Nanoparticles-mediated CRISPR-Cas9 gene therapy in inherited retinal diseases: applications, challenges, and emerging opportunities.

Inherited Retinal Diseases (IRDs) are considered one of the leading causes of blindness worldwide. However, the majority of them still lack a safe and effective treatment due to their complexity and genetic heterogeneity. Recently, gene therapy is gaining importance as an efficient strategy to address IRDs which were previously considered incurable. The development of the clustered regularly-interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system has strongly empowered the field of gene therapy. However, successful gene modifications rely on the efficient delivery of CRISPR-Cas9 components into the complex three-dimensional (3D) architecture of the human retinal tissue. Intriguing findings in the field of nanoparticles (NPs) meet all the criteria required for CRISPR-Cas9 delivery and have made a great contribution toward its therapeutic applications. In addition, exploiting induced pluripotent stem cell (iPSC) technology and in vitro 3D retinal organoids paved the way for prospective clinical trials of the CRISPR-Cas9 system in treating IRDs. This review highlights important advances in NP-based gene therapy, the CRISPR-Cas9 system, and iPSC-derived retinal organoids with a focus on IRDs. Collectively, these studies establish a multidisciplinary approach by integrating nanomedicine and stem cell technologies and demonstrate the utility of retina organoids in developing effective therapies for IRDs.

Superrepellent Doubly Reentrant Geometry Promotes Antibiofouling and Prevention of Coronavirus Contamination.

The fomite transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has drawn attention because of its highly contagious nature. Therefore, surfaces that can prevent coronavirus contamination are an urgent and unmet need during the coronavirus disease 2019 (COVID-19) pandemic. Conventional surfaces are usually based on superhydrophobic or antiviral coatings. However, these coatings may be dysfunctional because of biofouling, which is the undesired adhesion of biomolecules. A superhydrophobic surface independent of the material content and coating agents may serve the purpose of antibiofouling and preventing viral transmission. Doubly reentrant topology (DRT) is a unique structure that can meet the need. This study demonstrates that the DRT surfaces possess a striking antibiofouling effect that can prevent viral contamination. This effect still exists even if the DRT surface is made of a hydrophilic material such as silicon oxide and copper. To the best of our knowledge, this work first demonstrates that fomite transmission of viruses may be prevented by minimizing the contact area between pathogens and surfaces even made of hydrophilic materials. Furthermore, the DRT geometry per se features excellent antibiofouling ability, which may shed light on the applications of pathogen elimination in alleviating the COVID-19 pandemic.

Nature-Inspired Surface Structures Design for Antimicrobial Applications.

Surface contamination by microorganisms such as viruses and bacteria may simultaneously aggravate the biofouling of surfaces and infection of wounds and promote cross-species transmission and the rapid evolution of microbes in emerging diseases. In addition, natural surface structures with unique anti-biofouling properties may be used as guide templates for the development of functional antimicrobial surfaces. Further, these structure-related antimicrobial surfaces can be categorized into microbicidal and anti-biofouling surfaces. This review introduces the recent advances in the development of microbicidal and anti-biofouling surfaces inspired by natural structures and discusses the related antimicrobial mechanisms, surface topography design, material application, manufacturing techniques, and antimicrobial efficiencies.

Superrepellent Doubly Reentrant Geometry Promotes Antibiofouling and Prevention of Coronavirus Contamination

