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Central Nervous System Agents in... 2022The emergence of new diseases poses therapeutic challenges in modern medicine. Polyurethane hydrogels that comprise polyol, copolymer and extender could be prepared from...
BACKGROUND
The emergence of new diseases poses therapeutic challenges in modern medicine. Polyurethane hydrogels that comprise polyol, copolymer and extender could be prepared from diverse chemical compounds with adjuvants such as ascorbic acid and sorbitol, among others. Their mechano-physicochemical properties are functions of their biological activities. Therefore, there is a need to assess their therapeutic potentials.
METHODS
Relevant literature on the synthesis and medical uses of polyurethane-hydrogels, polyurethane- aerogels, and polyurethane-graphene nanocomposite materials was searched in order to identify their sources, synthesis, mechanical and physiochemical properties, biomedical applications, chirality, and the relevance of Lipinski's rule of five in the synthesis of oral polyurethane nanocomposite materials.
RESULTS
The prepared hydrogels and aerogels could be used as polymer carriers for intradermal, cutaneous, and intranasal drugs. They can be fabricated and used as prosthetics. In addition, the strength modulus (tensile stress-tensile strain ratio), biodegradability, biocompatibility, and nontoxic effects of the polyurethane hydrogels and aerogels are highly desirable properties. However, body and environmental temperatures may contribute to their instability; hence, there is need to improve the synthesis of aerogels and hydrogels of polyurethane in order to ensure that they can last for many years. Alcoholism, diabetes, pyrogenic diseases, mechanical and physical forces, and physiological variability may also reduce the life span of polyurethane aerogels and hydrogels.
CONCLUSION
Synthesis of polyurethane hydrogel-aerogel complex that can be used in complex, rare biomedical cases is of paramount importance. These hydrogels and aerogels may be hydrophobic, hydrophilic, aerophobic-aerophilic or amphiphilic, and sometimes lipophilic, depending on structural components and the intended biomedical uses. Polyurethane graphene nanocomposite materials are used in the treatment of a myriad of diseases, including cancer and bacterial infection.
Topics: Graphite; Hydrogels; Hydrophobic and Hydrophilic Interactions; Nanocomposites; Polyurethanes
PubMed: 35507789
DOI: 10.2174/1871524922666220429115124 -
Methods in Molecular Biology (Clifton,... 2024Beta-glucans with diverse chemical structures are produced by a variety of microorganisms and are commonly found in microbial cell walls. β-(1,3)-D-glucans are present...
Beta-glucans with diverse chemical structures are produced by a variety of microorganisms and are commonly found in microbial cell walls. β-(1,3)-D-glucans are present in yeast and fungi, and, for this reason, their traces are commonly used as a sign of yeast or fungal infection or contamination. Despite being less immunologically active than endotoxins, beta-glucans are pro-inflammatory and can activate cytokines and other immunological responses via their cognate pattern recognition receptors. Unlike endotoxins, there is no established threshold pyrogen dose for beta-glucans; as such, their quantity in pharmaceutical products is not regulated. Nevertheless, regulatory agencies recognize the potential contribution of beta-glucans to the immunogenicity of protein-containing drug products and recommend assessing beta-glucans to aid the interpretation of immunotoxicity studies and assess the risk of immunogenicity. The protocol for the detection and quantification of β-(1,3)-D-glucans in nanoparticle formulations is based on a modified limulus amoebocyte lysate assay. The results of this test are used to inform immunotoxicity studies of nanotechnology-based drug products.
Topics: beta-Glucans; Saccharomyces cerevisiae; Glucans; Endotoxins; Nanoparticles
PubMed: 38506995
DOI: 10.1007/978-1-0716-3786-9_10 -
Biomedicines May 2021The blue blood of the horseshoe crab is a natural, irreplaceable, and precious resource that is highly valued by the biomedical industry. The Limulus amebocyte lysate... (Review)
Review
Outstanding Contributions of LAL Technology to Pharmaceutical and Medical Science: Review of Methods, Progress, Challenges, and Future Perspectives in Early Detection and Management of Bacterial Infections and Invasive Fungal Diseases.
