Ultrasensitive NIR fluorometric assay for inorganic pyrophosphatase detection via Cu-PPi interaction using bimetallic Au-Ag nanoclusters.

Background: Inorganic pyrophosphatase (PPase) is key enzyme playing a key role in biochemical transformations such as biosynthesis of DNA and RNA, bone formation, metabolic pathways associated with lipid, carbohydrate and phosphorous. It has been reported that lung adenocarcinomas, colorectal cancer, and hyperthyroidism disorders can result from abnormal level of PPase. Therefore, it is of notable significance to develop simple and effective real time assay for PPase enzyme activity monitoring for screening of many metabolic pathways as well as for early disease diagnosis.

Chitosan functionalized doxorubicin loaded poly(methacrylamide) based copolymeric nanoparticles for enhanced cellular internalization and in vitro anticancer evaluation.

Doxorubicin (Dox), a chemotherapeutic agent, encounters challenges such as a short half-life, dose-dependent toxicity, and low solubility. In this context, the present study involved the fabrication of N-(2-hydroxypropyl)methacrylamide (HPMA) and N-(3-aminopropyl)methacrylamide (APMA) bearing P(HPMA-s-APMA) copolymeric nanoparticles (P(HPMA-s-APMA) NPs) and their investigation for efficient delivery of Dox. Furthermore, the synthesized nanoparticles (NPs) were coated with chitosan (Cht) to generate positively charged nanoformulations.

Exploring the potential of radiolabeled duramycin as an infection imaging probe.

The continuous pursuit of designing an ideal infection imaging agent is a crucial and ongoing endeavor in the field of biomedical research. Duramycin, an antimicrobial peptide exerts its antimicrobial action on bacteria by specific recognition of phosphatidylethanolamine (PE) moiety present on most bacterial membranes, particularly Escherichia coli (E. coli).

A liposomal radionanoformulation for targeted drug delivery and real time monitoring by radionuclide imaging for HER2 overexpressing cancers.

Liposomal formulations carrying chemotherapeutic drugs have demonstrated great potential as effective drug delivery systems. Smart nanoformulations decorated with targeting agents and probes are desired for site specific delivery of drugs and real time monitoring. In this study, we aimed to develop liposomal formulation loaded with doxorubicin and tagged with trastuzumab antibody (Ab) for targeting human epidermal growth factor receptor 2 (HER2) positive tumors.

Investigating the Role of Classical Ayurveda-Based Incineration Process on the Synthesis of Zinc Oxide Based Jasada Bhasma Nanoparticles and Zn Bioavailability.

Jasada bhasma (JB) is a zinc oxide-based Indian traditional Ayurveda-based herbo-metallic nanoparticle used for the treatment of zinc (Zn) deficiency and autoimmune and inflammatory disorders. JB is made by following the Ayurveda-based guidelines using zinc oxide (ZnO) as a raw material and going through 17 cycles of the high-temperature incineration and trituration process known as "Ma̅raṇa" in the presence of herbal decoctions prepared from the leaves of and gel. These cycles improve the purity of the parent material and transform its physicochemical properties, converting it into nanoparticles.

Femtomolar detection of staphylococcal enterotoxin 'B' using a fluorescent quantum dot based hybrid Apta-immunosensor.

Food poisoning is a gastrointestinal illness caused by food-borne enterotoxin produced by the bacterium Staphylococcus aureus. The effective dose of Staphylococcal enterotoxin 'B' (SEB) is estimated to be 0.4 ng/kg of body weight, whereas the 50 % lethal dose is found to be 20 ng/kg of body weight for humans exposed by the inhalation route.

Targeting bacterial biofilms using vancomycin and multivalent cell-penetrating peptide labeled quantum dots.

Bacterial biofilms are highly resilient microbial musters that are difficult to eradicate, driving the development of novel therapeutic strategies. The current study aims to investigate the therapeutic efficacy of cell-penetrating peptide-based targeted delivery of vancomycin functionalized quantum dots in eradicating biofilm formation in gram-positive and gram-negative bacterial strains. The conjugate was characterized using fluorimetry, UV-visible spectroscopy, gel electrophoresis, and zeta potential.

Ultrasensitive aptasensor for arsenic detection using quantum dots and guanylated Poly(methacrylamide).

The present study demonstrate the first time usage of poly (HPMA-s-GPMA) copolymer for the fabrication of three-component based aptasensor for simple, selective, rapid and label free detection of arsenite (As). For this purpose, guanidinium bearing poly (HPMA-s-GPMA) copolymer and MPA-CdTe@CdS quantum dots (QDs) was employed in conjunction with As specific aptamer. This protocol utilizes the quenching phenomena displayed by QDs due to the competitive binding of As ions and cationic copolymer to the aptamer.

