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The use of polyelectrolytes is emerging as a fascinating strategy for the functionalization of biomedical membranes, due to their ability to enhance biological responses using the interaction effect of charged groups on multiple interface properties. Herein, two different polyelectrolytes were used to improve the antibacterial properties of polycaprolactone (PCL) nanofibers fabricated via electrospinning. First, a new cationic cellulose derivative, cellulose-bearing imidazolium tosylate (CIMD), was prepared via the nucleophilic substitution of the tosyl group using 1-methylimidazole, as confirmed by NMR analyses, and loaded into the PCL nanofibers. Secondly, sodium alginate (SA) was used to uniformly coat the fibers' surface via self-assembly, as remarked through SEM-EDX analyses. Polyelectrolyte interactions between the CIMD and the SA, initially detected using a FTIR analysis, were confirmed via Z potential measurements: the formation of a CMID/SA complex promoted a substantial charge neutralization of the fibers' surfaces with effects on the physical properties of the membrane in terms of water adsorption and in vitro degradation. Moreover, the presence of SA contributed to the in vitro response of human mesenchymal stem cells (hMSCs), as confirmed by a significant increase in the cells' viability after 7 days in the case of the PCL/CMID/SA complex with respect to the PCL and PCL/CMID membranes. Contrariwise, SA did not nullify the antibacterial effect of CMID, as confirmed by the comparable resistance exhibited by S. mutans, S. aureus, and E. coli to the PCL/CIMD and PCL/CIMD/SA membranes. All the reported results corroborate the idea that the CIMD/SA functionalization of PCL nanofibers has a great potential for the fabrication of efficient antimicrobial membranes for wound healing.
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Escherichia coli , Nanofibras , Humanos , Nanofibras/química , Celulose/química , Staphylococcus aureus , Polieletrólitos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Poliésteres/químicaRESUMO
The escalating interest in bacterial cellulose (BC) confronts a substantial obstacle due to its biologically inert properties. Hence, BC was modified with ethanolic mango peel extract (EEMP) for various industrial and medical applications of the novel nanocomposite (BC/EEMP). High-performance liquid chromatography (HPLC) delineated the phenolic composition of EEMP, revealing a repertoire of polyphenolic compounds, notably chlorogenic acid, gallic acid, catechin, and ellagic acid. EEMP exhibited broad-spectrum antimicrobial activity against Candida albicans and Staphylococcus aureus, with MIC of 0.018 mg/mL and 0.009 mg/mL, respectively. The removal mechanism of Pb2+ and Ni2+ by BC/EEMP nanocomposite membrane via SEM, EDX, FT-IR, and XRD was characterized, indicating deposition and aggregation of heavy metals with diminished porosity. Heavy metal removal optimization using the Box-Behnken design achieved maximal removal of 95.5 % and 90 % for Pb2+ and Ni2+, respectively. Moreover, BC/EEMP nanocomposite demonstrated selective dose-dependent anticancer activity toward hepatoma (HepG-2, IC50 of 208.8 µg/mL), skin carcinoma (A431, IC50 of 216.7 µg/mL), and breast carcinoma (MDA, IC50 of 197.5 µg/mL), attributed to the enhanced availability of biologically active polyphenolic compounds and physical characteristics of BC. This study underscores the remarkable potential of BC/EEMP nanocomposite for multifaceted industrial and biomedical applications, marking a pioneering contribution to the field.
