Browse
Subjects
Records with Subject: Biosystems
Showing records 1 to 25 of 439. [First] Page: 1 2 3 4 5 Last
Identifying Shared Risk Genes between Nonalcoholic Fatty Liver Disease and Metabolic Traits by Cross-Trait Association Analysis
Hongping Guo, Zuguo Yu
January 24, 2022 (v1)
Subject: Biosystems
Keywords: metabolic trait, nonalcoholic fatty liver disease, shared gene
Nonalcoholic fatty liver disease (NAFLD) generally co-occurs with metabolic disorders, but it is unclear which genes have a pleiotripic effect on NAFLD and metabolic traits. We performed a large-scale cross-trait association analysis to identify the overlapping genes between NAFLD and nine metabolic traits. Among all the metabolic traits, we found that obesity and type II diabetes are associated with NAFLD. Then, a multitrait association analysis among NAFLD, obesity and type II diabetes was conducted to improve the overall statistical power. We identified 792 significant variants by a cross-trait meta-analysis involving 100 pleiotripic genes. Moreover, we detected another two common genes by a genome-wide gene test. The results from the pathway enrichment analysis show that the 102 shared risk genes are enriched in cancer, diabetes, insulin secretion, and other related pathways. This study can help us understand the molecular mechanisms underlying comorbid NAFLD and metabolic disorder... [more]
Centrifugal Microfluidic Integration of 4-Plex ddPCR Demonstrated by the Quantification of Cancer-Associated Point Mutations
Franziska Schlenker, Elena Kipf, Nadine Borst, Nils Paust, Roland Zengerle, Felix von Stetten, Peter Juelg, Tobias Hutzenlaub
January 24, 2022 (v1)
Subject: Biosystems
Keywords: centrifugal step emulsification, digital droplet polymerase chain reaction (ddPCR), droplet fluorescence evaluation, droplet stability, microfluidics, multiplexing
We present the centrifugal microfluidic implementation of a four-plex digital droplet polymerase chain reaction (ddPCR). The platform features 12 identical ddPCR units on a LabDisk cartridge, each capable of generating droplets with a diameter of 82.7 ± 9 µm. By investigating different oil−surfactant concentrations, we identified a robust process for droplet generation and stabilization. We observed high droplet stability during thermocycling and endpoint fluorescence imaging, as is required for ddPCRs. Furthermore, we introduce an automated process for four-color fluorescence imaging using a commercial cell analysis microscope, including a customized software pipeline for ddPCR image evaluation. The applicability of ddPCRs is demonstrated by the quantification of three cancer-associated KRAS point mutations (G12D, G12V and G12A) in a diagnostically relevant wild type DNA background. The four-plex assay showed high sensitivity (3.5−35 mutant DNA copies in 15,000 wild type DNA copies) a... [more]
A Fructan Sucrase Secreted Extracellular and Purified in One-Step by Gram-Positive Enhancer Matrix Particles
Jingyue Wang, Huazhi Xiao, Fangkun Zhao, Bo Zhao, Min Xu, Zhijiang Zhou, Ye Han
December 6, 2021 (v1)
Subject: Biosystems
Keywords: Bacillus subtilis, Escherichia coli, fructan sucrase, secretory expression
Fructan sucrase is a kind of biological enzyme that catalyzes the synthesis of fructan, and fructan is a polysaccharide product with important industrial application value. In this study, the Fructan sucrase gene of Bacillus subtilis was cloned to plasmid PET-28A-ACMA-Z, and three clones were obtained after the transformation of Escherichia coli BL21, namely BS-FF, BSO, and BS. The clones BS-FF and BSO secreted the recombinant enzymes outside the cells, while the clone BS expressed them inside the cells. The induction experiment results showed that the optimum IPTG concentration in the medium was 0.5 mM and 1.0 mM for clones BS-FF and BSO, respectively, while the incubation conditions were at 28 °C for 8 h. The recombinant fructan sucrase was purified one step using a material called GEM particles. The results indicated that 95.25% of fructan sucrase expressed by the clone BS-FF could be secreted into the extracellular area, and even 98.78% by the clone BSO. With the above purification... [more]
Set Membership Estimation for Dynamic Flux Balance Models
Xin Shen, Hector Budman
October 21, 2021 (v1)
Subject: Biosystems
Keywords: dynamic flux balance model, multiparametric programming, multiplicity, set membership estimation, variable structure system, weighted primal dual method
A set membership estimator (SME) based on limited number of measurements is proposed for estimating metabolite concentrations using dynamic flux balance models (DFBMs). To deal with multiplicity of solutions of the DFBM, a weighted primal dual method is used to find solutions that best fit the data. Multiparametric nonlinear programming is applied to propagate uncertainty in initial concentrations along a batch/fed-batch operation. The proposed method has been applied to E. coli batch and fed-batch fermentation without noise.
