Liposomal Systems as Nanocarriers for the Antiviral Agent Ivermectin

Development and in vitro antiviral activity of ivermectin liposomes as a potential drug carrier system

This study aimed to assess and compare diverse formulations of ivermectin-loaded liposomes, employing lipid film hydration and ethanol injection methods. Three lipids (DOPC, SPC, and DSPC) were used in predetermined molar ratios. A total of 18 formulations were created, and a factorial design determined the optimal formulation based on particle size, polydispersity index (PDI), zeta potential, and encapsulation efficiency. The average mean particle size, PDI and zeta potential of the selected formulations (F1, F2, F7, F9, and F11) was, respectively, 196.40 ± 44.60 nm, 0.39 ± 0.09, and -40.24 ± 9.17. The encapsulation efficiency exceeded 80%, with a mean loading capacity of 4.00 ± 1.70%. In vitro studies included transmission electron microscopy, Fourier transform infrared spectroscopy, drug release, and antiviral activity assessments against SARS-CoV-2. The liposomal formulations demonstrated superior antiviral activity compared to free ivermectin, as indicated by lower IC50 values. The results of this study emphasize the effectiveness of ivermectin-loaded liposomes in inhibiting viral activity, highlighting their potential as promising candidates for antiviral therapy. The findings suggest that the strategic use of liposomes as drug carriers can significantly modulate and improve the antiviral properties of ivermectin, offering a novel approach to harnessing its full therapeutic potential. Collectively, these results provide a robust foundation for further exploration of ivermectin as a viral protection tool and optimization of its delivery mechanisms.

Vector-Transmitted Flaviviruses: An Antiviral Molecules Overview

Flaviviruses cause numerous pathologies in humans across a broad clinical spectrum with potentially severe clinical manifestations, including hemorrhagic and neurological disorders. Among human flaviviruses, some viral proteins show high conservation and are good candidates as targets for drug design. From an epidemiological point of view, flaviviruses cause more than 400 million cases of infection worldwide each year. In particular, the Yellow Fever, dengue, West Nile, and Zika viruses have high morbidity and mortality-about an estimated 20,000 deaths per year. As they depend on human vectors, they have expanded their geographical range in recent years due to altered climatic and social conditions. Despite these epidemiological and clinical premises, there are limited antiviral treatments for these infections. In this review, we describe the major compounds that are currently under evaluation for the treatment of flavivirus infections and the challenges faced during clinical trials, outlining their mechanisms of action in order to present an overview of ongoing studies. According to our review, the absence of approved antivirals for flaviviruses led to in vitro and in vivo experiments aimed at identifying compounds that can interfere with one or more viral cycle steps. Still, the currently unavailability of approved antivirals poses a significant public health issue.

Nano-Enabled Antivirals for Overcoming Antibody Escaped Mutations Based SARS-CoV-2 Waves

This review discusses receptor-binding domain (RBD) mutations related to the emergence of various SARS-CoV-2 variants, which have been highlighted as a major cause of repetitive clinical waves of COVID-19. Our perusal of the literature reveals that most variants were able to escape neutralizing antibodies developed after immunization or natural exposure, pointing to the need for a sustainable technological solution to overcome this crisis. This review, therefore, focuses on nanotechnology and the development of antiviral nanomaterials with physical antagonistic features of viral replication checkpoints as such a solution. Our detailed discussion of SARS-CoV-2 replication and pathogenesis highlights four distinct checkpoints, the S protein (ACE2 receptor coupling), the RBD motif (ACE2 receptor coupling), ACE2 coupling, and the S protein cleavage site, as targets for the development of nano-enabled solutions that, for example, prevent viral attachment and fusion with the host cell by either blocking viral RBD/spike proteins or cellular ACE2 receptors. As proof of this concept, we highlight applications of several nanomaterials, such as metal and metal oxide nanoparticles, carbon-based nanoparticles, carbon nanotubes, fullerene, carbon dots, quantum dots, polymeric nanoparticles, lipid-based, polymer-based, lipid-polymer hybrid-based, surface-modified nanoparticles that have already been employed to control viral infections. These nanoparticles were developed to inhibit receptor-mediated host-virus attachments and cell fusion, the uncoating of the virus, viral gene expression, protein synthesis, the assembly of progeny viral particles, and the release of the virion. Moreover, nanomaterials have been used as antiviral drug carriers and vaccines, and nano-enabled sensors have already been shown to enable fast, sensitive, and label-free real-time diagnosis of viral infections. Nano-biosensors could, therefore, also be useful in the remote testing and tracking of patients, while nanocarriers probed with target tissue could facilitate the targeted delivery of antiviral drugs to infected cells, tissues, organs, or systems while avoiding unwanted exposure of non-target tissues. Antiviral nanoparticles can also be applied to sanitizers, clothing, facemasks, and other personal protective equipment to minimize horizontal spread. We believe that the nanotechnology-enabled solutions described in this review will enable us to control repeated SAR-CoV-2 waves caused by antibody escape mutations.

