Search results for: bioactive nanoparticles

Authors: Manal Kamel, Sara Maher, Hanan El Baz, Faten Salah, Omar Sayyouh, Zeinab Demerdash

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In the recent COVID 19 pandemic, experts of public health have emphasized testing, tracking infected people, and tracing their contacts as an effective strategy to reduce the spread of the virus. Development of rapid and sensitive diagnostic assays to replace reverse transcription polymerase chain reaction (RT-PCR) is mandatory..Our innovative test strip relying on the application of nanoparticles conjugated to recombinant nanobodies for SARS-COV-2 spike protein (S1) & angiotensin-converting enzyme 2 (that is responsible for the virus entry into host cells) for rapid detection of SARS-COV-2 spike protein (S1) in saliva or sputum specimens. Comparative tests with RT-PCR will be held to estimate the significant effect of using COVID 19 nanobodies for the first time in the development of lateral flow test strip. The SARS-CoV-2 S1 (3 ng of recombinant proteins) was detected by our developed LFIA in saliva specimen of COVID-19 Patients No cross-reaction was detected with Middle East respiratory syndrome coronavirus (MERS-CoV) or SARS- CoV antigens..Our developed system revealed 96 % sensitivity and 100% specificity for saliva samples compared to 89 % and 100% sensitivity and specificity for nasopharyngeal swabs. providing a reliable alternative for the painful and uncomfortable nasopharyngeal swab process and the complexes, time consuming PCR test. An increase in testing compliances to be expected.

Keywords: COVID 19, diagnosis, LFIA, nanobodies, ACE2

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Authors: R. Tajau, R. Rohani, M. S. Alias, N. H. Mudri, K. A. Abdul Halim, M. H. Harun, N. Mat Isa, R. Che Ismail, S. Muhammad Faisal, M. Talib, M. R. Mohamed Zin

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Bio-based polymeric materials are increasingly used for a variety of applications, including surface coating, drug delivery systems, and tissue engineering. These polymeric materials are ideal for the aforementioned applications because they are derived from natural resources, non-toxic, low-cost, biocompatible, and biodegradable, and have promising thermal and mechanical properties. The nature of hydrocarbon chains, carbon double bonds, and ester bonds allows various sources of oil (edible), such as soy, sunflower, olive, and oil palm, to fine-tune their particular structures in the development of innovative materials. Palm oil can be the most eminent raw material used for manufacturing new and advanced natural polymeric materials involving radiation techniques, such as coating resins, nanoparticles, scaffold, nanotubes, nanocomposites, and lithography for different branches of the industry in countries where oil palm is abundant. The radiation technique is among the most versatile, cost-effective, simple, and effective methods. Crosslinking, reversible addition-fragmentation chain transfer (RAFT), polymerisation, grafting, and degradation are among the radiation mechanisms. Exposure to gamma, EB, UV, or laser irradiation, which are commonly used in the development of polymeric materials, is used in these mechanisms. Therefore, this review focuses on current radiation processing technologies for the development of various radiation-curable bio-based polymeric materials with a promising future in biomedical and industrial applications. The key focus of this review is on radiation curable palm oil-based products, which have been published frequently in recent studies.

Keywords: palm oil, radiation processing, surface coatings, VOC

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Authors: Garima, S. Pushpavanam

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In this work, analysis of an Aqueous two-phase (polymer-salt) system for extraction of sunset yellow dye is carried out. A polymer-salt ATPS i.e.; Polyethylene glycol-600 and anhydrous sodium sulfate is used for the extraction. Conditions are chosen to ensure that the extraction results in a concentration of the dye in one of the phases. The dye has a propensity to come to the Polyethylene glycol-600 phase. This extracted sunset yellow dye is degraded photo catalytically into less harmful components. The cloud point method was used to obtain the binodal curve of ATPS. From the binodal curve, the composition of salt and Polyethylene glycol -600 was chosen such that the volume of Polyethylene glycol-600 rich phase is low. This was selected to concentrate the dye from a dilute solution in a large volume of contaminated solution into a small volume. This pre-concentration step provides a high reaction rate for photo catalytic degradation reaction. Experimentally the dye is extracted from the salt phase to Polyethylene glycol -600 phase in batch extraction. This was found to be very fast and all dye was extracted. The concentration of sunset yellow dye in salt and polymer phase is measured at 482nm by ultraviolet-visible spectrophotometry. The extraction experiment in micro channels under stratified flow is analyzed to determine factors which affect the dye extraction. Focus will be on obtaining slug flow by adding nanoparticles in micro channel. The primary aim is to exploit the fact that slug flow will help improve mass transfer rate from one phase to another through internal circulation in dispersed phase induced by shear.

Keywords: aqueous two phase system, binodal curve, extraction, sunset yellow dye

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Authors: J. Plocek, P. Holec, S. Kubickova, B. Pacakova, I. Matulkova, A. Mantlikova, I. Němec, D. Niznansky, J. Vejpravova

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This article presents summary on preparation and characterization of zinc, copper, cadmium and cobalt chromite nano crystals, embedded in an amorphous silica matrix. The ZnCr2O4/SiO2, CuCr2O4/SiO2, CdCr2O4/SiO2 and CoCr2O4/SiO2 nano composites were prepared by a conventional sol-gel method under acid catalysis. Final heat treatment of the samples was carried out at temperatures in the range of 900–1200 °C to adjust the phase composition and the crystallite size, respectively. The resulting samples were characterized by Powder X-ray diffraction (PXRD), High Resolution Transmission Electron Microscopy (HRTEM), Raman/FTIR spectroscopy and magnetic measurements. Formation of the spinel phase was confirmed in all samples. The average size of the nano crystals was determined from the PXRD data and by direct particle size observation on HRTEM; both results were correlated. The mean particle size (reviewed by HRTEM) was in the range from ~ 4 to 46 nm. The results showed that the sol-gel method can be effectively used for preparation of the spinel chromite nano particles embedded in the silica matrix and the particle size is driven by the type of the cation A2+ in the spinel structure and the temperature of the final heat treatment. Magnetic properties of the nano crystals were found to be just moderately modified in comparison to the bulk phases.

