Glutamic Acid Modified Gold Nanorod Sensor for the Detection of Calcium ions in Neuronal Cells

Calcium (Ca2+) ions play a crucial role in the functioning of neurons, governing various aspects of neuronal activity such as rapid modulation and alterations in gene expression. Ca2+ signaling has a significant impact on the development of diseases and the impairment of neuronal functions. Herein, the study reports a Ca2+ ion sensor in neuronal cells using a gold nanorod. The gold nanorod (GA-GNR) conjugated glutamic acid developed in the study was used as a nano-bio probe for the experimental and in vitro detection of calcium. The nanosensor is colloidally stable, preserves plasmonic properties, and shows good viability in neuronal cells, as well as promoting neuron cell line growth. The cytotoxicity and cell penetration of the nanosensor are studied using Raman spectroscopy, brightfield and darkfield microscopy imaging, and MTT assays. The quantification of Ca2+ ions in neuronal cells is determined by monitoring the surface plasmon resonance (SPR) of the GA-GNR. The change in the intensity profile in the presence of Ca2+ incubated neurons was effectively used to develop a portable prototype of an optical Ca2+ sensor, proposing it as a tool for neurodegenerative disease diagnosis and neuromodulation evaluation.

Patient-specific mechanical analysis of PCL periodontal membrane: Modeling and simulation

This research fills a knowledge gap in bone tissue engineering by examining the mechanical characteristics of scaffolds at bone-tissue interfaces utilizing a cutting-edge technique involving the creation of 3D scaffolds from Polycaprolactone (PCL). The work employs Finite element analysis to measure the scaffolds' maximum principal and Von Mises stresses and strains. CT scans of the Maxilla and Mandible were used to apply load conditions to 3D models of the upper central incisor. In the derived computational model, four different load situations considered were: the masticatory load (70-100 N at 45°), two parafunctional habits (100-130 N) and 500-550 N at the incisal edge, both at 45°), and a trauma case (800-850 N applied perpendicularly from the inwards direction at 90°). The findings revealed that the central tooth region experiences the highest stress concentration, while the Maxilla and Mandible regions show the least stress. These results provide critical insights into the mechanical behavior of scaffolds at bone-tissue interfaces, suggesting a research direction for developing scaffolds that closely mimic real bone characteristics. The results of this study are particularly significant for using bone replacement materials, providing an approach to more effective healing options for bone traumas and degenerative bone disorders.

Porphyrin and doxorubicin mediated nanoarchitectonics of copper clusters: a bimodal theranostics for cancer diagnosis and treatment in vitro

Nanoarchitectonics, an emerging strategy, presents a promising alternative for developing highly efficient next-generation functional materials. Multifunctional materials developed using nanoarchitectonics help to mimic biological molecules. Porphyrin-based molecules can be effectively utilized to design such assemblies. Metal nanocluster is one of the functional materials that can shed more insight into developing nanoarchitectonic materials. Herein, an inherently near-infrared (NIR) fluorescing copper nanocluster (CuC)-mediated structural assembly via protoporphyrin IX (PPIX) and doxorubicin (Dox) is demonstrated as the functional material. Dox-loaded porphyrin-mediated CuC assembly shows singlet oxygen generation and 66% drug release at 15 min. Furthermore, the efficacy of this material is tested for cancer diagnosis and bimodal therapeutic strategy due to the fluorescing ability of the cluster and loading of PPIX as well as the drug, respectively. The nanoarchitecture exhibits targeted imaging and 83% cell death in HeLa cells upon laser irradiation with 10 nmoles and 20 nmoles of PPIX and Dox, respectively.

Cold Plasma Technology Based Eco-Friendly Food Packaging Biomaterials

Biopolymers have intrinsic drawbacks compared to traditional plastics, such as hydrophilicity, poor thermo-mechanical behaviours, and barrier characteristics. Therefore, biopolymers or their film modifications offer a chance to create packaging materials with specified properties. Cold atmospheric plasma (CAP) or Low temperature plasma (LTP) has a wide range of applications and has recently been used in the food industry as a potent tool for non-thermal food processing. Though its original purpose was to boost polymer surface energy for better adherence and printability, it has since become an effective technique for surface decontamination of food items and food packaging materials. These revolutionary innovative food processing methods enable the balance between the economic constraints and higher quality while ensuring food stability and minimal processing. For CAP to be considered as a viable alternative food processing technology, it must positively affect food quality. Food products may have their desired functional qualities by adjusting the conditions for cold plasma formation. Cold plasma is a non-thermal method that has little effects on the treated materials and is safe for the environment. In this review, we focus on recent cold plasma advances on various food matrices derived from plants and animals with the aim of highlighting potential applications, ongoing research, and market trends.

Characterization of materials used for 3D printing dental crowns and hybrid prostheses

OBJECTIVES

To compare the filler weight percentage (wt%), filler and resin composition, flexural strength, modulus, and hardness of several 3D-printed resins to direct and indirect restorative materials.

MATERIALS AND METHODS

Four 3D-printed resins (C&B MFH, Ceramic Crown, OnX, and OnX Tough), one milled resin composite (Lava Ultimate), one conventional composite (Filtek Supreme), and one ceramic (IPS e.max CAD) were evaluated. Filler wt% was determined by the burned ash technique, and filler particle morphology and composition were analyzed by scanning electron microscopy and energy-dispersive spectroscopy, respectively. Organic resin composition was analyzed by Fourier transform infrared spectroscopy. Three-point bend flexural strength and modulus of the materials were determined by ISO 4049 or ISO 6872. Vickers microhardness was measured. Data were compared with a one-way analysis of variance (ANOVA) and Tukey post hoc analysis. Linear regression analysis was performed for filler wt% versus flexural strength, modulus, and hardness.

