Nanoscale Advances

Graphene oxide (GO), an oxidized derivative of graphene, has found application in cryo-electron microscopy (cryo-EM) as a hydrophilic and transparent solid support on which to adsorb biological macromolecules, providing an alternative to traditional aqueous films. Current applications generally adsorb the macromolecule directly onto unmodified GO or modify the GO surface with polyethylene glycol-amine reagents. This nucleophilic amine reaction must be performed in an aprotic organic solvent and therefore precludes the use of biological samples such as nucleic acids and peptides. The utility of GO could be expanded by the ability to covalently modify its surface with biochemical affinity reagents such as small- molecule metabolites, peptides, or nucleic acids, in aqueous buffer at neutral pH. Presented here is a chemical procedure that converts all oxygen functionalities of GO to highly amine- reactive glycidyl epoxide groups, achieved without the need of specialized laboratory equipment. We show that single sheets of glycidyl epoxide-modified GO react on the EM grid with primary amines at micromolar concentrations in minutes at room temperature in aqueous buffer. Given the ease of derivatizing biochemical reagents with amines, the chemistry described here will enable imaging of macromolecules immobilized on GO through specific biochemical and biologically relevant binding interactions.

Stealth properties of nanoparticles are essential for their proper functionalization in biological systems. To address limitations of polyethylene glycol (PEG), commonly used for this purpose, we explore the potential of polysarcosine (PSar) as stealth shell in peptide-functionalized dye-loaded polymeric NPs. To this end, polymeric NPs loaded with rhodamine dye with bulky hydrophobic counterion and bearing azide groups at their surface were grafted with PSar of different lengths ranging from 5 to 19 sarcosine units using strain-promoted cycloaddition. The obtained peptide-functionalized NPs showed remarkable colloidal stability in physiological media. The length of PSar showed a profound effect on stealth properties of NPs. The increase in the length of grafted PSar lead to decrease in the negative surface charge to nearly neutral values and decreased protein adsorption according to fluorescence correlation spectroscopy. The NPs with 19mer PSar showed minimal interactions with live cells and glass surfaces in a complex biological medium, in contrast to its shorter PSar analogues. These stealth NPs bearing HaloTag ligand enabled specific targeting of proteins at the cell surface. The obtained results show that a relatively short PSar peptide can be used for achieving stealth properties in polymeric NPs, allowing specific protein targeting with minimized non-specific interactions. The obtained PSar-functionalized polymeric NPs appear as a powerful platform for the fabrication of the next generation of nanomaterials for bioimaging and biosensing applications.

Recent outbreak of novel coronavirus (COVID-19) caused around 7 million deaths people worldwide and still afflicting on the global health, economy and social setup. Timely detection and diagnosis are crucial steps to reduce the spread and prevention of any pandemic. Different types of diagnosis methos has been used. In last decade nanomaterials and metal organic frameworks (MOFs) based biosensors has been developed to detect the other viruses. We have designed the Zeolitic imidazolate framework-8 (ZIF-8) based biosensor to detect the COVID-19. ZIF-8 work as fluorescence quenching and re-emergence platform to detect the COVID-19 RNA sequences. ZIF-8 platform is highly sensitive which can distinguish the highly conserved single strand RNA and with 200 pM concentrations. It can distinguish down to the single mismatch nucleotide in RNA sequences.