Keywords: sol-gel method, nanocomposites, Rietveld refinement, Raman spectroscopy, Fourier transform infrared spectroscopy, magnetic properties, spinel, chromite

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Authors: Attila Kiss, Erzsébet Némedi, Zoltán Naár

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As natural prebiotic (non-digestible) carbohydrates stimulate the growth of colon microflora and contribute to maintain the health of the host, analytical studies aiming at revealing the chemical behavior of these beneficial food components came to the forefront of interest. Food processing (especially baking) may lead to a significant conversion of the parent compounds, hence it is of utmost importance to characterize the transformation patterns and the plausible decomposition products formed by thermal degradation. The relevance of this work is confirmed by the wide-spread use of these carbohydrates (fructo-oligosaccharides, cyclodextrins, raffinose and resistant starch) in the food industry. More and more functional foodstuffs are being developed based on prebiotics as bioactive components. 12 different types of oligosaccharides have been investigated in order to reveal their thermal degradation characteristics. Different carbohydrate derivatives (D-fructose and D-glucose oligomers and polymers) have been exposed to elevated temperatures (150 °C 170 °C, 190 °C, 210 °C, and 220 °C) for 10 min. An advanced HPLC method was developed and used to identify the decomposition products of carbohydrates formed as a consequence of thermal treatment. Gradient elution was applied with binary solvent elution (acetonitrile, water) through amine based carbohydrate column. Evaporative light scattering (ELS) proved to be suitable for the reliable detection of the UV/VIS inactive carbohydrate degradation products. These experimental conditions and applied advanced techniques made it possible to survey all the formed intermediers. Change in oligomer distribution was established in cases of all studied prebiotics throughout the thermal treatments. The obtained results indicate increased extent of chain degradation of the carbohydrate moiety at elevated temperatures. Prevalence of oligomers with shorter chain length and even the formation of monomer sugars (D-glucose and D-fructose) might be observed at higher temperatures. Unique oligomer distributions, which have not been described previously are revealed in the case of each studied, specific carbohydrate, which might result in various prebiotic activities. Resistant starches exhibited high stability when being thermal treated. The degradation process has been modeled by a plausible reaction mechanism, in which proton catalyzed degradation and chain cleavage take place.

Keywords: prebiotics, thermal degradation, fructo-oligosaccharide, HPLC, ELS detection

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Authors: Siti Hajar Muhamad Rosli, Xin Yi Lim, Terence Yew Chin Tan, Muhammad nor Farhan Sa’At, Syazwani Sirdar Ali, Ami Fazlin Syed Mohamed

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A growing interest on therapeutic benefits of hemp (Cannabis sativa subsp. sativa) is evident in the pharmaceutical market, attributed to its lower levels of psychoactive constituent delta-9-tetrahydronannabidiol (THC). Deemed as a legal and safer alternative to its counterpart marijuana, the use of medicinal hemp is highly debatable as current scientific evidence on the efficacy for clinical use is yet to be established This study was aimed to provide an overview of the current landscape of hemp research, through recent clinical findings specific to the pharmacological properties of the hemp plant and its derived compounds. A systematic search was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analysis-ScR (PRISMA) checklist on electronic databases (MEDLINE, OVID, Cochrane Library Central, and Clinicaltrials.gov) for articles published from 2009 to 2019. With predetermined inclusion criteria, all human trials with hemp intervention were included. A total of 18 human trials were identified, investigating therapeutic effects on the neuronal, gastrointestinal, musculoskeletal and immune system, with sample sizes ranging from one to 194 subjects. Three randomised controlled trials showed hempseed pills (in Traditional Chinese Medicine formulation MaZiRenWan) consumption significantly improved spontaneous bowel movement in functional constipation. The use of commercial cannabidiol (CBD) sourced from hemp suggested benefits in cannabis dependence, epilepsy, and anxiety disorders. However, there was insufficient evidence to suggest analgesic or anxiolytics effects of hemp being equivalent to marijuana. All clinical trials reviewed varied in terms of test item formulation and standardisation, which made it challenging to confirm overall efficacy for a specific disease or condition. Published efficacy data on hemp are still at a preliminary level, with limited high quality clinical evidence for any specific therapeutic indication. With multiple variants of this plant having different phytochemical and bioactive compounds, future empirical research should focus on uniformity in experimental designs to further strengthen the notion of using medicinal hemp.

Keywords: cannabis, complementary medicine, hemp, herbal medicine.

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Authors: Mrinalini Amritkar, Disha Patil, Swapna Kulkarni, Sukratu Barve, Suresh Gosavi

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Micro-mixers play an important role in the lab-on-a-chip applications and micro total analysis systems to acquire the correct level of mixing for any given process. The mixing process can be classified as active or passive according to the use of external energy. Literature of microfluidics reports that most of the work is done on the models of steady laminar flow; however, the study of unsteady laminar flow is an active area of research at present. There are wide applications of this, out of which, we consider nanoparticle synthesis in micro-mixers. In this work, we have developed a model for unsteady flow to study the mixing performance of a passive micro mixer for reactants used for such synthesis. The model is developed in Finite Volume Method (FVM)-based software, OpenFOAM. The model is tested by carrying out the simulations at Re of 0.5. Mixing performance of the micro-mixer is investigated using simulated concentration values of mixed species across the width of the micro-mixer and calculating the variance across a line profile. Experimental validation is done by passing dyes through a Y shape micro-mixer fabricated using polydimethylsiloxane (PDMS) polymer and comparing variances with the simulated ones. Gold nanoparticles are later synthesized through the micro-mixer and collected at two different times leading to significantly different size distributions. These times match with the time scales over which reactant concentrations vary as obtained from simulations. Our simulations could thus be used to create design aids for passive micro-mixers used in nanoparticle synthesis.

Keywords: Lab-on-chip, LOC, micro-mixer, OpenFOAM, PDMS

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Authors: Priya Ruban, Thirunavoukkarasu Manikkannan, Sakthivel Ramasamy

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Sulfide is one of the major pollutants of tannery effluent which is mainly generated during the process of unhairing. Recovery of Hydrogen green fuel from sulfide wastewater using photocatalysis is a ‘Cleaner Production Method’, since renewable solar energy is utilized. It has triple advantages of the generation of H2, waste minimization and odor or pollution control. Designing of safe and green photocatalysts and developing suitable solar photoreactor is important for promoting this technology to large-scale application. In this study, green photocatalyst i.e., spinach derived carbon dots (SCDs 5 wt % and 10 wt %)/TiO2 nanocomposite was synthesized for generation of H2 from sulfide wastewater using lab-scale solar photocatalytic reactor. The physical characterization of the synthesized solar light responsive nanocomposites were studied by using DRS UV-Vis, XRD, FTIR and FESEM analysis. The absorption edge of TiO2 nanoparticles is extended to visible region by the incorporation of SCDs, which was used for converting noxious pollutant sulfide into eco-friendly solar fuel H2. The SCDs (10 wt%)-TiO2 nanocomposite exhibits enhanced photocatalytic hydrogen production i.e. ~27 mL of H2 (180 min) from simulated sulfide wastewater under LED visible light irradiation which is higher as compared to SCDs. The enhancement in the photocatalytic generation of H2 is attributed to combining of SCDs which increased the charge mobility. This work may provide new insights to usage of naturally available and cheap materials to design novel nanocomposite as a visible light active photocatalyst for the generation of H2 from sulfide containing wastewater.

