine-tuning the synthesis techniques, precursor ingredients and nano-structural alterations.

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