Dopamine-Functionalized, Red Carbon Quantum Dots for In Vivo Bioimaging, Cancer Therapeutics, and Neuronal Differentiation.

One of the crucial requirements of quantum dots for biological applications is their surface modification for very specific and enhanced biological recognition and uptake. Toward this end, we present the green synthesis of bright, red-emitting carbon quantum dots derived from mango leaf extract (mQDs). These mQDs are conjugated electrostatically with dopamine to form mQDs-dopamine (mQDs:DOPA) bioconjugates. Bright-red fluorescence of mQDs was used for bioimaging and uptake in cancerous and noncancerous cell lines, tissues, and in vivo models like zebrafish. mQDs exhibited the highest uptake in brain tissue compared to the heart, kidney, and liver. mQD:DOPA conjugates killed breast cancer cells and increased uptake in epithelial RPE-1 cells and zebrafish. Additionally, mQDs:DOPA promoted neuronal differentiation of SH-SY5Y cells to differentiated neurons. Both mQDs and mQDs:DOPA exhibited the potential for higher collective cell migrations, implicating their future potential as next-generation tools for advanced biological and biomedical applications.

Catalytic Sabatier Process under Thermally and Magnetically Induced Heating: A Comparative Case Study for Titania-Supported Nickel Catalyst.

In the present paper, we compare the activity, selectivity, and stability of a supported nickel catalyst in classical heating conditions and in magnetically activated catalysis by using iron wool as a heating agent. The catalyst, 5 wt% Ni supported on titania (Degussa P25), was prepared via an organometallic decomposition method and was thoroughly characterized by using elemental, microscopic, and diffraction techniques. In the event of magnetic induction heating, the % CO2 conversion reached a maximum of ~85% compared to ~78% for thermal conditions at a slightly lower temperature (~335 °C) than the thermal heating (380 °C). More importantly, both processes were found to be stable for 45 h on stream. Moreover, the effects of magnetic induction and classical heating over the catalyst evolution were discussed. This study demonstrated the potential of magnetic heating-mediated methanation, which is currently under investigation for the development of pilot-scale reactors.

Designer, Programmable DNA-peptide hybrid materials with emergent properties to probe and modulate biological systems.

The chemistry of DNA endows it with certain functional properties that facilitate the generation of self-assembled nanostructures, offering precise control over their geometry and morphology, that can be exploited for advanced biological applications. Despite the structural promise of these materials, their applications are limited owing to lack of functional capability to interact favourably with biological systems, which has been achieved by functional proteins or peptides. Herein, we outline a strategy for functionalizing DNA structures with short-peptides, leading to the formation of DNA-peptide hybrid materials. This proposition offers the opportunity to leverage the unique advantages of each of these bio-molecules, that have far reaching emergent properties in terms of better cellular interactions and uptake, better stability in biological media, an acceptable and programmable immune response and high bioactive molecule loading capacities. We discuss the synthetic strategies for the formation of these materials, namely, solid-phase functionalization and solution-coupling functionalization. We then proceed to highlight selected biological applications of these materials in the domains of cell instruction & molecular recognition, gene delivery, drug delivery and bone & tissue regeneration. We conclude with discussions shedding light on the challenges that these materials pose and offer our insights on future directions of peptide-DNA research for targeted biomedical applications.

Red emitting fluorescent carbon nanoparticles to track spatio-temporal dynamics of endocytic pathways in model neuroblastoma neurons.

One of the biggest challenges limiting the biological applications of fluorescent carbon-based nanoparticles is their capacity to emit in the red region of the spectrum and simultaneously maintaining the smaller size. These two parameters always go in inverse proportion, thus lagging their applications in biological imaging. Endocytic pathways play important roles in regulating major cellular functions such as cellular differentiation. The Spatio-temporal dynamics of endocytic pathways adopted by various ligands (including nanoparticles) over longer durations in cellular differentiation remain unstudied. Here we have used red-emitting fluorescent carbon nanoparticles to study the endocytic pathways in neuronal cells at different stages of differentiation. These small-sized, bright, red-emitting carbon nanoparticles (CNPs) can be internalized by live cells and imaged for extended periods, thus capturing the Spatio-temporal dynamics of endocytic pathways in model SH-SY5Y derived neuroblastoma neurons. We find that these nanoparticles are preferably taken up via clathrin-mediated endocytosis and follow the classical recycling pathways at all the stages of neuronal differentiation. These nanoparticles hold immense potential for their size, composition, surface and fluorescence tunability, thus maximizing their applications in spatio-temporally tracking multiple cellular pathways in cells and tissues simultaneously.