Towards the Development of a Diagnostic Test for Autism Spectrum Disorder: Big Data Meets Metabolomics
Juergen Hahn
October 21, 2021 (v1)
Subject: Biosystems
Keywords: autism spectrum disorder, fisher discriminant analysis, kernel partial least squares
Autism Spectrum Disorders (ASD) are a group of neurological disorders that present with limited social communication/interaction and restricted, repetitive behaviors/interests. The current estimate is that approximately 1.9% of children in the US are diagnosed with ASD. While this is a high prevalence and the economic burden by ASD is significant, there is still considerable debate regarding the underlying pathophysiology of ASD. Because of this lack of biological knowledge, autism diagnoses are restricted to observational behavioral and psychometric tools. This work takes a step towards the goal of incorporating bio-chemical data into ASD diagnosis by analyzing measurements of metabolite concentrations of the folate-dependent one-carbon metabolism and transulfuration pathways. Unlike traditional approaches that are based upon comparing differences in individual metabolite concentrations between children with and without an ASD diagnosis, we made use of multivariate classification via... [more]
Dynamic Modelling of T Cell Vaccination Response
Alisa Douglas, Thomas A Adams II, David A Christian
October 21, 2021 (v1)
Subject: Biosystems
Keywords: Dynamic Modelling, stochastic modelling, T cells, vaccine
In our previous work, a mathematical, agent-based dynamic model was developed which simulates the response of the mammalian omentum to a T cell vaccine injection during the expansion phase. The model tracks how each individual naïve T cell interacts with antigen presenting cells, and subsequently primes and divides over an 8-day period following vaccine injection. The model works from first principles; individual phenomena based on experimental observation and theory are incorporated into the model, and the collection of many such phenomena together create a nuanced model of the system as a whole. In this work, we show that the model works well in other relevant tissues, such as the spleen.
Ozone Sterilization of N95 Masks
Mohammad Irfan Malik, Karen Bechwaty, François Guitzhofer, Inès Esma Achouri
October 21, 2021 (v1)
Subject: Biosystems
Keywords: COVID-19, N95 mask, organic compounds, ozone disinfectant
The rapid spread of the COVID-19 worldwide pandemic at the beginning of 2020 has significantly affect-ed the global economy with severe human and economic losses. Despite the shortage of personal protective equipment, the facemask serves as a fundamental means to protect health care professionals' and re-strict the spread of the coronavirus. However, due to the limited stock of facemasks, many sterilization methods were developed to eliminate the infection and established strategies for fast and repeated reuse without affecting the filtration efficiency. The current study extrapolates the effective utilization of the ozonic sterilization of the N95 mask. First, we demonstrated the potential of ozone as a disinfectant that successfully destructs the organic food colour compounds deposited on the N95 mask; In the quantitative part of this research, the N95 facemask pieces were soaked in diphenylamine solution and later oxidized with ozone under the different intervals of time. Finally,... [more]
Green Synthesis of Copper Oxide Nanoparticles Using Protein Fractions from an Aqueous Extract of Brown Algae Macrocystis pyrifera
Karla Araya-Castro, Tzu-Chiao Chao, Benjamín Durán-Vinet, Carla Cisternas, Gustavo Ciudad, Olga Rubilar
October 14, 2021 (v1)
Subject: Biosystems
Keywords: brown seaweed, copper oxide nanoparticles, green synthesis, proteins, size exclusion chromatography