RESULTS

3D-printed resins were composed of various sized and shaped silica fillers and various types of methacrylate resins. Significant differences were found among filler wt% with some materials around 3% (C&B MFH), others between 33% and 38% (OnX Tough and OnX), others around 50% (Ceramic Crown), and some around 72% (Filtek Supreme and Lava Ultimate). All 3D-printed resins had significantly lower flexural strength, modulus, and hardness than the conventional and milled resin composites and ceramic material (p < 0.001). Filler wt% demonstrated a linear relationship with modulus (p = 0.013, R2  = 0.821) and hardness (p = 0.018, R2  = 0.787) but not flexural strength (p = 0.056, R2  = 0.551).

CONCLUSIONS

3D-printed resins contain from 3% to 50% filler content. Filler wt% alone does not affect flexural strength, but strength may be affected by resin composition as well. Although the 3D-printed resins had lower flexural strength, modulus, and hardness than milled and conventional composite and ceramic, they demonstrated nonbrittle plastic behavior.

CLINICAL SIGNIFICANCE

The properties of 3D-printed resins vary based on their composition, which affects their clinical applications.

Low-Temperature Plasma Techniques in Biomedical Applications and Therapeutics: An Overview

Plasma, the fourth fundamental state of matter, comprises charged species and electrons, and it is a fascinating medium that is spread over the entire visible universe. In addition to that, plasma can be generated artificially under appropriate laboratory techniques. Artificially generated thermal or hot plasma has applications in heavy and electronic industries; however, the non-thermal (cold atmospheric or low temperature) plasma finds its applications mainly in biomedicals and therapeutics. One of the important characteristics of LTP is that the constituent particles in the plasma stream can often maintain an overall temperature of nearly room temperature, even though the thermal parameters of the free electrons go up to 1 to 10 keV. The presence of reactive chemical species at ambient temperature and atmospheric pressure makes LTP a bio-tolerant tool in biomedical applications with many advantages over conventional techniques. This review presents some of the important biomedical applications of cold-atmospheric plasma (CAP) or low-temperature plasma (LTP) in modern medicine, showcasing its effect in antimicrobial therapy, cancer treatment, drug/gene delivery, tissue engineering, implant modifications, interaction with biomolecules, etc., and overviews some present challenges in the field of plasma medicine.

Low-Temperature Plasmas Improving Chemical and Cellular Properties of Poly (Ether Ether Ketone) Biomaterial for Biomineralization

Osteoblastic and chemical responses to Poly (ether ether ketone) (PEEK) material have been improved using a variety of low-temperature plasmas (LTPs). Surface chemical properties are modified, and can be used, using low-temperature plasma (LTP) treatments which change surface functional groups. These functional groups increase biomineralization, in simulated body fluid conditions, and cellular viability. PEEK scaffolds were treated, with a variety of LTPs, incubated in simulated body fluids, and then analyzed using multiple techniques. First, scanning electron microscopy (SEM) showed morphological changes in the biomineralization for all samples. Calcein staining, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) confirmed that all low-temperature plasma-treated groups showed higher levels of biomineralization than the control group. MTT cell viability assays showed LTP-treated groups had increased cell viability in comparison to non-LTP-treated controls. PEEK treated with triethyl phosphate plasma (TEP) showed higher levels of cellular viability at 82.91% ± 5.00 (n = 6) and mineralization. These were significantly different to both the methyl methacrylate (MMA) 77.38% ± 1.27, ethylene diamine (EDA) 64.75% ± 6.43 plasma-treated PEEK groups, and the control, non-plasma-treated group 58.80 ± 2.84. FTIR showed higher levels of carbonate and phosphate formation on the TEP-treated PEEK than the other samples; however, calcein staining fluorescence of MMA and TEP-treated PEEK had the highest levels of biomineralization measured by pixel intensity quantification of 101.17 ± 4.63 and 96.35 ± 3.58, respectively, while EDA and control PEEK samples were 89.53 ± 1.74 and 90.49 ± 2.33, respectively. Comparing different LTPs, we showed that modified surface chemistry has quantitatively measurable effects that are favorable to the cellular, biomineralization, and chemical properties of PEEK.

Fat mass: a novel digital biomarker for remote monitoring that may indicate risk for malnutrition and new complications in decompensated cirrhosis

BACKGROUND

Cirrhosis is associated with sarcopaenia and fat wasting, which drive decompensation and mortality. Currently, nutritional status, through body composition assessment, is not routinely monitored in outpatients. Given the deleterious outcomes associated with poor nutrition in decompensated cirrhosis, there is a need for remotely monitoring this to optimise community care.

METHODS

A retrospective analysis was conducted on patients monitored remotely with digital sensors post hospital discharge, to assess outcomes and indicators of new cirrhosis complications. 15 patients had daily fat mass measurements as part of monitoring over a median 10 weeks, using a Withing's bioimpedance scale. The Clinical Frailty Score (CFS) was used to assess frailty and several liver disease severity scores were assessed.

RESULTS

73.3% (11/15) patients were male with a median age of 63 (52-68). There was a trend towards more severe liver disease based on CLIF-Consortium Acute Decompensation (CLIF-C AD) scores in frail patients vs. those not frail (53 vs 46, p = 0.072). When the cohort was split into patients who gained fat mass over 8 weeks vs. those that lost fat mass, the baseline CLIF-C AD scores and WBC were significantly higher in those that lost fat (58 vs 48, p = 0.048 and 11.2 × 109 vs 4.7 × 109, p = 0.031).