La-Cu based heterogeneous perovskite catalyst for highly selective benzene hydroxylation under mild conditions.

Direct hydroxylation of benzene towards phenol with high conversion and selectivity remains a great challenge. We report herein an efficient La2 CuO4 perovskite catalyst for one-step oxidation of benzene using hydrogen peroxide under mild conditions. The catalyst was characterized using XRD, TEM, XPS, TG-DTA, and other advanced techniques. The one-pot hydroxylation reaction carried out at 60 °C under optimum reaction conditions in the presence of catalytic material shows benzene to phenol transformation with 51% conversion with >99% selectivity with 65 percent peroxide efficiency, respectively. The influence of reaction conditions such as temperature, amount of oxidant, reaction time and mode of addition of the oxidant was crucial in selectivity optimization.

Peptide functionalized DNA hydrogel enhances neuroblastoma cell growth and differentiation.

Designing programmable biomaterials that could act as extracellular matrices and permit functionalization is a current need for tissue engineering advancement. DNA based hydrogels are gaining significant attention owing to their self-assembling properties, biocompatibility, chemical robustness and low batch to batch variability. The real potential of DNA hydrogels in the biomedical domain remains to be explored. In this work, a DNA hydrogel was coated on a glass surface and coupled to a synthetic IKVAV peptide by a chemical crosslinker. We observe enhanced neuronal differentiation, prolonged neurite length, dynamic movement of microtubules and cytoskeleton, and altered endocytic mechanisms in neuroblastoma-based stem cells for the peptide modified DNA hydrogel compared to the unmodified DNA hydrogel and controls. We anticipate that a peptide-modified DNA hydrogel could emerge as a promising scaffold coating material to develop nerve tissue conduits in the future for application in neuroscience and neuroregeneration.

Role of Doxorubicin on the Loading Efficiency of ICG within Silk Fibroin Nanoparticles.

The effective loading or encapsulation of multimodal theranostic agents within a nanocarrier system plays an important role in the clinical development of cancer therapy. In recent years, the silk fibroin protein-based delivery system has been drawing significant attention to be used in nanomedicines due to its biocompatible and biodegradable nature. In this study, silk fibroin nanoparticles (SNPs) have been synthesized by a novel and cost-effective ultrasonic atomizer-based technique for the first time. The fabricated SNPs were coencapsulated by the FDA-approved indocyanine green (ICG) dye and the chemotherapeutic drug doxorubicin (DOX). The synthesized SNPs are spherical, with an average diameter of ∼37 ± 4 nm, and the ICG-DOX-coencapsulated SNPs (ID-SNPs) have a diameter size of ∼47 ± 6 nm. For the first time, here we demonstrate that DOX helps in the higher loading of ICG within the ID-SNPs, which enhances the encapsulation efficiency of ICG by ∼99%. This could be attributed to the interaction of ICG and DOX molecules with the silk fibroin protein, which helps ICG to get loaded more efficiently within these nanoparticles. The overall finding of this study suggests that the ID-SNPs could be utilized for enhanced ICG-complemented multimodal deep-tissue bioimaging and synergistic chemo-photothermal therapy.

α-Synuclein fibrils explore actin-mediated macropinocytosis for cellular entry into model neuroblastoma neurons.