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AIM: This study aims to investigate the hepatoprotective effect of the antipsychotic drug trifluoperazine (TFP) against cyclophosphamide (CPA)-induced hepatic injury by exploring its effect on autophagy and the Nrf2/HO-1 signaling pathway. MAIN METHODS: The hepatotoxicity of CPA was assessed by biochemical analysis of the serum hepatotoxicity markers (ALT, AST, and direct bilirubin), histopathological examination, and ultrastructure analysis by transmission electron microscopy (TEM). The ELISA technique was used to assess the hepatic content of oxidative stress (MDA and SOD) and inflammatory markers (IL-1ß and TNF-α). Immunohistochemical assessment was used to investigate the hepatic expression of NF-κB, Nrf2, caspase-3, as well as autophagy flux markers (p62 and LC3B). The mRNA expression of HO-1 was assessed using RT-qPCR. Western blot assay was used to determine the expression of p-AKT and p-mTOR. KEY FINDINGS: TFP improved CPA-induced hepatotoxicity by reducing the elevated hepatotoxicity markers, and alleviating the histopathological changes with improving ultrastructure alterations. It also reduced oxidative stress by reducing MDA content and upregulating SOD activity. In addition, it exhibited anti-inflammatory and anti-apoptotic effects by decreasing NF-κB expression, IL-1ß, TNF-α levels, and caspase-3 expression. Furthermore, TFP-induced hepatoprotection was mediated by favoring Nrf2 expression and increasing the mRNA level of HO-1. As well, it improved autophagy by increasing LC3B expression concurrently with reducing p62 expression. Moreover, TFP modulated the AKT/mTOR pathway by reducing the expression of p-AKT and p-mTOR. SIGNIFICANCE: TFP significantly protected against CPA-induced hepatotoxicity by upregulating Nrf2/HO-1 signaling along with enhancement of protective autophagy via inhibition of the AKT/mTOR signaling pathway.
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Doença Hepática Induzida por Substâncias e Drogas , Trifluoperazina , Camundongos , Animais , Trifluoperazina/farmacologia , Fator 2 Relacionado a NF-E2/metabolismo , Caspase 3/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , NF-kappa B/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/patologia , Estresse Oxidativo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Apoptose , Autofagia , Ciclofosfamida/farmacologia , RNA Mensageiro/metabolismo , Superóxido Dismutase/metabolismoRESUMO
In recent years, polyelectrolytes have been successfully used as an alternative to non-collagenous proteins to promote interfibrillar biomineralization, to reproduce the spatial intercalation of mineral phases among collagen fibrils, and to design bioinspired scaffolds for hard tissue regeneration. Herein, hybrid nanofibers were fabricated via electrospinning, by using a mixture of Poly É-caprolactone (PCL) and cationic cellulose derivatives, i.e., cellulose-bearing imidazolium tosylate (CIMD). The obtained fibers were self-assembled with Sodium Alginate (SA) by polyelectrolyte interactions with CIMD onto the fiber surface and, then, treated with simulated body fluid (SBF) to promote the precipitation of calcium phosphate (CaP) deposits. FTIR analysis confirmed the presence of SA and CaP, while SEM equipped with EDX analysis mapped the calcium phosphate constituent elements, estimating an average Ca/P ratio of about 1.33-falling in the range of biological apatites. Moreover, in vitro studies have confirmed the good response of mesenchymal cells (hMSCs) on biomineralized samples, since day 3, with a significant improvement in the presence of SA, due to the interaction of SA with CaP deposits. More interestingly, after a decay of metabolic activity on day 7, a relevant increase in cell proliferation can be recognized, in agreement with the beginning of the differentiation phase, confirmed by ALP results. Antibacterial tests performed by using different bacteria populations confirmed that nanofibers with an SA-CIMD complex show an optimal inhibitory response against S. mutans, S. aureus, and E. coli, with no significant decay due to the effect of CaP, in comparison with non-biomineralized controls. All these data suggest a promising use of these biomineralized fibers as bioinspired membranes with efficient antimicrobial and osteoconductive cues suitable to support bone healing/regeneration.