CONCLUSIONS

This proof-of-principle study shows feasibility for remote monitoring of fat mass and nutritional reserve in decompensated cirrhosis. Our results suggest fat mass is associated with greater severity of acute decompensation and may serve as an indicator of systemic inflammatory response. Further prospective studies are required to validate this digital biomarker.

A multi-targeting bionanomatrix coating to reduce capsular contracture development on silicone implants

BACKGROUND

Capsular contracture is a critical complication of silicone implantation caused by fibrotic tissue formation from excessive foreign body responses. Various approaches have been applied, but targeting the mechanisms of capsule formation has not been completely solved. Myofibroblast differentiation through the transforming growth factor beta (TGF-β)/p-SMADs signaling is one of the key factors for capsular contracture development. In addition, biofilm formation on implants may result chronic inflammation promoting capsular fibrosis formation with subsequent contraction. To date, there have been no approaches targeting multi-facted mechanisms of capsular contracture development.

METHODS

In this study, we developed a multi-targeting nitric oxide (NO) releasing bionanomatrix coating to reduce capsular contracture formation by targeting myofibroblast differentiation, inflammatory responses, and infections. First, we characterized the bionanomatrix coating on silicon implants by conducting rheology test, scanning electron microcsopy analysis, nanoindentation analysis, and NO release kinetics evaluation. In addition, differentiated monocyte adhesion and S. epidermidis biofilm formation on bionanomatrix coated silicone implants were evaluated in vitro. Bionanomatrix coated silicone and uncoated silicone groups were subcutaneously implanted into a mouse model for evaluation of capsular contracture development for a month. Fibrosis formation, capsule thickness, TGF-β/SMAD 2/3 signaling cascade, NO production, and inflammatory cytokine production were evaluated using histology, immunofluorescent imaging analysis, and gene and protein expression assays.

RESULTS

The bionanomatrix coating maintained a uniform and smooth surface on the silicone even after mechanical stress conditions. In addition, the bionanomatrix coating showed sustained NO release for at least one month and reduction of differentiated monocyte adhesion and S. epidermidis biofilm formation on the silicone implants in vitro. In in vivo implantation studies, the bionanomatrix coated groups demonstrated significant reduction of capsule thickness surrounding the implants. This result was due to a decrease of myofibroblast differentiation and fibrous extracellular matrix production through inhibition of the TGF-β/p-SMADs signaling. Also, the bionanomatrix coated groups reduced gene expression of M1 macrophage markers and promoted M2 macrophage markers which indicated the bionanomatrix could reduce inflammation but promote healing process.

CONCLUSIONS

In conclusion, the bionanomatrix coating significantly reduced capsular contracture formation and promoted healing process on silicone implants by reducing myfibroblast differentiation, fibrotic tissue formation, and inflammation. A multi-targeting nitric oxide releasing bionanomatrix coating for silicone implant can reduce capsular contracture and improve healing process. The bionanomatrix coating reduces capsule thickness, α-smooth muscle actin and collagen synthesis, and myofibroblast differentiation through inhibition of TGF-β/SMADs signaling cascades in the subcutaneous mouse models for a month.

Correction: Zare et al. Encapsulation of miRNA and siRNA into Nanomaterials for Cancer Therapeutics. Pharmaceutics 2022, 14, 1620

In the original publication [...].

Plasma Surface Engineering of Natural and Sustainable Polymeric Derivatives and Their Potential Applications

Recently, natural as well as synthetic polymers have been receiving significant attention as candidates to replace non-renewable materials. With the exponential developments in the world each day, the collateral damage to the environment is incessant. Increased demands for reducing pollution and energy consumption are the driving force behind the research related to surface-modified natural fibers (NFs), polymers, and various derivatives of them such as natural-fiber-reinforced polymer composites. Natural fibers have received special attention for industrial applications due to their favorable characteristics, such as low cost, abundance, light weight, and biodegradable nature. Even though NFs offer many potential applications, they still face some challenges in terms of durability, strength, and processing. Many of these have been addressed by various surface modification methodologies and compositing with polymers. Among different surface treatment strategies, low-temperature plasma (LTP) surface treatment has recently received special attention for tailoring surface properties of different materials, including NFs and synthetic polymers, without affecting any of the bulk properties of these materials. Hence, it is very important to get an overview of the latest developments in this field. The present article attempts to give an overview of different materials such as NFs, synthetic polymers, and composites. Special attention was placed on the low-temperature plasma-based surface engineering of these materials for diverse applications, which include but are not limited to environmental remediation, packaging, biomedical devices, and sensor development.

Encapsulation of miRNA and siRNA into Nanomaterials for Cancer Therapeutics

Globally, cancer is amongst the most deadly diseases due to the low efficiency of the conventional and obsolete chemotherapeutic methodologies and their many downsides. The poor aqueous solubility of most anticancer medications and their low biocompatibility make them ineligible candidates for the design of delivery systems. A significant drawback associated with chemotherapy is that there are no advanced solutions to multidrug resistance, which poses a major obstacle in cancer management. Since RNA interference (RNAi) can repress the expression of genes, it is viewed as a novel tool for advanced drug delivery. this is being explored as a promising drug targeting strategy for the treatment of multiple diseases, including cancer. However, there are many obstructions that hinder the clinical uses of siRNA drugs due to their low permeation into cells, off-target impacts, and possible unwanted immune responses under physiological circumstances. Thus, in this article, we review the design measures for siRNA conveyance frameworks and potential siRNA and miRNA drug delivery systems for malignant growth treatment, including the use of liposomes, dendrimers, and micelle-based nanovectors and functional polymer-drug delivery systems. This article sums up the advancements and challenges in the use of nanocarriers for siRNA delivery and remarkably centers around the most critical modification strategies for nanocarriers to build multifunctional siRNA and miRNA delivery vectors. In short, we hope this review will throw light on the dark areas of RNA interference, which will further open novel research arenas in the development of RNAi drugs for cancer.