The blue blood of the horseshoe crab is a natural, irreplaceable, and precious resource that is highly valued by the biomedical industry. The Limulus amebocyte lysate (LAL) obtained from horseshoe crab blood cells functions as a surprisingly sophisticated sensing system that allows for the extremely sensitive detection of bacterial and fungal cell-wall components. Notably, LAL tests have markedly contributed to the quality control of pharmaceutical drugs and medical devices as successful alternatives to the rabbit pyrogen test. Furthermore, LAL-based endotoxin and (1→3)-β-D-glucan (β-glucan) assay techniques are expected to have optimal use as effective biomarkers, serving as adjuncts in the diagnosis of bacterial sepsis and fungal infections. The innovative β-glucan assay has substantially contributed to the early diagnosis and management of invasive fungal diseases; however, the clinical significance of the endotoxin assay remains unclear and is challenging to elucidate. Many obstacles need to be overcome to enhance the analytical sensitivity and clinical performance of the LAL assay in detecting circulating levels of endotoxin in human blood. Additionally, there are complex interactions between endotoxin molecules and blood components that are attributable to the unique physicochemical properties of lipopolysaccharide (LPS). In this regard, while exploring the potential of new LPS-sensing technologies, a novel platform for the ultrasensitive detection of blood endotoxin will enable a reappraisal of the LAL assay for the highly sensitive and reliable detection of endotoxemia.
PubMed: 34064994
DOI: 10.3390/biomedicines9050536 -
Metabolites Mar 2023Fever represents an elevation of body temperature, that exerts a protective effect against pathogens. Innate immune cells and neurons are implicated in the regulation of... (Review)
Review
Microbial and Host Metabolites at the Backstage of Fever: Current Knowledge about the Co-Ordinate Action of Receptors and Molecules Underlying Pathophysiology and Clinical Implications.
Fever represents an elevation of body temperature, that exerts a protective effect against pathogens. Innate immune cells and neurons are implicated in the regulation of body temperature. Pathogen-associated molecular patterns, i.e., lipopolysaccharides from Gram-negative bacteria and peptidoglycan and lipoteichoic acid from Gram-positive bacteria are exogenous pyrogens, that bind to Toll-like receptors on immune and non-immune cells. The subsequent release of pro-inflammatory cytokines [interleukin-1 (IL-1), IL-6 and Tumor necrosis factor-alpha] and their passage through the brain trigger the febrile response. In fact, neurons of the pre-optic area produce prostaglandin E2 (PGE2), that, in turn, bind to the PGE2 receptors; thus, generating fever. Apart from classical non-steroidal anti-inflammatory drugs, i.e., aspirin and acetaminophen, various botanicals are currently used as antipyretic agents and, therefore, their mechanisms of action will be elucidated.
PubMed: 36984901
DOI: 10.3390/metabo13030461 -
Journal of Labelled Compounds &... Oct 2019We report an efficient protocol for the radiosynthesis of diastereomerically pure (E)-[ C]ABP688, a positron emission tomography (PET) tracer for metabotropic glutamate...
We report an efficient protocol for the radiosynthesis of diastereomerically pure (E)-[ C]ABP688, a positron emission tomography (PET) tracer for metabotropic glutamate type 5 (mGlu5) receptor imaging. The protocol reliably provides sterile and pyrogen-free formulation of (E)-[ C]ABP688 suitable for preclinical and clinical PET imaging with >99% diastereomeric excess (d.e.), >99% overall radiochemical purity (RCP), 14.9 ± 4.3% decay-corrected radiochemical yield (RCY), and 148.86 ± 79.8 GBq/μmol molar activity in 40 minutes from the end of bombardment.
Topics: Carbon Radioisotopes; Chemistry Techniques, Synthetic; Oximes; Positron-Emission Tomography; Pyridines; Radiochemistry; Stereoisomerism
PubMed: 31418468
DOI: 10.1002/jlcr.3802 -
Biomolecules Dec 2021Nonwoven textiles are used extensively in the field of medicine, including wound healing, but these textiles are mostly from conventional nondegradable materials, e.g.,...