The fomite transmission of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has drawn attention because of its highly contagious nature. Therefore, surfaces that can prevent coronavirus contamination are an urgent and unmet need during the coronavirus disease 2019 (COVID‐19) pandemic. Conventional surfaces are usually based on superhydrophobic or antiviral coatings. However, these coatings may be dysfunctional because of biofouling, which is the undesired adhesion of biomolecules. A superhydrophobic surface independent of the material content and coating agents may serve the purpose of antibiofouling and preventing viral transmission. Doubly reentrant topology (DRT) is a unique structure that can meet the need. This study demonstrates that the DRT surfaces possess a striking antibiofouling effect that can prevent viral contamination. This effect still exists even if the DRT surface is made of a hydrophilic material such as silicon oxide and copper. To the best of our knowledge, this work first demonstrates that fomite transmission of viruses may be prevented by minimizing the contact area between pathogens and surfaces even made of hydrophilic materials. Furthermore, the DRT geometry per se features excellent antibiofouling ability, which may shed light on the applications of pathogen elimination in alleviating the COVID‐19 pandemic. The findings demonstrate that a unique fabricated doubly reentrant topology (DRT) structure carries remarkable superrepellent properties against biofouling of protein, blood, bacteria, and viruses. Moreover, this characteristic results from a highly minimized contact area and still exists even if the DRT surface is made of a hydrophilic material, such as silicon oxide.

Evaluation of the diagnostic accuracy of COVID-19 antigen tests: A systematic review and meta-analysis.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic continues to affect countries worldwide. To inhibit the transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), testing of patients, contact tracing, and quarantine of their close contacts have been used as major nonpharmaceutical interventions. The advantages of antigen tests, such as low cost and rapid turnaround, may allow for the rapid identification of larger numbers of infectious persons. This meta-analysis aimed to evaluate the diagnostic accuracy of antigen tests for SARS-CoV-2. METHODS: We searched PubMed, Embase, Cochrane Library, and Biomed Central databases from inception to January 2, 2021. Studies evaluating the diagnostic accuracy of antigen testing for SARS-CoV-2 with reference standards were included. We included studies that provided sufficient data to construct a 2 × 2 table on a per-patient basis. Only articles in English were reviewed. Summary sensitivity and specificity for antigen tests were generated using a random-effects model. RESULTS: Fourteen studies with 8624 participants were included. The meta-analysis for antigen testing generated a pooled sensitivity of 79% (95% CI, 66%-88%; 14 studies, 8624 patients) and a pooled specificity of 100% (95% CI, 99%-100%; 14 studies, 8624 patients). The subgroup analysis of studies that reported specimen collection within 7 days after symptom onset showed a pooled sensitivity of 95% (95% CI, 78%-99%; four studies, 1342 patients) and pooled specificity of 100% (95% CI, 97%-100%; four studies, 1342 patients). Regarding the applicability, the patient selection, index tests, and reference standards of studies in our meta-analysis matched the review title. CONCLUSION: Antigen tests have moderate sensitivity and high specificity for the detection of SARS-CoV-2. Antigen tests might have a higher sensitivity in detecting SARS-CoV-2 within 7 days after symptom onset. Based on our findings, antigen testing might be an effective method for identifying contagious individuals to block SARS-CoV-2 transmission.

Modifications of intravitreal injections in response to the COVID-19 pandemic.

The Coronavirus disease 2019 (COVID-19) pandemic has caused unprecedented disruption to the normal operation of the healthcare system. On a worldwide scale, hospitals suspended nonurgent surgeries and outpatient visits to downsize clinical loadings to redistribute manpower to counteract the pandemic's impact. So far, there is no evidence-based guideline defining a clear line between urgent and nonurgent indications of intravitreal injections (IVI). Herein, we aimed to summarize IVI algorithm modifications and discuss the patient prioritization according to medical needs in the hostile environment in the COVID crisis. Assessing current literature, we found that neovascular age-related macular degeneration is considered the utmost priority among conditions that require IVI. Other conditions assigned with a high priority include monocular or quasi-monocular patients (only one eye > 20/40), neovascular glaucoma, and new patients with significant vision loss. Although patients with central retinal vein occlusion and proliferative diabetic retinopathy are not advised to delay treatments, we found no consistent evidence that correlated with a worse outcome. Diabetic macular edema and branch retinal vein occlusion patients undertaking treatment delay should be regularly followed up every 2 to 3 months. Serving as the principle of management behind the algorithm modifications, the reduction of both patient visit and IVI therapy counts should be reckoned together with the risk of permanent visual loss and COVID infection.