Pharmaceutical nanotechnology: Antimicrobial peptides as potential new drugs against WHO list of critical, high, and medium priority bacteria

Nanobiotechnology is a relatively unexplored area that has, nevertheless, shown relevant results in the fight against some diseases. Antimicrobial peptides (AMPs) are biomacromolecules with potential activity against multi/extensively drug-resistant bacteria, with a lower risk of generating bacterial resistance. They can be considered an excellent biotechnological alternative to conventional drugs. However, the application of several AMPs to biological systems is hampered by their poor stability and lifetime, inactivating them completely. Therefore, nanotechnology plays an important role in the development of new AMP-based drugs, protecting and carrying the bioactive to the target. This is the first review article on the different reported nanosystems using AMPs against bacteria listed on the WHO priority list. The current shortage of information implies a nanobiotechnological potential to obtain new drugs or repurpose drugs based on the AMP-drug synergistic effect.

Ivermectin: recent approaches in the design of novel veterinary and human medicines

Ivermectin (IVM) is a drug widely used in veterinary and human medicine for the management of parasitic diseases. Its repositioning potential has been recently considered for the treatment of different diseases, such as cancer and viral infections. However, IVM faces some limitations to its formulations due to its low water solubility and bioavailability, along with reports of drug resistance. In this sense, novel technological approaches have been explored to optimize its formulations and/or to develop innovative medicines. Therefore, this review discusses the strategies proposed in the last decade to improve the safety and efficacy of IVM and to explore its novel therapeutic applications. Among these technologies, the use of micro/nano-drug delivery systems is the most used approach, followed by long-acting formulations. In general, the development of these novel formulations seems to run side by side in veterinary and human health, showing a shared interface between the two areas. Although the technologies proposed indicate a promising future in the development of innovative dosage forms containing IVM, its safety and therapeutic targets must be further evaluated. Overall, these approaches comprise tailoring drug delivery profiles, decreasing the risks of developing drug resistance, and supporting the application of IVM for reaching different therapeutic targets.

Red blood cell-hitchhiking mediated pulmonary delivery of ivermectin: Effects of nanoparticle properties

Recent studies have demonstrated that ivermectin (IVM) exhibits antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative virus of coronavirus disease 2019 (COVID-19). However, the repurposing of IVM for the treatment of COVID-19 has presented challenges primarily due to the low IVM plasma concentration after oral administration, which was well below IC₅₀. Here, a red blood cell (RBC)-hitchhiking strategy was used for the targeted delivery of IVM-loaded nanoparticles (NPs) to the lung. IVM-loaded poly (lactic-co-glycolic acid) (PLGA) NPs (IVM-PNPs) and chitosan-coating IVM-PNPs (IVM-CSPNPs) were prepared and adsorbed onto RBCs. Both RBC-hitchhiked IVM-PNPs and IVM-CSPNPs could significantly enhance IVM delivery to lungs, improve IVM accumulation in lung tissue, inhibit the inflammatory responses and finally significantly alleviate the progression of acute lung injury. Specifically, the redistribution and circulation effects were related to the properties of NPs. RBC-hitchhiked cationic IVM-CSPNPs showed a longer circulation time, slower accumulation and elimination rates, and higher anti-inflammatory activities than RBC-hitchhiked anionic IVM-PNPs. Therefore, RBC-hitchhiking provides an alternative strategy to improve IVM pharmacokinetics and bioavailability for repurposing of IVM to treat COVID-19. Furthermore, according to different redistribution effects of different NPs, RBC-hitchhiked NPs may achieve various accumulation rates and circulation times for different requirements of drug delivery.

Potential of cell-penetrating peptides (CPPs) in delivery of antiviral therapeutics and vaccines

Viral infections are a great threat to human health. Currently, there are no effective vaccines and antiviral drugs against the majority of viral diseases, suggesting the need to develop novel and effective antiviral agents. Since the intracellular delivery of antiviral agents, particularly the impermeable molecules, such as peptides, proteins, and nucleic acids, are essential to exert their therapeutic effects, using a delivery system is highly required. Among various delivery systems, cell-penetrating peptides (CPPs), a group of short peptides with the unique ability of crossing cell membrane, offer great potential for the intracellular delivery of various biologically active cargoes. The results of numerous in vitro and in vivo studies with CPP conjugates demonstrate their promise as therapeutic agents in various medical fields including antiviral therapy. The CPP-mediated delivery of various antiviral agents including peptides, proteins, nucleic acids, and nanocarriers have been associated with therapeutic efficacy both in vitro and in vivo. This review describes various aspects of viruses including their biology, pathogenesis, and therapy and briefly discusses the concept of CPP and its potential in drug delivery. Particularly, it will highlight a variety of CPP applications in the management of viral infections.