Nonwoven textiles are used extensively in the field of medicine, including wound healing, but these textiles are mostly from conventional nondegradable materials, e.g., cotton or synthetic polymers such as polypropylene. Therefore, we aimed to develop nonwoven textiles from hyaluronan (HA), a biocompatible, biodegradable and nontoxic polysaccharide naturally present in the human body. For this purpose, we used a process based on wet spinning HA into a nonstationary coagulation bath combined with the wet-laid textile technology. The obtained HA nonwoven textiles are soft, flexible and paper like. Their mechanical properties, handling and hydration depend on the microscale fibre structure, which is tuneable by selected process parameters. Cell viability testing on two relevant cell lines (3T3, HaCaT) demonstrated that the textiles are not cytotoxic, while the monocyte activation test ruled out pyrogenicity. Biocompatibility, biodegradability and their high capacity for moisture absorption make HA nonwoven textiles a promising material for applications in the field of wound healing, both for topical and internal use. The beneficial effect of HA in the process of wound healing is well known and the form of a nonwoven textile should enable convenient handling and application to various types of wounds.
Topics: 3T3 Cells; Animals; Bandages; Humans; Hyaluronic Acid; Materials Testing; Mice; Textiles; Wound Healing
PubMed: 35053164
DOI: 10.3390/biom12010016 -
Chemosphere Apr 2022Biochar is a carbon-rich pyrogenic material for multifunctional environmental applications such as carbon sequestration, soil amendment, and pollutant management, etc.... (Review)
Review
Biochar is a carbon-rich pyrogenic material for multifunctional environmental applications such as carbon sequestration, soil amendment, and pollutant management, etc. Owing to long-term existing in the soil, biochar would inevitably suffer from natural geochemical weathering. Such ageing process could pose nonnegligible impacts on the physicochemical property and functionality of biochar. For an object-oriented design of biochar under different application ageing conditions, the latest research progress on ageing methods, biochar properties, and pollutant sorption performance needs to be fully understood. Specifically, the effect of soil components on biochar ageing is critically reviewed, which is of importance but not fully explored so far. The decrease of ash in aged biochar can inhibit the adsorption of heavy metals. The loss of aromatic components and the formation of three-dimensional water clusters during the ageing process have a negative impact on high-temperature biochar (>500° C) for organic pollutants adsorption. For long-term soil remediation, these results remind us to carefully use high-ash biochar for heavy metals and high-temperature biochar for organic pollutants. The interaction between soil minerals and biochar can form organometallic complexes and change functional groups to enhance the oxidation resistance of biochar. In the present review, the current research on biochar ageing are critical reviewed, and the further researches are prospected including developing advanced artificial ageing methods, exploring the impact of soil components on biochar ageing, and clarifying the long-term environmental behavior of modified biochar.
Topics: Adsorption; Charcoal; Environmental Pollutants; Soil; Soil Pollutants
PubMed: 34954191
DOI: 10.1016/j.chemosphere.2021.133427 -
Chemosphere Nov 2023Black carbon (BC) is generated as a result of the pyrolysis of biomass and fossil fuels. Different approaches have been taken to analyse BC in the environment, including... (Review)
Review
Black carbon (BC) is generated as a result of the pyrolysis of biomass and fossil fuels. Different approaches have been taken to analyse BC in the environment, including thermal, optical and chemical methods. The chemical approach which uses benzene polycarboxylic acids (BPCAs) as molecular markers of BC has gained popularity within the scientific community recently. These pyrogenic molecular markers can be used to reconstruct ancient fire history and human presence. Here we review the development of the BPCA protocols for the analysis of BC and the previous studies that have used these methods. Additionally, this review explores the biogeochemical factors that influence the content and composition of BPCAs, which in turn affect the sources attributed to BC. These factors include the generation temperature of char, photodegradation, biodegradation and the interference of non-pyrogenic organic matter (OM) in BPCA-BC analysis. Different combustion temperatures can yield charred BC with varying degrees of aromatic condensation throughout the BC continuum, while aged soot-BC undergoes photochemical degradation, causing the loss of its original condensed aromatic structure. Photodegradation reduces the degree of BC condensation by preferentially breaking down the most condensed forms, whereas biodegradation primarily mineralizes the smaller and more biolabile BC. Non-pyrogenic sources, such as humic acids (HAs), have been found to contribute up to 25% of BPCA-BC in soil, and their presence can lead to overestimations of BC. Future research should focus on calibrating contemporary BPCA protocols using known reference materials and investigating the role of non-pyrogenic OM in BPCA-BC analysis.