Amongst different living organisms studied as potential candidates for the green synthesis of copper nanoparticles, algal biomass is presented as a novel and easy-to-handle method. However, the role of specific biomolecules and their contribution as reductant and capping agents has not yet been described. This contribution reports a green synthesis method to obtain copper oxide nanoparticles (CuO-NPs) using separated protein fractions from an aqueous extract of brown algae Macrocystis pyrifera through size exclusion chromatography (HPLC-SEC). Proteins were detected by a UV/VIS diode array, time-based fraction collection was carried out, and each collected fraction was used to evaluate the synthesis of CuO-NPs. The characterization of CuO-NPs was evaluated by Dynamic Light Scattering (DLS), Z-potential, Fourier Transform Infrared (FTIR), Transmission Electron Microscope (TEM) equipped with Energy Dispersive X-ray Spectroscopy (EDS) detector. Low Molecular Weight (LMW) and High Molecular... [more]
Encapsulation of Lactoferrin for Sustained Release Using Particles from Gas-Saturated Solutions
Kento Ono, Hiroki Sakai, Shinichi Tokunaga, Tanjina Sharmin, Taku Michael Aida, Kenji Mishima
October 14, 2021 (v1)
Subject: Biosystems
Keywords: enteric polymer, gastric digestion, lactoferrin, PGSS, shellac
The particles from gas saturated solutions (PGSS) process were performed to encapsulate lactofer-rin, an iron-binding milk glycoprotein, using supercritical carbon dioxide (scCO2). A natural en-teric polymer, shellac, was used as a coating material of lactoferrin carried out by the PGSS pro-cess. Conditions were optimized by applying different temperatures (20−50 °C) and pressures (8−10 MPa) and the particles were evaluated for particle shape and size, lactoferrin encapsulation ef-ficiency, Fourier transform infrared (FTIR) spectroscopy to confirm lactoferrin entrapment and in vitro dissolution studies at different pH values. Particles with an average diameter of 75.5 ± 7 μm were produced with encapsulation efficiency up to 71 ± 2%. Furthermore, particles that showed high stability in low pH (pH 1.2) and a sustained release over time (t2h = 75%) in higher pH (pH 7.4) suggested an effective encapsulation process for the protection of lactoferrin from gastric di-gestion.
Molecular Dynamics Simulations in Drug Discovery and Pharmaceutical Development
Outi M. H. Salo-Ahen, Ida Alanko, Rajendra Bhadane, Alexandre M. J. J. Bonvin, Rodrigo Vargas Honorato, Shakhawath Hossain, André H. Juffer, Aleksei Kabedev, Maija Lahtela-Kakkonen, Anders Støttrup Larsen, Eveline Lescrinier, Parthiban Marimuthu, Muhammad Usman Mirza, Ghulam Mustafa, Ariane Nunes-Alves, Tatu Pantsar, Atefeh Saadabadi, Kalaimathy Singaravelu, Michiel Vanmeert
October 14, 2021 (v1)
Subject: Biosystems
Keywords: binding free energy, computational pharmaceutics, computer-aided drug design, conformational ensemble, drug formulations, drug targets, enhanced sampling methods, ligand binding kinetics, membrane interactions, protein flexibility
Molecular dynamics (MD) simulations have become increasingly useful in the modern drug development process. In this review, we give a broad overview of the current application possibilities of MD in drug discovery and pharmaceutical development. Starting from the target validation step of the drug development process, we give several examples of how MD studies can give important insights into the dynamics and function of identified drug targets such as sirtuins, RAS proteins, or intrinsically disordered proteins. The role of MD in antibody design is also reviewed. In the lead discovery and lead optimization phases, MD facilitates the evaluation of the binding energetics and kinetics of the ligand-receptor interactions, therefore guiding the choice of the best candidate molecules for further development. The importance of considering the biological lipid bilayer environment in the MD simulations of membrane proteins is also discussed, using G-protein coupled receptors and ion channels a... [more]
LC-UV and UPLC-MS/MS Methods for Analytical Study on Degradation of Three Antihistaminic Drugs, Ketotifen, Epinastine and Emedastine: Percentage Degradation, Degradation Kinetics and Degradation Pathways at Different pH
Anna Gumieniczek, Izabela Kozak, Paweł Żmudzki, Urszula Hubicka