Advanced Nanomaterials for Preparedness Against (Re-)Emerging Viral Diseases

While the coronavirus disease (COVID-19) accounts for the current global pandemic, the emergence of other unknown pathogens, named "Disease X," remains a serious concern in the future. Emerging or re-emerging pathogens continue to pose significant challenges to global public health. In response, the scientific community has been urged to create advanced platform technologies to meet the ever-increasing needs presented by these devastating diseases with pandemic potential. This review aims to bring new insights to allow for the application of advanced nanomaterials in future diagnostics, vaccines, and antiviral therapies, thereby addressing the challenges associated with the current preparedness strategies in clinical settings against viruses. The application of nanomaterials has advanced medicine and provided cutting-edge solutions for unmet needs. Herein, an overview of the currently available nanotechnologies is presented, highlighting the significant features that enable them to control infectious diseases, and identifying the challenges that remain to be addressed for the commercial production of nano-based products is presented. Finally, to conclude, the development of a nanomaterial-based system using a "One Health" approach is suggested. This strategy would require a transdisciplinary collaboration and communication between all stakeholders throughout the entire process spanning across research and development, as well as the preclinical, clinical, and manufacturing phases.

Natural Compounds With Antimicrobial and Antiviral Effect and Nanocarriers Used for Their Transportation

Due to the increasing prevalence of life-threatening bacterial, fungal and viral infections and the ability of these human pathogens to develop resistance to current treatment strategies, there is a great need to find and develop new compunds to combat them. These molecules must have low toxicity, specific activity and high bioavailability. The most suitable compounds for this task are usually derived from natural sources (animal, plant or even microbial). In this review article, the latest and most promising natural compounds used to combat bacteria, filamentous fungi and viruses are presented and evaluated. These include plant extracts, essential oils, small antimicrobial peptides of animal origin, bacteriocins and various groups of plant compounds (triterpenoids; alkaloids; phenols; flavonoids) with antimicrobial and antiviral activity. Data are presented on the inhibitory activity of each natural antimicrobial substance and on the putative mechanism of action against bacterial and fungal strains. The results show that among the bioactive compounds studied, triterpenoids have significant inhibitory activity against coronaviruses, but flavonoids have also been shown to inhibit SARS-COV-2. The last chapter is devoted to nanocarriers used to improve stability, bioavailability, cellular uptake/internalization, pharmacokinetic profile and reduce toxicity of natural compunds. There are a number of nanocarriers such as liposomes, drug delivery microemulsion systems, nanocapsules, solid lipid nanoparticles, polymeric micelles, dendrimers, etc. However, some of the recent studies have focused on the incorporation of natural substances with antimicrobial/antiviral activity into polymeric nanoparticles, niosomes and silver nanoparticles (which have been shown to have intrinsic antimicrobial activity). The natural antimicrobials isolated from animals and microorganisms have been shown to have good inhibitory effect on a range of pathogens, however the plants remain the most prolific source. Even if the majority of the studies for the biological activity evaluation are in silico or in vitro, their internalization in the optimum nanocarriers represents the future of “green therapeutics” as shown by some of the recent work in the field.

Regression of bovine cutaneous papillomas via ivermectin-induced immunostimulant and oxidative stress

OBJECTIVE

Ivermectin (IVM) could be used effectively to treat bovine cutaneous papillomatosis, a widespread viral skin disease that causes major economic losses in cattle. This study aimed to evaluate the regression of bovine cutaneous papillomas induced by IVM by estimating oxidative stress markers, besides clinicopathological and hematological findings.

MATERIALS AND METHODS

Twenty naturally infected animals with cutaneous papillomatosis were chosen randomly and diagnosed clinically and histopathologically. All the infected animals were divided into groups: Group I (n = 10), which received no treatment and was considered the control group. In Group II (n = 10), the animals were subcutaneously injected at 0.2 mg/kg of IVM 2 weeks apart during the 90-day experimental period. Papilloma regression was tracked clinically, papilloma biopsies were taken for histopathological analysis, and blood samples were taken for hematological and oxidative parameter testing.

RESULTS

From the 15th to 45th day after receiving IVM, papillomas began to fade. Necrotic areas, ulcerations, and lymphocytic infiltration were found in the histopathological studies, besides a decrease in papilloma epidermal proliferation. total erythrocytes count, packed cell volume, total leucocytes count, and lymphocytes values were increased significantly, and a large decrease in glutathione peroxidase and glutathione reduced was identified as signs of IVM-induced oxidative stress.

CONCLUSION

IVM has oxidative and immunostimulatory properties, and it can be used against cutaneous papillomatosis.

A secondary approach with conventional medicines and supplements to recuperate current COVID-19 status

Novel coronavirus 2019 (COVID-19) is a zoonosis that revised the global economic and societal progress since early 2020. The SARS-CoV-2 has been recognized as the responsible pathogen for COVID-19 with high infection and mortality rate potential. It has spread in 192 countries and infected about 1.5% of the world population, and still, a proper therapeutic approach is not unveiled. COVID-19 indication starts with fever to shortness of breathing, leading to ICU admission with the ventilation support in severe conditions. Besides the symptomatic mainstay clinical therapeutic approach, only Remdesivir has been approved by the FDA. Several pharmaceutical companies claimed different vaccines with exceptionally high efficacy (90–95%) against COVID-19; how long these vaccines can protect and long-term safety with the new variants are unpredictable. After the worldwide spread of the COVID-19 pandemic, numerous clinical trials with different phases are being performed to find the most appropriate solution to this condition. Some of these trials with old FDA-approved drugs showed promising results. In this review, we have precisely compiled the efforts to curb the disease and discussed the clinical findings of Ivermectin, Doxycycline, Vitamin-D, Vitamin-C, Zinc, and cannabidiol and their combinations. Additionally, the correlation of these molecules on the prophylactic and diseased ministration against COVID-19 has been explored.