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Using an in situ sol-gel technique, new nanoarchitectonics of propolis loaded zinc oxide nanoarchitectonics (PP/ZnO-NPs) were developed in order to improve the in vivo outcomes of collagen-chitosan gel in wounded rats. The obtained nanoarchitectonics were fully characterized. The XRD results indicate the presence of a Zincite phase for ZnO-NPs and Zincite accompanied by a minor amount of zinc hydroxide for PP/ZnO-NPs samples. While the TEM findings illustrate the transfer of the ZnO-NPs from agglomerated spheres with an average particle size of 230 ± 29 nm to needle-like NPs of 323 ± 173 nm length (PP1/ZnO-NPs) and to a sheet-like NPs of 500 ± 173 nm diameter (PP2/ZnO-NPs). In addition, the incorporation of PP results in an increase in the surface negativity of ZnO-NPs to -31.4 ± 6.4 mV for PP2/ZnO-NPs. The antimicrobial activities of the nanocomposite gel loaded with 10%PP1/ZnO-NPs (G6) revealed the highest inhibition zone against E. coli (26 ± 2.31 mm). Remarkably, the in vivo outcomes showed that the nanocomposite gel (G6) has exceptional collagen deposition, quick wound closure rates, and re-epithelization. The outcomes demonstrate the nanocomposite gel encouraging biological properties for the treatment of damaged and infected wounds.
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Quitosana , Própole , Óxido de Zinco , Ratos , Animais , Antibacterianos/uso terapêutico , Própole/farmacologia , Nanogéis , Escherichia coli , Cicatrização , Colágeno , BandagensRESUMO
The demand for the functionalization of additive materials based on bacterial cellulose (BC) is currently high due to their potential applications across various sectors. The preparation of BC-based additive materials typically involves two approaches: in situ and ex situ. In situ modifications entail the incorporation of additive materials, such as soluble and dispersed substances, which are non-toxic and not essential for bacterial cell growth during the production process. However, these materials can impact the yield and self-assembly of BC. In contrast, ex situ modification occurs subsequent to the formation of BC, where the additive materials are not only adsorbed on the surface but also impregnated into the BC pellicle, while the BC slurry was homogenized with other additive materials and gelling agents to create composite films using the casting method. This review will primarily focus on the in situ and ex situ functionalization of BC then sheds light on the pivotal role of functionalized BC in advancing biomedical technologies, wound healing, tissue engineering, drug delivery, bone regeneration, and biosensors.
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Celulose , Engenharia Tecidual , Celulose/metabolismo , Bactérias/metabolismo , Materiais Biocompatíveis/metabolismoRESUMO
Microbial enzymes are crucial catalysts in various industries due to their versatility and efficiency. The microbial enzymes market has recently expanded due to increased demand for many reasons. Among them are eco-friendly solutions, developing novel microbial strains with enhanced enzymes that perform under harsh conditions, providing sustainability, and raising awareness about the benefits of enzyme-based products. By 2030, the global enzyme market is expected to account for $525 billion, with a growth rate of 6.7â¯%. L-asparaginase and L-glutaminase are among the leading applied microbial enzymes in antitumor therapy, with a growing market share of 16.5â¯% and 9.5â¯%, respectively. The use of microbial enzymes has opened new opportunities to fight various tumors, including leukemia, lymphosarcoma, and breast cancer, which has increased their demand in the pharmaceutical and medicine sectors. Despite their promising applications, commercial use of microbial enzymes faces challenges such as short half-life, immunogenicity, toxicity, and other side effects. Therefore, this review explores the industrial production, purification, formulation, and commercial utilization of microbial enzymes, along with an overview of the global enzyme market. With ongoing discoveries of novel enzymes and their applications, enzyme technology offers promising avenues for cancer treatment and other therapeutic interventions.