Multiple Sclerosis (MS) is a chronic, inflammatory disease of the central nervous system. Despite the pharmacological arsenal approved for MS, there are treatment-reluctant patients for whom cell therapy appears as the only therapeutic alternative. Myeloid-derived suppressor cells (MDSCs) are immature cells of the innate immune response able to immunosuppress T lymphocytes and to promote oligodendroglial differentiation in experimental autoimmune encephalomyelitis (EAE), a preclinical model for MS. Culture devices need to be designed so that MDSCs maintain a state of immaturity and immunosuppressive function similar to that exerted in the donor organism. Graphene oxide (GO) has been described as a biocompatible material with the capacity to biologically modulate different cell types, including immune cells. In the present work, we show how MDSCs isolated from immune organs of EAE mice maintain an immature phenotype and highly immunosuppressive activity on T lymphocytes after being cultured on 2D reduced GO films (rGO200) compared to those grown on glass. This activity is depleted when MDSCs are exposed to slightly rougher and more oxidized GO substrates (rGO90). The greater reduction in cell size of cells exposed to rGO90 compared to rGO200 is associated with the activation of apoptosis processes. Taken together, the exposure of MDSCs to GO substrates with different redox state and roughness appears as a good strategy to control MDSC activity in vitro. This versatility of GO nanomaterials and the impact of their physico-chemical properties in immunomodulation open the door to its possible selective therapeutic use for pathologies where MDSCs need to be enhanced or inhibited.

Despite the worldwide success of mRNA-LNP Covid-19 vaccines, the nanoscale structure of these formulations is still poorly understood. To fill this gap, we used a combination of atomic force microscopy (AFM), dynamic light scattering (DLS), transmission electron microscopy (TEM), cryogenic transmission electron microscopy (cryo-TEM) and the determination of LNP pH gradient to analyze the nanoparticles (NPs) in BNT162b2 (Comirnaty), comparing it with the well characterized pegylated liposomal doxorubicin (Doxil). Comirnaty NPs had similar size to Doxil, however, unlike Doxil liposomes, wherein the stable ammonium and pH gradient enables accumulation of 14C-methylamine in the intraliposomal aqueous phase, Comirnaty LNPs lack such pH gradient in spite of the fact that the pH 4, at which LNPs are prepared, is raised to pH 7.2 after loading of the mRNA. Mechanical manipulation of Comirnaty NPs with AFM revealed soft, compliant structures. The sawtooth-like force transitions seen during cantilever retraction implies that molecular strands, corresponding to mRNA, can be pulled out of NPs, and the process is accompanied by stepwise rupture of mRNA-lipid bonds. Unlike Doxil, cryo-TEM of Comirnaty NPs revealed a granular, solid core enclosed by mono- and bilayers. Negative staining TEM shows 2-5 nm electron-dense spots in the liposoms interior that are aligned into strings, semicircles, or labyrinth-like networks, which may imply crosslink-stabilized supercoils. The neutral intra-LNP core questions the dominance of ionic interactions holding together this scaffold, raising the alternative possibility of hydrogen bonding between the mRNA and the lipids. Such interaction, described previously for another mRNA/lipid complex, is consistent with the steric structure of ionizable lipid in Comirnaty, ALC-0315, displaying free =O and -OH groups. It is hypothesized that the latter groups can get into steric positions that enable hydrogen bonding with the nitrogenous bases in the mRNA. These newly recognized structural features of mRNA-LNP may be important for the vaccines efficacy.

Ovarian cancer immunotherapy remains a challenge based on the "cold" tumor microenvironment. Herein we present a rational design to create immunogenic nanoparticles as a multi-agent platform that promotes immune response in a mouse model of ovarian cancer. The hybrid lipid-silica nanosystem is capable of co-loading four types of cargo molecules including a model antigen, nucleic acid-based adjuvant Cytosine-p-linked to Guanine (CpG, TLR3/9 agonist), lipid-based adjuvant (MPLA, TLR4 agonist) integrated into the lipid coat, and optionally a small molecule drug, such as the chemotherapeutic agent oxaliplatin, a well-established treatment for ovarian cancer. The optimization of the nanoplatform in terms of lipid composition, functionalized silica dendritic core formation, and final charge, as well as their compatibility with the complex loading profile highlights an opportunity for enhanced survival of mice with advanced ovarian cancer compared to monotherapy. Furthermore, intraperitoneal administration led to preferential accumulation within tumor-burdened tissues with selective accumulation in myeloid cells. High myeloid cell cytotoxicity negated the benefits of oxaliplatin. The inclusion of CpG in the nanoparticle formulation enhanced the survival of mice with ovarian cancer. To interpret these outcomes and guide future design, we also developed a mathematical model of nanoparticle-driven immune activation, which quantified treatment efficacy and identified key parameters governing tumor response. The presented hybrid nanoparticle i tunable, enabling delivery of alternative molecules therefore, thereby highlighting a promising platform for the treatment of peritoneal cancers. Graphical TOC O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=69 SRC="FIGDIR/small/657862v1_ufig1.gif" ALT="Figure 1000"> View larger version (26K): org.highwire.dtl.DTLVardef@1434599org.highwire.dtl.DTLVardef@18e79e6org.highwire.dtl.DTLVardef@e5285corg.highwire.dtl.DTLVardef@bcc604_HPS_FORMAT_FIGEXP M_FIG C_FIG