Use of nanotechnology in combating coronavirus

Recent COVID-19 pandemic situation caused due to the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) affected global health as well as economics. There is global attention on prevention, diagnosis as well as treatment of COVID-19 infection which would help in easing the current situation. The use of nanotechnology and nanomedicine has been considered to be promising due to its excellent potential in managing various medical issues such as viruses which is a major threat. Nanoparticles have shown great potential in various biomedical applications and can prove to be of great use in antiviral therapy, especially over other conventional antiviral agents. This review focusses on the pathophysiology of SARS-CoV-2 and the progression of the COVID-19 disease followed by currently available treatments for the same. Use of nanotechnology has been elaborated by exploiting various nanoparticles like metal and metal oxide nanoparticles, carbon-based nanoparticles, quantum dots, polymeric nanoparticles as well as lipid-based nanoparticles along with its mechanism of action against viruses which can prove to be beneficial in COVID-19 therapeutics. However, it needs to be considered that use of these nanotechnology-based approaches in COVID-19 therapeutics only aids the human immunity in fighting the infection. The main function is performed by the immune system in combatting any infection.

COVID-19 and Ivermectin: Potential threats associated with human use

Drugs re-purposing due to COVID-19 virus has declared a number of useful candidates for treatment and prevention of the virus. Ivermectin (IVM) has gained much popularity due to a strong background of magical applications against a broad spectrum of pathogens. The in- vitro studies of ivermectin have shown promise, the thorough clinical trials of its efficacy in the treatment and prevention of SARS-CoV-2 are still warranted. Useful strategies for analyzing projected use of IVM in human coronaviruses might be developed. It may be done by concluding ongoing clinical trials and culturing lessons from IVM usage in veterinary practice. The potential toxicity and careful dosage analyses are urgently required before declaring it as an anti-SARS-CoV-2 drug candidate. This manuscript overviews the background and potential threats associated with the off-label use of IVM as prophylactic drug or treatment option against COVID-19 virus.

The Molecular Basis of COVID-19 Pathogenesis, Conventional and Nanomedicine Therapy

In late 2019, a new member of the Coronaviridae family, officially designated as "severe acute respiratory syndrome coronavirus 2" (SARS-CoV-2), emerged and spread rapidly. The Coronavirus Disease-19 (COVID-19) outbreak was accompanied by a high rate of morbidity and mortality worldwide and was declared a pandemic by the World Health Organization in March 2020. Within the Coronaviridae family, SARS-CoV-2 is considered to be the third most highly pathogenic virus that infects humans, following the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV). Four major mechanisms are thought to be involved in COVID-19 pathogenesis, including the activation of the renin-angiotensin system (RAS) signaling pathway, oxidative stress and cell death, cytokine storm, and endothelial dysfunction. Following virus entry and RAS activation, acute respiratory distress syndrome develops with an oxidative/nitrosative burst. The DNA damage induced by oxidative stress activates poly ADP-ribose polymerase-1 (PARP-1), viral macrodomain of non-structural protein 3, poly (ADP-ribose) glycohydrolase (PARG), and transient receptor potential melastatin type 2 (TRPM2) channel in a sequential manner which results in cell apoptosis or necrosis. In this review, blockers of angiotensin II receptor and/or PARP, PARG, and TRPM2, including vitamin D3, trehalose, tannins, flufenamic and mefenamic acid, and losartan, have been investigated for inhibiting RAS activation and quenching oxidative burst. Moreover, the application of organic and inorganic nanoparticles, including liposomes, dendrimers, quantum dots, and iron oxides, as therapeutic agents for SARS-CoV-2 were fully reviewed. In the present review, the clinical manifestations of COVID-19 are explained by focusing on molecular mechanisms. Potential therapeutic targets, including the RAS signaling pathway, PARP, PARG, and TRPM2, are also discussed in depth.

Evaluation of the effectiveness and safety of adding ivermectin to treatment in severe COVID-19 patients

Background and objectives

An effective treatment option is not yet available for SARS-CoV2, which causes the COVID-19 pandemic and whose effects are felt more and more every day. Ivermectin is among the drugs whose effectiveness in treatment has been investigated. In this study; it was aimed to investigate the presence of gene mutations that alter ivermectin metabolism and cause toxic effects in patients with severe COVID-19 pneumonia, and to evaluate the effectiveness and safety of ivermectin use in the treatment of patients without mutation.

