Development of Copper Nanoparticles Based Antimicrobial Coatings Mediated by Zingiber Officinale to Combat Antimicrobial Resistance

Novel antimicrobial agents with better functionality and multitarget modes of action are needed to combat the global rise in antibiotic resistance in bacteria. Copper nanoparticles (CuNPs) have been found to be efficient against many bacterial strains. Thus, combining CuNPs with antibiotics might provide a new approach for designing CuNPs-based antimicrobial drugs. This work is designed to produce CuNPs utilizing ginger rhizome extract as a capping and reducing agent and to evaluate their antibacterial, antioxidant, and antileishmanial properties. The biosynthesized CuNPs were physiochemically characterized by using UV-visible spectroscopy, Fourier transform infrared spectroscopy, X-ray powder diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. Agar well diffusion assay, disc diffusion assay, free radical scavenging assay, and MTT assay were employed to determine the antibacterial, antioxidant, and antileishmanial potential of CuNPs. The successful contact between microbial cell membrane and CuNPs was thought to account for the microbial cell membrane leakage and thus CuNPs were found effective in inhibiting the growth of both gram positive and gram-negative bacteria including Proteus vulgaris, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis, and fungus Candida albicans. As determined by the size of inhibition zones, the maximum antibacteril activity was observed against Staphylococcus epidermidis (28.12±1.7 mm) and the minimum against Pseudomonas aeruginosa (11±0.5 mm). CuNPs have been demonstrated to have a synergistic impact in the suppression of bacteria when combined with broad and narrow spectrum antibiotics such as Ciprofloxacin, Gentamicin, Vancomycin, and Ceftriaxone etc. Furthermore, the significant antioxidant and antileishmanial properties make the CuNPs a multifunctional agent to be used in therapeutics. It is concluded that CuNPs have the potential to be used as antimicrobial agent in the development of alternatives to commercially available antibiotics and antibacterial coatings for medical implants to reduce the chances of infections

Bioactive Betulin and PEG Loaded Poly(vinyl alcohol) Nanofibers as Biodegradable Coatings for Neural Implants

Degradable polymeric coatings offer significant advantages when applied to medical implants. These coatings provide controlled degradation, ensuring that they gradually break down over time in harmony with the body’s healing processes. This controlled degradation can reduce the risk of long-term complications. The aim of our work was to prepare poly(vinyl alcohol) (PVA) nanofibers containing biodegradable polyanhydrides based on betulin disuccinate (DBB) and dicarboxylic derivatives of poly(ethylene glycol) (PEG) and to investigate their morphology, surface properties and biocompatibility. In this regard, PVA and DBB/PEG-loaded PVA nanofibers were fabricated using an electrospinning method. The average diameter of PVA and DBB/PEG-loaded PVA nanofibers were 132 nm and 247 nm, respectively. Surface roughness (Ra) of PVA and DBB/PEG-loaded PVA nanofibers was 96.2 nm and 117.6 nm, respectively, which is in agreement with previous studies on PVA nanofibers. To evaluate cell viability, human neuroblastoma SH-SY5Y cells were cultured for 48h on the surface of electrospun materials. All samples were found to be biocompatible, however, DBB/PEG-loaded PVA nanofibers indicated the highest percentage of viable cells when compared with PVA nanofibers and the control sample. The developed coating indicated promising properties for future application, particularly for the modification of metallic scaffolds used in neural tissue engineering

A flexible strain-responsive sensor fabricated from a biocompatible electronic ink via an additive-manufacturing process

Biosensor technologies are of great interest for applications in wearable electronics, soft robotics and implantable biomedical devices. To accelerate the adoption of electronics for chronic recording of physiological parameters in health and disease, there is a demand for biocompatible, conductive & flexible materials that can integrate with various tissues while remaining biologically inert. Conventional techniques used to fabricate biosensors, such as mask lithography and laser cutting, lack the versatility to produce easily customisable, micro-fabricated biosensors in an efficient, cost-effective manner. In this paper, we describe the development and characterisation of an electronic ink made from an environmentally sustainable copolymer - x-pentadecalactone-co-e-decalactone, (PDL) incorporating silver nanowires (AgNW), which are known for their antimicrobial and conductive properties. The composites were shown to possess a low percolation threshold (1% w/w of AgNW to PDL), achieve a low electrical resistance (320 +/- 9 O/sq) and a high electrical capacitance (2.06 +/- 0.06 mF/cm2). PDL nanocomposites were biocompatible, demonstrated in vitro through the promotion of neural adhesion and prevention of astrocyte activation. An optimised ink formulation was subsequently used to fabricate strain-responsive biosensors with high spatial resolution (sub-100 mm) using a direct write additive manufacturing process. Using a customized in vitro set-up, the sensitivity of these biosensors to biologically-relevant strains was assessed under simulated physiological conditions for 21 days. Critically, these 3D printed biosensors have applications in chronic prophylactic monitoring of pressure changes within the body and related pathologies.This publication has emanated from research conducted with the financial support of the Science Foundation Ireland (SFI) Technology Innovation Development Programme, grant no. 15/TIDA/2992 and was co-funded under the European Regional Development Fund under Grant Number 13/RC/2073 and the Hardiman PhD Research Scholarship from the National University of Ireland, Galway. This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 713690. The authors acknowledge the facilities and scientific and technical assistance of the Centre for Microscopy & Imaging at the National University of Ireland Galway, a facility that is funded by NUIG and the Irish Government's Programme for Research in Third Level Institutions, Cycles 4 and 5, National Development Plan 20072013.r The Basque Government GV/EJ (Department of Education, Linguistic Politics and Culture) is also acknowledged for financial support to the consolidated research groups project IT927-16 (UPV/EHU, GIC/152)