October 14, 2021 (v1)
Subject: Biosystems
Keywords: degradation in solutions, epinastine and emedastine, ketotifen, LC-UV and UPLC-MS/MS methods, new degradation products, pH and high temperature
Evaluation of pH-dependent reactivity of drugs is an essential component in the pharmaceutical industry. Thus, the stability of three antihistaminic drugs, i.e., ketotifen, epinastine and emedastine, was tested, in solutions of five pH values, i.e., 1.0, 3.0, 7.0, 10.0 and 13.0, at high temperature (70 °C). LC-UV isocratic methods were developed to estimate percentage degradation as well as the kinetics of degradation. Generally, epinastine was shown to be the most stable compound with degradation below 14%. Emedastine was labile in all pH conditions, with degradation in the range 29.26−51.88%. Ketotifen was moderately stable at pH 1−7 (degradation ≤ 14.04%). However, at pH ≥ 10, its degradation exceeded 30%. The kinetics of degradation of ketotifen, epinastine and emedastine was shown as a pseudo-first-order reaction with the rate constants in the range 10−4−10−3 min−1 Finally, the UPLC-MS/MS method was applied to identify the main degradants and suggest degradation pathways. Degradat... [more]
Fabrication and Analysis of Polydimethylsiloxane (PDMS) Microchannels for Biomedical Application
Shahzadi Tayyaba, Muhammad Waseem Ashraf, Zubair Ahmad, Ning Wang, Muhammad Javaid Afzal, Nitin Afzulpurkar
October 11, 2021 (v1)
Subject: Biosystems
Keywords: biocompatibility, curvilinear microchannel, fuzzy, internet of things (IoT), polydimethylsiloxane (PDMS), sterilization
In this research work, Polydimethylsiloxane (PDMS) has been used for the fabrication of microchannels for biomedical application. Under the internet of things (IoT)-based controlled environment, the authors have simulated and fabricated bio-endurable, biocompatible and bioengineered PDMS-based microchannels for varicose veins implantation exclusively to avoid tissue damaging. Five curved ascending curvilinear micro-channel (5CACMC) and five curved descending curvilinear micro-channels (5CDCMC) are simulated by MATLAB (The Math-Works, Natick, MA, USA) and ANSYS (ANSYS, The University of Lahore, Pakistan) with actual environments and confirmed experimentally. The total length of each channel is 1.6 cm. The diameter of both channels is 400 µm. In the ascending channel, the first to fifth curve cycles have the radii of 2.5 mm, 5 mm, 7.5 mm, 10 mm, and 2.5 mm respectively. In the descending channel, the first and second curve cycles have the radii of 12.5 mm and 10 mm respectively. The thir... [more]
Expression of the Thermobifida fusca β-1,3-Glucanase in Yarrowia lipolytica and Its Application in Hydrolysis of β-1,3-Glucan from Four Kinds of Polyporaceae
Wei-Lin Chen, Jo-Chieh Hsu, Chui-Li Lim, Cheng-Yu Chen, Chao-Hsun Yang
October 11, 2021 (v1)
Subject: Biosystems
Keywords: antioxidant activity, Pycnoporus sanguineus, Thermobifida fusca, Wolfiporia cocos, Yarrowia lipolytica, β-1,3-glucanase
The gene encoding a thermostable β-1,3-glucanase was cloned from Thermobifida fusca and expressed constitutively by Yarrowia lipolytica using plasmid pYLSC1. The expression level of the recombinant β-1,3-glucanase reached up to 270 U/mL in the culture medium. After a treatment with endo-β-N-acetyl-glucosaminidase H, the recombinant protein appeared as a single protein band, with a molecular size of approximately 66 kDa on the SDS-polyacrylamide gel. The molecular weight was consistent with the size predicted from the nucleotide sequence. The optimum temperature and pH of the transformant β-1,3-glucanase were 60 °C and pH 8.0, respectively. This β-1,3-glucanase was tolerant to 10% methanol, ethanol, and DMSO, retaining 70% activity. The enzyme markedly hydrolyzed Wolfiporia cocos and Pycnoporus sanguineus glucans. The DPPH and ABTS scavenging potential, reducing power and total phenolic contents of these two Polyporaceae hydrolysates, were significantly increased after 18 h of the enzym... [more]