Materials and methods

Patients with severe COVID19 pneumonia were included in the study, which was planned as a prospective, randomized, controlled, single-blind phase 3 study. Two groups, the study group and the control group, took part in the study. Ivermectin 200 mcg/kg/day for 5 days in the form of a solution prepared for enteral use added to the reference treatment protocol -hydroxychloroquine + favipiravir + azithromycin- of patients included in the study group. Patients in the control group were given only reference treatment with 3 other drugs without ivermectin. The presence of mutations was investigated by performing sequence analysis in the mdr1/abcab1 gene with the Sanger method in patients included in the study group according to randomization. Patients with mutations were excluded from the study and ivermectin treatment was not continued. Patients were followed for 5 days after treatment. At the end of the treatment and follow-up period, clinical response and changes in laboratory parameters were evaluated.

Results

A total of 66 patients, 36 in the study group and 30 in the control group were included in the study. Mutations affecting ivermectin metabolism was detected in genetic tests of six (16.7%) patients in the study group and they were excluded from the study. At the end of the 5-day follow-up period, the rate of clinical improvement was 73.3% (22/30) in the study group and was 53.3% (16/30) in the control group (p = 0.10). At the end of the study, mortality developed in 6 patients (20%) in the study group and in 9 (30%) patients in the control group (p = 0.37). At the end of the follow-up period, the average peripheral capillary oxygen saturation (SpO2) values of the study and control groups were found to be 93.5 and 93.0%, respectively. Partial pressure of oxygen (PaO2)/FiO2 ratios were determined as 236.3 ± 85.7 and 220.8 ± 127.3 in the study and control groups, respectively. While the blood lymphocyte count was higher in the study group compared to the control group (1698 ± 1438 and 1256 ± 710, respectively) at the end of the follow-up period (p = 0.24); reduction in serum C-reactive protein (CRP), ferritin and D-dimer levels was more pronounced in the study group (p = 0.02, p = 0.005 and p = 0.03, respectively).

Conclusions

According to the findings obtained, ivermectin can provide an increase in clinical recovery, improvement in prognostic laboratory parameters and a decrease in mortality rates even when used in patients with severe COVID-19. Consequently, ivermectin should be considered as an alternative drug that can be used in the treatment of COVID-19 disease or as an additional option to existing protocols.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06104-9.

Evaluation of the effectiveness and safety of adding ivermectin to treatment in severe COVID-19 patients

BACKGROUND AND OBJECTIVES

An effective treatment option is not yet available for SARS-CoV2, which causes the COVID-19 pandemic and whose effects are felt more and more every day. Ivermectin is among the drugs whose effectiveness in treatment has been investigated. In this study; it was aimed to investigate the presence of gene mutations that alter ivermectin metabolism and cause toxic effects in patients with severe COVID-19 pneumonia, and to evaluate the effectiveness and safety of ivermectin use in the treatment of patients without mutation.

MATERIALS AND METHODS

Patients with severe COVID19 pneumonia were included in the study, which was planned as a prospective, randomized, controlled, single-blind phase 3 study. Two groups, the study group and the control group, took part in the study. Ivermectin 200 mcg/kg/day for 5 days in the form of a solution prepared for enteral use added to the reference treatment protocol -hydroxychloroquine + favipiravir + azithromycin- of patients included in the study group. Patients in the control group were given only reference treatment with 3 other drugs without ivermectin. The presence of mutations was investigated by performing sequence analysis in the mdr1/abcab1 gene with the Sanger method in patients included in the study group according to randomization. Patients with mutations were excluded from the study and ivermectin treatment was not continued. Patients were followed for 5 days after treatment. At the end of the treatment and follow-up period, clinical response and changes in laboratory parameters were evaluated.

RESULTS

A total of 66 patients, 36 in the study group and 30 in the control group were included in the study. Mutations affecting ivermectin metabolism was detected in genetic tests of six (16.7%) patients in the study group and they were excluded from the study. At the end of the 5-day follow-up period, the rate of clinical improvement was 73.3% (22/30) in the study group and was 53.3% (16/30) in the control group (p = 0.10). At the end of the study, mortality developed in 6 patients (20%) in the study group and in 9 (30%) patients in the control group (p = 0.37). At the end of the follow-up period, the average peripheral capillary oxygen saturation (SpO2) values of the study and control groups were found to be 93.5 and 93.0%, respectively. Partial pressure of oxygen (PaO2)/FiO2 ratios were determined as 236.3 ± 85.7 and 220.8 ± 127.3 in the study and control groups, respectively. While the blood lymphocyte count was higher in the study group compared to the control group (1698 ± 1438 and 1256 ± 710, respectively) at the end of the follow-up period (p = 0.24); reduction in serum C-reactive protein (CRP), ferritin and D-dimer levels was more pronounced in the study group (p = 0.02, p = 0.005 and p = 0.03, respectively).

CONCLUSIONS

According to the findings obtained, ivermectin can provide an increase in clinical recovery, improvement in prognostic laboratory parameters and a decrease in mortality rates even when used in patients with severe COVID-19. Consequently, ivermectin should be considered as an alternative drug that can be used in the treatment of COVID-19 disease or as an additional option to existing protocols.