Topics: Humans; Aged; Benzene; Soot; Carboxylic Acids; Biodegradation, Environmental; Biomarkers; Carbon
PubMed: 37689153
DOI: 10.1016/j.chemosphere.2023.140112 -
Frontiers in Oncology 2022According to the WHO, cancer is the second leading cause of death in the world. This is an important global problem and a major challenge for researchers who have been... (Review)
Review
According to the WHO, cancer is the second leading cause of death in the world. This is an important global problem and a major challenge for researchers who have been trying to find an effective anticancer therapy. A large number of newly discovered compounds do not exert selective cytotoxic activity against tumorigenic cells and have too many side effects. Therefore, research on muramyl dipeptide (MDP) analogs has attracted interest due to the urgency for finding more efficient and safe treatments for oncological patients. MDP is a ligand of the cytosolic nucleotide-binding oligomerization domain 2 receptor (NOD2). This molecule is basic structural unit that is responsible for the immune activity of peptidoglycans and exhibits many features that are important for modern medicine. NOD2 is a component of the innate immune system and represents a promising target for enhancing the innate immune response as well as the immune response against cancer cells. For this reason, MDP and its analogs have been widely used for many years not only in the treatment of immunodeficiency diseases but also as adjuvants to support improved vaccine delivery, including for cancer treatment. Unfortunately, in most cases, both the MDP molecule and its synthesized analogs prove to be too pyrogenic and cause serious side effects during their use, which consequently exclude them from direct clinical application. Therefore, intensive research is underway to find analogs of the MDP molecule that will have better biocompatibility and greater effectiveness as anticancer agents and for adjuvant therapy. In this paper, we review the MDP analogs discovered in the last 10 years that show promise for antitumor therapy. The first part of the paper compiles the achievements in the field of anticancer vaccine adjuvant research, which is followed by a description of MDP analogs that exhibit promising anticancer and antiproliferative activity and their structural changes compared to the original MDP molecule.
PubMed: 36237313
DOI: 10.3389/fonc.2022.970967 -
Microbiology Spectrum Feb 2023Three mutants individually of both staphylococcal enterotoxins B and C were prepared by site-specific mutagenesis of enterotoxin amino acids that contact host T...
Three mutants individually of both staphylococcal enterotoxins B and C were prepared by site-specific mutagenesis of enterotoxin amino acids that contact host T lymphocyte immune cell receptor sites (N23A, Q210A, and N23A/Q210A); these amino acids are shared between the two enterotoxins, and mutations reduce the interaction with the variable part of the β-chain of the T lymphocyte receptor. The mutant proteins, as expressed in Staphylococcus aureus RN4220, lacked biological toxicity as measured by the loss of (i) stimulation of rabbit splenocyte proliferation, (ii) pyrogenicity, and (iii) the ability to enhance the lethality of endotoxin shock, compared to wild-type enterotoxins. In addition, the mutants were able to vaccinate rabbits against pyrogenicity, the enhancement of endotoxin shock, and lethality in a pneumonia model when animals were challenged with methicillin-resistant S. aureus. Three vaccine injections (one primary and two boosters) protected rabbits for at least 3.5 months postvaccination when challenged with wild-type enterotoxins (last time point tested). These mutant proteins have the potential to function as toxoid vaccines against these two causes of nonmenstrual toxic shock syndrome (TSS). Toxic shock syndrome toxin 1 (TSST-1) and staphylococcal enterotoxins B and C cause the majority of cases of staphylococcal toxic shock syndrome. Previously, vaccine toxoids of TSST-1 have been prepared. In this study, vaccine toxoids of enterotoxins B and C were prepared. The toxoids lost biological toxicity but were able to vaccinate rabbits against lethal TSS.
PubMed: 36815779
DOI: 10.1128/spectrum.04446-22