Keywords: carbon dots, hydrogen fuel, hydrogen sulfide, photocatalysis, sulfide wastewater

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Authors: P. G. Siddheshwar, T. N. Sakshath

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In the paper we make linear and non-linear stability analyses of Rayleigh-Bénard convection of a Newtonian nanoliquid in a rotating medium (called as Rayleigh-Bénard-Taylor convection). Rigid-rigid isothermal boundaries are considered for investigation. Khanafer-Vafai-Lightstone single phase model is used for studying instabilities in nanoliquids. Various thermophysical properties of nanoliquid are obtained using phenomenological laws and mixture theory. The eigen boundary value problem is solved for the Rayleigh number using an analytical method by considering trigonometric eigen functions. We observe that the critical nanoliquid Rayleigh number is less than that of the base liquid. Thus the onset of convection is advanced due to the addition of nanoparticles. So, increase in volume fraction leads to advanced onset and thereby increase in heat transport. The amplitudes of convective modes required for estimating the heat transport are determined analytically. The tri-modal standard Lorenz model is derived for the steady state assuming small scale convective motions. The effect of rotation on the onset of convection and on heat transport is investigated and depicted graphically. It is observed that the onset of convection is delayed due to rotation and hence leads to decrease in heat transport. Hence, rotation has a stabilizing effect on the system. This is due to the fact that the energy of the system is used to create the component V. We observe that the amount of heat transport is less in the case of rigid-rigid isothermal boundaries compared to free-free isothermal boundaries.

Keywords: nanoliquid, rigid-rigid, rotation, single phase

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Authors: Yong Zhang

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Light has proven to be useful in a wide range of biomedical applications such as fluorescence imaging, photoacoustic imaging, optogenetics, photodynamic therapy, photothermal therapy, and light controlled drug/gene delivery. Taking photodynamic therapy (PDT) as an example, PDT has been proven clinically effective in early lung cancer, bladder cancer, head, and neck cancer and is the primary treatment for skin cancer as well. However, clinical use of PDT is severely constrained by the low penetration depth of visible light through thick tissue, limiting its use to target regions only a few millimeters deep. One way to enhance the range is to use invisible near-infrared (NIR) light within the optical window (700–1100nm) for biological tissues, extending the depth up to 1cm with no observable damage to the intervening tissue. We have demonstrated use of NIR-to-visible upconversion fluorescent nanoparticles (UCNPs), emitting visible fluorescence when excited by a NIR light at 980nm, as a nanotransducer for PDT to convert deep tissue-penetrating NIR light to visible light suitable for activating photosensitizers. The unique optical properties of UCNPs enable the upconversion wavelength to be tuned and matched to the activation absorption wavelength of the photosensitizer. At depths beyond 1cm, however, tissue remains inaccessible to light even within the NIR window, and this critical depth limitation renders existing phototherapy ineffective against most deep-seated cancers. We have demonstrated some new treatment modalities for deep-seated cancers based on UCNP hydrogel implants and miniaturized, wirelessly powered optoelectronic devices for light delivery to deep tissues.

Keywords: upconversion, fluorescent, nanoparticle, bioimaging, photodynamic therapy

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Authors: Sudip Mondal, Biswanath Mondal, Sudit S. Mukhopadhyay, Apurba Dey

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Bioactive materials improve devices for a long lifespan but have mechanical limitations. Mechanical characterization is one of the very important characteristics to evaluate the life span and functionality of the scaffold material. After implantation of scaffold material the primary stage rejection of scaffold occurs due to non biocompatible effect of host body system. The second major problems occur due to the effect of mechanical failure. The mechanical and biocompatibility failure of the scaffold materials can be overcome by the prior evaluation of the scaffold materials. In this study chemically treated Labeo rohita scale is used for synthesizing hydroxyapatite (HAp) biomaterial. Thermo-gravimetric and differential thermal analysis (TG-DTA) is carried out to ensure thermal stability. The chemical composition and bond structures of wet ball-milled calcined HAp powder is characterized by Fourier Transform Infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray (EDX) analysis. Fish scale derived apatite materials consists of nano-sized particles with Ca/P ratio of 1.71. The biocompatibility through cytotoxicity evaluation and MTT assay are carried out in MG63 osteoblast cell lines. In the cell attachment study, the cells are tightly attached with HAp scaffolds developed in the laboratory. The result clearly suggests that HAp material synthesized in this study do not have any cytotoxic effect, as well as it has a natural binding affinity for mammalian cell lines. The synthesized HAp powder further successfully used to develop porous scaffold material with suitable mechanical property of ~0.8GPa compressive stress, ~1.10 GPa a hardness and ~ 30-35% porosity which is acceptable for implantation in trauma region for animal model. The histological analysis also supports the bio-affinity of processed HAp biomaterials in Wistar rat model for investigating the contact reaction and stability at the artificial or natural prosthesis interface for biomedical function. This study suggests the natural sourced fish scale-derived HAp material could be used as a suitable alternative biomaterial for tissue engineering application in near future.

Keywords: biomaterials, hydroxyapatite, scaffold, mechanical property, tissue engineering

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Authors: Eun-Young Kwon, Myung-Sook Choi, Su-Jung Cho, Ji-Young Choi, So Young Kim, Youngji Han

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Overweight and obesity have been linked to a low-grade chronic inflammatory response and an increased risk of developing metabolic syndrome including insulin resistance, type 2 diabetes mellitus and certain types of cancers. Luteolin is a dietary flavonoid with anti-inflammatory, anti-oxidant, anti-cancer and anti-diabetic properties. However, little is known about the detailed mechanism associated with the effect of luteolin on inflammation-related obesity and its complications. The aim of the present study was to reveal the anti-diabetic effect of luteolin in diet-induced obesity mice using “transcriptomics” tool. Thirty-nine male C57BL/6J mice (4-week-old) were randomly divided into 3 groups and were fed normal diet, high-fat diet (HFD, 20% fat) and HFD+0.005% (w/w) luteolin for 16 weeks. Luteolin improved insulin resistance, as measured by HOMA-IR and glucose tolerance, along with preservation action of pancreatic β-cells, compared to the HFD group. Luteoiln was significantly decreased the levels of leptin and ghrelin that play a pivotal role in energy balance, and the macrophage low-grade inflammation marker sCD163 (soluble Cd antigen 163) in plasma. Activities of hepatic anti-oxidant enzymes (catalase and glutathione peroxidase) were increased, while the levels of plasma transaminase (GOT and GPT) and oxidative damage markers (hepatic mitochondria H2O2 and TBARS) were markedly decreased by luteolin supplementation. In addition, luteolin increased oxidative capacity and fatty acid utilization by presenting decrease in enzyme activities of citrate synthase, cytochrome C oxidase and β-hydroxyacyl CoA dehydrogenase and UCP3 gene expression compared to high-fat diet. Moreover, our microarray results of muscle also revealed down-regulated gene expressions associated with TCA cycle by HFD were reversed to normal level by luteolin treatment. Taken together, our results indicate that luteolin is one of bioactive components for improving insulin resistance by increasing oxidative capacity, modulating anti-oxidant metabolism and suppressing inflammatory signaling cascades in diet-induced obese mice. These results provide possible therapeutic targets for prevention and treatment of diet-induced obesity and its complications.