Alpha-synuclein (α-Syn), an intrinsically disordered protein (IDP), is associated with neurodegenerative disorders, including Parkinson's disease (PD or other α-synucleinopathies. Recent investigations propose the transmission of α-Syn protein fibrils, in a prion-like manner, by entering proximal cells to seed further fibrillization in PD. Despite the recent advances, the mechanisms by which extracellular protein aggregates internalize into the cells remain poorly understood. Using a simple cell-based model of human neuroblastoma-derived differentiated neurons, we present the cellular internalization of α-Syn PFF to check cellular uptake and recycling kinetics along with the standard endocytic markers Transferrin (Tf) marking clathrin-mediated endocytosis (CME) and Galectin3 (Gal3) marking clathrin-independent endocytosis (CIE). Specific inhibition of endocytic pathways using chemical inhibitors reveals no significant involvement of CME, CIE and caveolae-mediated endocytosis (CvME). A substantial reduction in cellular uptake was observed after perturbation of actin polymerization and treatment with macropinosomes inhibitor. Our results show that α-Syn PFF mainly internalizes into the SH-SY5Y cells and differentiated neurons via the macropinocytosis pathway. The elucidation of the molecular and cellular mechanism involved in the α-Syn PFF internalization will help improve the understanding of α-synucleinopathies including PD, and further design specific inhibitors for the same.

Charge neutralization of lysine via carbamylation reveals hidden aggregation hot-spots in tau protein flanking regions.

Tau protein is found abundantly in neurofibrillary tangles in Alzheimer's disease (AD). The longest human tau isoform (2N4R) has 44 lysine residues. Several lysine-based post-translational modifications (PTMs) such as glycation, acetylation, ubiquitination, and sumoylation have been implicated not only in AD, but also in other tauopathies. Carbamylation is one such lysine neutralizing age-related nonenzymatic PTM which can modulate the aggregation propensity of tau. In this work, we have studied the aggregation potential of lysine-rich regions of tau upon carbamylation which do not aggregate in their native form. Using an array of biophysical and microscopic analyses, such as ThT kinetic assay, fluorescence microscopy, Congo red staining, and scanning electron microscopy, we demonstrate that peptides derived from four of five such regions exhibit robust fibrillar amyloid formation. These regions are found in the N-terminal projection domain that encompasses proline-rich domain (148-153 and 223-230), repeat domain R1 (253-260), as well as fibrillary core region (368-378), and can be described as hidden aggregation hot-spots which become activated upon carbamylation. We have further compared the impact of carbamylation with acetylation on the aggregation propensity of lysine-rich peptide (254 KKVAVV259 ) using biophysical experiments and molecular dynamics simulations and deduced that carbamylation is a much stronger driver of aggregation than acetylation. Our findings may offer more insight into amyloid fibrils' interaction with hidden aggregation-prone nucleating sequences that act as hot-spots for inducing tau fibrillation.

Effect of Doxorubicin on the Near-Infrared Optical Properties of Indocyanine Green.

In recent years, chemo-photothermal therapy (chemo-PTT) has been extensively studied for the upgradation of cancer treatment. The combined therapeutic approach reduces the overall cytotoxicity and enhances the therapeutic effect against the cancerous cells. In chemo-PTT, Indocyanine green (ICG) dye, a near-infrared chromophore, is used for PTT in combination with doxorubicin (DOX), a chemotherapeutic drug. ICG and DOX work very efficiently in synergy against cancer. However, the effect of DOX on the optical properties of ICG has not been studied yet. Here, for the first time, we report the effect of DOX on the optical properties of ICG in detail. DOX interacts with ICG and induces the aggregation of ICG even at a low concentration. The coincubation of both the molecules causes H and J aggregations in ICG. However, the J aggregation becomes more prominent with an increasing DOX concentration. These findings suggest that the optical properties of ICG change upon incubation with the DOX, which might affect the efficacy of PTT.

Rheology and direct write printing of chitosan - graphene oxide nanocomposite hydrogels for differentiation of neuroblastoma cells.

The direct write printing method has gained popularity in synthesizing scaffolds for tissue engineering. To achieve an excellent printability of scaffolds, a thorough evaluation of rheological properties is required. We report the synthesis, characterization, rheology, and direct-write printing of chitosan - graphene oxide (CH - GO) nanocomposite hydrogels at a varying concentration of GO in 3 and 4 wt% CH polymeric gels. Rheological characterization of CH - GO hydrogels shows that an addition of only 0.5 wt% of GO leads to a substantial increase in storage modulus (G'), viscosity, and yield stress of 3 and 4 wt% of CH hydrogels. A three-interval thixotropy test (3ITT) shows that 3 wt% CH with 0.5 wt% GO hydrogel has 94% recovery of G' after 7 sequential stress cycles and is the best candidate for direct-write printing. Neuronal cell culture on 3 wt% CH with 0.5 wt% hydrogels reveals that GO promotes the differentiation of SH-SY5Y cells.