Nanotechnology plays a crucial role in vaccine development. It allows the design of functional nanoparticles (NPs) that can act both as antigen carriers and as adjuvants to enhance the immune response. The present study aims to evaluate complex coacervate-like NPs composed of poly(allylamine hydrochloride) (PAH) and tripolyphosphate (TPP) as a safe vehicle and adjuvant for systemic vaccines. We investigated the activation of different antigen-presenting cells (APCs) with NPs and their adjuvanticity in Balbc/c and different KO mice that were intraperitoneally immunized with NP-OVA. We found that NPs increased the expression of CD86 and MHCII and promoted the production and secretion of interleukin-1{beta} (IL-1{beta}) and IL-18 through the inflammasome NLRP3 when macrophages and dendritic cells were co-incubated with LPS and NPs. We evidenced an unconventional IL-1{beta} release through the autophagosome pathway. The inhibition of autophagy with 3-methyladenine reduced the LPS/NPs-induced IL-1{beta} secretion. Additionally, our findings showed that the systemic administration of mice with NP-OVA triggered a significant induction of serum OVA-specific IgG and IgG2a, an increased secretion of IFN-{gamma} by spleen cells, and high frequencies of LT CD4+IFN-{gamma}+ and LT CD8+IFN-{gamma}+. Our findings show that NPs promoted the inflammasome activation of innate cells with Th1-dependent adjuvant properties, making them valuable for formulating novel preventive or therapeutic vaccines for infectious and non-infectious diseases. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=193 HEIGHT=200 SRC="FIGDIR/small/601578v2_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@60d382org.highwire.dtl.DTLVardef@de17b2org.highwire.dtl.DTLVardef@e5aebeorg.highwire.dtl.DTLVardef@13347b0_HPS_FORMAT_FIGEXP M_FIG C_FIG

T-cell-dependent immunomodulation of carbohydrate antigens under benign conditions is the most promising approach for carbohydrate-based vaccine development. However, to achieve such adaptive immune responses, well-defined multifunctional nanocarriers loaded with immunogenic materials must be explored. Current efforts to use gold nanoparticles (AuNPs) as antigen carriers in vaccine development have conveniently introduced considerable diversity. Here, we show that the shape of AuNPs markedly influences carbohydrate-based antigen processing in murine dendritic cells (mDCs) and subsequent T-cell activation. In the study, CpG-adjuvant coated sphere-, rod-, and star-shaped AuNPs were conjugated to the tripodal Tn-glycopeptide antigen to study their DC uptake and the activation of T-cells in the DCs/T-cell co-culture assay. Our results showed that sphere- and star-shaped AuNPs displayed relatively weak receptor-mediated uptake but induced a high level of T helper-1 (Th1) biasing immune responses compared with rod-shaped AuNPs, showing that receptor-mediated uptake and cytokine secretion of nanostructures are two independent mechanisms. Significantly, the shapes of AuNPs and antigen/adjuvant conjugation synergistically work together to modulate the effective anti-Tn-glycopeptide immunoglobulin (IgG) antibody response after in vivo administration of the AuNPs. These results show that by varying the shape parameter, one can alter the immunomodulation, leading to the development of carbohydrate vaccines.