The role of micronutrient and immunomodulation effect in the vaccine era of COVID-19.

Different dietary nutrients have distinct effects, including enhancing immune response activity and supporting mucous membrane integrity. These effects are critical in fighting against pathogenic agents, which cover coronavirus disease 2019 (COVID-19), the coronavirus disease that shuts down globally. Recent researches have shown that micronutrient deficiency is commonly associated with compromised immune responses, respiratory tract infections, or even susceptibility to COVID-19. The relationship between Vit A and infection is its role in mucosal epithelium integrity (skin and mucous membrane), the supplementation could be an option for assisted-treating the SARS-CoV-2 virus and a possible prevention of lung infection. Vit C/ascorbic acid stimulates oxygen radical scavenging activity of the skin and enhances epithelial barrier function. Ascorbic acid alone or with other natural compounds (baicalin and theaflavin) may inhibit the expression of angiotensin-converting enzyme II in human small alveolar epithelial cells and limited the entry of SARS-CoV-2. Vitamin D receptors can be expressed by immune cells, and different immune cells (macrophages, monocytes, dendritic cells, T cells, and B cells) can convert Vit D into its active form 1,25-(OH)2 D. Oral vitamin D intake can be a readily way to restrict the viral infection through downregulation of ACE2 receptor and to attenuate the disease severity by decreasing the frequency of cytokine storm and pulmonary pro-inflammatory response. Vit E supports T-cell mediated functions, optimization of Th1 response, and suppression of Th2 response. Vitamin E supplementation can lower the production of superoxides and may favors the antioxidants and benefit the progress of COVID-19 treatment. Zinc plays an essential role in both innate and adaptive immune systems and cytokine production, and Zinc-dependent viral enzymes to initiate the infectious process have proved the Zinc levels are directly associated with symptoms relieved of COVID-19. Iron is an essential component of enzymes involved in the activation of immune cells, lower iron levels predispose to severe symptoms of SARS-CoV-2, and monitoring the status can predict the disease severity and mortality. Selenium participates in the adaptive immune response by supporting antibody production and development. Deficiency can reduce antibody concentration, decreased cytotoxicity of NK cells, compromised cellular immunity, and an attenuated response to vaccination. The COVID-19 vaccines including three broad categories, protein-based vaccines, gene-based vaccines (mRNA vaccines and DNA vaccines), combination of gene and protein-based vaccines. Micronutrients are involved in immunity from the virus entering the human to innate immune response and adaptive immune response. Micronutrients are indispensable in immune response of vaccination.

Clinical manifestation and disease progression in COVID-19 infection.

Coronavirus disease 2019 (COVID-19) is mainly an infectious disease of the respiratory system transmitted through air droplets, and pulmonary symptoms constitute main presentations of this disease. However, COVID-19 demonstrates a clinically diverse manifestation ranging from asymptomatic presentation to critically illness with severe pneumonia, acute respiratory distress syndrome, respiratory failure, or multiple organ failure. Accumulating evidences demonstrated that COVID-19 has extrapulmonary involvement, including neurological, smelling sensation, cardiovascular, digestive, hepatobiliary, renal, endocrinologic, dermatologic system, and others. Over a third of COVID-19 patients manifest a wide range of neurological symptoms involving the central/peripheral nervous system. Underlying cardiovascular comorbidities were associated with detrimental outcomes, meanwhile the occurrence of cardiovascular complications correlate to poor survival. Gastrointestinal symptoms frequently occur and have been associated with a longer period of illness. Impaired hepatic functions were associated with the severity of the disease. Higher rate of acute kidney injury was reported in critically ill patients with COVID-19. Endocrinologic presentations of COVID-19 include exacerbating hyperglycemia, euglycemic ketosis, and diabetic ketoacidosis. The most common cutaneous manifestation was acro-cutaneous (pernio or chilblain-like) lesions, and other skin lesions consist of maculopapular rash, vesicular lesions, livedoid/necrotic lesions, exanthematous rashes, and petechiae. This review article summarized the general clinical signs and symptoms, radiologic features, and disease manifestation with progression in patients with COVID-19.

