Paclitaxel and myricetin encapsulated hemoglobin nanoparticles: characterization and application.

Hb is used as a carrier protein to encapsulate hydrophobic drugs PTX and MYN and has applications in cancer treatment. PTX and MYN encapsulated Hb NPs are synthesized by the acid denature method and are characterized by spectroscopic and electron microscopic techniques. The binding constant calculated for Hb and PTX is 3.

Supramolecular J- and H-Aggregation of Naphthalimide-Conjugated Dipeptide in Mixed-Solvent Systems and its Application in Cell Imaging.

In this work, a core-substituted NMI-conjugated dipeptide (4MNLV) was extensively studied in mixed solvent systems to explore the polarity effect on the self-assembly pattern and their photophysical property. 4MNLV adopted J- or H- type aggregation pattern depending upon the polarity index of the solvent system chosen. The self-assembly process was achieved through the anti-solvent effect.

Investigating the preferential interaction between imatinib mesylate and VEGF G-quadruplex DNA as therapeutic strategies for cancer treatment: Biophysical and molecular modelling approaches.

G-Quadruplex DNA (GQ-DNA) is one of the most important non-canonical nucleic acid structures. GQ-DNA forming sequences are present in different crucial genomic regions and are abundant in promoter regions of several oncogenes. Therefore, GQ-DNA is an important target for anticancer drugs and hence binding interactions between GQ-DNA and small molecule ligands are of great importance.

Revealing the Improved Binding Interaction of Plant Alkaloid Harmaline with Human Hemoglobin in Molecular Crowding Condition.

Harmaline and harmine are two structurally similar β-carboline alkaloids with several therapeutic activities, such as anti-inflammatory, antioxidant, neuroprotective, nephroprotective, antidiabetic, and antitumor activities. It has been previously reported that the interaction between harmaline and hemoglobin (Hb) is weak in buffer media compared to harmine. Crowding agents induce a molecular crowding environment in the condition, which is almost similar to the intracellular environment.

Quercetin Exhibits Preferential Binding Interaction by Selectively Targeting HRAS1 I-Motif DNA-Forming Promoter Sequences.

I-Motif (iM) DNA structures represent among the most significant noncanonical nucleic acid configurations. iM-forming DNA sequences are found in an array of vital genomic locations and are particularly frequent in the promoter islands of various oncogenes. Thus, iM DNA is a crucial candidate for anticancer medicines; therefore, binding interactions between iM DNA and small molecular ligands, such as flavonoids, are critically important.

Green to deep-red emissive carbon dot formation by Cion implantation on nitrogen beam created self-masked nano-template.

We report the formation of green to red emissive arrays of carbon dot on silicon-nitride nano-templates by successive implantation of nitrogen and carbon broad ion beams. The patterned nano-templates are formed by 14 keV Nion-bombardment at grazing incident (70°) on Si. Subsequently, 5 keV Cions are implanted at the selective sites of the pyramidal nano-template by taking advantage of the self-masking effect.

Docking assisted mechanistic elucidation of bio conversion of hexavalent chromium by Serratia marcescens AJRR-22 that is effective yet long term sustainable in bio-geosphere.

Environmental accumulation of hexavalent chromium [Cr(VI)] in the food chain can induce detrimental effects on plants and animals, which calls for effective remediation strategies using biological entities. The bacterium isolated from an iron mine in Odisha, India, is identified asSerratia marcescensAJRR-22. This multi-metal tolerant strain is capable of bio-converting up to 350 mg/L Cr(VI) within 72 h of incubation.

Untying the regulatory roles of miRNAs in CuO-NPs stress response mechanism in maize: A genome-wide sRNA transcriptome analysis.

MicroRNAs (miRNAs), a group of tiny non-coding RNAs play pivotal role in plant responses to environmental stress. The present small RNA transcriptome study aims to untie the role of miRNAs in CuO-NPs stress adaptation in maize seedlings. Restricted seedling growth, enhanced ROS generation and higher membrane damage were recorded under CuO-NPs [<50 nm, 8 mM] treatment.

Exploring the Structural Importance of the C3=C4 Double Bond in Plant Alkaloids Harmine and Harmaline on Their Binding Interactions with Hemoglobin.

Harmine and harmaline are two structurally similar heterocyclic β-carboline plant alkaloids with various therapeutic properties, having a slight structural difference in the C3=C4 double bond. In the present study, we have reported the nature of the interaction between hemoglobin (Hb) with harmine and harmaline by employing several multispectroscopic, calorimetric, and molecular docking approaches. Fluorescence spectroscopic studies have shown stronger interaction of harmine with Hb compared to that of almost structurally similar harmaline.