Targeting the immune system with nanoparticles (NPs) to deliver immunomodulatory molecules emerged as a solution to address intra-tumoral immunosuppression and enhance therapeutic response. While the potential of nanoimmunotherapies in reactivating immune cells has been evaluated in several preclinical studies, the impact of drug-free nanomaterials on the immune system remains unknown. Here, we characterize the molecular and functional response of human NK cells and pan T cells to a selection of five NPs that are commonly used in biomedical applications. After a pre-screen to evaluate the toxicity of these nanomaterials on immune cells, we selected ultrasmall silica-based gadolinium (Si-Gd) NPs and poly(lactic-co-glycolic acid) (PLGA) NPs for further investigation. Bulk RNA-sequencing and flow cytometry analysis showcase that PLGA NPs trigger a transcriptional priming towards activation in NK and pan T cells. While PLGA NPs improved NK cells anti-tumoral functions in cytokines-deprived environment, Si-Gd NPs significantly impaired T cells activation as well as functional responses to a polyclonal antigenic stimulation. Altogether, we identified PLGAs NPs as suitable and promising candidates for further targeting approaches aiming to reactivate the immune system of cancer patients.

Carbon quantum dots (CQDs) are zero-dimensional fluorescence nanoparticles that are less than 10 nm in size. They have unique properties like tunable surface functionality, biocompatibility, fluorescence, and low toxicity. This study outlines a detailed protocol for synthesizing CQDs from mango leaf powder using a reflux method at 160 C and 400 rpm for a duration of two hours. The synthesized CQDs were comprehensively characterized using the following techniques, including UV-visible spectroscopy, fluorescent spectrophotometry, atomic force microscopy, dynamic light scattering and zeta potential measurement, Fourier transform infrared spectroscopy, and scanning electron microscopy. In vitro analysis was conducted through an MTT assay, revealing that the CQDs exhibit reduced toxicity in RPE1 cells compared to the control group. Additionally, a concentration-dependent cellular uptake assay was performed to further evaluate the biological performance of the CQDs. The findings suggest the potential of CQDs as safe and effective nanomaterials for various biological applications, including drug delivery and bioimaging.

AO_SCPLOWBSTRACTC_SCPLOWWe have developed Fullerene-C60 nanoformulations containing discrete sized nanoparticles by dispersing concentration range of Fullerene. Small sized particles are cytotoxic while larger ones are cell proliferative. The cell proliferative property is used for tissue repair in cellular and animal wound models.

We introduce a method for conjugating antigens to gold nanoparticles (GNPs) while synthesizing them using gas plasma, which eliminates the need for chemical linkers intended to facilitate the conjugation procedure for immunotherapy purposes. We report a physical approach to conjugate antigen Nestin (NES) as a marker in malignant tumors to GNPs. Two approaches were used to perform the conjugation of GNPs and NES. The first method involved using citrate to synthesize GNPs, and then NES was conjugated onto the GNPs surface by plasma. In the second method, GNPs were simultaneously synthesized and linker-freely conjugated to NES by plasma treatment. Enzyme-linked immunosorbent assay with the protocol defined in this study, Zeta-sizer, Ultraviolet-visible spectroscopy, and Transmission Electron Microscopy results confirmed NES conjugation to GNPs. In addition, the toxicity of the prepared samples was investigated in vitro using peripheral blood mononuclear cells (PBMCs) and flow cytometry, which proved the non-toxicity of the samples. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/570950v2_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@1bffa43org.highwire.dtl.DTLVardef@c75811org.highwire.dtl.DTLVardef@166f4b3org.highwire.dtl.DTLVardef@4b4def_HPS_FORMAT_FIGEXP M_FIG C_FIG