Reversible Bonding of Thermoplastic Elastomers for Cell Patterning Applications
Byeong-Ui Moon, Keith Morton, Kebin Li, Caroline Miville-Godin, Teodor Veres
October 11, 2021 (v1)
Subject: Biosystems
Keywords: cell migration, cell patterning, reversible bonding, thermoplastic elastomers
In this paper, we present a simple, versatile method that creates patterns for cell migration studies using thermoplastic elastomer (TPE). The TPE material used here can be robustly, but reversibly, bonded to a variety of plastic substrates, allowing patterning of cultured cells in a microenvironment. We first examine the bonding strength of TPE to glass and polystyrene substrates and com-pare it to thermoset silicone-based PDMS under various conditions and demonstrate that the TPE can be strongly and reversibly bonded on commercially available polystyrene culture plates. In cell migration studies, cell patterns are templated around TPE features cored from a thin TPE film. We show that the significance of fibroblast cell growth with fetal bovine serum (FBS)-cell culture media compared to the cells cultured without FBS, analyzed over two days of cell culture. This simple approach allows us to generate cell patterns without harsh manipulations like scratch assays and to avoid damaging th... [more]
Cancer Stem Cell Microenvironment Models with Biomaterial Scaffolds In Vitro
Ghmkin Hassan, Said M. Afify, Shiro Kitano, Akimasa Seno, Hiroko Ishii, Yucheng Shang, Michiya Matsusaki, Masaharu Seno
September 22, 2021 (v1)
Subject: Biosystems
Keywords: biomaterial scaffolds, cancer stem cells, drug screening, tumor microenvironment
Defined by its potential for self-renewal, differentiation and tumorigenicity, cancer stem cells (CSCs) are considered responsible for drug resistance and relapse. To understand the behavior of CSC, the effects of the microenvironment in each tissue are a matter of great concerns for scientists in cancer biology. However, there are many complicated obstacles in the mimicking the microenvironment of CSCs even with current advanced technology. In this context, novel biomaterials have widely been assessed as in vitro platforms for their ability to mimic cancer microenvironment. These efforts should be successful to identify and characterize various CSCs specific in each type of cancer. Therefore, extracellular matrix scaffolds made of biomaterial will modulate the interactions and facilitate the investigation of CSC associated with biological phenomena simplifying the complexity of the microenvironment. In this review, we summarize latest advances in biomaterial scaffolds, which are explo... [more]
Thermophilic Anaerobic Digestion of Second Cheese Whey: Microbial Community Response to H2 Addition in a Partially Immobilized Anaerobic Hybrid Reactor
Giuseppe Lembo, Silvia Rosa, Valentina Mazzurco Miritana, Antonella Marone, Giulia Massini, Massimiliano Fenice, Antonella Signorini
September 22, 2021 (v1)
Subject: Biosystems
Keywords: anaerobic hybrid reactor, cheese whey, in situ hydrogen addition, microbial community, thermophilic anaerobic digestion
In this study, we investigated thermophilic (55 °C) anaerobic digestion (AD) performance and microbial community structure, before and after hydrogen addition, in a novel hybrid gas-stirred tank reactor (GSTR) implemented with a partial immobilization of the microbial community and fed with second cheese whey (SCW). The results showed that H2 addition led to a 25% increase in the methane production rate and to a decrease of 13% in the CH4 concentration as compared with the control. The recovery of methane content (56%) was reached by decreasing the H2 flow rate. The microbial community investigations were performed on effluent (EF) and on interstitial matrix (IM) inside the immobilized area. Before H2 addition, the Anaerobaculaceae (42%) and Lachnospiraceae (27%) families dominated among bacteria in the effluent, and the Thermodesulfobiaceae (32%) and Lachnospiraceae (30%) families dominated in the interstitial matrix. After H2 addition, microbial abundance showed an increase in the ba... [more]