Uncovering the Contrasting Binding Behavior of Plant Flavonoids Fisetin and Morin Having Subsidiary Hydroxyl Groups (-OH) with HRAS1 and HRAS2 i-Motif DNA Structures: Decoding the Structural Alterations and Positional Influences.

Research on the interactions of naturally existing flavonoids with various noncanonical DNA such as i-motif (IM) DNA structures is helpful in comprehending the molecular basis of binding mode as well as providing future direction for the application and invention of novel effective therapeutic drugs. IM DNA structures have been identified as prospective anticancer therapeutic targets, and flavonoids are smaller molecules with a variety of health-promoting attributes, including anticancer activities. The extensive investigation comprising a series of techniques reveals the contrasting mode of the binding behavior of fisetin and morin with various IM DNA structures.

Carbazole Integrated Tetrakis-(1 H-pyrrole-2-carbaldehyde): A Highly Selective Fluorescent Probe for HPO.

A new carbazole-coupled tetrakis-(1 H-pyrrole-2-carbaldehyde) anion receptor 1 has been designed and synthesized. Anion binding studies in organic media using fluorescence and UV-vis spectroscopy revealed that receptor 1 is capable of sensing HPO with high selectivity. Addition of HPO to THF solution of 1 resulted in the emergence of a new broad band at longer wavelength along with quenching of the original emission band forming a ratiometric response.

Fluorosensing of benzaldehydes by CuI-graphene: A spectroscopy, thermodynamics and docking supported phenomenon.

Benzaldehyde and 4-methyl benzaldehyde constitute a major part of the harmful volatile organic compounds (VOCs) found in the environment. Hence, rapid and selective detection of benzaldehyde derivatives are required to minimize the environmental degradation as well as the potential hazards on human health. In this study, the surface of the graphene nanoplatelets were functionalized with CuI nanoparticles for specific and selective detection of benzaldehyde derivatives by fluorescence spectroscopy.

Fluorescent nanodiamond for nanotheranostic applications.

The interest in application of nanodiamonds as nanotheranostics is increasing rapidly over recent years. The combination of properties, such as high refractive index, low toxicity, inertness, high carrier capacity and rich surface functionalities, as well as unique magneto-optical properties of the nitrogen-vacancy centre, renders fluorescent nanodiamonds superior to other nanomaterials as nanotheranostics. In this review, the current state of research on the applications of nanodiamonds as theranostics where they have been utilised in combination with both diagnostics/imaging and therapy simultaneously is discussed.

Nucleic acid extraction from complex biofluid using toothpick-actuated over-the-counter medical-grade cotton.

Nucleic acid amplification technique (NAAT)-assisted detection is the primary intervention for pathogen molecular diagnostics. However, NAATs such as quantitative real-time polymerase chain reaction (qPCR) require prior purification or extraction of target nucleic acid from the sample of interest since the latter often contains polymerase inhibitors. Similarly, genetic disease screening is also reliant on the successful extraction of pure patient genomic DNA from the clinical sample.

Limited-resource preparable chitosan magnetic particles for extracting amplification-ready nucleic acid from complex biofluids.

Extraction and concentration of pure nucleic acid from complex biofluids are the prerequisite for nucleic acid amplification test (NAAT) applications in pathogen detection, biowarfare prevention, and genetic diseases. However, conventional spin-column mediated nucleic acid extraction is constricted by the requirement for costly power-intensive centralized lab infrastructure, making it unsuitable for limited-resource settings. Significant progress in lab-on-a-chip devices or cartridges (, Cepheid GeneXpert®) that integrate nucleic acid extraction and amplification has been made, but these approaches either require additional equipment or are costly.

Correction: Inverse heavy-atom effect in near infrared photoluminescent gold nanoclusters.

Correction for 'Inverse heavy-atom effect in near infrared photoluminescent gold nanoclusters' by Goutam Pramanik et al., Nanoscale, 2021, DOI: 10.1039/d1nr02440j.

Inverse heavy-atom effect in near infrared photoluminescent gold nanoclusters.

Fluorophores functionalized with heavy elements show enhanced intersystem crossing due to increased spin-orbit coupling, which in turn shortens the fluorescence decay lifetime (τPL). This phenomenon is known as the heavy-atom effect (HAE). Here, we report the observation of increased τPL upon functionalisation of near-infrared photoluminescent gold nanoclusters with iodine.

Toward Quantitative Bio-sensing with Nitrogen-Vacancy Center in Diamond.