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Therapeutic proteins have been employed for centuries and reached approximately 50â¯% of all drugs investigated. By 2023, they represented one of the top 10 largest-selling pharma products ($387.03 billion) and are anticipated to reach around $653.35 billion by 2030. Growth hormones, insulin, and interferon (IFN α, γ, and ß) are among the leading applied therapeutic proteins with a higher market share. Protein-based therapies have opened new opportunities to control various diseases, including metabolic disorders, tumors, and viral outbreaks. Advanced recombinant DNA biotechnology has offered the production of therapeutic proteins and peptides for vaccination, drugs, and diagnostic tools. Prokaryotic and eukaryotic expression host systems, including bacterial, fungal, animal, mammalian, and plant cells usually applied for recombinant therapeutic proteins large-scale production. However, several limitations face therapeutic protein production and applications at the commercial level, including immunogenicity, integrity concerns, protein stability, and protein degradation under different circumstances. In this regard, protein-engineering strategies such as PEGylation, glycol-engineering, Fc-fusion, albumin conjugation, and fusion, assist in increasing targeting, product purity, production yield, functionality, and the half-life of therapeutic protein circulation. Therefore, a comprehensive insight into therapeutic protein research and findings pave the way for their successful implementation, which will be discussed in the current review.
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Peptídeos , Humanos , Peptídeos/química , Peptídeos/uso terapêutico , Animais , Viroses/tratamento farmacológico , Viroses/prevenção & controle , Proteínas Recombinantes/uso terapêutico , Engenharia de Proteínas/métodos , Antivirais/uso terapêutico , VírusRESUMO
Bacterial cellulose (BC) is currently among the most promising natural polymers. However, the production costs and biological inactivity are still challenges. The current study exploited the enzymatically hydrolyzed prickly pear peels (PPP) for BC production, which supported about 2.94 g/L as the sole production medium. The BC production was further optimized through a central composite design, where the maximum BC production was 6.01 g/L at 68 % PPPE at pH 4 after 11 days of incubation at 20 °C. The produced BC was characterized by FT-IR spectroscopy, XRD, and SEM analysis, and the results showed that PPPE is a promising carbon source for pure BC production. The BC membrane was separately loaded with several fruit byproduct extracts to enhance its biological activity for multiple applications. BC loaded with pomegranate peel extract (BC/PPE) revealed significant broad-spectrum antimicrobial activity, followed by BC loaded with pomegranate molasses (BC/PM). The BC/PPE membrane enhanced the shelf-life storage of strawberry fruits by about 5 days, with a reduction in the fruits' weight loss of 15 % compared to the uncovered group. The current study revealed the successful application of PPE for sustainable BC production with its packaging potential for enhancing strawberry shelf-life when loaded with PPE or PM.
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Anti-Infecciosos , Fragaria , Frutas , Celulose/química , Espectroscopia de Infravermelho com Transformada de Fourier , Anti-Infecciosos/farmacologiaRESUMO
In biomedical applications, bacterial cellulose (BC) is widely used because of its cytocompatibility, high mechanical properties, and ultrafine nanofibrillar structure. However, biomedical use of neat BC is often limited due to its lack of antimicrobial properties. In the current article, we proposed a novel technique for preparing cationic BC hydrogel through in situ incorporation of cationic water-soluble cellulose derivative, cellulose bearing imidazolium tosylate function group (Cell-IMD), in the media used for BC preparation. Different concentrations of cationic cellulose derivative (2, 4, and 6%) were embedded into a highly inter-twined BC nanofibrillar network through the in situ biosynthesis until forming cationic cellulose gels. Cationic functionalization was deeply examined by the Fourier transform infrared (FT-IR), NMR spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) methods. In vitro studies with L929 cells confirmed a good cytocompatibility of BC/cationic cellulose derivatives, and a significant increase in cell proliferation after 7 days, in the case of BC/Cell-IMD3 groups. Finally, antimicrobial assessment against Staphylococcus aureus, Streptococcus mutans, and Candida albicans was assessed, recording a good sensitivity in the case of the higher concentration of the cationic cellulose derivative. All the results suggest a promising use of cationic hybrid materials for biomedical and bio-sustainable applications (i.e., food packaging).
