The purpose of this quick guide is to help new modelers who have little or no background in comparative modeling yet are keen to produce high-resolution protein 3D structures for their study by ...following systematic good modeling practices, using affordable personal computers or online computational resources. Through the available experimental 3D-structure repositories, the modeler should be able to access and use the atomic coordinates for building homology models. We also aim to provide the modeler with a rationale behind making a simple list of atomic coordinates suitable for computational analysis abiding to principles of physics (e.g., molecular mechanics). Keeping that objective in mind, these quick tips cover the process of homology modeling and some postmodeling computations such as molecular docking and molecular dynamics (MD). A brief section was left for modeling nonprotein molecules, and a short case study of homology modeling is discussed.
Nanomaterials in agriculture are becoming popular due to the impressive advantages of these particles. However, their bioavailability and toxicity are key features for their massive employment. ...Herein, we comprehensively summarize the latest findings on the phytotoxicity of nanomaterial products based on essential metals used in plant protection. The metal nanoparticles (NPs) synthesized from essential metals belong to the most commonly manufactured types of nanomaterials since they have unique physical and chemical properties and are used in agricultural and biotechnological applications, which are discussed. The paper discusses the interactions of nanomaterials and vascular plants, which are the subject of intensive research because plants closely interact with soil, water, and atmosphere; they are also part of the food chain. Regarding the accumulation of NPs in the plant body, their quantification and localization is still very unclear and further research in this area is necessary.
Hypoxia‐inducible factor 1 (HIF‐1) plays an indispensable role in the hypoxic tumor microenvironment. Hypoxia and HIF‐1 are involved in multiple aspects of tumor progression, such as metastasis, ...angiogenesis, and immune evasion. In innate and adaptive immune systems, malignant tumor cells avoid their recognition and destruction by HIF‐1. Tumor immune evasion allows cancer cells to proliferate and metastasize and is associated with immunotherapy failure and chemoresistance. In the hypoxic tumor microenvironment, HIF‐1 signaling suppresses the innate and adaptive immune systems to evade immune attack by inducing the expression of immunosuppressive factors and immune checkpoint molecules, including vascular endothelial growth factor, prostaglandin E2, and programmed death‐ligand 1/programmed death‐1. Moreover, HIF‐1 blocks tumor‐associated antigen presentation via major histocompatibility complex class I chain‐related/natural killer group 2, member D signaling. Tumor‐associated autophagy and the release of tumor‐derived exosomes contribute to HIF‐1‐mediated immune evasion. This review focuses on recent findings on the potential mechanism(s) underlying the effect of hypoxia and HIF‐1 signaling on tumor immune evasion in the hypoxic tumor microenvironment. The effects of HIF‐1 on immune checkpoint molecules, immunosuppressive molecules, autophagy, and exosomes have been described. Additionally, the potential role of HIF‐1 in the regulation of tumor‐derived exosomes, as well as the roles of HIF‐1 and exosomes in tumor evasion, are discussed. This study will contribute to our understanding of HIF‐1‐mediated tumor immune evasion, leading to the development of effective HIF‐1‐targeting drugs and immunotherapies.
Bacterial biofilms are multicellular communities firmly attached to solid extracellular substrates. They are considered the primary cause of huge economic losses, from medicine due to medical ...implants’ failure to large infrastructure due to enhanced pipe corrosion. Therefore, their eradication is highly desirable. Here, the preparation of ZnO self‐propelled micromotors is reported, programming their morphology and motion properties through Ag doping. The ZnO:Ag micromotors actively move upon light irradiation via a self‐electrophoretic mechanism, showing excellent light‐controlled on/off switching motion. At the same time, the rapid and effective removal of both gram‐positive and gram‐negative bacteria biofilms from the solid surface is demonstrated, exploiting the well‐known antibacterial activity of both Ag and ZnO as well as the enhanced diffusion of the micromotors. The new concept for the low‐cost and scalable preparation of chemically programmable Ag‐doped ZnO micromotors here illustrated opens a new route toward the formulation of a new class of light‐driven semiconducting self‐propelled micromotors for environmental applications.
Controlled doping of ZnO microparticles with Ag allows the formulation of intrinsically asymmetric micromotors able to autonomously move under UV‐light irradiation via a self‐electrophoretic mechanism. The self‐propelled microswimmers show the effective eradication of gram‐positive and gram‐negative bacterial biofilms from solid surfaces by increased solution mixing, enhanced ROS generation, and the rapid release of Ag ions in water.
Since the desire for the real-time food quality monitoring, plenty of research effort has been made to develop novel tools and to offer extremely efficient detection of food contaminants. Unique ...electrical, mechanical, and thermal properties make graphene an important material in the field of sensor research. The material can be manufactured into flakes, sheets, films and with its oxidized derivatives could be almost used for a limitless set of application. Herein, current graphene-based sensors for food quality monitoring, novel designs, sensing mechanisms and elements of sensor systems and potential challenges will be outlined and discussed.
