Therapeutic and diagnostic applications of nanoparticles in the management of COVID-19: a comprehensive overview.

In December 2019, Coronavirus Disease 2019 (COVID-19) was reported in Wuhan, China. Comprehensive strategies for quick identification, prevention, control, and remedy of COVID-19 have been implemented until today. Advances in various nanoparticle-based technologies, including organic and inorganic nanoparticles, have created new perspectives in this field. These materials were extensively used to control COVID-19 because of their specific attribution to preparing antiviral face masks, various safety sensors, etc. In this review, the most current nanoparticle-based technologies, applications, and achievements against the coronavirus were summarized and highlighted. This paper also offers nanoparticle preventive, diagnostic, and treatment options to combat this pandemic.

Multisystem Inflammatory Syndrome and Autoimmune Diseases Following COVID-19: Molecular Mechanisms and Therapeutic Opportunities.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), has led to huge concern worldwide. Some SARS-CoV-2 infected patients may experience post-COVID-19 complications such as multisystem inflammatory syndrome, defined by symptoms including fever and elevated inflammatory markers (such as elevation of C reactive protein (CRP), erythrocyte sedimentation rate, fibrinogen, procalcitonin test, D-dimer, ferritin, lactate dehydrogenase or IL-6, presence of neutrophilia, lymphopenia, decreased albumin, and multiple organ dysfunction). Post-COVID-19 complications may also manifest as autoimmune diseases such as Guillain-Barré syndrome and systemic lupus erythematosus. Signaling disorders, increased inflammatory cytokines secretion, corticosteroid use to treat COVID-19 patients, or impaired immune responses are suggested causes of autoimmune diseases in these patients. In this review, we discuss the molecular and pathophysiological mechanisms and therapeutic opportunities for multisystem inflammatory syndrome and autoimmune diseases following SARS-CoV-2 infection with the aim to provide a clear view for health care providers and researchers.

Complement inhibition: A possible therapeutic approach in the fight against Covid-19.

The complement system, as a vital part of innate immunity, has an important role in the clearance of pathogens; however, unregulated activation of this system probably has a key role in the pathogenesis of acute lung injury, which is induced by highly pathogenic viruses (i.e. influenza A viruses and severe acute respiratory syndrome [SARS] coronavirus). The novel coronavirus SARS-CoV-2, which is the causal agent for the ongoing global pandemic of the coronavirus disease 2019 (Covid-19), has recently been spread to almost all countries around the world. Although most people are immunocompetent to SARS-CoV-2, a small group develops hyper-inflammation that leads to complications like acute respiratory distress syndrome, disseminated intravascular coagulation, and multi-organ failure. Emerging evidence demonstrates that the complement system exerts a crucial role in this inflammatory reaction. Additionally, patients with the severe form of Covid-19 show over-activation of the complement in their skin, sera, and lungs. This study aims to summarise current knowledge concerning the interaction of SARS-CoV-2 with the complement system and to critically appraise complement inhibition as a potential new approach for Covid-19 treatment.

Worldwide prevalence of microbial agents' coinfection among COVID-19 patients: A comprehensive updated systematic review and meta-analysis.

BACKGROUND: To provide information about pathogens' coinfection prevalence with SARS-CoV-2 could be a real help to save patients' lives. This study aims to evaluate the pathogens' coinfection prevalence among COVID-19 patients. METHOD: In order to find all of the relevant articles, we used systematic search approach. Research-based databases including PubMed, Web of Science, Embase, and Scopus, without language restrictions, were searched to identify the relevant bacterial, fungal, and viral coinfections among COVID-19 cases from December 1, 2019, to August 23, 2021. In order to dig deeper, other scientific repositories such as Medrxiv were probed. RESULTS: A total of 13,023 studies were found through systematic search. After thorough analysis, only 64 studies with 61,547 patients were included in the study. The most common causative agents of coinfection among COVID-19 patients were bacteria (pooled prevalence: 20.97%; 95% CI: 15.95-26.46; I2 : 99.9%) and less frequent were virus coinfections (pooled prevalence: 12.58%; 95% CI: 7.31-18.96; I2 : 98.7%). The pooled prevalence of fungal coinfections was also 12.60% (95% CI: 7.84-17.36; I2 : 98.3%). Meta-regression analysis showed that the age sample size and WHO geographic region did not influenced heterogeneity. CONCLUSION: We identified a high prevalence of pathogenic microorganism coinfection among COVID-19 patients. Because of this rate of coinfection empirical use of antibacterial, antifungal, and antiviral treatment are advisable specifically at the early stage of COVID-19 infection. We also suggest running simultaneously diagnostic tests to identify other microbiological agents' coinfection with SARS-CoV-2.