Exposure to air pollution, including nanoparticles (NPs), is a major health concern associated with various diseases, triggered by subtle inflammatory responses in the lung. To investigate the dynamic immune response in vivo, lung intravital microscopy (L-IVM), was used to analyze the behavior of alveolar macrophages (AMs) and neutrophils, combined with ventilator-assisted inhalation of nebulized NPs in mice. Inhalation of fluorescent quantum dot NPs (cQDs) and soot-like carbon black NPs (CNPs, ambient pollutants), led to rapid spatially focused recruitment of neutrophils near alveolar deposited NPs. Neutrophil recruitment was initiated by NPs uptake by AMs, dependent on AM motility and AM NP surface recognition. Prior airway application of neutralizing antibodies against alveolar ICAM-1 and LFA-1, leading to reduced AM motility, inhibition of C5aR1 and Fc{gamma}RI receptor mediated NPs uptake by AMs, as well as neutralizing of TNF and application of a cellular degranulation inhibitor, abolished the early immune response induced by NPs. Overall, our data demonstrates the crucial role of AM activity (migration, phagocytosis, cytokine release) in the rapid and site-specific recruitment of neutrophils during the early phase of particle inhalation, suggesting these processes to be key events in mounting the immune response upon NP inhalation in the lung. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=175 HEIGHT=200 SRC="FIGDIR/small/623349v1_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@d67e38org.highwire.dtl.DTLVardef@1f8c139org.highwire.dtl.DTLVardef@55be9dorg.highwire.dtl.DTLVardef@1555042_HPS_FORMAT_FIGEXP M_FIG C_FIG

The presence of magnetic nanoparticles in animal species, including humans, has been growing steadily, but none have reported the presence in mollusks apart from the radula of chitons, in 1962. In shells this is the first time. Magnetite (Fe3O4) nanoparticles were extracted (using three distinct and rather simple protocols) from the shells of freshwater Limnoperna fortunei (Dunker 1857) and marine Perna perna (Linnaeus 1758) mussels and were fully physically-chemically characterized. Due to the spatial distribution, the ferrimagnetic particles in the shells are in low concentration and present a superparamagnetic behavior characteristic of materials of nanometric sizes. Transmission electron microscopy (TEM, especially HRTEM) indicated that the 50-100 nm round magnetic particles are in fact aggregates of 5-10 nm nanoparticles. Using analysis TEM techniques on the shell of the L fortunei we have not found any iron oxide particle at the periostracum layer nor in the calcite layer. Nevertheless, roughly round nanoparticle aggregates of iron hydroxy/oxide were found in the nacar layer, the aragonite layer. Being the aragonite layer responsible for more than 97% of the shell of the L fortunei and considering the estimated size of magnetic nanoparticles we could infer that they might be distributed throughout the nacar layer.

Carbon quantum dots (CQDs) are materials that are made up of particles that are only a few n anometers wide. They have no dimensions and can change their fluorescence qualities. They are also verybiocompatible and have a lot of potential to change the chemistry of their surface. Their eco-friendly synthesis from precursors, like citric acid (CA) and ascorbic acid (AA), provides a sustainable approach to highly fluorescent nanomaterials with promising applications in bioimaging, drug delivery, and other biomedical fields. Green-emitting carbon quantum dots (GCQDs) were synthesized via a simple reflux approach using citric acid and ascorbic acid as biomolecular precursors in a solvent solution of ethanol-water (1:2). The obtained GCQDs solution was purified using a dialysis process. Besides this, pH maintenance, lyophilization, and further submission for detailed physicochemical evaluation and characterization are done. The spectroscopic analysis, including UV-visible spectroscopy, fluorescence spectroscopy, and FTIR, confirmed the presence of surface functional groups and strong fluorescence properties and quantum yield calculations of the synthesized GCQDs. Microscopic and structural analyses using XRD, AFM, and TEM revealed the nanoscale, predominantly spherical morphology of the synthesized GCQDs. In addition, in vitro biological evaluations such as MTT assay and cellular uptake analysis were undertaken to evaluate cytocompatibility and intracellular distribution. We study the endocytosis pathway of these GCQDs, with size variations ranging from 3 to 5 nm, in mouse tissue-derived primary cells, tissues, and zebrafish embryos. GCQDs were internalized into mouse kidney and liver primary cells through a clathrin-mediated pathway. The findings confirmed that the produced GCQDs exhibit good water solubility, favorable biocompatibility, and significant potential as candidates for biomedical imaging applications.