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Bee propolis is one of the most common natural extracts and has gained significant interest in biomedicine due to its high content of phenolic acids and flavonoids, which are responsible for the antioxidant activity of natural products. The present study report that the propolis extract (PE) was produced by ethanol in the surrounding environment. The obtained PE was added at different concentrations to cellulose nanofiber (CNF)/poly(vinyl alcohol) (PVA), and subjected to freezing thawing and freeze drying methods to develop porous bioactive matrices. Scanning electron microscope (SEM) observations displayed that the prepared samples had an interconnected porous structure with pore sizes in the range of 10-100 µm. The high performance liquid chromatography (HPLC) results of PE showed around 18 polyphenol compounds, with the highest amounts of hesperetin (183.7 µg/mL), chlorogenic acid (96.9 µg/mL) and caffeic acid (90.2 µg/mL). The antibacterial activity results indicated that both PE and PE-functionalized hydrogels exhibited a potential antimicrobial effects against Escherichia coli, Salmonella typhimurium, Streptococcus mutans, and Candida albicans. The in vitro test cell culture experiments indicated that the cells on the PE-functionalized hydrogels had the greatest viability, adhesion, and spreading of cells. Altogether, these data highlight the interesting effect of propolis bio-functionalization to enhance the biological features of CNF/PVA hydrogel as a functional matrix for biomedical applications.
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Nanofibras , Própole , Própole/farmacologia , Própole/química , Álcool de Polivinil/química , Celulose , Egito , Porosidade , Extratos Vegetais/química , Hidrogéis/químicaRESUMO
Biologically active phytochemicals from pumpkin reveal versatile medical applications, though little is known about their antiviral activity. The fucose-rich polysaccharide extraction conditions were optimized through Box-Behnken design and purified by column chromatography. The purified fucose-rich polysaccharide was characterized through SEM, FT-IR, 1H NMR, XRD, TGA, and GS-MS. The analysis results revealed an irregular and porous surface of the purified polysaccharide with high fucose, rhamnose, galactose, and glucose contents. The tested fucose-rich polysaccharides revealed significant antioxidant and anti-inflammatory activity at very low concentrations. The purified fucose-rich polysaccharides exerted a broad-spectrum antiviral activity against both DNA and RNA viruses, accompanied by high safety toward normal cells, where the maximum safe doses (EC100) were estimated to be about 3-3.9 mg/mL for both Vero and PBMC cell lines. Treatment of HCV, ADV7, HSV1, and HIV viruses with the purified polysaccharides showed a potent dose-dependent inhibitory activity with IC50 values of 95.475, 20.96, 5.213, and 461.75 µg/mL, respectively. This activity was hypothesized to be through inhibiting the viral entry in HCV infection and inhibiting the reverse transcriptase activity in HIV. The current study firstly reported the antioxidant, anti-inflammatory, and antiviral activities of Cucurbita maxima fucose-rich polysaccharide against several viral infections.
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Cucurbita , Infecções por HIV , Antioxidantes/farmacologia , Antioxidantes/química , Cucurbita/química , Fucose/química , Espectroscopia de Infravermelho com Transformada de Fourier , Antivirais/farmacologia , Leucócitos Mononucleares , Polissacarídeos/farmacologia , Polissacarídeos/químicaRESUMO
This study aims to investigate novel applications for chicken feather waste hydrolysate through a green, sustainable process. Accordingly, an enzymatically degraded chicken feather (EDCFs) product was used as a dual carbon and nitrogen source in the production medium of bacterial cellulose (BC). The yield maximization was attained through applying experimental designs where the optimal level of each significant variable was recorded and the yield rose 2 times. The produced BC was successfully characterized by FT-IR, XRD and SEM. On the other hand, sludge from EDCFs was used as a paper coating agent. The mechanical features of the coated papers were evaluated by bulk densities, maximum load, breaking length, tensile index, Young's modulus, work to break and coating layer. The results showed a decrease in tensile index and an increase in elongation at break. These indicate more flexibility of the coated paper. The coated paper exhibits higher resistance to water vapor permeability and remarkable oil resistance compared to the uncoated one. Furthermore, the effectiveness of sludge residue in removing heavy metals was evaluated, and the sorption capacities were ordered as Cu ++ > Fe ++ > Cr ++ > Co ++ with high affinity (3.29 mg/g) toward Cu ++ and low (0.42 mg/g) towards Co ++ in the tested metal solution.