Ideal Feedstock and Fermentation Process Improvements for the Production of Lignocellulolytic Enzymes
Attia Iram, Deniz Cekmecelioglu, Ali Demirci
September 22, 2021 (v1)
Subject: Biosystems
Keywords: cellulase, enzyme production, hemicellulase, lignin modifying enzymes, lignocellulolytic enzymes, lignocellulosic biomass, pretreatment
The usage of lignocellulosic biomass in energy production for biofuels and other value-added products can extensively decrease the carbon footprint of current and future energy sectors. However, the infrastructure in the processing of lignocellulosic biomass is not well-established as compared to the fossil fuel industry. One of the bottlenecks is the production of the lignocellulolytic enzymes. These enzymes are produced by different fungal and bacterial species for degradation of the lignocellulosic biomass into its reactive fibers, which can then be converted to biofuel. The selection of an ideal feedstock for the lignocellulolytic enzyme production is one of the most studied aspects of lignocellulolytic enzyme production. Similarly, the fermentation enhancement strategies for different fermentation variables and modes are also the focuses of researchers. The implementation of fermentation enhancement strategies such as optimization of culture parameters (pH, temperature, agitation,... [more]
Plant-Based Tacca leontopetaloides Biopolymer Flocculant (TBPF) Produced High Removal of Heavy Metal Ions at Low Dosage
Nurul Shuhada Mohd Makhtar, Juferi Idris, Mohibah Musa, Yoshito Andou, Ku Halim Ku Hamid, Siti Wahidah Puasa
September 22, 2021 (v1)
Subject: Biosystems
Keywords: flocculation mechanism, heavy metal, hydroxide ion, polymer flocculant, Tacca leontopetaloides biopolymer flocculant (TBPF)
High removal of heavy metals using plant-based bioflocculant under low concentration is required due to its low cost, abundant source, and nontoxicity for improved wastewater management and utilization in the water industry. This paper presents a treatment of synthetic wastewater using plant-based Tacca leontopetaloides biopolymer flocculant (TBPF) without modification on its structural polymer chains. It produced a high removal of heavy metals (Zn, Pb, Ni, and Cd) at a low concentration of TBPF dosage. In our previous report, TBPF was characterized and successfully reduced the turbidity, total suspended solids, and color for leachate treatment; however, its effectiveness for heavy metal removal has not been reported. The removal of these heavy metals was performed using a standard jar test procedure at different pH values of synthetic wastewater and TBPF dosages. The effects of hydroxide ion, pH, initial TBPF concentration, initial metal ion concentration, and TBPF dosage were examine... [more]
Adsorption of Tetracycline and Sulfadiazine onto Three Different Bioadsorbents in Binary Competitive Systems
Raquel Cela-Dablanca, Manuel Conde-Cid, Gustavo Ferreira-Coelho, Manuel Arias-Estévez, David Fernández-Calviño, Avelino Núñez-Delgado, María J. Fernández-Sanjurjo, Esperanza Álvarez-Rodríguez
September 21, 2021 (v1)
Subject: Biosystems
Keywords: antibiotics, competitive sorption, retention/release, sorbents
Different antibiotics contained in manure, slurry, wastewater or sewage sludge are spread into the environment. The harmful effects of these antibiotics could be minimized by means of immobilization onto bioadsorbent materials. This work investigates the competitive adsorption/desorption of tetracycline (TC) and sulfadiazine (SDZ) onto pine bark, oak ash and mussel shell. The study was carried out using batch-type experiments in binary systems (with both antibiotics present simultaneously), adding 5 equal concentrations of the antibiotics (between 1 and 50 µmol L−1). The adsorption percentages were higher for TC (close to 100% onto pine bark and oak ash, and between 40 and 85% onto mussel shell) than for SDZ (75−100% onto pine bark, and generally less than 10% on oak ash and mussel shell). Pine bark performed as the best adsorbent since TC adsorption remained close to 100% throughout the entire concentration range tested, while it was between 75 and 100% for SDZ. Desorption was always... [more]
