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The global pandemic sparked by the emergence of SARS-CoV-2 and its variants has imposed a substantial burden of morbidity and mortality. Central to the battle against these viral threats is the immune response, with a spotlight on the pivotal role played by neutralizing antibodies. This comprehensive review delves into current research, unravelling the dual functionality of neutralizing antibodies acting as formidable barriers to viral replication and crucial facilitators of adaptive immune memory. Beyond this dual purpose, the review illuminates the nuanced variability characterizing neutralizing antibody responses to SARS-CoV-2. Emphasizing the dynamic nature of these responses, the review advocates for the plausible challenges in targeted therapeutic interventions. This review also attempts to compare various vaccination approaches and their impact on SARS-CoV-2, as well as offer insights into various Omicron variations. Recognizing the ever-evolving viral landscape, this exploration underscores the necessity of flexible approaches to address the diverse challenges posed by SARS-CoV-2 and its variants, contributing valuable insights to the ongoing global efforts in pandemic mitigation and public health safeguarding.

The COVID-19 pandemic has affected the world unprecedentedly, with both positive and negative impacts. COVID-19 significantly impacted the immune system, and understanding the immunological consequences of COVID-19 is essential for developing effective treatment strategies. The purpose of this review is to comprehensively explore and provide insights into the immunological aspects of long COVID-19, a phenomenon where individuals continue to experience a range of symptoms and complications, even after the acute phase of COVID-19 infection has subsided. The immune system responds to the initial infection by producing various immune cells and molecules, including antibodies, T cells, and cytokines. However, in some patients, this immune response becomes dysregulated, leading to chronic inflammation and persistent symptoms. Long COVID-19 encompasses diverse persistent symptoms affecting multiple organ systems, including the respiratory, cardiovascular, neurological, and gastrointestinal systems. In the post-COVID-19 immunological era, long COVID-19 and its impact on immune response have become a significant concern. Post-COVID-19 immune pathology, including autoimmunity and immune-mediated disorders, has also been reported in some patients. This review provides an overview of the current understanding of long COVID-19, its relationship to immunological responses, and the impact of post-COVID-19 immune pathology on patient outcomes. Additionally, the review addresses the current and potential treatments for long COVID-19, including immunomodulatory therapies, rehabilitation programs, and mental health support, all of which aim to improve the quality of life for individuals with long COVID-19. Understanding the complex interplay between the immune system and long COVID-19 is crucial for developing targeted therapeutic strategies and providing optimal care in the post-COVID-19 era.

Biocompatible nanogels are highly in demand and have the potential to be used in various applications, e.g., for the encapsulation of sensitive biomacromolecules. In the present study, we have developed water-in-oil microemulsions of sodium alginate sol/hexane/Span 20 as a template for controlled synthesis of alginate nanogels, cross-linked with 3d transition metal cations (Mn2+, Fe3+, and Co2+). The results suggest that the stable template of 110 nm dimensions can be obtained by microemulsion technique using Span 20 at concentrations of 10mM and above, showing a zeta potential of −57.3 mV. A comparison of the effects of the cross-links on the morphology, surface charge, protein (urease enzyme) encapsulation properties, and stability of the resulting nanogels were studied. Alginate nanogels, cross-linked with Mn2+, Fe3+, or Co2+ did not show any gradation in the hydrodynamic diameter. The shape of alginate nanogels, cross-linked with Mn2+ or Co2+, were spherical; whereas, nanogels cross-linked with Fe3+ (Fe–alginate) were non-spherical and rice-shaped. The zeta potential, enzyme loading efficiency, and enzyme activity of Fe–alginate was the highest among all the nanogels studied. It was found that the morphology of particles influenced the percent immobilization, loading capacity, and loading efficiency of encapsulated enzymes. These particles are promising candidates for biosensing and efficient drug delivery due to their relatively high loading capacity, biocompatibility, easy fabrication, and easy handling.

A thermostable solvent-tolerant lipase was isolated from Pseudomonas mendocina M-37. The lipase production medium was optimized for cost-effective production. Olive oil as a carbon source, and glycine as a nitrogen source were selected as the best for maximum lipase production. Medium optimization led to 3.75-fold increase in the lipase production. The extracellular lipase was purified 42.2-fold to homogeneity by precipitation using polyethyleneglycol, ultrafiltration and hydrophobic interaction chromatography. Its molecular mass, determined with sodium dodecyl sulphate polyacrylamide gel electrophoresis, was 32 kDa. The enzyme was further immobilized on microcrystalline cellulose. The lipase showed an optimal water activity of 0.53 for both, acidolysis and interesterification reactions. Six- to sevenfold increase in synthetic activity of immobilized lipase was observed when interesterification activity of 0.139 IU/mg and transesterification activity of 0.181 IU/mg, respectively, were obtained. This is the first report on Pseudomonas mendocina lipase with synthetic activity immobilized on microcrystalline cellulose.

Objective: To investigate the in vitro antibacterial potential, phytochemical constituents and thinlayer chromatography (TLC) bioautography of Mesua ferrea and Piper cubeba fruit extracts. The antibacterial activities of various solvent extracts prepared were assessed against five multi-drug resistant clinical isolates from both Gram-negative and positive bacteria isolated from human infection. Materials and Methods: The antibacterial activity of solvent extracts from Mesua ferrea and Piper cubeba was evaluated by agar well diffusion method. The antibacterial activity was evaluated using the TLC-bioautographic method. Preliminary phytochemical analysis was conducted. Results: All the evaluated extracts exibited moderate to significant antibacterial activity against all clinical isolates except Klebsiella sp. and Pseudomonas aeruginosa. The maximum zone of inhibition was found to be 22.5 ± 0.90 mm in M. ferrea and17.6 ± 0.80 mm in P. cubeba against Enterococcus sp. The qualitative phytochemical analysis showed the presence of most of the phytochemicals such as flavonoids, steroids, reducing sugars, cardiac glycosides and triterpenoids in all the solvent extract tested. TLC and bioautography agar overlay assay of hexane extracts of M. ferrea indicated flavonoids as the active compounds against multidrug-resistant Enterococcus sp. Conclusions: The solvent extracts of both the plants possessing antibacterial potential against clinical isolates can be utilized in the treatment of microbial infections. [ABSTRACT FROM AUTHOR]