Advanced Nanobiomedical Approaches to Combat Coronavirus Disease of 2019

New infectious diseases are making themselves known as the human population grows, expands into new regions, and becomes more dense, increasing contact with each other and animal populations. Ease of travel has also increased infectious disease transmission and has now culminated into a global pandemic. The emergence of the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019 has already infected over 83.7 million people and caused over 1.8 million deaths. While there have been vaccine candidates produced and supportive care implemented, the world is impatiently waiting for a commercially approved vaccine and treatment for the coronavirus disease of 2019 (COVID-19). The different vaccine types investigated for the prevention of COVID-19 all have great promise but face safety obstacles that must be first addressed. Some vaccine candidates of key interest are whole inactivated viruses, adeno-associated viruses, virus-like particles, and lipid nanoparticles. This review examines nanobiomedical techniques for combatting COVID-19 in terms of vaccines and therapeutics.

A systematic review of experimental evidence for antiviral effects of ivermectin and an in silico analysis of ivermectin's possible mode of action against SARS-CoV-2

Viral infections remain a major cause of economic loss with an unmet need for novel therapeutic agents. Ivermectin is a putative antiviral compound; the proposed mechanism is the inhibition of nuclear translocation of viral proteins, facilitated by mammalian host importins, a necessary process for propagation of infections. We systematically reviewed the evidence for the applicability of ivermectin against viral infections including SARS‐CoV‐2 regarding efficacy, mechanisms and selective toxicity. The SARS‐CoV‐2 genome was mined to determine potential nuclear location signals for ivermectin and meta‐analyses for in vivo studies included all comparators over time, dose range and viral replication in multiple organs. Ivermectin inhibited the replication of many viruses including those in Flaviviridae, Circoviridae and Coronaviridae families in vitro. Real and mock nuclear location signals were identified in SARS‐CoV‐2, a potential target for ivermectin and predicting a sequestration bait for importin β, stopping infected cells from reaching a virus‐resistant state. While pharmacokinetic evaluations indicate that ivermectin could be toxic if applied based on in vitro studies, inhibition of viral replication in vivo was shown for Porcine circovirus in piglets and Suid herpesvirus in mice. Overall standardized mean differences and 95% confidence intervals for ivermectin versus controls were −4.43 (−5.81, −3.04), p < 0.00001. Based on current results, the potential for repurposing ivermectin as an antiviral agent is promising. However, further work is needed to reconcile in vitro studies with clinical efficacy. Developing ivermectin as an additional antiviral agent should be pursued with an emphasis on pre‐clinical trials in validated models of infection.

Harnessing biomaterials for therapeutic strategies against COVID-19

With the emergence of the coronavirus disease 2019 (COVID-19), the world is experiencing a profound human health crisis. The number of infections and deaths due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to increase every minute, pinpointing major shortcomings in our ability to prevent viral outbreaks. Although several COVID-19 vaccines have been recently approved for emergency use, therapeutic options remain limited, and their long-term potency has yet to be validated. Biomaterials science has a pivotal role to play in pushing the boundaries of emerging technologies for antiviral research and treatment. In this perspective, we discuss how biomaterials can be harnessed to develop accurate COVID-19 infection models, enhance antiviral drug delivery, foster new antiviral strategies, and boost vaccine efficacy. These efforts will not only contribute to stop or mitigate the current pandemic but will also provide unorthodox platforms to understand, prevent, and protect us from future viral outbreaks.

Advances in Antiviral Material Development

The rise in human pandemics demands prudent approaches in antiviral material development for disease prevention and treatment via effective protective equipment and therapeutic strategy. However, the current state of the antiviral materials research is predominantly aligned towards drug development and its related areas, catering to the field of pharmaceutical technology. This review distinguishes the research advances in terms of innovative materials exhibiting antiviral activities that take advantage of fast-developing nanotechnology and biopolymer technology. Essential concepts of antiviral principles and underlying mechanisms are illustrated, followed with detailed descriptions of novel antiviral materials including inorganic nanomaterials, organic nanomaterials and biopolymers. The biomedical applications of the antiviral materials are also elaborated based on the specific categorization. Challenges and future prospects are discussed to facilitate the research and development of protective solutions and curative treatments.

Ivermectin: Potential Role as Repurposed Drug for COVID-19

Severe acute respiratory illness caused by 2019 novel coronavirus (2019-nCoV), officially named severe acute respiratory syndrome coronavirus (SARS-CoV-2) in late December 2019 is an extremely communicable disease. World Health Organization (WHO) declared coronavirus disease 2019 (COVID-19) as a pandemic as it has spread to at least 200 countries in a short span of time. Being a new disease there is lack of information about pathogenesis and proliferation pathways of this new coronavirus. Currently there is no effective treatment for coronavirus infection; major effort is to develop vaccine against the virus and development of therapeutic drugs for the disease. The development of genome-based vaccine and therapeutic antibodies require thorough testing for safety and will be available after some time. In the meanwhile, the available practical approach is to repurpose existing therapeutic agents, with proven safety record as a rapid response measure for the current pandemic. Here we discuss the presently used repurposed drugs for COVID-19 and the potential for ivermectin (IVM) to be used as a therapeutic option in COVID-19.