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Plumas , Metais Pesados , Animais , Plumas/química , Galinhas , Esgotos/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Metais Pesados/análise , Celulose/metabolismoRESUMO
Bacterial cellulose (BC) is an ecofriendly biopolymer with diverse commercial applications. Its use is limited by the capacity of bacterial production strains and cost of the medium. Mining for novel organisms with well-optimized growth conditions will be important for the adoption of BC. In this study, a novel BC-producing strain was isolated from rotten fruit samples and identified as Lactiplantibacillus plantarum from 16S rRNA sequencing. Culture conditions were optimized for supporting maximal BC production using one variable at a time, Plackett-Burman design, and Box Behnken design approaches. Results indicated that a modified Yamanaka medium supported the highest BC yield (2.7 g/l), and that yeast extract, MgSO4, and pH were the most significant variables influencing BC production. After optimizing the levels of these variables through Box Behnken design, BC yield was increased to 4.51 g/l. The drug delivery capacity of the produced BC membrane was evaluated through fabrication with sodium alginate and gentamycin antibiotic at four different concentrations. All membranes (normal and fabricated) were characterized by scanning electron microscope, Fourier transform-infrared spectroscopy, X-ray diffraction, and mechanical properties. The antimicrobial activity of prepared composites was evaluated by using six human pathogens and revealed potent antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Streptococcus mutans, with no detected activity against Pseudomonas aeruginosa and Candida albicans.
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Anti-Infecciosos/farmacologia , Técnicas de Cultura de Células/métodos , Celulose/biossíntese , Lactobacillaceae/química , Lactobacillaceae/genética , Membranas/química , Alginatos/farmacologia , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Celulose/química , Celulose/isolamento & purificação , Meios de Cultura , Gentamicinas/farmacologia , Lactobacillaceae/isolamento & purificação , Lactobacillaceae/metabolismo , Microscopia Eletrônica de Varredura , Polissacarídeos Bacterianos/biossíntese , Polissacarídeos Bacterianos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Difração de Raios XRESUMO
The promising features of most bacterial celluloses (BC) promote the continuous mining for a cost-effective production approach toward wide and sustainable applications. Herein, cantaloupe peels (CP) were successfully implemented for sustainable BC production. Results indicated that the enzymatically hydrolyzed CP supported the maximum BC production of approximately 3.49 g/L when used as a sole fermentation media. The produced BC was fabricated with polyvinyl alcohol (PVA) and chitosan (Ch), and loaded with green synthesized copper oxide nanoparticles (CuO-NPs) to improve its biological activity. The novel composite showed an antimicrobial activity against several human pathogens such as Staphylococcus aureus, Streptococcus mutans, Salmonella typhimurium, Escherichia coli, and Pseudomonas fluorescens. Furthermore, the new composite revealed a significant in vitro anticancer activity against colon (Caco-2), hepatocellular (HepG-2), and breast (MDA) cancer cells, with low IC50 of 0.48, 0.27, and 0.33 mg/mL for the three cell lines, respectively. On the other hand, the new composite was remarkably safe for human skin fibroblast (HSF) with IC50 of 1.08 mg/mL. Interestingly, the composite membranes exhibited lethal effects against all stages of larval instar and pupal stage compared with the control. In this study, we first report the diverse potential applications of BC/PVA/Ch/CuO-NPs composites based on green synthesized CuO-NPs and sustainably produced BC membrane.