Plasma Electroless Reduction: A Green Process for Designing Metallic Nanostructure Interfaces onto Polymeric Surfaces and 3D Scaffolds

The design of metal nanoparticle-modified polymer surfaces in a green and scalable way is both desirable and highly challenging. Herein, a new green low-temperature plasma-based in situ surface reduction strategy termed plasma electroless reduction (PER) is reported for achieving in situ metallic nanostructuring on polymer surfaces. Proof of concept for this new method was first demonstrated on hydrophilic cellulose papers. Cellulose papers were dip-coated with different metal ion (Ag⁺ and Au³⁺) solutions and then subjected to hydrogen plasma treatment for this PER process. Transmission electron microscopy (TEM) analysis has revealed that this PER process caused anisotropic growth of either gold or silver nanoparticles, resulting in the time-dependent formation of both distinct spherical nanoparticles (∼20 nm) and anisotropic 2D nanosheets. Furthermore, we have demonstrated the adaptability of this process by applying it to hydrophobic fibrous and 3D printed polymeric materials such as surgical face masks and 3D printed polylactic acid scaffolds. The PER process on these hydrophobic polymer surfaces was accomplished via a sequential combination of air plasma and hydrogen plasma treatment. The metallic nanostructuring caused by the PER process on these hydrophobic surfaces was systematically studied using different surface imaging techniques including 3D confocal laser surface scanning microscopy and scanning electron microscopy. We have also systematically optimized the PER process on the surface of 3D scaffolds via varying the concentration of the silver ion precursor and by different postprocessing methods such as sonication and medium soaking. These optimization processes were found to be very important in generating uniform metallic nanoparticle-modified 3D printed scaffolds while simultaneously improving cytocompatibility. Through joint disk diffusion and inhibitory concentration testing, the antibacterial efficacy of silver coatings on face masks and 3D scaffolds was established. Altogether, these results clearly suggest the excellent futuristic potential of this new PER method for designing metallic nanostructured interfaces for different biomedical applications.

Uni-Directionally Oriented Fibro-Porous PLLA/Fibrin Bio-Hybrid Scaffold: Mechano-Morphological and Cell Studies

In this study, we report a biohybrid oriented fibrous scaffold based on nanofibers of poly(l-lactic acid) (PLLA)/fibrin produced by electrospinning and subsequent post-treatment. Induced hydrolytic degradation of the fibers in 0.25 M NaOH solution for various time periods followed by the immobilization of fibrin on the hydrolyzed fiber surfaces was shown to significantly affect the mechanical properties, with the tensile strength (40.6 MPa ± 1.3) and strain at failure (38% ± 4.5) attaining a value within the range of human ligaments and ligament-replacement grafts. Unidirectional electrospinning with a mandrel rotational velocity of 26.4 m/s produced highly aligned fibers with an average diameter of 760 ± 96 nm. After a 20-min hydrolysis treatment in NaOH solution, this was further reduced to an average of 457 ± 89 nm, which is within the range of collagen bundles found in ligament tissue. Based on the results presented herein, the authors hypothesize that a combination of fiber orientation/alignment and immobilization of fibrin can result in the mechanical and morphological modification of PLLA tissue scaffolds for ligament-replacement grafts. Further, it was found that treatment with NaOH enhanced the osteogenic differentiation of hMSCs and the additional inclusion of fibrin further enhanced osteogenic differentiation, as demonstrated by decreased proliferative rates and increased ALP activity.

Efficacy in degradation of carcinogenic pollutant sulforhodamine B by green synthesized silver nanoparticles

Colloidal Silver nano-particles were grown at room temperature using leaf extract of Ocimum tenuiflorum. The silver nanoparticles suspended in the solution were found to be stable for over a period of 2 months. Structural, optical and photo catalytic behavior of the suspended silver (Ag) nano-particles (NPs) was characterized. From TEM analysis the size of the silver nanoparticles was estimated to be 25–30 nm. Our findings suggest that the ratio between the molarity of AgNO3 and the volume of leaf extract does not have any role in controlling the size of the Ag nano-particles. These green synthesized Ag nano-particles exhibit degradation of the carcinogenic organic pollutant sulforhodamine B in absence of light.

[Evaluation of rule out strategy for patients with non-ST-elevation acute coronary syndrome with single measurement of high-sensitivity cardiac troponin I from one sample tested beetween 3 and 6 hours after chest pain onset]

BACKGROUND

Guidelines recommend to consider excluding non-ST-segment elevation myocardial infarction (NSTEMI) when high-sensitivity cardiac troponin is below the limit of quantification and a single blood sample is taken > 6 h after the onset of chest pain. The aim of our study was to assess such exclusion when a single blood sample was taken 3-6 h after the onset of permanent chest pain.

METHODS

This observational study included consecutive patients admitted into the emergency room of our hospital with chest pain and suspected NSTEMI, with non-contributive electrocardiograms and a single high-sensitivity cardiac troponin I (hs-cTnI) blood sample taken 3-6 h after the onset of chest pain and hs-cTnI < 4 ng/l (Abbott Diagnostic). Clinical follow-up was undertaken 1 month after admission.