Comparative Study of Dry Eye Indices Following Cataract Surgery.

BACKGROUND: This study aims to assess dry eye indices following cataract surgery. MATERIALS AND METHODS: A single center descriptive and comparative study was performed. A total of 100 eyes of 100 cases fulfilling the inclusion criteria from 1st June 2017 to 30th May 2018 were enrolled. Out of 100 eyes, 50 eyes each went through manual small incision cataract surgery (MSICS) and phacoemulsification respectively. For objective analysis : schirmer 1 test(ST-I), tear breakup Time(TBUT) along with lissamine Green Surface Staining(LGSS) was performed on pre-operative day, 1st, 4th and 12th week respectively. Ocular Surface Disease Index (OSDI) was done for subjective analysis on pre-operative day and at 12th week. RESULTS: The mean age of the patient was 53.66 ± 7.839 years with 34 (68%) being female in a small incision cataract surgery group. In the phacoemulsification group, mean age was 54.72 ± 7.985 years and 32 (64%) were female. On analyzing the objective dry eye indices: ST-I,TBUT and LGSS at 12thweek was 18.80 ± 7.393 mm, 11.30 ± 5.456 seconds and 1.62 ± 1.193 in Small incision cataract surgery group and 27.10 ± 6.326 mm, 16.60 ± 4.699 seconds and 0.38 ± 0.602 in Phacoemulsification group respectively which was statistically significant. (p< 0.001). CONCLUSION: Regardless of the type of cataract surgery, dry eye disease is unavoidable affecting both tear quality and quantity postoperatively. In our study, phacoemulsification had lesser effect in dry eye indices than small incision cataract surgery.

Carbamoylated chitosan hydrogels with improved viscoelastic properties and stability for potential 3D cell culture applications.

We demonstrate a benign and straightforward method to modify the chitosan (CH) by carbamoylation. The free amines on CH are converted into carbamyl functionalities by reacting with potassium cyanate (KCNO). One wt% CH solution, when reacted with KCNO ⩾ 0.1 M, leads to the sol-gel transition of CH through the hydrogen bonding to form carbamoylated chitosan (CCH) hydrogel. Gelation time of CCH decreases with an increase in the KCNO concentration and an interconnected porous network is formed as observed under SEM. Rheological studies show that while one wt% CH solution is a viscous liquid, the CCH hydrogel with 0.5 M KCNO has a storage modulus (G') of 104Pa. The CCH hydrogel is proved to be non-cytotoxic and promotes the attachment and growth of the small lung cancer model A549, and the neuroblastoma SH-SY5Y cell lines. CCH hydrogel also promotes the differentiation of SH-SY5Y cells into neuronal cells, as supported by immunostaining and thus demonstrating its utility as a versatile scaffold for three-dimensional cell-culture systems.

Dual engineered gold nanoparticle based synergistic prophylaxis delivery system for HIV/AIDS.

HIV is a pandemic and continuously raises problem across the world. This disease puts an immense pressure on treatment modalities. There are only few clinically accepted drugs available for the treatment and few molecules under clinical development. Although, the antiretroviral drugs give reliable and positive response on control of virus replication but during the long treatment, it has been affirmed that there are number of side effects. With recent advancements in biotechnology, nanomaterials such as gold and silver etc. are proving to be a game changer in targeted drug delivery treatment. As gold nanoparticles (AuNPs) are biocompatible natural excipients, a lot of scientists are very eager to investigate more about the immune effects of AuNPs to create a safe and cost effective treatment that could potentially help in the reduction of numerous toxic effects present in the existing treatments of various critical diseases like cancer and HIV etc. In this context, the present hypothesis recommends the use of combination drug delivery strategy based on gold nanoparticles that could pave the way to overcome adverse results of existing delivery techniques of antiretroviral drugs to treat HIV. This review also highlights the fact that a proper development of this gold nanoparticle combination antiretroviral drug delivery approach will not only help to suppress the virus multiplication but also target the viral entry area by attaching with gp120 (glycoprotein 120), and inhibit the binding with CD4 (Cluster of differentiation 4) T cells.