Keywords: anti-oxidant metabolism, diabetes, luteolin, oxidative capacity

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Authors: Emil F. Khisamutdinov

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Development of functional materials undergoing structural transformations in response to an external stimulus such as environmental changes (pH, temperature, etc.), the presence of particular proteins, or short oligonucleotides are of great interest for a variety of applications ranging from medicine to electronics. The dynamic operations of most nucleic acid (NA) devices, including circuits, nano-machines, and biosensors, rely on networks of NA strand displacement processes in which an external or stimulus strand displaces a target strand from a DNA or RNA duplex. The rate of strand displacement can be greatly increased by the use of “toeholds,” single-stranded regions of the target complex to which the invading strand can bind to initiate the reaction, forming additional base pairs that provide a thermodynamic driving force for transformation. Herein, we developed a highly robust nanoparticle shape transition, sequentially transforming DNA polygons from one shape to another using the toehold-mediated DNA strand displacement technique. The shape transformation was confirmed by agarose gel electrophoresis and atomic force microscopy. Furthermore, we demonstrate that our approach is applicable for RNA shape transformation from triangle to square, which can be detected by fluorescence emission from malachite green binding RNA aptamer. Using gel-shift and fluorescence assays, we demonstrated efficient transformation occurs at isothermal conditions (37°C) that can be implemented within living cells as reporter molecules. This work is intended to provide a simple, cost-effective, and straightforward model for the development of biosensors and regulatory devices in nucleic acid nanotechnology.

Keywords: RNA nanotechnology, bionanotechnology, toehold mediated DNA switch, RNA split fluorogenic aptamers

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Authors: Banu Hatice Gürcüm, Pınar Arslan, Mahmut Yalçın

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From the oldest production methods with yarns used to weave, knit, braid and knot to the newest production methods with fibres used to stitch, bond or structures of innovative technologies, laminates, nanoparticles, composites or 3D printing systems, textile industry advanced through materials, processes and context mostly within the last five decades. The creative momentum of fabric like 3D printed structures have come to the point of transforming as for the newest form of textile applications. Moreover, pioneering studies on the applications of 3D Printing Technology and Additive Manufacturing have been focusing on fashion and apparel sector from the last two decades beginning with fashion designers. After the advent of chain-mail like structures and flexible micro or meso structures created by SLS rapid manufacturing a more textile-like behavior is achieved. Thus, the primary aim of this paper is to discuss the most important properties of traditional fabrics that are to be expected of future fabrics. For this reason, this study deals primarily with the physical properties like softness, hand, flexibility, drapability and wearability of 3D Printed structures necessary to identify the possible ways in which it can be used instead of contemporary textile structures, namely knitted and woven fabrics. The aim of this study is to compare the physical properties of 3D printed fabrics regarding different rapid manufacturing methods (FDM and SLS). The implemented method was Material Driven Design (MDD), which comprise the use of innovative materials according to the production techniques such as 3D printing system. As a result, advanced textile processes and materials enable to the creation of new types of fabric structures and rapid solutions in the field of textiles and 3D fabrics on the other hand, are to be used in this regard.

Keywords: 3D printing technology, FDM, SLS, textile structure

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Authors: Samaneh Farokhirad, Fatemeh Ahmadpoor

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Biological membranes are constantly in contact with various filamentous soft nanostructures that either reside on their surface or are being transported between the cell and its environment. In particular, viral infections are determined by the interaction of viruses (such as filovirus) with cell membranes, membrane protein organization (such as cytoskeletal proteins and actin filament bundles) has been proposed to influence the mechanical properties of lipid membranes, and the adhesion of filamentous nanoparticles influence their delivery yield into target cells or tissues. The goal of this research is to integrate the rapidly increasing but still fragmented experimental observations on the adhesion and self-assembly of nanofilaments (including filoviruses, actin filaments, as well as natural and synthetic nanofilaments) on cell membranes into a general, rigorous, and unified knowledge framework. The global outbreak of the coronavirus disease in 2020, which has persisted for over three years, highlights the crucial role that nanofilamentbased delivery systems play in human health. This work will unravel the role of a unique property of all cell membranes, namely flexoelectricity, and the significance of nanofilaments’ flexibility in the adhesion and self-assembly of nanofilaments on cell membranes. This will be achieved utilizing a set of continuum mechanics, statistical mechanics, and molecular dynamics and Monte Carlo simulations. The findings will help address the societal needs to understand biophysical principles that govern the attachment of filoviruses and flexible nanofilaments onto the living cells and provide guidance on the development of nanofilament-based vaccines for a range of diseases, including infectious diseases and cancer.

Keywords: virus nanofilaments, cell mechanics, computational biophysics, statistical mechanics

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Authors: Ayat Adnan Atwah, Muhammad A. Khan

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Self-cleaning surfaces are getting significant attention in industrial fields. Especially for textile fabrics, it is observed that self-cleaning textile fabric surfaces are created by manipulating the surface features with the help of coatings and nanoparticles, which are considered costly and far more complicated. However, controlling the fabrication parameters of textile fabrics at the microscopic level by exploring the potential for self-cleaning has not been addressed. This study aimed to establish the context of self-cleaning textile fabrics by controlling the fabrication parameters of the textile fabric at the microscopic level. Therefore, 3D-printed textile fabrics were fabricated using the low-cost fused filament fabrication (FFF) technique. The printing parameters, such as orientation angle (O), layer height (LH), and extruder width (EW), were used to control the microscopic features of the printed fabrics. The combination of three printing parameters was created to provide the best self-cleaning textile fabric surface: (LH) (0.15, 0.13, 0.10 mm) and (EW) (0.5, 0.4, 0.3 mm) along with two different (O) of (45º and 90º). Three different thermoplastic flexible filament materials were used: (TPU 98A), (TPE felaflex), and (TPC flex45). The printing parameters were optimised to get the optimum self-cleaning ability of the printed specimens. Furthermore, the impact of these characteristics on mechanical strength at the fabric-woven structure level was investigated. The study revealed that the printing parameters significantly affect the self-cleaning properties after adjusting the selected combination of layer height, extruder width, and printing orientation. A linear regression model was effectively developed to demonstrate the association between 3D printing parameters (layer height, extruder width, and orientation). According to the experimental results, (TPE felaflex) has a better self-cleaning ability than the other two materials.