RESULTS

The mean age of the 432 patients was 48.5 ± 5.6 years and 51% were male. Based on a clinical algorithm, the pre-test probability of NSTEMI was low in 70%, and intermediate in 21% of patients. Among 419 patients with available 1-month follow-up data, there were no myocardial infarctions or deaths. Thirty-eight patients (9%) were admitted into hospital but none for cardiac reasons.

CONCLUSIONS

Our results suggest that exclusion of NSTEMI in patients with a non-contributive electrocardiogram and a single "negative" troponin test in a blood sample taken 3-6 h after the onset of symptoms is valid.

Nanoscience and quantum science-led biocidal and antiviral strategies

The severe acute respiratory syndrome coronavirus (SARS-CoV-2) caused the COVID-19 pandemic. According to the World Health Organization, this pandemic continues to be a serious threat to public health due to the worldwide spread of variants and their higher rate of transmissibility. A range of measures are necessary to slow the pandemic and save lives, which include constant evaluation and the careful adjustment of public-health responses augmented by medical treatments, vaccines and protective gear. It is hypothesized that nanostructured particulates underpinned by nanoscience and quantum science yield high-performing antiviral strategies, which can be applied in preventive, diagnostic, and therapeutic applications such as face masks, respirators, COVID test kits, vaccines, and drugs. This review is aimed at providing comprehensive and cohesive perspectives on various nanostructures that are suited to intensifying and amplifying the effectiveness of antiviral strategies. Growing scientific literature over the past eighteen months indicates that quantum dots, iron oxide, silicon oxide, polymeric and metallic nanoparticles have been employed in COVID-19 diagnostic assays, vaccines, and personal protective equipment (PPE). Quantum dots have displayed their suitability as more sensitive imaging probes in diagnostics and prognostics, and as controlled drug-release carriers that target the virus. Nanoscience and quantum science have assisted the design of advanced vaccine delivery since nanostructured materials are suited for antigen delivery, as mimics of viral structures and as adjuvants. Furthermore, the quantum science- and nanoscience-supported tailored functionalization of nanostructured materials offers insight and pathways to deal with future pandemics. This review seeks to illustrate several examples, and to explain the underpinning quantum science and nanoscience phenomena, which include wave functions, electrostatic interactions, van der Waals forces, thermal and electrodynamic fluctuations, dispersion forces, local field-enhancement effects, and the generation of reactive oxygen species (ROS). This review discusses how nanostructured materials are helpful in the detection, prevention, and treatment of the SARS-CoV-2 infection, other known viral infection diseases, and future pandemics.

Novel Poly(ester urethane urea)/Polydioxanone Blends: Electrospun Fibrous Meshes and Films

In this work, we report the electrospinning and mechano-morphological characterizations of scaffolds based on blends of a novel poly(ester urethane urea) (PHH) and poly(dioxanone) (PDO). At the optimized electrospinning conditions, PHH, PDO and blend PHH/PDO in Hexafluroisopropanol (HFIP) solution yielded bead-free non-woven random nanofibers with high porosity and diameter in the range of hundreds of nanometers. The structural, morphological, and biomechanical properties were investigated using Differential Scanning Calorimetry, Scanning Electron Microscopy, Atomic Force Microscopy, and tensile tests. The blended scaffold showed an elastic modulus (~5 MPa) with a combination of the ultimate tensile strength (2 ± 0.5 MPa), and maximum elongation (150% ± 44%) in hydrated conditions, which are comparable to the materials currently being used for soft tissue applications such as skin, native arteries, and cardiac muscles applications. This demonstrates the feasibility of an electrospun PHH/PDO blend for cardiac patches or vascular graft applications that mimic the nanoscale structure and mechanical properties of native tissue.

2D materials as a diagnostic platform for the detection and sensing of the SARS-CoV-2 virus: a bird's-eye view

Worldwide infections and fatalities caused by the SARS-CoV-2 virus and its variants responsible for COVID-19 have significantly impeded the economic growth of many nations. People in many nations have lost their livelihoods, it has severely impacted international relations and, most importantly, health infrastructures across the world have been tormented. This pandemic has already left footprints on human psychology, traits, and priorities and is certainly going to lead towards a new world order in the future. As always, science and technology have come to the rescue of the human race. The prevention of infection by instant and repeated cleaning of surfaces that are most likely to be touched in daily life and sanitization drives using medically prescribed sanitizers and UV irradiation of textiles are the first steps to breaking the chain of transmission. However, the real challenge is to develop and uplift medical infrastructure, such as diagnostic tools capable of prompt diagnosis and instant and economic medical treatment that is available to the masses. Two-dimensional (2D) materials, such as graphene, are atomic sheets that have been in the news for quite some time due to their unprecedented electronic mobilities, high thermal conductivity, appreciable thermal stability, excellent anchoring capabilities, optical transparency, mechanical flexibility, and a unique capability to integrate with arbitrary surfaces. These attributes of 2D materials make them lucrative for use as an active material platform for authentic and prompt (within minutes) disease diagnosis via electrical or optical diagnostic tools or via electrochemical diagnosis. We present the opportunities provided by 2D materials as a platform for SARS-CoV-2 diagnosis.