Physico-Chemical and Pharmaco-Technical Characterization of Inclusion Complexes Formed by Rutoside with β-Cyclodextrin and Hydroxypropyl-β-Cyclodextrin Used to Develop Solid Dosage Forms
Teodora Balaci, Bruno Velescu, Oana Karampelas, Adina Magdalena Musuc, George Mihai Nițulescu, Emma Adriana Ozon, Georgiana Nițulescu, Cerasela Elena Gîrd, Catalina Fița, Dumitru Lupuliasa
September 21, 2021 (v1)
Subject: Biosystems
Keywords: antioxidant activity, hydroxypropyl-β-cyclodextrin, inclusion complexes, rutoside, β-cyclodextrin
The aim of our study was to obtain rutoside (RUT) inclusion complexes in β-cyclodextrin (β-CD) and in hydroxypropyl-β-cyclodextrin (HP-β-CD), in a 1:1 molar ratio, using the lyophilization method of complexation in solution. The complexes were confirmed and characterized, in comparison with the raw materials and their simple physical mixtures, by SEM, DSC, and FT-IR analyses. The antioxidant activity of the compounds was assessed by using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2’-azino-bis(3-ethylbenzothiazolin-6-sulfonic) acid (ABTS) radicals, determining the radical scavenging activity, and by ferric reducing antioxidant power (FRAP) assay. The results revealed superior antioxidant ability for the inclusion complexes towards rutoside alone. The inclusion complexes were used as active ingredients in formulations of immediate-release tablets. The preformulation studies were performed on the powders for direct compression obtained after mixing the active ingredients with the exci... [more]
Advanced 3D Cell Culture Techniques in Micro-Bioreactors, Part II: Systems and Applications
Brigitte Altmann, Christoph Grün, Cordula Nies, Eric Gottwald
September 21, 2021 (v1)
Subject: Biosystems
Keywords: (hydro)gels, 3D cell culture, co-culture, flow, micro-bioreactor, multicellular aggregates, scaffold, simulations
In this second part of our systematic review on the research area of 3D cell culture in micro-bioreactors we give a detailed description of the published work with regard to the existing micro-bioreactor types and their applications, and highlight important results gathered with the respective systems. As an interesting detail, we found that micro-bioreactors have already been used in SARS-CoV research prior to the SARS-CoV2 pandemic. As our literature research revealed a variety of 3D cell culture configurations in the examined bioreactor systems, we defined in review part one “complexity levels” by means of the corresponding 3D cell culture techniques applied in the systems. The definition of the complexity is thereby based on the knowledge that the spatial distribution of cell-extracellular matrix interactions and the spatial distribution of homologous and heterologous cell−cell contacts play an important role in modulating cell functions. Because at least one of these parameters ca... [more]
Alpha Amylase from Bacillus pacificus Associated with Brown Algae Turbinaria ornata: Cultural Conditions, Purification, and Biochemical Characterization
Mona Alonazi, Aida Karray, Ahmed Yacine Badjah-Hadj-Ahmed, Abir Ben Bacha
September 16, 2021 (v1)
Subject: Biosystems
Keywords: Bacillus pacificus, characterization, purification, α-amylase
We aimed in the current study, the identification of a marine bacterial amylase produced by Bacillus pacificus, which was associated with Turbinaria ornata. Cultural conditions were optimized for the highest amylase production on Tryptic soy broth media supplemented with starch 1% at initial pH 9, 55 °C for 24 h. The newly purified amylase was characterized for a possible biotechnological application. Data indicated that the obtained amylase with a molecular weight of 40 kD and the N-terminal sequence of the first 30 amino acids of amBp showed a high degree of homology with known alpha amylase, and was stable at 60 °C of pH 11. Among the tested substrate analogs, amBp was almost fully active on Alylose and Alylopectine (97%), but moderately hydrolyzed glycogen < sucrose < maltose < lactose. Therefore, the current amylase mainly generated maltohexaose from starch. Mg2+ and Zn2+ improved amylase activity up to 170%. While ethylenediamine tetraacetic acid (EDTA) similarly induced... [more]