Ivermectin: a systematic review from antiviral effects to COVID-19 complementary regimen

Ivermectin proposes many potentials effects to treat a range of diseases, with its antimicrobial, antiviral, and anti-cancer properties as a wonder drug. It is highly effective against many microorganisms including some viruses. In this comprehensive systematic review, antiviral effects of ivermectin are summarized including in vitro and in vivo studies over the past 50 years. Several studies reported antiviral effects of ivermectin on RNA viruses such as Zika, dengue, yellow fever, West Nile, Hendra, Newcastle, Venezuelan equine encephalitis, chikungunya, Semliki Forest, Sindbis, Avian influenza A, Porcine Reproductive and Respiratory Syndrome, Human immunodeficiency virus type 1, and severe acute respiratory syndrome coronavirus 2. Furthermore, there are some studies showing antiviral effects of ivermectin against DNA viruses such as Equine herpes type 1, BK polyomavirus, pseudorabies, porcine circovirus 2, and bovine herpesvirus 1. Ivermectin plays a role in several biological mechanisms, therefore it could serve as a potential candidate in the treatment of a wide range of viruses including COVID-19 as well as other types of positive-sense single-stranded RNA viruses. In vivo studies of animal models revealed a broad range of antiviral effects of ivermectin, however, clinical trials are necessary to appraise the potential efficacy of ivermectin in clinical setting.

Orally Administrable Therapeutic Synthetic Nanoparticle for Zika Virus

The spread of Zika virus (ZIKV) infection across the USA and various countries in the last three years will not only have a direct impact on the U.S. health care system but has caused international concerns as well. The ultimate impact of ZIKV infection remains to be understood. Currently, there are no therapeutic or vaccine options available to protect those infected by ZIKV. The drug ivermectin (IVM) was found to be a viable agent for the prevention of transmission of ZIKV. Ivermectin is unstable in the presence of water and does not remain in adequate concentration in the human bloodstream to be effective in treatment for ZIKV. Biodegradable nanoparticles would aid in the delivery of ivermectin by providing a high enough concentration of drug and ensuring the drug is gradually released to maintain an appropriate level in the body. The overall goal of this study was to develop and optimize an orally administrable nanoformulation of IVM which can circulate in the blood for a long period for efficient delivery. To achieve the goal, we synthesized and optimized a synthetic nanoformulation of IVM for oral use which can cross the intestinal epithelial barrier to enter the bloodstream. Our studies documented that when delivered with the synthetic nanoparticle (NP), IVM can be accumulated in the blood at a higher concentration and preliminary studies highlighted that NP delivered IVM has the ability to target nonstructural 1 protein of ZIKV. For potential clinical relevance, long-term storable formulation of IVM-nanoparticle in dry powder state for inclusion in a capsule form and cryoprotectant containing frozen forms revealed promising findings. Further, our preliminary in vitro studies documented that ivermectin crosses the placental barrier, thus making it unsafe for the pregnant ZIKV population, whereas the ivermectin-loaded nanoparticle did not show any significant placental barrier crossing, thus indicating its potential suitability for such population. We envision that this work will fill a great unmet need by developing safer and more effective therapies for the treatment of viral infections, including ZIKV.

Orally Administrable Therapeutic Synthetic Nanoparticle for Zika Virus

The spread of Zika virus (ZIKV) infection across the USA and various countries in the last three years will not only have a direct impact on the U.S. health care system but has caused international concerns as well. The ultimate impact of ZIKV infection remains to be understood. Currently, there are no therapeutic or vaccine options available to protect those infected by ZIKV. The drug ivermectin (IVM) was found to be a viable agent for the prevention of transmission of ZIKV. Ivermectin is unstable in the presence of water and does not remain in adequate concentration in the human bloodstream to be effective in treatment for ZIKV. Biodegradable nanoparticles would aid in the delivery of ivermectin by providing a high enough concentration of drug and ensuring the drug is gradually released to maintain an appropriate level in the body. The overall goal of this study was to develop and optimize an orally administrable nanoformulation of IVM which can circulate in the blood for a long period for efficient delivery. To achieve the goal, we synthesized and optimized a synthetic nanoformulation of IVM for oral use which can cross the intestinal epithelial barrier to enter the bloodstream. Our studies documented that when delivered with the synthetic nanoparticle (NP), IVM can be accumulated in the blood at a higher concentration and preliminary studies highlighted that NP delivered IVM has the ability to target nonstructural 1 protein of ZIKV. For potential clinical relevance, long-term storable formulation of IVM-nanoparticle in dry powder state for inclusion in a capsule form and cryoprotectant containing frozen forms revealed promising findings. Further, our preliminary in vitro studies documented that ivermectin crosses the placental barrier, thus making it unsafe for the pregnant ZIKV population, whereas the ivermectin-loaded nanoparticle did not show any significant placental barrier crossing, thus indicating its potential suitability for such population. We envision that this work will fill a great unmet need by developing safer and more effective therapies for the treatment of viral infections, including ZIKV.