Keywords: 3D printing, self-cleaning fabric, microscopic features, printing parameters, fabrication

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Authors: Yagahira E. Castro-Sesquen, Robert H. Gilman, Carolina Mejia, Daniel E. Clark, Jeong Choi, Melissa J. Reimer-Mcatee, Rocio Castro, Jorge Flores, Edward Valencia-Ayala, Faustino Torrico, Ricardo Castillo-Neyra, Lance Liotta, Caryn Bern, Alessandra Luchini

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Early diagnosis of reactivation of Chagas disease in HIV patients could be lifesaving; however, in Latin American the diagnosis is performed by detection of parasitemia by microscopy which lacks sensitivity. To evaluate if levels of T. cruzi antigens in urine determined by Chunap (Chagas urine nanoparticle test) are correlated with parasitemia levels in T. cruzi/HIV co-infected patients. T. cruzi antigens in urine of HIV patients (N=55: 31 T. cruzi infected and 24 T. cruzi serology negative) were concentrated using hydrogel particles and quantified by Western Blot and a calibration curve. The percentage of Chagas positive patients determined by Chunap compared to blood microscopy, qPCR, and ELISA was 100% (6/6), 95% (18/19) and 74% (23/31), respectively. Chunap specificity was 91.7%. Linear regression analysis demonstrated a direct relationship between parasitemia levels (determined by qPCR) and urine T. cruzi antigen concentrations (p<0.001). A cut-off of > 105 pg was chosen to determine patients with reactivation of Chagas disease (6/6). Urine antigen concentration was significantly higher among patients with CD4+ lymphocyte counts below 200/mL (p=0.045). Chunap shows potential for early detection of reactivation and with appropriate adaptation can be used for monitoring Chagas disease status in T. cruzi/HIV co-infected patients.

Keywords: antigenuria, Chagas disease, Chunap, nanoparticles, parasitemia, poly N-isopropylacrylamide (NIPAm)/trypan blue particles (polyNIPAm/TB), reactivation of Chagas disease.

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Authors: Brian Chi Yan Cheng, Hui Guo, Tao Su, Xiu‐qiong Fu, Ting Li, Zhi‐ling Yu

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Rheumatoid arthritis (RA) affects around 1% of the globe population. Yet, there is still no cure for RA. Toll-like receptor 4 (TLR4) signalling has been found to be involved in the pathogenesis of RA, making it a potential therapeutic target for RA treatment. A herbal formula (RL) consisting of fruits of Rosa Multiflora (Eijitsu rose) and flowers of Lonicera Japonica (Japanese honeysuckle) has been used in treating various inflammatory disorders for more than a thousand year. Both of them are rich sources of nutrients and bioactive phytochemicals, which can be used in producing different food products and supplements. In this study, we would evaluate the anti-arthritic effect of RL on collagen-induced arthritis (CIA) in rats and investigate the involvement of TLR4 signaling in the mode of action of RL. Anti-arthritic efficacy was evaluated using CIA rats induced by bovine type II collagen. The treatment groups were treated with RL (82.5, 165, and 330 mg/kg bw per day, p.o.) or positive control indomethacin (0.25 mg/kg bw per day, p.o.) for 35 days. Clinical signs (hind paw volume and arthritis severity scores), changes in serum inflammatory mediators, pro-/antioxidant status, histological and radiographic changes of joints were investigated. Spleens and peritoneal macrophages were used to determine the effects of RL on innate and adaptive immune responses in CIA rats. The involvement of TLR4 signalling pathways in the anti-arthritic effect of RL was examined in cartilage tissue of CIA rats, murine RAW264.7 macrophages and human THP-1 monocytic cells. The severity of arthritis in the CIA rats was significantly attenuated by RL. Antioxidant status, histological score and radiographic score were efficiently improved by RL. RL could also dose-dependently inhibit pro-inflammatory cytokines in serum of CIA rats. RL significantly inhibited the production of various pro-inflammatory mediators, the expression and/or activity of the components of TLR4 signalling pathways in animal tissue and cell lines. RL possesses anti-arthritic effect on collagen-induced arthritis in rats. The therapeutic effect of RL may be related to its inhibition on pro-inflammatory cytokines in serum. The inhibition of the TAK1/NF-κB and TAK1/MAPK pathways participate in the anti-arthritic effects of RL. This provides a pharmacological justification for the dietary use of RL in the control of various arthritic diseases. Further investigation should be done to develop RL into a anti-arthritic food products and/or supplements.

Keywords: japanese honeysuckle, rheumatoid arthritis, rosa multiflora, rosehip

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Authors: S. Ghosh, L. Ramos, A. N. Kouamé, A.-L. Teillout, H. Remita

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Catalytic materials have attracted continuous attention due to their promising applications in a variety of energy and environmental applications including clean energy, energy conversion and storage, purification and separation, degradation of pollutants and electrochemical reactions etc. With the advanced synthetic technologies, polymer nanostructures and nanocomposites can be directly synthesized through soft template mediated approach using swollen hexagonal mesophases and modulate the size, morphology, and structure of polymer nanostructures. As an alternative to conventional catalytic materials, one-dimensional PDPB polymer nanostructures shows high photocatalytic activity under visible light for the degradation of pollutants. These photocatalysts are very stable with cycling. Transmission electron microscopy (TEM), and AFM-IR characterizations reveal that the morphology and structure of the polymer nanostructures do not change after photocatalysis. These stable and cheap polymer nanofibers and metal polymer nanocomposites are easy to process and can be reused without appreciable loss of activity. The polymer nanocomposites formed via one pot chemical redox reaction with 3.4 nm Pd nanoparticles on poly(diphenylbutadiyne) (PDPB) nanofibers (30 nm). The reduction of Pd (II) ions is accompanied by oxidative polymerization leading to composites materials. Hybrid Pd/PDPB nanocomposites used as electrode materials for the electrocatalytic oxidation of ethanol without using support of proton exchange Nafion membrane. Hence, these conducting polymer nanofibers and nanocomposites offer the perspective of developing a new generation of efficient photocatalysts for environmental protection and in electrocatalysis for fuel cell applications.

Keywords: conducting polymer, swollen hexagonal mesophases, solar photocatalysis, electrocatalysis, water depollution

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Authors: Devendra Sillu, Shekhar Agnihotri

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The 'nano-biocatalyst' utilizes an ordered assembling of enzyme on to nanomaterial carriers to catalyze desirable biochemical kinetics and substrate selectivity. The current study describes an inter-disciplinary approach for converting agriculture waste, sugarcane bagasse into D-glucose exploiting halloysite nanotubes (HNTs) decorated cellulase enzyme as nano-biocatalytic system. Cellulase was successfully immobilized on HNTs employing polydopamine as an eco-friendly crosslinker while iron oxide nanoparticles were attached to facilitate magnetic recovery of material. The characterization studies (UV-Vis, TEM, SEM, and XRD) displayed the characteristic features of both cellulase and magnetic HNTs in the resulting nanocomposite. Various factors (i.e., working pH, temp., crosslinker conc., enzyme conc.) which may influence the activity of biocatalytic system were investigated. The experimental design was performed using Response Surface Methodology (RSM) for process optimization. Analyses data demonstrated that the nanobiocatalysts retained 80.30% activity even at elevated temperature (55°C) and excellent storage stabilities after 10 days. The repeated usage of system revealed a remarkable consistent relative activity over several cycles. The immobilized cellulase was employed to decompose agro-waste and the maximum decomposition rate of 67.2 % was achieved. Conclusively, magnetic HNTs can serve as a potential support for enzyme immobilization with long term usage, good efficacy, reusability and easy recovery from solution.