The long-dreamed-of capability of monitoring the molecular machinery in living systems has not been realized yet, mainly due to the technical limitations of current sensing technologies. However, recently emerging quantum sensors are showing great promise for molecular detection and imaging. One of such sensing qubits is the nitrogen-vacancy (NV) center, a photoluminescent impurity in a diamond lattice with unique room-temperature optical and spin properties.

Reversible photo- and thermal-effects on the luminescence of gold nanoclusters: implications for nanothermometry.

The optical properties of colloidal near-infrared (NIR) emitting gold nanoclusters (AuNCs) are thoroughly investigated at variable temperatures and excitation powers. Both absorption and photoluminescence (PL) excitation spectra reveal optical transitions expected from literature models of thiolated AuNCs - with the exception of the lowest energy transition which has the form of a featureless absorption tail partially overlapping with the PL band. The absorption cross section is determined via the PL saturation and PL modulation techniques to be in the range of 2-3 × 10 cm for excitation at 405 nm (relatively large value for such small clusters) and decreases ∼20 times toward 633 nm.

Synthesis of Near-Infrared Emitting Gold Nanoclusters for Biological Applications.

Over the past decade, fluorescent gold nanoclusters (AuNCs) have witnessed growing popularity in biological applications and enormous efforts have been devoted to their development. In this protocol, a recently developed, facile method for preparation of water soluble, biocompatible, and colloidally stable near-infrared emitting AuNCs have been described in detail. This room-temperature, bottom-up chemical synthesis provides easily functionalizable AuNCs capped with thioctic acid and thiol-modified polyethylene glycol in aqueous solution.

Gold nanoclusters with bright near-infrared photoluminescence.

The increase in nonradiative pathways with decreasing emission energy reduces the luminescence quantum yield (QY) of near-infrared photoluminescent (NIR PL) metal nanoclusters. Efficient surface ligand chemistry can significantly improve the luminescence QY of NIR PL metal nanoclusters. In contrast to the widely reported but modestly effective thiolate ligand-to-metal core charge transfer, we show that metal-to-ligand charge transfer (MLCT) can be used to greatly enhance the luminescence QY of NIR PL gold nanoclusters (AuNCs).

NIR-emitting and photo-thermal active nanogold as mitochondria-specific probes.

We report a bioinspired multifunctional albumin derived polypeptide coating comprising grafted poly(ethylene oxide) chains, multiple copies of the HIV TAT derived peptide enabling cellular uptake as well as mitochondria targeting triphenyl-phosphonium (TPP) groups. Exploring these polypeptide copolymers for passivating gold nanoparticles (Au NPs) yielded (i) NIR-emitting markers in confocal microscopy and (ii) photo-thermal active probes in optical coherence microscopy. We demonstrate the great potential of such multifunctional protein-derived biopolymer coatings for efficiently directing Au NP into cells and to subcellular targets to ultimately probe important cellular processes such as mitochondria dynamics and vitality inside living cells.

Stealth Amphiphiles: Self-Assembly of Polyhedral Boron Clusters.

This is the first experimental evidence that both self-assembly and surface activity are common features of all water-soluble boron cluster compounds. The solution behavior of anionic polyhedral boranes (sodium decaborate, sodium dodecaborate, and sodium mercaptododecaborate), carboranes (potassium 1-carba-dodecaborate), and metallacarboranes {sodium [cobalt bis(1,2-dicarbollide)]} was extensively studied, and it is evident that all the anionic boron clusters form multimolecular aggregates in water. However, the mechanism of aggregation is dependent on size and polarity.

DNA-Based Self-Assembly of Fluorescent Nanodiamonds.

As a step toward deterministic and scalable assembly of ordered spin arrays we here demonstrate a bottom-up approach to position fluorescent nanodiamonds (NDs) with nanometer precision on DNA origami structures. We have realized a reliable and broadly applicable surface modification strategy that results in DNA-functionalized and perfectly dispersed NDs that were then self-assembled in predefined geometries. With optical studies we show that the fluorescence properties of the nitrogen-vacancy color centers in NDs are preserved during surface modification and DNA assembly.

Self-assembly of high molecular weight polypeptide copolymers studied via diffusion limited aggregation.

The assembly of high molecular weight polypeptides into complex architectures exhibiting structural complexity ranging from the nano- to the mesoscale is of fundamental importance for various protein-related diseases but also hold great promise for various nano- and biotechnological applications. Here, the aggregation of partially unfolded high molecular weight polypeptides into multiscale fractal structures is investigated by means of diffusion limited aggregation and atomic force microscopy. The zeta potential, the hydrodynamic radius, and the obtained fractal morphologies were correlated with the conformation of the polypeptide backbones as obtained from circular dichroism measurements.