Targeting Non-coding RNA for Glioblastoma Therapy: The Challenge of Overcomes the Blood-Brain Barrier.

Glioblastoma (GBM) is the most malignant form of all primary brain tumors, and it is responsible for around 200,000 deaths each year worldwide. The standard therapy for GBM treatment includes surgical resection followed by temozolomide-based chemotherapy and/or radiotherapy. With this treatment, the median survival rate of GBM patients is only 15 months after its initial diagnosis.

Reduced RBPMS Levels Promote Cell Proliferation and Decrease Cisplatin Sensitivity in Ovarian Cancer Cells.

Worldwide, the number of cancer-related deaths continues to increase due to the ability of cancer cells to become chemotherapy-resistant and metastasize. For women with ovarian cancer, a staggering 70% will become resistant to the front-line therapy, cisplatin. Although many mechanisms of cisplatin resistance have been proposed, the key mechanisms of such resistance remain elusive.

Iron Chelator Transmetalative Approach to Inhibit Human Ribonucleotide Reductase.

Efforts directed at curtailing the bioavailability of intracellular iron could lead to the development of broad-spectrum anticancer drugs given the metal's role in cancer proliferation and metastasis. Human ribonucleotide reductase (RNR), the key enzyme responsible for synthesizing the building blocks of DNA replication and repair, depends on Fe binding at its R2 subunit to activate the catalytic R1 subunit. This work explores an intracellular iron chelator transmetalative approach to inhibit RNR using the titanium(IV) chemical transferrin mimetic (cTfm) compounds Ti(HBED) and Ti(Deferasirox).

Sensing platform for pico-molar level detection of ethyl parathion using Au-Ag nanoclusters based enzymatic strategy.

This work demonstrates a simple, cost effective and ultrasensitive detection of ethyl parathion, an organophosphorus (OPs) pesticide, using enzyme based fluorometric sensing strategy by employing bimetallic BSA@AuAg nanoclusters (NC). The sensing assay is based on the "quenched off" state of bimetallic NC with the addition of Cu ions that can be "switched on" due to generation of thiocholine (TCh), a catalytic product of enzymatic reaction of acetylthiocholine (ATCh) using acetylcholinesterase (AChE) enzyme. The generated TCh preferably seize Cu ions from BSA@AuAg NC-Cu ensemble and recovered the fluorescence of BSA@AuAg NC.

Interplay of Self-Assembling Aromatic Amino Acids and Functionalized Gold Nanoparticles Generating Supramolecular Structures.

In the recent years, protein metabolite-based self-assembled supramolecular structures have been linked to various pathological disorders. The self-assembly of protein over nanoparticle surfaces can lead to the formation of corona aggregates that have gained much attention owing to biomedical healthcare relevance. However, limited studies are available at the interface of amyloid formation and nanoparticle surfaces.

Quantification of adsorbed and dangling citrate ions on gold nanoparticle surface using thermogravimetric analysis.

A novel approach involving thermo-gravimetricanalysis (TGA) for the quantification of citrate ions present on the surface of gold nanoparticles has been reported. TGA study was carried out on AuNPs in response to parameters such as concentration of tri-sodium citrate and pH of gold nanoparticles depicting that the number of citrate ion present on gold nanoparticles is highly pH dependent. In general, the citrate ions were observed to be higher in alkaline conditions contradicting earlier beliefs.

Phenylalanine dimer assembly structure as the basic building block of an amyloid like photoluminescent nanofibril network.

A phenylalanine dimer assembly (Phe-DA) is reported as a basic constituent of a light emitting β-amyloid type nanofibril network. The size and composition of the Phe-DA structure were characterized using various theoretical and experimental techniques. Further, the mechanism involved in the phenylalanine self-assembly process from Phe-DA to the nanofibril network was studied using optical spectroscopy and small angle X-ray scattering (SAXS).

Peptide- and Drug-Functionalized Fluorescent Quantum Dots for Enhanced Cell Internalization and Bacterial Debilitation.

This report illustrates a strategy for designing a nanoconjugate derived vector that efficiently delivers antimicrobial drug directly into bacterial cells. The nanoconjugate comprises of negatively charged CDTe@CdS quantum dots (QDs) with its surface functionalized using cationic BP-100 (KKLFKKILKYL-amide), a known cell-penetrating peptide (CPP), via electrostatic approach. The interactions between QD and CPP in QD-functionalized CPPs (QD-CPP) have been well analyzed using fluorescence spectroscopy, gel electrophoresis, and ζ-potential analysis.

Optical pico-biosensing of lead using plasmonic gold nanoparticles and a cationic peptide-based aptasensor.

