Surface Functionalization of Gold Nanorods Improves Nanostructure Assemblies on Amyloid Fibril Scaffolds.

A hybrid scaffold containing gold nanorods and lysozyme amyloid fibrils has been fabricated, and the effect of surface modification on improving nanostructure assembly on the biological template has been investigated. The nanohybrid system was characterized by monitoring surface plasmon resonance bands, dynamic light scattering spectroscopy, Thioflavin-T assay, and transmission electron microscopy. Surface of gold nanorods (GNRs) was modified with polystyrene sulfonate (PSS), and possible difference in assembly of the pristine and modified nanostructures was compared upon interaction with amyloid fibrils.

PDMS Nano-Modified Scaffolds for Improvement of Stem Cells Proliferation and Differentiation in Microfluidic Platform.

Microfluidics cell-based assays require strong cell-substrate adhesion for cell viability, proliferation, and differentiation. The intrinsic properties of PDMS, a commonly used polymer in microfluidics systems, regarding cell-substrate interactions have limited its application for microfluidics cell-based assays. Various attempts by previous researchers, such as chemical modification, plasma-treatment, and protein-coating of PDMS revealed some improvements.

Synergistic Antibacterial Activity and Wound Healing Properties of Selenium-Chitosan-Mupirocin Nanohybrid System: An in Vivo Study on Rat Diabetic Staphylococcus aureus Wound Infection Model.

The current study aimed to formulate Selenium-Chitosan-Mupirocin (M-SeNPs-CCH) complex. The nanohybrid system was prepared using chitosan-cetyltrimethylammonium bromide (CTAB)-based hydrogel (CCH) that entrapped mupirocin (M) and selenium nanoparticles (SeNPs). The in vitro studies were performed by evaluation of the antibacterial activity and toxicity on L929 mouse fibroblast cell line.

Synthesis and Characterization of Selenium Nanoparticles-Lysozyme Nanohybrid System with Synergistic Antibacterial Properties.

In the light of promising potency of selenium nanoparticles in biomedical applications, this is the first study to report the synergistic antibacterial activity of these nanoparticles and lysozyme. The nanohybrid system was prepared with various concentrations of each component. Resistance of Escherichia coli and Staphylococcus aureus was compared in the presence of individual Nano and Bio counterparts as well as the nanohybrid system.

A sensitive gold-nanorods-based nanobiosensor for specific detection of Campylobacter jejuni and Campylobacter coli.

Background: Campylobacteriosis is a zoonotic infectious disease that can be mostly undiagnosed or unreported due to fastidious Campylobacter species. The aim of this study was to develop a simple, sensitive, and quick assay for the detection of Campylobacter spp. and taking advantage of the great sensitivity of gold nanorods (GNRs) to trace changes in the local environment and interparticle distance.

RGD-HK Peptide-Functionalized Gold Nanorods Emerge as Targeted Biocompatible Nanocarriers for Biomedical Applications.

Gold nanorods (GNRs) have been nominated as a promising candidate for a variety of biological applications; however, the cationic surfactant layer that surrounds a nanostructure places limits on its biological applicability. Herein, CTAB-GNRs were functionalized via a ligand exchange method using a (C(HK)4-mini PEG-RGD)-peptide to target the overexpressed αvβ3 integrin in cancerous cells, increase the biocompatibility, and gain the ability of gene/drug delivery, simultaneously. To confirm an acceptable functionalization, UV-Visible, FTIR, and Raman spectroscopy, zeta potential, and transmission electron microscopy of nanostructures were done.

In Vitro Cytotoxicity of Folate-Silica-Gold Nanorods on Mouse Acute Lymphoblastic Leukemia and Spermatogonial Cells.

Objective: The purpose of this study was to evaluate in vitro cytotoxicity of gold nanorods (GNRs) on the viability of spermatogonial cells (SSCs) and mouse acute lymphoblastic leukemia cells (EL4s).

Materials And Methods: In this experimental study, SSCs were isolated from the neonate mice, following enzymatic digestion and differential plating. GNRs were synthesized, then modified by silica and finally conjugated with folic acid to form F-Si-GNRs.

Versatile nano-platform for tailored immuno-magnetic carriers.

Custom immuno-magnetic devices are desirable tools for biomedical and biotechnological applications. Herein, surface active maghemite nanoparticles (SAMNs) are proposed as a versatile platform for developing tailored immuno-magnetic nano-carriers by simple wet reactions. Two examples for conjugating native and biotinylated antibodies were presented along with their successful applications in the recognition of specific foodborne pathogens.

Assembly of Gold Nanorods on HSA Amyloid Fibrils to Develop a Conductive Nanoscaffold for Potential Biomedical and Biosensing Applications.

Today, Gold Nanorods have promised variety of applications in conjugation with biomolecules of interest. Discovery of functional amyloids has also been highlighted with possible use in designing high performance materials. To exploit dual properties of both Nano and Bio counterparts in new functional materials, this effort has focused on synthesis of a potential hybrid system of Gold nanorods (GNRs) and HSA amyloid fibrils to develop a conductive nanoscaffold.

Synthesis and Characterization of a Nano-Polyplex system of GNRs-PDMAEA-pDNA: An Inert Self-Catalyzed Degradable Carrier for Facile Gene Delivery.

