The Prolyl-tRNA Synthetase Inhibitor Halofuginone Inhibits SARS-CoV-2 Infection

Summary ParagraphWe identify the prolyl-tRNA synthetase (PRS) inhibitor halofuginone1, a compound in clinical trials for anti-fibrotic and anti-inflammatory applications2, as a potent inhibitor of SARS-CoV-2 infection and replication. The interaction of SARS-CoV-2 spike protein with cell surface heparan sulfate (HS) promotes viral entry3. We find that halofuginone reduces HS biosynthesis, thereby reducing spike protein binding, SARS-CoV-2 pseudotyped virus, and authentic SARS-CoV-2 infection. Halofuginone also potently suppresses SARS-CoV-2 replication post-entry and is 1,000-fold more potent than Remdesivir4. Inhibition of HS biosynthesis and SARS-CoV-2 infection depends on specific inhibition of PRS, possibly due to translational suppression of proline-rich proteins. We find that pp1a and pp1ab polyproteins of SARS-CoV-2, as well as several HS proteoglycans, are proline-rich, which may make them particularly vulnerable to halofuginones translational suppression. Halofuginone is orally bioavailable, has been evaluated in a phase I clinical trial in humans and distributes to SARS-CoV-2 target organs, including the lung, making it a near-term clinical trial candidate for the treatment of COVID-19.

Overview of in situ gelling injectable hydrogels for diabetic wounds.

Diabetes mellitus (DM) is an endocrine disorder that causes increased blood glucose than usual due to insulin impairment. In DM, several complications arise in which diabetic wound (DW) is the most devastating complication. About 25% of patients with DM expected to develop DWs in their lifetime and undergo limb amputations. Even though several treatments such as surgery, debridement, wound dressings, advanced therapies were available, the overall conclusion has been that with very few exceptions, patients still suffer from limitations like pain, frequent dress changing, high rates of failure, and cost involvement. Further, the treatments involving the delivery of therapeutic agents in treating DWs have limited success due to abnormal levels of proteases in the DW environment. In this backdrop, in situ gelling injectable hydrogels have gained special attention due to their easy encapsulation of therapeutic medications and prolonged release, filling the wound defect areas, ease of handling, and minimally invasive surgical procedures. Though the in situ gelling injectable hydrogels are developed a couple of decades ago, their use for treating DW has not yet been explored thoroughly. Thus, in this review, we have covered the sequential events of DW healing, pathophysiology, current treatments, and its limitations, along with a particular emphasis on the mechanism of action of these in situ gelling injectable hydrogels treating DWs.

A Synthetic Defective Interfering SARS-CoV-2

Viruses thrive by exploiting the cells they infect but must also produce viral proteins to replicate and infect other cells. As a consequence, they are also susceptible to exploitation by defective versions of themselves that do not produce such proteins. A defective viral genome with deletions in protein-coding genes could still replicate in cells coinfected with full-length viruses, and even replicate faster due to its shorter size, interfering with the replication of the virus. We have created a synthetic defective interfering version of SARS-CoV-2, the virus causing the recent Covid-19 pandemic, assembling parts of the viral genome that do not code for any functional protein but enable it to be replicated and packaged. This synthetic defective genome replicates three times faster than SARS-CoV-2 in coinfected cells, and interferes with it, reducing the viral load of a cell by half in 24 hours. The synthetic genome is transmitted as efficiently as the full-length genome, confirming the location of the putative packaging signal of SARS-CoV-2. A version of such a synthetic construct could be used as a self-promoting antiviral therapy: by enabling replication of the synthetic genome, the virus promotes its own demise. O_FIG O_LINKSMALLFIG WIDTH=153 HEIGHT=200 SRC="FIGDIR/small/393587v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@60aa77org.highwire.dtl.DTLVardef@57a965org.highwire.dtl.DTLVardef@132574dorg.highwire.dtl.DTLVardef@18e2e_HPS_FORMAT_FIGEXP M_FIG Graphic summary C_FIG

Vaccines in the United States: a systematic review on history of evolution, regulations, licensing, and future challenges.

Vaccines are credited with reducing or effectively eradicating a number of infectious diseases such as smallpox, measles, and diphtheria. Particularly in nations like the United States, where a large number of infectious diseases were prevalent, vaccines proved to be timely interventions. The approval procedure for vaccines in the United States is regulated by the Center for Biologics Evaluation and Research. Vaccine development is often found to be demanding and requires astute knowledge and understanding of recent developments by physicians and researchers to ensure that effective vaccines are made available to the masses with minimum risk. This article aims to illustrate the regulatory scenario with regards to vaccine development and licensure in the United States with a brief look at the origin of vaccines and their regulations in the nation. Also, it details the challenges faced by the United States vaccine industry to remain relevant in today's constantly evolving world.

Microemulsion Based Gel of Sulconazole Nitrate for Topical Application.