The aim of this chapter was to understand the influence of nanoparticle challenge on physicochemical characteristics of the cells and to correlate these changes with cytotoxic response of nanoparticles. A nanoparticle surface charge and a concentration-dependent cytotoxic response were observed in the breast cancer cell lines MDA MB 231 and SKBR3. The cationic gold nanoparticles were more cytotoxic to cells as compared to anionic gold nanoparticles. It was also observed that cationic nanoparticles compromised the integrity of the plasma membrane at higher concentrations. Cationic nanoparticle challenge also caused changes in physicochemical characteristics of plasma membrane. Higher concentration of cationic nanoparticles caused an irreversible change in the surface charge density of cells. However, anionic gold nanoparticles did not show any such effect. It was observed that the ROS-mediated oxidative stress was the mechanism of cationic gold nanoparticle-mediated cytotoxic effect. Mitochondrial depolarization was observed in both anionic and cationic nanoparticle challenge. Therefore, the role of mitochondrial ROS in nanoparticle-mediated cytotoxicity is questionable. Finally, a generalized model involving modulation of intracellular Ca2+ can potentially provide an explanation for the observed pluralistic response of the cells towards nanoparticle challenge.

The adhesive function of cell surface proteins can be visually assessed through direct observation; however, the underlying structures that mediate adhesion typically remain invisible at the nanoscale level. This hinders knowledge on the diversity of molecular architectures responsible for cell-cell adhesion. Drosophila E-cadherin (DE-cadherin), a classical cadherin with a unique domain structure, demonstrates adhesive function; however, it lacks a structural model that explains its adhesion mechanism. In this study, we present a novel application of DNA origami technology to create a cell-free, flat environment in which full DE-cadherin ectodomains are anchored using SNAP-tags and biotin-streptavidin interactions. DNA origami was assembled into a 120 nm long block, bearing 5 or 14 biotin:streptavidin sites that were evenly spaced on one lateral face. DE-cadherin ectodomain fragments were attached via biotinylated SNAP-tags. These decorated DNA origami nanoblocks were subjected to transmission electron and high-speed atomic force microscopy, which revealed a hinge-like site that separated the membrane-distal and -proximal portions of the DE-cadherin ectodomain, suggesting a role in mechanical flexibility. We also observed interactions between DE-cadherin ectodomains via their membrane-distal portions on single DNA origami nanoblocks. We reconstituted an adhesion-like process via pairing DNA origami nanoblocks using DE-cadherin ectodomain interactions. Homophilic associations of functional DE-cadherin ectodomains between the paired DNA origami nanoblocks were visualized at the nanoscale, displaying strand-like molecular configurations, likely representing the extracellular cadherin repeats without regular arrays of structural elements. This study introduces a DNA origami-based platform for reconstituting and visualizing cadherin ectodomain interactions, with potential applications for a broader range of adhesion molecules. HighlightsO_LIDNA origami technology was applied to perform a structure-function study of cadherin. C_LIO_LIDNA origami nanoblocks decorated with DE-cadherin ectodomains were observed by TEM/HS-AFM. C_LIO_LIA hinge-like site that separated the membrane-distal and -proximal portions of the DE-cadherin ectodomain was revealed. C_LIO_LIAn adhesion-like process was mimicked via pairing two nanoblocks using DE-cadherin ectodomain interactions. C_LIO_LIHomophilic associations of DE-cadherin ectodomains between the nanoblocks were visualized at the nanoscale level. C_LI