Unravelling the potency of triazole analogues for inhibiting α-synuclein fibrillogenesis and in vitro disaggregation.

A series of triazole-based compounds was synthesized using a click chemistry approach and evaluated for the inhibition of α-synuclein (α-syn) fibrillogenesis and its disaggregation. Compounds Tr3, Tr7, Tr12, Tr15, and Tr16 exhibited good effect in inhibiting α-syn fibrillogenesis confirmed by Thioflavin-T assay and fluorescence microscopy and α-syn disaggregation confirmed by fluorescence microscopy. Molecular docking was used to understand the plausible mechanism of the test compounds for inhibiting the α-syn fibrillogenesis and to verify the in vitro results. Compounds Tr3, Tr7, Tr12, Tr15 and Tr16 showed good binding interactions with the essential amino acid residues of α-syn. The compounds which were found to be good inhibitors or disaggregators had no toxic effects on the SH-SY5Y cell line. These compounds have the potential to be developed as therapeutic interventions against synucleinopathies including Parkinson's disease and Lewy body dementia.

Spatiotemporal Dynamics of Endocytic Pathways Adapted by Small DNA Nanocages in Model Neuroblastoma Cell-Derived Differentiated Neurons.

Multiple endocytic pathways operate on the plasma membrane of cells at any moment with diverse but specific cellular functions. Knowledge of uptake of synthetic nanoparticles and ligands with respect to endocytic pathways is crucial to device the appropriate ligands for therapeutic delivery into differentiated neurons for targeting neuronal diseases. We herein explore the mechanisms of cellular uptake of 3D tetrahedral DNA nanocages at different stages of differentiating neurons. We monitored the uptake, kinetics, and dynamics of DNA cages of different geometries, and interestingly we find a specific pattern and adaptability of the uptake of DNA devices with respect to the geometry of the ligand and specific endocytic pathways. We find that tetrahedral DNA nanocages get endocytosed mostly via clathrin-mediated endocytosis in fully mature neurons. This endocytic uptake and intracellular choreography of DNA nanodevices will help us design the smartly targeted biotherapeutics for targeting neuronal disorders.

Diphenyl triazine hybrids inhibit α-synuclein fibrillogenesis: Design, synthesis and in vitro efficacy studies.

Aggregation of α-synuclein (α-syn) is one of the central hypotheses for Parkinson's disease (PD), therefore, its inhibition and disaggregation is an optimistic approach for the treatment of PD. Here, we report design, synthesis and in-vitro efficacy studies of a series of diphenyl triazine hybrids as potential inhibitors of α-syn fibrillogenesis. From the docking studies, we concluded that compounds A1, A2, A4, A8 and A9 display promising binding affinity with the essential residues of α-syn with binding energy values: -6.0, -7.0, -6.3, -6.6 and -6.7 kcal/mol respectively. The target compounds were synthesized using multistep organic synthesis reactions. Compounds A1, A2 A4, A8 and A9 showed a significant lowering of the α-syn fibril formation during Thioflavin-T assay and fluorescence microscopy. In addition, these compounds A1, A2, A4, A8 and A9 also proved to be good disaggregators in the pre-aggregated form of α-syn. Most of the compounds exhibited no cytotoxicity in mouse embryonic fibroblast (MEF) and human adenocarcinomic alveolar basal epithelial cells (A549) except A2. Overall, diphenyl triazine-based compounds can be further investigated for the treatment of synucleinopathies and for Lewy body dementia in which α-syn is predominantly observed.

Mercury, arsenic, lead and cadmium in waters of the Singrauli coal mining and power plants industrial zone, Central East India.