Tissue Engineering Strategies for Retina Regeneration

The retina is a complex and fragile photosensitive part of the central nervous system which is prone to degenerative diseases leading to permanent vision loss. No proven treatment strategies exist to treat or reverse the degenerative conditions. Recent investigations demonstrate that cell transplantation therapies to replace the dysfunctional retinal pigment epithelial (RPE) cells and or the degenerating photoreceptors (PRs) are viable options to restore vision. Pluripotent stem cells, retinal progenitor cells, and somatic stem cells are the main cell sources used for cell transplantation therapies. The success of retinal transplantation based on cell suspension injection is hindered by limited cell survival and lack of cellular integration. Recent advances in material science helped to develop strategies to grow cells as intact monolayers or as sheets on biomaterial scaffolds for transplantation into the eyes. Such implants are found to be more promising than the bolus injection approach. Tissue engineering techniques are specifically designed to construct biodegradable or non-degradable polymer scaffolds to grow cells as a monolayer and construct implantable grafts. The engineered cell construct along with the extracellular matrix formed, can hold the cells in place to enable easy survival, better integration, and improved visual function. This article reviews the advances in the use of scaffolds for transplantation studies in animal models and their application in current clinical trials.

Fibro-porous PLLA/gelatin composite membrane doped with cerium oxide nanoparticles as bioactive scaffolds for future angiogenesis

Functionalized cerium oxide nanoparticle (CeNP)-loaded fibro-porous poly-l-lactic acid (PLLA)/gelatin composite membranes were prepared via an electrospinning technology. Considering the importance of such membrane scaffolds for promoting angiogenesis in tissue engineering and drug screening, a series of PLLA/gelatin composite fiber membranes loaded with different doses of CeNPs was prepared. The prepared composite membranes demonstrated hydrophilicity, water absorption, and improved mechanical properties compared to a PLLA and PLLA/gelatin membrane. Also, cell viability assay using somatic hybrid endothelial cells (EA.hy926) proved the biocompatible nature of the scaffolds. The biocompatibility was further supported by in vivo chick embryo angiogenesis assay using fertilized eggs. Our initial results support that these membrane scaffolds could be useful for angiogenesis-related disease treatment after further investigations.

Science-Based Strategies of Antiviral Coatings with Viricidal Properties for the COVID-19 Like Pandemics

The worldwide, extraordinary outbreak of coronavirus pandemic (i.e., COVID-19) and other emerging viral expansions have drawn particular interest to the design and development of novel antiviral, and viricidal, agents, with a broad-spectrum of antiviral activity. The current indispensable challenge lies in the development of universal virus repudiation systems that are reusable, and capable of inactivating pathogens, thus reducing risk of infection and transmission. In this review, science-based methods, mechanisms, and procedures, which are implemented in obtaining resultant antiviral coated substrates, used in the destruction of the strains of the different viruses, are reviewed. The constituent antiviral members are classified into a few broad groups, such as polymeric materials, metal ions/metal oxides, and functional nanomaterials, based on the type of materials used at the virus contamination sites. The action mode against enveloped viruses was depicted to vindicate the antiviral mechanism. We also disclose hypothesized strategies for development of a universal and reusable virus deactivation system against the emerging COVID-19. In the surge of the current, alarming scenario of SARS-CoV-2 infections, there is a great necessity for developing highly-innovative antiviral agents to work against the viruses. We hypothesize that some of the antiviral coatings discussed here could exert an inhibitive effect on COVID-19, indicated by the results that the coatings succeeded in obtaining against other enveloped viruses. Consequently, the coatings need to be tested and authenticated, to fabricate a wide range of coated antiviral products such as masks, gowns, surgical drapes, textiles, high-touch surfaces, and other personal protective equipment, aimed at extrication from the COVID-19 pandemic.

HuBiogel incorporated fibro-porous hybrid nanomatrix graft for vascular tissue interfaces

Native extracellular matrix (ECM) possesses the biochemical cues to promote cell survival. However, decellularized, the ECM loses its cell supporting mechanical integrity. We report, here, a novel biohybrid vascular graft of polycaprolactone (PCL), poliglecaprone (PGC) incorporated with human biomatrix as functional materials for vascular tissue interfacing by electrospinning, thus harnessing the biochemical cues from the ECM and the mechanical integrity of the polymer blends. The fabricated fibro-porous tubular small diameter graft (i.d. = 4 mm) from polymer blend was coated with a cocktail of collagenous matrix derived from human placenta called HuBiogel™. The compositional, morphological, and mechanical properties of graft were measured and compared with a non-coated tubular PCL/PGC graft using Fourier Transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). BCA assay was used to calculate the protein content and coating-uniformity throughout the hybrid graft. Mechanical properties such as tensile strength (1.6 MPa), Young's modulus (2.4 MPa), burst pressure (>1900 mmHg), and suture retention strength (2.3 N) of hybrid graft were found to be comparable to native blood vessels. Protein coating has improved the hydrophilicity and the biocompatibility (cell viability and cell-attachment) enhanced with human umbilical vein endothelial cells (HUVECs) seeded in vitro onto the lumen layer of the graft over two weeks. The overall results promise this new biohybrid graft to be a potential candidate for vascular tissue interface and regeneration.

Dietary Oxalate Induces Urinary Nanocrystals in Humans

Introduction

Crystalluria is thought to be associated with kidney stone formation and can occur when urine becomes supersaturated with calcium, oxalate, and phosphate. The principal method used to identify urinary crystals is microscopy, with or without a polarized light source. This method can detect crystals above 1 μm in diameter (microcrystals). However, analyses of calcium oxalate kidney stones have indicated that crystallite components in these calculi are 50–100 nm in diameter. Recent studies have suggested that nanocrystals (<200 nm) elicit more injury to renal cells compared to microcrystals. The purpose of this study was to determine whether (i) urinary nanocrystals can be detected and quantified by nanoparticle tracking analysis (NTA, a high-resolution imaging technology), (ii) early-void urine samples from healthy subjects contain calcium nanocrystals, and (iii) a dietary oxalate load increases urinary nanocrystal formation.