Study on the Extraction Technology of Candida antarctica Lipase B by Foam Separation
Wenyao Shao, Ying Lin, Yinghua Lu
September 16, 2021 (v1)
Subject: Biosystems
Keywords: enrichment ratio, Fermentation, foam separation, lipase, recovery rate, surfactant
Candida antarctica Lipase B (CALB) has a wide range of applications in many fields. In this study, Pichia pastoris was used to express CALB for fermentation tank culture. Sodium dodecyl sulfate (SDS) was used as a surfactant, and foam separation technology was used to explore the best experimental conditions for the harvest of CALB. The results showed that the optimal technological conditions for the foam separation and recovery of CALB were as follows: liquid volume was 150 mL, separating gas velocity was 600 mL/min, pH value was 7, and surfactant SDS concentration was 0.5 mg/mL. Under these conditions, the enrichment ratio of CALB was 0.95, and recovery rate R was 80.32%, respectively, indicating that the foam separation technology is feasible to extract lipase B.
Ad-Dressing Stem Cells: Hydrogels for Encapsulation
Leonidas Kandilogiannakis, Eirini Filidou, George Kolios, Vasilis Paspaliaris
August 2, 2021 (v1)
Subject: Biosystems
Keywords: biomaterials, encapsulation, hydrogels, stem cells
Regenerative medicine is a novel scientific field that employs the use of stem cells as cell-based therapy for the regeneration and functional restoration of damaged tissues and organs. Stem cells bear characteristics such as the capacity for self-renewal and differentiation towards specific lineages and, therefore, serve as a backup reservoir in case of tissue injuries. Therapeutically, they can be autologously or allogeneically transplanted for tissue regeneration; however, allogeneic stem cell transplantation can provoke host immune responses leading to a host-versus-transplant reaction. A probable solution to this problem is stem cell encapsulation, a technique that utilizes various biomaterials for the creation of a semi-permeable membrane that encases the stem cells. Stem cell encapsulation can be accomplished by employing a great variety of natural and/or synthetic hydrogels and offers many benefits in regenerative medicine, including protection from the host’s immune system and... [more]
Microalgae Biomolecules: Extraction, Separation and Purification Methods
Priscila S. Corrêa, Wilson G. Morais Júnior, António A. Martins, Nídia S. Caetano, Teresa M. Mata
August 2, 2021 (v1)
Subject: Biosystems
Keywords: biomolecules, cell disruption, chromatography, microalgae, purification, supercritical fluids
Several microalgae species have been exploited due to their great biotechnological potential for the production of a range of biomolecules that can be applied in a large variety of industrial sectors. However, the major challenge of biotechnological processes is to make them economically viable, through the production of commercially valuable compounds. Most of these compounds are accumulated inside the cells, requiring efficient technologies for their extraction, recovery and purification. Recent improvements approaching physicochemical treatments (e.g., supercritical fluid extraction, ultrasound-assisted extraction, pulsed electric fields, among others) and processes without solvents are seeking to establish sustainable and scalable technologies to obtain target products from microalgae with high efficiency and purity. This article reviews the currently available approaches reported in literature, highlighting some examples covering recent granted patents for the microalgae’s compone... [more]
Showing records 1 to 25 of 439. [First] Page: 1 2 3 4 5 Last
[Show All Subjects]