Keywords: halloysite nanotubes, enzyme immobilization, cellulase, response surface methodology, magnetic recovery

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Authors: Z. Terzopoulou, I. Koliakou, D. Bikiaris

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Tissue engineering offers a new approach to regenerate diseased or damaged tissues such as bone. Great effort is devoted to eliminating the need of removing non-degradable implants at the end of their life span, with biodegradable polymers playing a major part. Poly(ε-caprolactone) (PCL) is one of the best candidates for this purpose due to its high permeability, good biodegradability and exceptional biocompatibility, which has stimulated extensive research into its potential application in the biomedical fields. However, PCL degrades much slower than other known biodegradable polymers and has a total degradation of 2-4 years depending on the initial molecular weight of the device. This is due to its relatively hydrophobic character and high crystallinity. Consequently, much attention has been given to the tunable degradation of PCL to meet the diverse requirements of biomedicine. Poly(ε-caprolactone) (PCL) is a biodegradable polyester that lacks bioactivity, so when used in bone tissue engineering, new bone tissue cannot bond tightly on the polymeric surface. Therefore, it is important to incorporate reinforcing fillers into PCL matrix in order to result in a promising combination of bioactivity, biodegradability, and strength. Natural clay halloysite nanotubes (HNTs) were incorporated into PCL polymeric matrix, via in situ ring-opening polymerization of caprolactone, in concentrations 0.5, 1 and 2.5 wt%. Both unmodified and modified with aminopropyltrimethoxysilane (APTES) HNTs were used in this study. The effect of nanofiller concentration and functionalization with end-amino groups on the physicochemical properties of the prepared nanocomposites was studied. Mechanical properties were found enhanced after the incorporation of nanofillers, while the modification increased further the values of tensile and impact strength. Thermal stability of PCL was not affected by the presence of nanofillers, while the crystallization rate that was studied by Differential Scanning Calorimetry (DSC) and Polarized Light Optical Microscopy (POM) increased. All materials were subjected to enzymatic hydrolysis in phosphate buffer in the presence of lipases. Due to the hydrophilic nature of HNTs, the biodegradation rate of nanocomposites was higher compared to neat PCL. In order to confirm the effect of hydrophilicity, contact angle measurements were also performed. In vitro biomineralization test confirmed that all samples were bioactive as mineral deposits were detected by X-ray diffractometry after incubation in SBF. All scaffolds were tested in relevant cell culture using osteoblast-like cells (MG-63) to demonstrate their biocompatibility

Keywords: biomaterials, nanocomposites, scaffolds, tissue engineering

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Authors: Sangwoo Oh, Jaewoo Kim, Dongmin Seo, Jaewon Park, Yongha Hwang, Sungkyu Seo

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Plasmonics has been regarded one of the most powerful bio-sensing modalities to evaluate bio-molecular interactions in real-time. However, most of the plasmonic sensing methods are based on labeling metallic nanoparticles, e.g. gold or silver, as optical modulation markers, which are non-recyclable and expensive. This plasmonic modulation can be usually achieved through various nano structures, e.g., nano-hole arrays. Among those structures, plasmonic lens has been regarded as a unique plasmonic structure due to its light focusing characteristics. In this study, we introduce a custom designed plasmonic lens array for bio-sensing, which was simulated by finite-difference-time-domain (FDTD) approach and fabricated by top-down approach. In our work, we performed the FDTD simulations of various plasmonic lens designs for bacteria sensor, i.e., Samonella and Hominis. We optimized the design parameters, i.e., radius, shape, and material, of the plasmonic lens. The simulation results showed the change in the peak intensity value with the introduction of each bacteria and antigen i.e., peak intensity 1.8711 a.u. with the introduction of antibody layer of thickness of 15nm. For Salmonella, the peak intensity changed from 1.8711 a.u. to 2.3654 a.u. and for Hominis, the peak intensity changed from 1.8711 a.u. to 3.2355 a.u. This significant shift in the intensity due to the interaction between bacteria and antigen showed a promising sensing capability of the plasmonic lens. With the batch processing and bulk production of this nano scale design, the cost of biological sensing can be significantly reduced, holding great promise in the fields of clinical diagnostics and bio-defense.

Keywords: plasmonic lens, FDTD, fabrication, bacteria sensor, salmonella, hominis

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Authors: Rajani Kant Rai, Jayakrishnan Athipet

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There have been several attempts to prepare polymers with antimicrobial properties by doping with various N-halamines. Hydantoins (Cyclic N-halamine) is of importance due to their stability rechargeable chloroamide function, broad-spectrum anti-microbial action and ability to prevent resistance to the organisms. Polymerizable hydantoins are synthesized by tethering vinyl moieties to 5,5,-dialkyl hydantoin sacrificing the imide hydrogen in the molecule thereby restricting the halogen capture only to the amide nitrogen that results in compromised antibacterial activity. In order to increase the activity of the antimicrobial polymer, we have developed a scheme to maximize the attachment of chlorine to the amide and the imide moieties of hydantoin. Vinyl hydantoin monomer, (Z)-5-(4-((3-methylbuta-1,3-dien-2-yl)oxy)benzylidene)imidazolidine-2,4-dione (MBBID) was synthesized and copolymerized with a commercially available monomer, methyl methacrylate, by free radical polymerization. The antimicrobial activity of hydantoin is strongly dependent on their surface area and hence their microbial activity increases when incorporated in microspheres or nanoparticles as compared to their bulk counterpart. In this regard, smooth and rough surface microsphere of the vinyl monomer (MBBID) with commercial monomer was synthesized. The oxidative chlorine content of the copolymer ranged from 1.5 to 2.45 %. Further, to demonstrate the water purification potential, the thin column was packed with smooth or rough microspheres and challenged with simulated contaminated water that exhibited 6 log kill (total kill) of the bacteria in 20 minutes of exposure with smooth (25 mg/ml) and rough microsphere (15.0 mg/ml).

Keywords: cyclic N-halamine, vinyl hydantoin monomer, rough surface microsphere, simulated contaminated water

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Authors: Peng Zhang, Cai Liang

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The non-biodegradable plastic wastes have posed severe environmental and ecological contaminations. Numerous technologies, such as pyrolysis, incineration, and landfilling, have already been employed for the treatment of plastic waste. Compared with conventional methods, microwave has displayed unique advantages in the rapid production of hydrogen from plastic wastes. Understanding the interaction between microwave radiation and materials would promote the optimization of several parameters for the microwave reaction system. In this work, various carbon materials have been investigated to reveal microwave heating performance and the ensuing catalytic activity. Results showed that the diversity in the heating characteristic was mainly due to the dielectric properties and the individual microstructures. Furthermore, the gaps and steps among the surface of carbon materials would lead to the distortion of the electromagnetic field, which correspondingly induced plasma discharging. The intensity and location of local plasma were also studied. For high-yield H₂ production, iron nanoparticles were selected as the active sites, and a series of iron/carbon bifunctional catalysts were synthesized. Apart from the high catalytic activity, the iron particles in nano-size close to the microwave skin depth would transfer microwave irradiation to the heat, intensifying the decomposition of plastics. Under microwave radiation, iron is supported on activated carbon material with 10wt.% loading exhibited the best catalytic activity for H₂ production. Specifically, the plastics were rapidly heated up and subsequently converted into H₂ with a hydrogen efficiency of 85%. This work demonstrated a deep understanding of microwave reaction systems and provided the optimization for plastic treatment.