Methods

Healthy subjects consumed a controlled low-oxalate diet for 3 days before a dietary oxalate load. Urinary crystals were isolated by centrifugation and assessed using NTA before and 5 hours after the oxalate load. The morphology and chemical composition of crystals was assessed using electron microscopy, Fourier-transform infrared spectroscopy (FTIR), and ion chromatography-mass spectrometry (IC–MS).

Results

Urinary calcium oxalate nanocrystals were detected in pre-load samples and increased substantially following the oxalate load.

Conclusion

These findings indicate that NTA can quantify urinary nanocrystals and that meals rich in oxalate can promote nanocrystalluria. NTA should provide valuable insight about the role of nanocrystals in kidney stone formation.

Non-equilibrium organosilane plasma polymerization for modulating the surface of PTFE towards potential blood contact applications

We report a novel and facile organosilane plasma polymerization method designed to improve the surface characteristics of poly(tetrafluoroethylene) (PTFE). We hypothesized that the polymerized silane coating would provide an adhesive surface for endothelial cell proliferation due to a large number of surface hydroxyl groups, while the large polymer networks on the surface of PTFE would hinder platelet attachment. The plasma polymerized PTFE surfaces were then systematically characterized via different analytical techniques such as FTIR, XPS, XRD, Contact angle, and SEM. The key finding of the characterization is the time-dependent deposition of an organosilane layer on the surface of PTFE. This layer was found to provide favorable surface properties to PTFE such as a very high surface oxygen content, high hydrophilicity and improved surface mechanics. Additionally, in vitro cellular studies were conducted to determine the bio-interface properties of the plasma-treated and untreated PTFE. The important results of these experiments were rapid endothelial cell growth and decreased platelet attachment on the plasma-treated PTFE compared to untreated PTFE. Thus, this new surface modification technique could potentially address the current challenges associated with PTFE for blood contact applications, specifically poor endothelial cell growth and risk of thrombosis.

Non-equilibrium hybrid organic plasma processing for superhydrophobic PTFE surface towards potential bio-interface applications

Superhydrophobic surfaces have gained increased attention due to the high water-repellency and self-cleaning capabilities of these surfaces. In the present study, we explored a novel hybrid method of fabricating superhydrophobic poly(tetrafluoroethylene) (PTFE) surfaces by combining the physical etching capability of oxygen plasma with the plasma-induced polymerization of a organic monomer methyl methacrylate (MMA). This novel hybrid combination of oxygen-MMA plasma has resulted in the generation of superhydrophobic PTFE surfaces with contact angle of 154°. We hypothesized that the generation of superhydrophobicity may be attributed to the generation of fluorinated poly(methyl methacrylate) (PMMA) moieties formed by the combined effects of physical etching causing de-fluorination of PTFE and the subsequent plasma polymerization of MMA. The plasma treated PTFE surfaces were then systematically characterized via XPS, FTIR, XRD, DSC and SEM analyses. The results have clearly shown a synergistic effect of the oxygen/MMA combination in comparison with either the oxygen plasma alone or MMA vapors alone. Furthermore, the reported new hybrid combination of Oxygen-MMA plasma has been demonstrated to achieve superhydrophobicity at lower power and short time scales than previously reported methods in the literature. Hence the reported novel hybrid strategy of fabricating superhydrophobic PTFE surfaces could have futuristic potential towards biointerface applications.

A benchmark for Monte Carlo simulation in gamma-ray spectrometry

Monte Carlo (MC) simulation is widely used in gamma-ray spectrometry, however, its implementation is not always easy and can provide erroneous results. The present action provides a benchmark for several MC software for selected cases. The examples are based on simple geometries, two types of germanium detectors and four kinds of sources, to mimic eight typical measurement conditions. The action outputs (input files and efficiency calculation results, including practical recommendations for new users) are made available on a dedicated webpage.

The Mobile Analyzer of Radioactive Gases OuTflows (MARGOT): A promising environmental xenon radionuclides detection system

An ultra-compact and unshielded spectrometer for analysis of atmospheric xenon radionuclides has been developed: the MARGOT system. This system works at ambient temperature and high pressure, and has a 54.3 cm³ inner active volume. Atmospheric xenon radionuclide activities are determined with the electron-photon coincidence technique using both NaI(Tl) detectors and large pixellized Si-PIN detectors. The MARGOT system integrates an enhanced version of the PIPSBox™, Geant4 simulation and first calibration results are discussed.

Vimentin intermediate filament assembly regulates fibroblast invasion in fibrogenic lung injury

Idiopathic pulmonary fibrosis (IPF) is a progressive disease, with a median survival of 3-5 years following diagnosis. Lung remodeling by invasive fibroblasts is a hallmark of IPF. In this study, we demonstrate that inhibition of vimentin intermediate filaments (VimIFs) decreases the invasiveness of IPF fibroblasts and confers protection against fibrosis in a murine model of experimental lung injury. Increased expression and organization of VimIFs contribute to the invasive property of IPF fibroblasts in connection with deficient cellular autophagy. Blocking VimIF assembly by pharmacologic and genetic means also increases autophagic clearance of collagen type I. Furthermore, inhibition of expression of collagen type I by siRNA decreased invasiveness of fibroblasts. In a bleomycin injury model, enhancing autophagy in fibroblasts by an inhibitor of VimIF assembly, withaferin A (WFA), protected from fibrotic lung injury. Additionally, in 3D lung organoids, or pulmospheres, from patients with IPF, WFA reduced the invasiveness of lung fibroblasts in the majority of subjects tested. These studies provide insights into the functional role of vimentin, which regulates autophagy and restricts the invasiveness of lung fibroblasts.