The increasing number of scientific publications focusing on magnetic materials indicates growing interest in the broader scientific community. Substantial progress was made in the synthesis of ...magnetic materials of desired size, morphology, chemical composition, and surface chemistry. Physical and chemical stability of magnetic materials is acquired by the coating. Moreover, surface layers of polymers, silica, biomolecules, etc. can be designed to obtain affinity to target molecules. The combination of the ability to respond to the external magnetic field and the rich possibilities of coatings makes magnetic materials universal tool for magnetic separations of small molecules, biomolecules and cells. In the biomedical field, magnetic particles and magnetic composites are utilized as the drug carriers, as contrast agents for magnetic resonance imaging (MRI), and in magnetic hyperthermia. However, the multifunctional magnetic particles enabling the diagnosis and therapy at the same time are emerging. The presented review article summarizes the findings regarding the design and synthesis of magnetic materials focused on biomedical applications. We highlight the utilization of magnetic materials in separation/preconcentration of various molecules and cells, and their use in diagnosis and therapy.
Bacterial biofilms are composed of a consortium of bacteria that communicate with each other through quorum sensing. Therefore, bacteria can form an extracellular matrix, which is a mucus composed of ...exopolysaccharides, peptidoglycans, and extracellular DNA, through these communication molecules. The matrix protects the community of bacteria from the adverse effects of the external environment, including antibiotics, biocides, and eradicating agents. Self‐propelled functional microrobots offer great promises in the biomedical field. The self‐propelled microrobots represent an innovative platform in microrobotic research, aiming to have an important role in the biomedical field. One of the potential applications is removal of bacterial biofilms. Herein, the specific design of multifunctional microrobots is demonstrated using antimicrobial‐designed peptides for eradication of methicillin‐resistant Staphylococcus aureus (MRSA)‐produced biofilms. The designed microrobots can perform various tasks, including autonomous navigation toward bacterial cells, mechanical entry into bacterial biofilms, and blockage of the replication of bacterial DNA by indolicidin peptides. The implemented design extends the microrobot applications not only to the removal of biological aggregates but also to the delivery and release of drugs or even target manipulation, demonstrating their great potential for use in biomedical research.
This study demonstrate simultaneous manipulation of microrobots motion and targeted antimicrobial activity. The peptide modified microrobots exhibit excellent selectivity and antimicrobial performance against methicillin‐resistant Staphylococcus aureus (MRSA) biofilm eradication. It shows a general strategy for targeted delivery of microrobots and boosting of antimicrobial effect against resistant MRSA biofilms.
Selenium nanoparticles as a nutritional supplement Skalickova, Sylvie, M.Sc; Milosavljevic, Vedran, M.Sc; Cihalova, Kristyna, M.Sc ...
Nutrition (Burbank, Los Angeles County, Calif.),
01/2017, Volume:
33
Journal Article
Peer reviewed
Abstract Selenium is an essential trace element in the diet, required for maintenance of health and growth; however, its toxicity could cause serious damage depending on dose and chemical form. ...Selenium nanoparticles (SeNPs) represent what we believe to be a novel prospect for nutritional supplementation because of their lower toxicity and ability to gradually release selenium after ingestion. In this review, we discuss various forms and types of SeNPs, as well as the way they are synthesized. We also discuss absorption and bioavailability of nanoparticles within the organism. SeNPs demonstrate anticancer and antimicrobial properties that may contribute to human health, not only as dietary supplements, but also as therapeutic agents.
Current studies give us inconsistent results regarding the association of neoplasms and zinc(II) serum and tissues concentrations. The results of to-date studies using meta-analysis are summarized in ...this paper.
Web of Science (Science citation index expanded), PubMed (Medline), Embase and CENTRAL were searched. Articles were reviewed by two evaluators; quality was assessed by Newcastle-Ottawa scale; meta-analysis was performed including meta-regression and publication bias analysis.
Analysis was performed on 114 case control, cohort and cross-sectional studies of 22737 participants. Decreased serum zinc level was found in patients with lung (effect size = -1.04), head and neck (effect size = -1.43), breast (effect size = -0.93), liver (effect size = -2.29), stomach (effect size = -1.59), and prostate (effect size = -1.36) cancers; elevation was not proven in any tumor. More specific zinc patterns are evident at tissue level, showing increase in breast cancer tissue (effect size = 1.80) and decrease in prostatic (effect size = -3.90), liver (effect size = -8.26), lung (effect size = -3.12), and thyroid cancer (effect size = -2.84). The rest of the included tumors brought ambiguous results, both in serum and tissue zinc levels across the studies. The association between zinc level and stage or grade of tumor has not been revealed by meta-regression.
This study provides evidence on cancer-specific tissue zinc level alteration. Although serum zinc decrease was associated with most tumors mentioned herein, further--prospective--studies are needed.
PDF