Keywords: plastic waste, recycling, hydrogen, microwave

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Authors: Apurva Gupta, Surendra Singh

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Spirulina spp., as a promising source of many commercially valuable products, is grown photo autotrophically in open ponds and raceways on a large scale. However, the economic exploitation in an open system seems to have been limited because of lack of multiple stress-tolerant strains. The present study aims to isolate a stable stress tolerant mutant of Spirulina platensis with improved growth rate and enhanced potential to produce its commercially valuable bioactive compounds. N-methyl-n'-nitro-n-nitrosoguanidine (NTG) at 250 μg/mL (concentration permitted 1% survival) was employed for chemical mutagenesis to generate random mutants and screened against NaCl. In a preliminary experiment, wild type S. platensis was treated with NaCl concentrations from 0.5-1.5 M to calculate its LC₅₀. Mutagenized colonies were then screened for tolerance at 0.8 M NaCl (LC₅₀), and the surviving colonies were designated as NaCl tolerant mutants of S. platensis. The mutant cells exhibited 1.5 times improved growth against NaCl stress as compared to the wild type strain in control conditions. This might be due to the ability of the mutant cells to protect its metabolic machinery against inhibitory effects of salt stress. Salt stress is known to adversely affect the rate of photosynthesis in cyanobacteria by causing degradation of the pigments. Interestingly, the mutant cells were able to protect its photosynthetic machinery and exhibited 4.23 and 1.72 times enhanced accumulation of Chl a and phycobiliproteins, respectively, which resulted in enhanced rate of photosynthesis (2.43 times) and respiration (1.38 times) against salt stress. Phycocyanin production in mutant cells was observed to enhance by 1.63 fold. Nitrogen metabolism plays a vital role in conferring halotolerance to cyanobacterial cells by influx of nitrate and efflux of Na+ ions from the cell. The NaCl tolerant mutant cells took up 2.29 times more nitrate as compared to the wild type and efficiently reduce it. Nitrate reductase and nitrite reductase activity in the mutant cells also improved by 2.45 and 2.31 times, respectively against salt stress. From these preliminary results, it could be deduced that enhanced nitrogen uptake and its efficient reduction might be a reason for adaptive and halotolerant behavior of the S. platensis mutant cells. Also, the NaCl tolerant mutant of S. platensis with significant improved growth and phycocyanin accumulation compared to the wild type can be commercially promising.

Keywords: chemical mutagenesis, NaCl tolerant mutant, nitrogen metabolism, photosynthetic machinery, phycocyanin

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Authors: Tassia Batista Pessato, Francielli Pires Ribeiro Morais, Fernanda Guimaraes Drummond Silva, Flavia Maria Netto

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Proteins and phenolic compounds can interact mainly by hydrophobic interactions. Those interactions may lead to structural changes in both molecules, which in turn could affect positively or negatively their functional and nutritional properties. Here, the structural changes of whey proteins (WPI) due to interaction with caffeic acid (CA) were investigated by intrinsic and extrinsic fluorescence. The effects of protein-phenolic compounds interactions on the total phenolic content and antioxidant activity were also assessed. The WPI-CA complexes were obtained by mixture of WPI and CA stock solutions in deionized water. The complexation was carried out at room temperature during 60 min, using 0.1 M NaOH to adjust pH at 7.0. The WPI concentration was fixed at 5 mg/mL, whereas the CA concentration varied in order to obtain four different WPI:CA molar relations (1:1; 2:1; 5:1; 10:1). WPI and phenolic solutions were used as controls. Intrinsic fluorescence spectra of the complexes (mainly due to Trp fluorescence emission) were obtained at λex = 280 nm and the emission intensities were measured from 290 to 500 nm. Extrinsic fluorescence was obtained as the measure of protein surface hydrophobicity (S0) using ANS as a fluorescence probe. Total phenolic content was determined by Folin-Ciocalteau and the antioxidant activity by FRAP and ORAC methods. Increasing concentrations of CA resulted in decreasing of WPI intrinsic fluorescence. The emission band of WPI red shifted from 332 to 354 nm as the phenolic concentration increased, which is related to the exposure of Trp residue to the more hydrophilic environment and unfolding of protein structure. In general, the complexes presented lower S0 values than WPI, suggesting that CA hindered ANS binding to hydrophobic sites of WPI. The total phenolic content in the complexes was lower than the sum of two compounds isolated. WPI showed negligible AA measured by FRAP. However, as the relative concentration of CA increased in the complexes, the FRAP values enhanced, indicating that AA measure by this technique comes mainly from CA. In contrast, the WPI ORAC value (82.3 ± 1.5 µM TE/g) suggest that its AA is related to the capacity of H+ transfer. The complexes exhibited no important improvement of AA measured by ORAC in relation to the isolated components, suggesting complexation partially suppressed AA of the compounds. The results hereby presented indicate that interaction of WPI and CA occurred, and this interaction caused a structural change in the proteins. The complexation can either hide or expose antioxidant sites of both components. In conclusion, although the CA can undergo an AA suppression due to the interaction with proteins, the AA of WPI could be enhanced due to protein unfolding and exposure of antioxidant sites.

Keywords: bioactive properties, milk proteins, phenolic acids, protein-phenolic compounds complexation

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Authors: Cristina Busuioc, Georgeta Voicu, Sorin-Ion Jinga

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The human bone presents in its dry form piezoelectric properties, which means that a mechanical stress results in electric polarization and an applied electric field causes strain. The immediate consequence was the revealing of piezoelectricity role in bone remodelling, as well as the integration of ceramic materials with piezoelectric behaviour in the composition of unitary or composite biomaterials. Thus, we prepared hydroxyapatite - collagen hybrid materials with barium titanate addition in order to achieve a better osseointegration. Barium titanate powder synthesized by a combined sol-gel-hydrothermal method, commercial hydroxyapatite and laboratory extracted collagen gel were employed as starting materials. Before the composites, fabrication, the powder with piezoelectric features was characterized in detail from the compositional, structural, morphological and electrical point of view. The next step was to elucidate the influence of barium titanate presence especially on the biological properties of the final materials. The biocompatibility of the hybrid supports without or with piezoelectric addition was investigated on mouse osteoblast cells through LDH cytotoxicity assay, LIVE/DEAD cell viability assay, and MTT cell proliferation assay. All results indicated that the analysed materials do not exert cytotoxic effects and present the ability to sustain cell survival and to promote their proliferation. In conclusion, barium titanate nanoparticles exhibit a good biocompatibility and osteoinductive properties, while the derived composite materials based on hydroxyapatite as oxide phase and collagen as polymeric phase can be successfully used for tissue engineering applications.