The present investigation is an attempt to assess the contamination of heavy metals in the ground and surface water of the Singrauli industrial belt area. Pollution indices like heavy metal index (HPI), contamination index (CD) and heavy metal evaluation index (HEI) are used for the evaluation of heavy metal pollution (arsenic As, mercury Hg, cadmium Cd, and lead Pb). Contour maps are constructed to interpret metal spatial distribution. Further, the land-use/land-cover (LULC) maps for the year 2000, 2010 and 2016 are prepared using Landsat satellite data. A total of 48 water samples (Groundwater (27), Surface water (21)) are analysed for heavy metal concentration. Eighty-eight percent of groundwater and 90% of surface water samples are contaminated with Hg. Similarly, high concentrations of Pb and Cd were found in the samples. Surprisingly, all the water samples have As concentration above the WHO permissible limit of 10 ppb. Further, 95% of the samples have an HPI value greater than 100 indicating high heavy metal contamination. CD value denotes contamination of 89% of the samples with heavy metals (As, Hg, Cd, Pb). Through spatial distribution, it can be interpreted that most of the contaminated samples lie near thermal power plants, ash ponds, and coal mines. LULC (land use/land cover) study shows a significant decrease in water bodies by (108 km2), agricultural land by (54 km2) and bare/fallow land by (51 km2) from 2000 to 2016. During these 16 years, there has been a fourfold increase in the overburden, a threefold increase in dumping yards, a 2.5 times increase in urban areas, and a twofold increase in mining areas. Both the environment and the water quality are deteriorating at an alarming rate. Such scientific investigations are relevant for risk management studies of potable water. The knowledge acquired from such assessment shall be considered with utmost priority by concerned authority considering degrading water quality in the study area. Hence, this study is applicable for designing action plans and control measures to reduce water resource pollution.

Green synthesis of near-infrared absorbing eugenate capped iron oxide nanoparticles for photothermal application.

Nanomaterials exhibit different interesting physical, chemical, electronic and magnetic properties that can be used in a variety of biomedical applications such as molecular imaging, cancer therapy, biosensing, and targeted drug delivery. Among various types of nanoparticles, super paramagnetic iron oxide nanoparticles (SPIONs) have emerged as exogenous contrast agents for in vitro and in vivo deep tissue imaging. Here, we propose a facile, rapid, non-toxic, and cost-effective single step green synthesis method to fabricate eugenate (4-allyl-2-methoxyphenolate) capped iron oxide nanoparticles (E-capped IONPs). The magnetic E-capped IONPs are first time synthesized using a medicinal aromatic plant, Pimenta dioica. The Pimenta dioica leaf extract was used as a natural reducing agent for E-capped IONPs synthesis. The crystalline structure and size of the synthesized spherical nanoparticles were confirmed using the x-ray diffraction and electron microscopic images respectively. In addition, the presence of the functional groups, responsible for capping and stabilizing the synthesized nanoparticles, were identified by the Fourier transform infra-red spectrum. These nanoparticles were found to be safe for human cervical cancer (HeLa) and human embryonic kidney 293 (HEK 293) cell lines and their safety was established using MTT[3-(4, 5-Dimethylthiazol-2-yl)-2, 5-Diphenyltetrazolium Bromide] assay. These green synthesized E-capped IONPs display a distinct absorbance in the tissue transparent near-infrared (NIR) wavelength region. This property was used for the NIR photothermal application of E-capped IONPs. The results suggest that these E-capped IONPs could be used for deep tissue photothermal therapy along with its application as an exogenous contrast agent in biomedical imaging.

A rare case of conjunctival malignant melanoma with orbital invasion.

BACKGROUND: Conjunctival malignant melanoma is a rare ocular malignancy most commonly affecting mostly the elderly population. It is a pigmented lesion which canarise from primary acquired melanosis, de novo or from preexisting nevus. CASE: A 63 year old male presented with a chief complaints rapidly increasing mass in the left eye for two months following trauma with a wooden stick. He had preexisting nevus in the same eye. His best corrected visual acuity was 6/12 in right eye and 1/60 left eye respectively. Slit lamp biomicroscopy examination showed 4 cm x 4 cm pigmented mass in the nasal bulbar and inferior palpebral conjunctiva causing mechanical ectropion of the lower lid with keratinization of palpebral conjunctiva. Incisionalbiopsy of conjunctiva showed malignant melanoma. On computed tomography, there was expansion of bony orbit. Considering all the findings, exenteration of the left orbitwas done. Histopathological report of exenterated mass was suggestive of malignantmelanoma of conjunctiva. CONCLUSION: Conjunctival melanoma is a rare malignant tumor of eye which has high metastasis rate and the treatment option is surgery with adjuvant therapy.