Engineering molecules at nano-scale is a promising approach in targeting and curing diseases. In this research, fabricated new hybrid system called nano-polyplex represents an example of the molecular engineering at nano-scale. Polymer of PDMAEAs with four different molecular weights were synthesized using the RAFT method, attached onto the gold nano-rod surface, which modified and produced a safe novel system with an average size less than 100 nm.

Improving the stability of chondroitinase ABC I via interaction with gold nanorods.

Chondroitinase ABC I (cABC I) cleaves glycosaminoglycan chains which are responsible for most of the inhibition of axon regrowth in spinal cord injury. The application of chondroitinase ABC I (cABC I) in damaged nervous tissue is found to prune glycosaminoglycan chains of proteoglycans and facilitate axon regeneration. However, a limiting factor for such application is the enzyme's instability.

Expression, purification, refolding and in vitro recovery of active full length recombinant human gelatinase MMP-9 in Escherichia coli.

Human gelatinase (MMP-9) is a member of matrix metalloproteinases family (MMPs), which has been associated with malignant tumor progression and metastasis by matrix degradation. Herein, active full length recombinant human MMP-9 (amino acid residues 107-707) has been expressed in the form of inclusion bodies in Escherichia coli BL21, using pET21a vector. Solubilization of inclusion bodies was carried out in Tris-HCl buffer with 6 M urea, and refolding was performed using dilution and urea gradient methods.

In Silico Analysis of the cadF Gene and Development of a Duplex Polymerase Chain Reaction for Species-Specific Identification of Campylobacter jejuni and Campylobacter coli.

Background: Campylobacteriosis is a zoonotic infectious disease caused by Campylobacter jejuni and C. coli. The cadF gene is considered as a genus-specific gene while other genes are mainly used for discrimination at the species level.

Development of a label-free SPR sensor for detection of matrixmetalloproteinase-9 by antibody immobilization on carboxymethyldextran chip.

Surface plasmon resonance (SPR) immunosensor has been widely utilized for monitoring antigen-antibody interactions. The sensor measures changes of refractive index upon binding of analyte molecules to specific ligand immobilized on the sensor chip. This effort reports development of SPR immunosensor for real-time and label-free detection of recombinant human matrix metalloproteinases-9 (MMP-9), which has been associated with malignant tumor progression and metastasis by matrix degradation.

Heat induced aggregation of gold nanorods for rapid visual detection of lysozyme.

Gold nanorods have been nominated as propitious candidates for nanobiodiagnostic applications. Herein, a technique has been introduced for rapid visual detection of lysozyme, as its high level of excretion in biological fluids is a characteristic sign of leukemia and kidney disorders. Gold nanorods were biofunctionalized with lysozyme aptamer and characterized with UV-Visible and FTIR spectroscopy, zeta potential analyzer and transmission electron microscopy.

Spectral properties and thermal stability of AS1411 G-quadruplex.

G-quadruplexes are supramolecular structures of G-rich nucleic acid, formed by non-canonical base pairing in the presence of specific environmental inducers. These structures have been vastly considered in diagnostic and therapeutic applications. However, detailed information on structure, optical properties and thermal stability of G-quadruplex potent oligonucleotides is scarce.

Structure-function analysis of a new bacterial lipase: effect of local structure reorganization on lipase activity.

Like many other bacterial lipases Pseudomonas aeruginosa lipase has a very strong structure-function relationship. Herein, the effect of structural compactness of lipase has been investigated on its activity. P.

Functional motions of Candida antarctica lipase B: a survey through open-close conformations.

Candida antarctica lipase B (CALB) belongs to psychrophilic lipases which hydrolyze carboxyl ester bonds at low temperatures. There have been some features reported about cold-activity of the enzyme through experimental methods, whereas there is no detailed information on its mechanism of action at molecular level. Herein, a comparative molecular dynamics simulation and essential dynamics analysis have been carried out at three temperatures (5, 35 and 50 °C) to trace the dominant factors in the psychrophilic properties of CALB under cold condition.

Conformation and activity of lysozyme on binding to two types of gold nanorods: a comparative study.

The unique morphology of anisotropic rod-shaped gold nanostructures has offered new prospects for biomedical and biosensing applications. This study investigates the interaction of two types of rod-shaped nanostructures, gold nanorods and gold nanorices with lysozyme as a model protein, comparing the probable structural, activity and kinetic stability alterations. Circular dichroism spectropolarimeter revealed that lysozyme retains high fraction of its native conformation in the presence of both nanostructures, with a slight increase in the helical and beta content.

Interaction of lysozyme with gold nanorods: conformation and activity investigations.

Gold nanorods, with their unique morphology and optical properties have offered new prospects for biomedical and biosensing applications. Herein, the interaction between gold nanorods and a model protein has been monitored using spectroscopic techniques. The enzyme retains high fraction of its native structure with a slight increase in the helical content at the expense of β-turns.

Differential scanning calorimetry techniques: applications in biology and nanoscience.

This paper reviews the best-known differential scanning calorimetries (DSCs), such as conventional DSC, microelectromechanical systems-DSC, infrared-heated DSC, modulated-temperature DSC, gas flow-modulated DSC, parallel-nano DSC, pressure perturbation calorimetry, self-reference DSC, and high-performance DSC. Also, we describe here the most extensive applications of DSC in biology and nanoscience.