Keywords: barium titanate, hybrid composites, piezoelectricity, tissue engineering

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Authors: Kanika S. Raheja, A. Pandey, Shaila Bahl, Pratik Kumar, S. P. Lochab

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The subject of undertaking for this paper is the study of BaSO4 nanophosphor doped with Europium in which mainly the concentration of the rare earth impurity Eu (0.05, 0.1, 0.2, 0.5, and 1 mol %) has been varied. A comparative study of the thermoluminescence(TL) properties of the given nanophosphor has also been done using a well-known standard dosimetry material i.e. TLD-100.Firstly, a number of samples were prepared successfully by the chemical co-precipitation method. The whole lot was then compared to a well established standard material (TLD-100) for its TL sensitivity property. BaSO4:Eu ( 0.2 mol%) showed the highest sensitivity out of the lot. It was also found that when compared to the standard TLD-100, BaSo4:Eu (0.2mol%) showed surprisingly high sensitivity for a large range of doses. The TL response curve for all prepared samples has also been studied over a wide range of doses i.e 10Gy to 2kGy for gamma radiation. Almost all the samples of BaSO4:Eu showed a remarkable linearity for a broad range of doses, which is a characteristic feature of a fine TL dosimeter. The graph remained linear even beyond 1kGy for gamma radiation. Thus, the given nanophosphor has been successfully optimised for the concentration of the dopant material to achieve its highest TL sensitivity. Further, the comparative study with the standard material revealed that the current optimised sample shows an astonishingly better TL sensitivity and a phenomenal linear response curve for an incredibly wide range of doses for gamma radiation (Co-60) as compared to the standard TLD-100, which makes the current optimised BaSo4:Eu quite promising as an efficient gamma radiation dosimeter. Lastly, the present phosphor has been optimised for its annealing temperature to acquire the best results while also studying its fading and reusability properties.

Keywords: gamma radiation, nanoparticles, radiation dosimetry, thermoluminescence

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Authors: Deepanjali Gurav, Kun Qian

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In-vitro metabolic diagnosis relies on designed materials-based analytical platforms for detection of selected metabolites in biological samples, which has a key role in disease detection and therapeutic evaluation in clinics. However, the basic challenge deals with developing a simple approach for metabolic analysis in bio-samples with high sample complexity and low molecular abundance. In this work, we report a designer plasmonic nanoshells based platform for direct detection of small metabolites in clinical samples for in-vitro metabolic diagnostics. We first synthesized a series of plasmonic core-shell particles with tunable nanoshell structures. The optimized plasmonic nanoshells as new matrices allowed fast, multiplex, sensitive, and selective LDI MS (Laser desorption/ionization mass spectrometry) detection of small metabolites in 0.5 μL of bio-fluids without enrichment or purification. Furthermore, coupling with isotopic quantification of selected metabolites, we demonstrated the use of these plasmonic nanoshells for disease detection and therapeutic evaluation in clinics. For disease detection, we identified patients with postoperative brain infection through glucose quantitation and daily monitoring by cerebrospinal fluid (CSF) analysis. For therapeutic evaluation, we investigated drug distribution in blood and CSF systems and validated the function and permeability of blood-brain/CSF-barriers, during therapeutic treatment of patients with cerebral edema for pharmacokinetic study. Our work sheds light on the design of materials for high-performance metabolic analysis and precision diagnostics in real cases.

Keywords: plasmonic nanoparticles, metabolites, fingerprinting, mass spectrometry, in-vitro diagnostics

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Authors: Maki Mizogami, Hironori Tsuchiya, Yoshiroh Hayabuchi, Kenji Shigemi

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Since drugs exhibit significant structure-dependent differences in activity and toxicity, their differentiation based on the mechanism of action should have implications for comparative drug efficacy and safety. We aimed to differentiate drug stereoisomers by their stereostructure-selective membrane interactions underlying pharmacological and toxicological effects. Biomimetic lipid bilayer membranes were prepared with phospholipids and sterols (either cholesterol or epicholesterol) to mimic the lipid compositions of neuronal and cardiomyocyte membranes and to provide these membranes with the chirality. The membrane preparations were treated with different classes of stereoisomers at clinically- and pharmacologically-relevant concentrations (25-200 μM), followed by measuring fluorescence polarization to determine the membrane interactivity of drugs to change the physicochemical property of membranes. All the tested drugs acted on lipid bilayers to increase or decrease the membrane fluidity. Drug stereoisomers could not be differentiated when interacting with the membranes consisting of phospholipids alone. However, they stereostructure-selectively interacted with neuro-mimetic and cardio-mimetic membranes containing 40 mol% cholesterol ((3β)-cholest-5-en-3-ol) to show the relative potencies being local anesthetic R(+)-bupivacaine > rac-bupivacaine > S(‒)-bupivacaine, α2-adrenergic agonistic D-medetomidine > rac-medetomidine > L-medetomidine, β-adrenergic antagonistic R(+)-propranolol > rac-propranolol > S(–)-propranolol, NMDA receptor antagonistic S(+)-ketamine > rac-ketamine, analgesic monoterpenoid (+)-menthol > (‒)-menthol, non-steroidal anti-inflammatory S(+)-ibuprofen > rac-ibuprofen > R(‒)-ibuprofen, and bioactive flavonoid (+)-epicatechin > (‒)-epicatechin. All of the order of membrane interactivity were correlated to those of beneficial and adverse effects of the tested stereoisomers. In contrast, the membranes prepared with epicholesterol ((3α)-chotest-5-en-3-ol), an epimeric form of cholesterol, reversed the rank order of membrane interactivity to be S(‒)-enantiomeric > racemic > R(+)-enantiomeric bupivacaine, L-enantiomeric > racemic > D-enantiomeric medetomidine, S(–)-enantiomeric > racemic > R(+)-enantiomeric propranolol, racemic > S(+)-enantiomeric ketamine, (‒)-enantiomeric > (+)-enantiomeric menthol, R(‒)-enantiomeric > racemic > S(+)-enantiomeric ibuprofen, and (‒)-enantiomeric > (+)-enantiomeric epicatechin. The opposite configuration allows drug molecules to interact with chiral sterol membranes enantiomer-selectively. From the comparative results, it is speculated that a 3β-hydroxyl group in cholesterol is responsible for the enantioselective interactions of drugs. In conclusion, the differentiation of drug stereoisomers by their stereostructure-selective membrane interactions would be useful for designing and predicting drugs with higher activity and/or lower toxicity.

Keywords: chiral membrane, differentiation, drug stereoisomer, enantioselective membrane interaction

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