A novel biosensor for the rapid detection of lead ions employing the optical properties of AuNPs, a lead-specific aptamer and a cationic peptide has been demonstrated. The limit of detection of the biosensor was 98.7 pM, the lowest so far obtained using colorimetry.

Enhanced and selective adsorption of cationic dyes using novel biocompatible self-assembled peptide fibrils.

Herein, bio-compatible self-assembled peptide fibrils have been developed for adsorption of organic pollutants for water remediation with high adsorption capacity. The different morphological motifs of self-assembled dipeptide Fmoc-FW-OMe was formulated using solvent modulation which was characterized by optical microscopy, SEM, XRD and FT-IR. Specifically, the fibril structures were used for selective adsorption of cationic dyes from aqueous solutions with exceptional adsorption capacity noted for crystal violet (625 mg/g).

Fueling a Hot Debate on the Application of TiO Nanoparticles in Sunscreen.

Titanium is one of the most abundant elements in the earth's crust and while there are many examples of its bioactive properties and use by living organisms, there are few studies that have probed its biochemical reactivity in physiological environments. In the cosmetic industry, TiO nanoparticles are widely used. They are often incorporated in sunscreens as inorganic physical sun blockers, taking advantage of their semiconducting property, which facilitates absorbing ultraviolet (UV) radiation.

Effective Topical Delivery of H-AgNPs for Eradication of Klebsiella pneumoniae-Induced Burn Wound Infection.

The aim of the present study was to explore the therapeutic efficacy of microemulsion-based delivery of histidine-capped silver nanoparticles in eradicating Klebsiella pneumoniae-induced burn wound infection. The developed microemulsion was characterized on the basis of differential light scattering, phase separation, refractive index, and specific conductance. Emulgel was prepared and characterized on the basis of thixotropy, texture, differential scanning calorimetry, and release kinetics.

Controlling the transverse proton relaxivity of magnetic graphene oxide.

The engineering of materials with controlled magnetic properties by means other than a magnetic field is of great interest in nanotechnology. In this study, we report engineered magnetic graphene oxide (MGO) in the nanocomposite form of iron oxide nanoparticles (IO)-graphene oxide (GO) with tunable core magnetism and magnetic resonance transverse relaxivity (r). These tunable properties are obtained by varying the IO content on GO.

Insights into cell penetrating peptide conjugated gold nanoparticles for internalization into bacterial cells.

Gold nanoparticles (AuNPs) functionalized with different biomolecules find extensive application in therapy, clinical diagnosis and biomedical imaging. Herein, two derivatives of TAT peptide with sequences YGRKKRRQRRR and YGRKKRRQRRR-(β-ala)-Cys-amide were conjugated with tannic acid capped gold nanoparticles which acted as a carrier for cell penetrating peptides (CPPs) into the bacterial cells. The interaction of YGRKKRRQRRR peptide with AuNPs was non-covalent in nature whereas YGRKKRRQRRR-(β-ala)-Cys-amide interacted covalently with the AuNPs due to presence of thiol group in cysteine which bind strongly to gold nanoparticles surface.

Inducing cell death in vitro in cancer cells by targeted delivery of cytochrome c via a transferrin conjugate.

One of the major drawbacks of many of the currently used cancer drugs are off-target effects. Targeted delivery is one method to minimize such unwanted and detrimental events. To actively target lung cancer cells, we have developed a conjugate of the apoptosis inducing protein cytochrome c with transferrin because the transferrin receptor is overexpressed by many rapidly dividing cancer cells.

A Facile Approach for Synthesis and Intracellular Delivery of Size Tunable Cationic Peptide Functionalized Gold Nanohybrids in Cancer Cells.

Peptide-based drug delivery systems have become a mainstay in the contemporary medicinal field, resulting in the design and development of better pharmaceutical formulations. However, most of the available reports employ tedious multiple reaction steps for the conjugation of bioactive cationic peptides with drug delivery vehicles. To overcome these limitations, the present work describes a one-step approach for facile and time efficient synthesis of highly cationic cell penetrating peptide functionalized gold nanoparticles and their intracellular delivery.

A supersensitive silver nanoprobe based aptasensor for low cost detection of malathion residues in water and food samples.

In the present study, we report a highly sensitive, rapid and low cost colorimetric monitoring of malathion (an organophosphate insecticide) employing a basic hexapeptide, malathion specific aptamer (oligonucleotide) and silver nanoparticles (AgNPs) as a nanoprobe. AgNPs are made to interact with the aptamer and peptide to give different optical responses depending upon the presence or absence of malathion. The nanoparticles remain yellow in color in the absence of malathion owing to the binding of aptamer with peptide which otherwise tends to aggregate the particles because of charge based interactions.