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Quitosana , Cucumis melo , Nanopartículas Metálicas , Nanopartículas , Humanos , Cobre , Celulose , Células CACO-2 , Escherichia coli , Bactérias , Quitosana/farmacologia , Álcool de Polivinil , Óxidos , Antibacterianos/farmacologiaRESUMO
The healthy immune system eliminates pathogens and maintains tissue homeostasis through extraordinarily complex networks with feedback systems while avoiding potentially massive tissue destruction. Many parameters influence humoral and cellular vaccine responses, including intrinsic and extrinsic, environmental, and behavioral, nutritional, perinatal and administrative parameters. The relative contributions of persisting antibodies and immune memory as well as the determinants of immune memory induction, to protect against specific diseases are the main parameters of long-term vaccine efficacy. Natural and vaccine-induced immunity and monoclonal antibody immunotherapeutic, may be evaded by SARS-CoV-2 variants. Besides the complications of the production of COVID-19 vaccinations, there is no effective single treatment against COVID-19. However, administration of a combined treatment at different stages of COVID-19 infection may offer some cure assistance. Combination treatment of antiviral drugs and immunomodulatory drugs may reduce inflammation in critical COVID-19 patients with cytokine release syndrome. Molnupiravir, remdesivir and paxlovid are the approved antiviral agents that may reduce the recovery time. In addition, immunomodulatory drugs such as lactoferrin and monoclonal antibodies are used to control inflammatory responses in their respective auto-immune conditions. Therefore, the widespread occurrence of highly transmissible variants like Delta and Omicron indicates that there is still a lot of work to be done in designing efficient vaccines and medicines for COVID-19. In this review, we briefly discussed the immunological response against SARS-CoV-2 and the vaccines approved by the World Health Organization (WHO) for COVID-19, their mechanisms, and side effects. Moreover, we mentioned various treatment trials and strategies for COVID-19.
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Tratamento Farmacológico da COVID-19 , COVID-19 , SARS-CoV-2 , Anticorpos Monoclonais , Anticorpos Antivirais , COVID-19/prevenção & controle , Humanos , VacinaçãoRESUMO
Novel and sustainable chitosan (CS)/activated charcoal (AC) composites were prepared by cross-linking with epichlorohydrin (ECH) to form a porous structure. Different titanium dioxide nanoparticle (TiO2 NPs) concentrations (0, 0.2, 0.4, and 0.8% w/w) were added to enhance the photocatalytic, antibacterial, larvicidal, and pupicidal activities' efficiency toward Rose Bengal (RB) dye and the Culex pipiens. The composites were characterized by FT-IR, XRD, XPS, BET and SEM. The SEM images revealed the porous structure of CS/AC and TiO2 nanoparticles were uniformly distributed in the CS/AC matrix. The degradation of RB dye was used to test the photocatalytic behavior of the composites. Supporting TiO2 on a CS/AC matrix resulted in a significant increase in photocatalytic performance. The antibacterial activities supported by CS/AC/TiO2 NPs were evaluated by bacterial growth inhibition against B. subtilis, S. aureus, E. coli, and P. aeruginosa. The results showed that CS/AC/TiO2 NPs composite has an inhibitory effect and therefore considered antibacterial agents. CS/AC/0.4%TiO2 NPs showed maximum efficacy against larvicidal activity and pupicidal of mosquito vector which recorded 99.00 ± 1.14, 95.00 ± 1.43, and 92.20 ± 2.64 for the first, second, and third larval instars and 66.00 ± 2.39 for pupal mortality, while the repellent activity reported high protection at 82.95 ± 2.99 with 3.24 mg/cm2 dose compared to control DEET.