The messenger ribose nucleic acid (mRNA) in lieu of Corona virus of 2019 (COVID-19) vaccines were effectively delivered through Lipid nanoparticles (LNP) which were proved effective carriers for clinical applications. In the present work, mRNA (erythropoietin (EPO)) encapsulated LNPs were prepared using a next generation state-of-the-art patented Sprayed Multi Absorbed-droplet Reposing Technology (SMART) coupled with Multi-channeled and Guided Inner-Controlling printheads (MaGIC) technologies. The LNP-mRNA were synthesized at different N/P ratios and the particles were characterized for particle size & zeta potential (Zetasizer), encapsulation or complexation (gel retardation assay) and transfection (Fluorescence microscopy) in MG63 sarcoma cells in vitro. The results showed a narrow distribution of mRNA-lipid particles of 200 nm when fabricated with SMART alone and then the size was reduced to approximately 50 nm with the combination of SMART-MaGIC technologies. The gel retardation assay showed that the N/P>1 showed strong encapsulation of mRNA with lipid. The in vitro results showed the toxicity profile of the lipids where N/P ratio of 5 is the optimized with >50% cell viability. The functional LNP-mRNA were prepared and analyzed with SMART-MaGIC technologies which could be a potential new fabrication method of mRNA loaded LNPs. HighlightsO_LIThe particle size was reduced to around 50 nm with implementation of SMART-MaGIC. C_LIO_LIThe loading efficiency is 100%. C_LIO_LIThe functionality of the mRNA is unaffected during the preparation process. C_LIO_LIThe transfection facilitated transient expression of the protein in vitro. C_LIO_LIThe EPO mRNA is more effective than EPO protein to reduce chemo-toxic effects in vitro. C_LI

Fungal adhesion to stainless steel, an alloy commonly used in food and beverage sectors, public and healthcare settings, and numerous medical devices, can give rise to serious infections, ultimately leading to morbidity, mortality, and significant healthcare expenses. In this study, we demonstrate that nanotextured stainless steel (nSS) fabricated using an electrochemical technique is an antibiotic-free biocidal surface against Candida Albicans and Fusarium Oxysporum with 98% and 97% reduction, respectively. The nanoprotrusion features on nSS can have both physical contact with cell membranes and chemical impact on cells through production of reactive species, this material should not contribute to drug resistant fungus as antibiotics can. As nSS is also antibacterial and compatible with mammalian cells, demonstration of antifungal activity gives nSS the potential to be used to create effective, scalable, and sustainable solutions to broadly and responsibly prevent fungal and other microbial infections caused by surface contamination. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=76 SRC="FIGDIR/small/616307v1_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@9c037dorg.highwire.dtl.DTLVardef@a93518org.highwire.dtl.DTLVardef@dccc6forg.highwire.dtl.DTLVardef@1f19515_HPS_FORMAT_FIGEXP M_FIG C_FIG

Nanoparticles synthesized using various peptides have optimized properties and functional abilities which can be achieved via peptide flexibility and site specificity. Using peptide Pd4 and other alanine substitution combinations of Pd4 attached to a green fluorescent protein (GFPuv), nanoparticles with well-defined sizes that are soluble in aqueous solutions can be produced. In this study, extensive molecular dynamics simulations explored the structural and functional differences between the free peptides and the peptides bound to the GFPuv used in nanoparticle production. Binding affinities of histidines of Pd4 peptide and its two mutants A6 and A11 to a palladium atom were calculated using the free energy perturbation method. Interestingly, the average particle sizes obtained from transmission electron microscopy (TEM) images correlated with our calculated free energies of different peptide sequences. Remarkably, when the peptide was bound to GFPuv, the free energies of histidine were very similar in the wild-type and other mutated peptides. However, this trend is not observed with free peptide simulations, where binding affinities differ by mutation of histidine residues. This study describes, at a molecular level, the role of amino acid sequence on binding affinity of the peptide to the surface of the palladium particles, and the functional ability of the GFPuv protein controlling these free energies irrespective of peptide sequence. Our study will provide a framework for designing free and protein attached peptides that facilitate peptide-mediated nanoparticle formation with well-regulated properties.