Highlight of severe acute respiratory syndrome coronavirus-2 vaccine development against COVID-19 pandemic.

The pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has brought an unprecedented impact upon the global economy and public health. Although the SARS-CoV-2 virology has been gradually investigated, measures to combat this new threat in public health are still absent. To date, no certificated drug or vaccine has been developed for the treatment or prevention of coronavirus disease Extensive researches and international coordination has been conducted to rapidly develop novel vaccines against SARS-CoV-2 pandemic. Several major breakthroughs have been made through the identification of the genetic sequence and structural/non-structural proteins of SARS-CoV-2, which enabled the development of RNA-, DNA-based vaccines, subunit vaccines, and attenuated viral vaccines. In this review article, we present an overview of the recent advances of SARS-CoV-2 vaccines and the challenges that may be encountered in the development process, highlighting the advantages and disadvantages of these approaches that may help in effectively countering COVID-19.

The pharmacological development of direct acting agents for emerging needed therapy against SARS-CoV-2

Recently, the SARS-CoV-2 was quickly identified as the causal pathogen leading to the outbreak of severe acute respiratory syndrome-like illness all over the world. As the SARS-CoV-2 infection pandemic proceeds, many efforts are being dedicated to the development of diverse treatment strategies. Increasing evidence showed potential therapeutic agents directly acting against SARS-CoV-2 virus, such as interferon, RNA-dependent RNA polymerase inhibitors, protease inhibitors, viral entry blockers, neuraminidase inhibitor, vaccine, antibody agent targeting the SARS-CoV-2 RNA genome, natural killer cells and nucleocytoplasmic trafficking inhibitor. To date, several direct anti-SARS-CoV-2 agents have demonstrated promising in vitro and clinical efficacy. This article reviews the current and future development of direct acting agents against SARS-CoV-2.

A Review of SARS-CoV-2 and the Ongoing Clinical Trials.

The sudden outbreak of 2019 novel coronavirus (2019-nCoV, later named SARS-CoV-2) in Wuhan, China, which rapidly grew into a global pandemic, marked the third introduction of a virulent coronavirus into the human society, affecting not only the healthcare system, but also the global economy. Although our understanding of coronaviruses has undergone a huge leap after two precedents, the effective approaches to treatment and epidemiological control are still lacking. In this article, we present a succinct overview of the epidemiology, clinical features, and molecular characteristics of SARS-CoV-2. We summarize the current epidemiological and clinical data from the initial Wuhan studies, and emphasize several features of SARS-CoV-2, which differentiate it from SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV), such as high variability of disease presentation. We systematize the current clinical trials that have been rapidly initiated after the outbreak of COVID-19 pandemic. Whereas the trials on SARS-CoV-2 genome-based specific vaccines and therapeutic antibodies are currently being tested, this solution is more long-term, as they require thorough testing of their safety. On the other hand, the repurposing of the existing therapeutic agents previously designed for other virus infections and pathologies happens to be the only practical approach as a rapid response measure to the emergent pandemic, as most of these agents have already been tested for their safety. These agents can be divided into two broad categories, those that can directly target the virus replication cycle, and those based on immunotherapy approaches either aimed to boost innate antiviral immune responses or alleviate damage induced by dysregulated inflammatory responses. The initial clinical studies revealed the promising therapeutic potential of several of such drugs, including favipiravir, a broad-spectrum antiviral drug that interferes with the viral replication, and hydroxychloroquine, the repurposed antimalarial drug that interferes with the virus endosomal entry pathway. We speculate that the current pandemic emergency will be a trigger for more systematic drug repurposing design approaches based on big data analysis.