Development of Multifunctional Biomaterials by Combining Electrochemistry, Microbiology, and Neural Tissue Engineering

The development of electroactive organic materials has been an unquestionable breakthrough for organic electronics, allowing for the design of polymer-based electrochromic and optoelectronic devices. Electroactive materials have been also considered as promising in the wide-field biomedical engineering, particularly considering their similarity with a living tissue in terms of elemental composition, surface morphology and mechanical properties. Electroactive materials are especially relevant in neural tissue engineering since the functionality of neural tissue is based on the transfer of electrical signals. Unfortunately, electroactive organic materials are also prone to bacterial colonization, which becomes as a considerable threat to patient’s health. In our group, we have been working on the development of biocompatible, antibacterial and conducting implant coatings based on conducting polymers [1] and diazonium-derived electroactive monolayers [2]. With the use of electrochemical techniques, we have fabricated a library of electroactive materials with various physicochemical characteristics, differing in the way how they interact with a living matter. Antimicrobial effects have been verified against model microorganisms: E. coli, S. aureus, and C. albicans, while the biocompatibility has been confirmed towards human neuroblastoma SH-SY5Y cells. Unique combination of biological activity of developed materials with their electroactivity allows for further enhancement of their modus operandi, through the possibility of applying electrical stimulation to facilitate treatment. In this way, the results of our work are a major step towards the development of advanced bio-optoelectronic-based therapies

Catalyst Design through Grafting of Diazonium Salts—A Critical Review on Catalyst Stability

In the pursuit of designing a reusable catalyst with enhanced catalytic activity, recent studies indicate that electrochemical grafting of diazonium salts is an efficient method of forming heterogeneous catalysts. The aim of this review is to assess the industrial applicability of diazonium-based catalysts with particular emphasis on their mechanical, chemical, and thermal stability. To this end, different approaches to catalyst production via diazonium salt chemistry have been compared, including the immobilization of catalysts by a chemical reaction with a diazonium moiety, the direct use of diazonium salts and nanoparticles as catalysts, the use of diazonium layers to modulate wettability of a carrier, as well as the possibility of transforming the catalyst into the corresponding diazonium salt. After providing descriptions of the most suitable carriers, the most common deactivation routes of catalysts have been discussed. Although diazonium-based catalysts are expected to exhibit good stability owing to the covalent bond created between a catalyst and a post-diazonium layer, this review indicates the paucity of studies that experimentally verify this hypothesis. Therefore, use of diazonium salts appears a promising approach in catalysts formation if more research efforts can focus on assessing their stability and long-term catalytic performance

Guidelines for a Morphometric Analysis of Prokaryotic and Eukaryotic Cells by Scanning Electron Microscopy

The invention of a scanning electron microscopy (SEM) pushed the imaging methods and allowed for the observation of cell details with a high resolution. Currently, SEM appears as an extremely useful tool to analyse the morphology of biological samples. The aim of this paper is to provide a set of guidelines for using SEM to analyse morphology of prokaryotic and eukaryotic cells, taking as model cases Escherichia coli bacteria and B-35 rat neuroblastoma cells. Herein, we discuss the necessity of a careful sample preparation and provide an optimised protocol that allows to observe the details of cell ultrastructure (≥ 50 nm) with a minimum processing effort. Highlighting the versatility of morphometric descriptors, we present the most informative parameters and couple them with molecular processes. In this way, we indicate the wide range of information that can be collected through SEM imaging of biological materials that makes SEM a convenient screening method to detect cell pathology

Evaluation of drug loading capacity and release characteristics of PEDOT/naproxen system: Effect of doping ions

Conducting polymers are versatile and robust materials that have recently become attractive as controlled drug delivery systems. Possessing ion exchangeable properties, they can serve as carriers for numerous biologically active species, showing particular applicability in neural tissue engineering and regional chemotherapy. In the pursuit of the design of the most effective controlled drug delivery system, we aimed to compare the performance of the conducting polymer-based matrix as a function of doping anion, using chloride, perchlorate and dodecyl sulfate, respectively, as the primary dopants. Due to their different ion radius and mobility, selected ions were found to provide substantial changes into polymer characteristics, having strong effects into the uptake and release of a model drug, naproxen sodium salt. PEDOT/ClO4 matrix, particularly, was found to possess superior properties providing highest mass of the formed polymer (103.45 +/- 10.09 mu g cm(-2)), charge storage capacity (44.9 mC cm(-2)) and ion exchange capacity (0.122 +/- 0.003 mu mol cm(-2)), leading also to the highest amounts of loaded (0.024 +/- 0.002 mu mol cm(-2)) and released (from 0.71 +/- 0.10 mu g cm(-2) to 1.61 +/- 0.59 mu g cm(-2)) drug. (C) 2018 Elsevier Ltd. All rights reserved.The authors are grateful to the National Science Centre in Poland for financing the research in the framework of Sonata (2016/23/D/ST5/01306). This publication has emanated from research conducted with the financial support of Science Foundation Ireland (SFI) and is co-funded under the European Regional Development Fund under Grant Number 13/RC/2073. This project has received funding from the European Union\u27s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 713690. The authors acknowledge the facilities and scientific and technical assistance of the Centre for Microscopy & Imaging at the National University of Ireland Galway, a facility that is funded by NUIG and the Irish Government\u27s Programme for Research in Third Level Institutions, Cycles 4 and 5, National Development Plan 2007–2013.2020-09-0