OBJECTIVES: Sulconazole is a broad spectrum antifungal agent of the imidazole class used against dermatophytes and other fungi to treat skin infections. The aim of the present work was to formulate and evaluate a microemulsion-based topical sulconazole gel. MATERIALS AND METHODS: Microemulsion formulation of sulconazole nitrate was prepared by using oil, surfactant, cosurfactant and water at different ratios. This was then subjected to clarity and particle size analysis, a centrifugation test, a dilution test, and freeze thawing. RESULTS: The zeta potential of formulation F1 was -41.3 and stable. The pH of the microemulsion formulation was within the range of pH of skin. F1 showed a higher percentage amount of drug as compared with the other formulations. The viscosity showed that F1 was optimum. The freezing and thawing results showed there was no phase separation and the formulation was stable. In vitro drug release showed that the drug release from the microemulsion of F1 was higher when compared to the other formulations. It revealed F1 had the highest drug content of 95.88±0.3% and % cumulative drug release was 88.75% release in 8 h. The in vivo skin irritation study on rats confirmed that formulation was nontoxic and nonirritant. CONCLUSION: The present study confirmed the safety of the formulated sulconazole loaded microemulsion gel for topical application.

SARS-CoV-2 Infection Depends on Cellular Heparan Sulfate and ACE2

We show that SARS-CoV-2 spike protein interacts with cell surface heparan sulfate and angiotensin converting enzyme 2 (ACE2) through its Receptor Binding Domain. Docking studies suggest a putative heparin/heparan sulfate-binding site adjacent to the domain that binds to ACE2. In vitro, binding of ACE2 and heparin to spike protein ectodomains occurs independently and a ternary complex can be generated using heparin as a template. Contrary to studies with purified components, spike protein binding to heparan sulfate and ACE2 on cells occurs codependently. Unfractionated heparin, non-anticoagulant heparin, treatment with heparin lyases, and purified lung heparan sulfate potently block spike protein binding and infection by spike protein-pseudotyped virus and SARS-CoV-2 virus. These findings support a model for SARS-CoV-2 infection in which viral attachment and infection involves formation of a complex between heparan sulfate and ACE2. Manipulation of heparan sulfate or inhibition of viral adhesion by exogenous heparin may represent new therapeutic opportunities.

Vaccines in the United States: a systematic review on history of evolution, regulations, licensing, and future challenges

Vaccines are credited with reducing or effectively eradicating a number of infectious diseases such as smallpox, measles, and diphtheria. Particularly in nations like the United States, where a large number of infectious diseases were prevalent, vaccines proved to be timely interventions. The approval procedure for vaccines in the United States is regulated by the Center for Biologics Evaluation and Research. Vaccine development is often found to be demanding and requires astute knowledge and understanding of recent developments by physicians and researchers to ensure that effective vaccines are made available to the masses with minimum risk. This article aims to illustrate the regulatory scenario with regards to vaccine development and licensure in the United States with a brief look at the origin of vaccines and their regulations in the nation. Also, it details the challenges faced by the United States vaccine industry to remain relevant in today’s constantly evolving world.

Vaccines in the United States: a systematic review on history of evolution, regulations, licensing, and future challenges

Vaccines are credited with reducing or effectively eradicating a number of infectious diseases such as smallpox, measles, and diphtheria. Particularly in nations like the United States, where a large number of infectious diseases were prevalent, vaccines proved to be timely interventions. The approval procedure for vaccines in the United States is regulated by the Center for Biologics Evaluation and Research. Vaccine development is often found to be demanding and requires astute knowledge and understanding of recent developments by physicians and researchers to ensure that effective vaccines are made available to the masses with minimum risk. This article aims to illustrate the regulatory scenario with regards to vaccine development and licensure in the United States with a brief look at the origin of vaccines and their regulations in the nation. Also, it details the challenges faced by the United States vaccine industry to remain relevant in today’s constantly evolving world.

A national approach to pharmacovigilance: The case of India as a growing hub of global clinical trials.

Pharmacovigilance is the pharmacological science associated with the detection, understanding and prevention of adverse effects, especially long-term and short-term adverse effects of medicines. In the present day pharmaceutical scenario, where the development and marketing of an ever-growing array of medicines has rendered their safety and therapeutic efficacy key to determining the success of a drug, pharmacovigilance has come about to play a critical and significant part. While pharmacovigilance, as a system, has witnessed considerable progress and evolution in the West, not as much has been accomplished in India. With India now being recognised as a hub of global clinical trials and with an increasing number of clinical trials and clinical research studies being conducted actively, the need for a dynamic pharmacovigilance network with an efficient and prudent operation methodology is felt, now more than ever. This article observes the evolution of the pharmacovigilance system in India, with a fundamental overview of the present system in place and also various schemes and proposals to establish and sustain the same. It also examines the challenges faced in the execution of an effective pharmacovigilance network as well as the future prospects with regards to the Indian market.