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Quitosana , Nanopartículas , Animais , Catálise , Carvão Vegetal/farmacologia , Quitosana/química , Escherichia coli , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus , Titânio/química , Titânio/farmacologiaRESUMO
BACKGROUND: The effect of polyaromatic hydrocarbons (PAHs) on human health differs depending on the duration and exposure path. OBJECTIVE: This study aimed to examine the effects of PAHs on the human health risks associated with long-term exposure both before and throughout the COVID-19 pandemic. METHODOLOGY: PM10 sampling for 24 h was conducted at six sampling sites (Al-Haram, Aziziyah, Al Nuzhah, Muzdalifah, Arafat, and Al Awali). On-site measurements were conducted from March 2020 to February 2021. PAHs were analyzed using Perkin Elmer GC/MS, which was adjusted with standard reagents for identifying 16 PAH mixtures. RESULTS: The 24 h average PM10 concentration showed considerable inconsistencies, exceeding the WHO standards used for median exposure (25.0 µgm-3). The PAH intensities fluctuated from 7.67 to 34.7 ng/m3 in a suburban area, near a rush-hour traffic road, and from 6.34 to 37.4 ng/m3 close to business and light manufacturing areas. The highest carcinogenic compound levels were found in the Al-Azizia, Al Muzdalifah, and Al Nuzah areas because of the high traffic density, and the lowest concentrations were found in the Al-Haram and Arafat areas throughout the year, as a result of the COVID-19 pandemic health precautions that were undertaken by the government of Saudi Arabia involving border entry limits and limitations of the Umrah and Hajj seasons. CONCLUSION: This study period is considered extraordinary as the Saudi Arabian government has undertaken successful preventive measures that have had a great effect both on the spread of the pandemic and in reducing air pollution in Makkah. More studies are required to examine PAHs' carcinogenic effects after the pandemic measures are eased across Makkah.
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Poluentes Atmosféricos , COVID-19 , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Carcinógenos/toxicidade , Monitoramento Ambiental , Humanos , Pandemias , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , SARS-CoV-2 , Arábia Saudita/epidemiologiaRESUMO
Enzymes have played a crucial role in mankind's challenges to use different types of biological systems for a diversity of applications. They are proteins that break down and convert complicated compounds to produce simple products. Fungal enzymes are compatible, efficient, and proper products for many uses in medicinal requests, industrial processing, bioremediation purposes, and agricultural applications. Fungal enzymes have appropriate stability to give manufactured products suitable shelf life, affordable cost, and approved demands. Fungal enzymes have been used from ancient times to today in many industries, including baking, brewing, cheese making, antibiotics production, and commodities manufacturing, such as linen and leather. Furthermore, they also are used in other fields such as paper production, detergent, the textile industry, and in drinks and food technology in products manufacturing ranging from tea and coffee to fruit juice and wine. Recently, fungi have been used for the production of more than 50% of the needed enzymes. Fungi can produce different types of enzymes extracellularly, which gives a great chance for producing in large amounts with low cost and easy viability in purified forms using simple purification methods. In the present review, a comprehensive trial has been advanced to elaborate on the different types and structures of fungal enzymes as well as the current status of the uses of fungal enzymes in various applications.
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Optimization of the culture parameters used for biocellulose (BC) production by a previously isolated bacterial strain (Komagataeibacter hansenii AS.5) was carried out. The effect of nine culture parameters on BC production was evaluated by implementing the Plackett-Burman design, and the results revealed that, the most significant variables affecting BC production were MgSO4, ethanol, pH and yeast extract. A three-level and four-factor Box-Behnken design was applied to determine the optimum level of each significant variable. According to the results of the Plackett-Burman (PBD) and Box-Behnken designs (BBD), the following medium composition and parameters were calculated to be optimum (g/l): glucose 25, yeast extract 13, MgSO4 0.15, KH2PO4 2, ethanol 7.18 ml/l, pH 5.5, inoclume size 7%, cultivation temperature 20 °C and incubation time 9 days. Characterization of purified BC was performed to determine the network morphology by scanning electron microscopy, crystallinity by X-ray diffraction, chemical structure and functional groups by Fourier-transform infrared spectroscopy, thermal stability by thermogravimetric analysis and mechanical properties such as Young's modulus, tensile strength and elongation at beak % of BC.