The role of lipids in the pathophysiology of coronavirus infections.

Coronaviruses, which have been known to cause diseases in animals since the 1930s, utilize cellular components during their replication cycle. Lipids play important roles in viral infection, as coronaviruses target cellular lipids and lipid metabolism to modify their host cells to become an optimal environment for viral replication. Therefore, lipids can be considered as potential targets for the development of antiviral agents. This review provides an overview of the roles of cellular lipids in different stages of the life cycle of coronaviruses.

The role of single-domain antibodies (or nanobodies) in SARS-CoV-2 neutralization.

The severe acute respiratory syndrome (SARS-CoV-2), a newly emerging of coronavirus, continues to infect humans in the absence of a viable treatment. Neutralizing antibodies that disrupt the interaction of RBD and ACE2 has been under the spotlight as a way of developing the COVID-19 treatment. Some animals, such as llamas, manufacture heavy-chain antibodies that have a single variable domain (VHH) instead of two variable domains (VH/VL) as opposed to typical antibodies. Nanobodies are antigen-specific, single-domain, changeable segments of camelid heavy chain-only antibodies that are recombinantly produced. These types of antibodies exhibit a wide range of strong physical and chemical properties, like high solubility, and stability. The VHH's high-affinity attachment to the receptor-binding domain (RBD) allowed the neutralization of SARS-CoV-2. To tackle COVID-19, some nanobodies are being developed against SARS-CoV-2, some of which have been recently included in clinical trials. Nanobody therapy may be useful in managing the COVID-19 pandemic as a potent and low-cost treatment. This paper describes the application of nanobodies as a new class of recombinant antibodies in COVID-19 treatment.

An overview on the seven pathogenic human coronaviruses.

To date, seven human coronaviruses (HCoVs) have been detected: HCoV-NL63, HCoV-229E, HCoV-HKU1, HCoV-OC43, severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV) and SARS-CoV-2. Four of these viruses, including HCoV-NL63, -229E, -HKU1 and -OC43, usually cause mild-to-moderate respiratory diseases with a seasonal pattern. Since 2000, three new HCoVs have emerged with a significant mortality rate. Although SARS-CoV and MERS-CoV caused an epidemic in some countries, SARS-CoV-2 escalated into a pandemic. All HCoVs can cause severe complications in the elderly and immunocompromised individuals. The bat origin of HCoVs, the presence of intermediate hosts and the nature of their viral replication suggest that other new coronaviruses may emerge in the future. Despite the fact that all HCoVs share similarities in viral replication, they differ in their accessory proteins, incubation period and pathogenicity. This study aims to review these differences between the seven HCoVs.

Bioinformatic HLA Studies in the Context of SARS-CoV-2 Pandemic and Review on Association of HLA Alleles with Preexisting Medical Conditions.

After the announcement of a new coronavirus in China in December 2019, which was then called SARS-CoV-2, this virus changed to a global concern and it was then declared as a pandemic by WHO. Human leukocyte antigen (HLA) alleles, which are one of the most polymorphic genes, play a pivotal role in both resistance and vulnerability of the body against viruses and other infections as well as chronic diseases. The association between HLA alleles and preexisting medical conditions such as cardiovascular diseases and diabetes mellitus is reported in various studies. In this review, we focused on the bioinformatic HLA studies to summarize the HLA alleles which responded to SARS-CoV-2 peptides and have been used to design vaccines. We also reviewed HLA alleles that are associated with comorbidities and might be related to the high mortality rate among COVID-19 patients. Since both genes and patients' medical conditions play a key role in both severity of the disease and the mortality rate in COVID-19 patients, a better understanding of the connection between HLA alleles and SARS-CoV-2 can provide a wider perspective on the behavior of the virus. Such understanding can help scientists, especially in terms of protecting healthcare workers and designing effective vaccines.

The Role of Bacterial and Fungal Human Respiratory Microbiota in COVID-19 Patients.

Recently, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent of coronavirus disease 2019 (COVID-19), has led to a worldwide pandemic with millions of infected patients. Alteration in humans' microbiota was also reported in COVID-19 patients. The alteration in human microbiota may contribute to bacterial or viral infections and affect the immune system. Moreover, human's microbiota can be altered due to SARS-CoV-2 infection, and these microbiota changes can indicate the progression of COVID-19. While current studies focus on the gut microbiota, it seems necessary to pay attention to the lung microbiota in COVID-19. This study is aimed at reviewing respiratory microbiota dysbiosis among COVID-19 patients to encourage further studies on the field for assessment of SARS-CoV-2 and respiratory microbiota interaction.