Effect of cylinder power and axis changes on vision in astigmatic participants

PURPOSE

To ascertain the impact of altering cylinder (cyl) power and axis on vision in astigmatism.

METHODS

In a prospective, randomized, participant-masked, crossover clinical trial, 28 astigmatic participants were tested for the following conditions on different days: full sphero-cyl correction and undercorrection by 0.25, 0.50, and 0.75 DC while maintaining spherical equivalence. Axis was also misaligned between -30° and +30°, in 10° steps. For each configuration, monocular high- and low-contrast visual acuities (HCVA, LCVA) were measured at 6 m, and participants rated vision clarity (1-10), vision satisfaction (1-10), and vision acceptability (yes/no). Linear mixed models were used to compare visual performance in the overall group and in low, medium, and high cyl subgroups.

RESULTS

Undercorrecting cyl power affected all groups equally (P≥0.073). Undercorrection by 0.75 DC was significantly different to full cyl power for all variables (P≤0.007), while 0.25 DC undercorrection did not cause any significant decreases (P>0.05). Undercorrection by 0.50 DC was significantly different to full cyl power for HCVA (P=0.006, however not clinically significant) and vision acceptability (P=0.034). Axis misalignment affected the cyl groups differently (P<0.001), with the greatest impact in the high cyl group, followed by the medium then the low-cyl group. Misalignment by ±30° caused significant decreases in almost all cases (P≤0.003), while misalignments by ±10° or ±20° caused significant decreases for some cyl groups and test variables.

CONCLUSION

Undercorrection of cyl by ≤0.50 DC while maintaining spherical equivalence has no significant effect on HCVA, LCVA, vision clarity, and vision satisfaction, while the amount of axis misalignment that can be tolerated is dependent on the cyl power. These results may have practical ophthalmic applications, such as reducing the total number of stock keeping units of toric contact lenses.

Green Synthesized Plasmonic Silver Systems for Potential Non-Linear Optical Applications: Optical Limiting and Dual Beam Mode Matched Thermal Lensing

Bioactive compound functionalized plasmonic systems are evolving as a promising branch of nanotechnology. In this communication the synthesis of bioactive compound mimosine-based silver nanoparticles (AgNPs) and their non-linear optical and thermo-optic properties are presented. UV-Visible spectroscopy, optical bandgap measurement, fluorescence spectroscopy, and high-resolution transmission electron microscopy (HRTEM) techniques were used to characterize the synthesized AgNPs. An open aperture z-scan technique was used to determine the non-linear optical parameters. A very strong reverse saturable absorption (RSA) and low optical limiting threshold were observed for the present mimosine decorated AgNP system. The thermo-optic property of the present system was evaluated using a highly sensitive dual beam mode matched thermal lensing spectroscopic technique. A comparison of the low limiting threshold (242MWcm−2) and thermo-optic property (thermal diffusivity, D=1.13×10−7m2s−1) with similar systems proves its capability for non-linear optical and thermo-optic applications.

Morphology dependent nonlinear optical and photocatalytic activity of anisotropic plasmonic silver

Anisotropic nanoparticles are ideal building blocks for a number of functional materials due to their exceptional and anisotropic optical, electronic, magnetic and mechanical properties. In this work we present systematic studies on morphology dependent ultra-sensitive thermal diffusivity and photodegradation capability of anisotropic plasmonic silver for the first time. Hydrogen peroxide centered synthesis was performed to prepare anisotropic silver nanosystems spherical (14 nm), quasi-spherical (17 nm), elliptical (18 m), rods (aspect ratio 2.1), hexagonal (22 nm) and prisms (19 nm). The synthesized nanosystems were characterized using UV-VIS spectroscopy, high resolution transmission electron microscopy (HRTEM) and band gap analysis. A dual beam mode matched thermal lensing method was adopted for evaluating the thermal diffusivity of the anisotropic system. The present anisotropic nanoparticle system exhibited strong morphology based thermal diffusivity. An increase of 140% in the thermal diffusivity value points to the nonlinear optical application potential of the anisotropic systems. Sunlight mediated photodegradation of methylene blue showed a promising increase in the degradation rate for anisotropic systems compared to other similar systems reported in the literature.

Recommendations on diagnostic tools for Batrachochytrium salamandrivorans

Batrachochytrium salamandrivorans (Bsal) poses a major threat to amphibian, and more specifically caudata, diversity. Bsal is currently spreading through Europe, and mitigation measures aimed at stopping its spread and preventing its introduction into naïve environments are urgently needed. Screening for presence of Bsal and diagnosis of Bsal-induced disease in amphibians are essential core components of effective mitigation plans. Therefore, the aim of this study was to present an overview of all Bsal diagnostic tools together with their limitations and to suggest guidelines to allow uniform interpretation. Here, we investigate the use of different diagnostic tools in post-mortem detection of Bsal and whether competition between Bd and Bsal occurs in the species-specific Bd and Bsal duplex real-time PCR. We also investigate the diagnostic sensitivity, diagnostic specificity and reproducibility of the Bsal real-time PCR and show the use of immunohistochemistry in diagnosis of Bsal-induced chytridiomycosis in amphibian samples stored in formaldehyde. Additionally, we have drawn up guidelines for the use and interpretation of the different diagnostic tools for Bsal currently available, to facilitate standardization of execution and interpretation.