Ivermectin: From theory to clinical application

Approximately 250 million people have been using ivermectin (IVM) annually to combat many parasitic diseases including filariasis, onchocerciasis, strongyloidiasis, scabies and pediculosis. Many clinical studies have proven its efficacy against these diseases and have reported the optimum dose and duration of treatment. Moreover, its antiparasitic range has increased to cover more parasitic infections, but it still requires further exploration, e.g. for trichinosis and myiasis. Furthermore, IVM showed high efficacy in killing vectors of disease-causing parasites such as mosquitoes, sandflies and tsetse flies. The World Health Organization (WHO) has managed many control programmes involving the use of IVM to achieve elimination of onchocerciasis and lymphatic filariasis and to reduce malaria transmission. However, IVM is not exempt from the possibility of resistance and, certainly, its intensive use has led to the emergence of resistance in some parasites. Recent research is investigating the possibility of novel drug delivery systems for IVM that increase its potential to treat a new range of diseases and to overcome the possibility of drug resistance. This review highlights the most common human uses of IVM, with special reference to the new and promising properties of IVM.

Lack of efficacy of ivermectin for prevention of a lethal Zika virus infection in a murine system

The antihelminthic drug ivermectin has been demonstrated to have antiviral activity against the Zika virus and other arboviruses in in vitro studies. The effectiveness of ivermectin for Zika virus infection, however, has never been studied in an animal model. In this study, ivermectin was found to be ineffective for prevention of a lethal infection with the Senegal strain of Zika virus in Ifnar1 knockout mice. In view of several study limitations, evaluation of ivermectin's anti-Zika virus activity in other animal models and against other Zika virus strains would be desirable.

Antivirus effectiveness of ivermectin on dengue virus type 2 in Aedes albopictus

Background

Dengue fever is the most rapidly spreading mosquito-borne viral disease over the past 50 years, with a 30-fold increase in global incidence. Dengue vector control is a key component for the dengue control strategy, since no absolutely effective vaccine or drug is available yet. However, the rapid rise and spread of mosquito insecticide resistance have become major threats to the efficiency of insecticide-based vector control activities. Thus, innovative vector control tools are badly needed. This study aims to confirm the antivirus effectiveness of ivermectin on dengue virus type 2 (DENV-2) in Aedes albopictus (Skuse, 1894), then to explore its potential use in the combating to the dengue epidemics.

Methods

Aedes albopictus were first infected with DENV-2 in human whole blood, and at the fourth day after infectious blood feeding, they were divided into eight groups. Seven of them were held for six days with access to 0, 2, 4, 8, 16, 32 and 64 ng/ml ivermectin, respectively, and the last one was set as a historical control group, which was stored at -80°C until being detected at the same time with the other groups. Each mosquito was detected using real-time fluorescent RT-PCR kit. DENV-2 RNA concentration (copies/ml) and infection rate in each group were compared.

Results

Both of quantitatively and qualitatively inhibiting effects of ivermectin have been detected in this study. Generally, DENV-2 replicated well in Aedes albopictus without ivermectin intervention, whose virus loads exhibited significantly higher when the mosquitoes were holding from 4 days to 10 days after infectious blood feeding. In contrast, with the treatment of ivermectin, the infection rate was reduced by as much as 49.63%. The regression equation between infection rates (Y₂) and ivermectin concentration log₂ values (X₂) was obtained as Y₂ = 91.41–7.21*X₂ with R² = 0.89.

Conclusion

Ivermectin can directly or indirectly inhibit DENV-2 multiplication in Aedes albopictus. Moreover, the actual concentration for application in zooprophylaxis needs to be confirmed in the further field trials.

Dengue fever is one of neglected vector-borne tropical diseases with a 30-fold increase in global incidence recently. In 2012, World Health Organization set a goal to reduce dengue mortality by at least 50% by 2020. Being faced with more challenges in the dengue control programs, such as the increase of dengue outbreaks, lacking absolutely effective vaccine, rise of vector insecticide resistance and so on; innovative vector control tools are urgently needed for current control programs on dengue fever. To find a new avenue in vector control, we for the first time assessed the inhibiting effectiveness of ivermectin on dengue virus type 2 (DENV-2) inside Aedes mosquitoes. We found that about 80% Aedes albopictus mosquitoes were effectively infected with DENV-2 without treatment of ivermectin. But in the groups of ivermectin treatment, the infection rate of DENV-2 and the median of virus loads were significantly reduced by up to 49.63% and 99.99%, respectively. Both quantitatively and qualitatively inhibiting effects of ivermectin were detected. We found out that ivermectin was able to effectively inhibit the DENV-2 multiplication in Aedes albopictus, which may gave us a hint that using ivermectin in some control programs as a zooprophylaxis to block dengue epidemic through inhibiting DENV-2 in field Aedes mosquitoes.