Boronic acid-modified lipid nanocapsules: a novel platform for the highly efficient inhibition of hepatitis C viral entry

Nanotechnology's frontier in combatting infectious and inflammatory diseases: prevention and treatment

Inflammation-associated diseases encompass a range of infectious diseases and non-infectious inflammatory diseases, which continuously pose one of the most serious threats to human health, attributed to factors such as the emergence of new pathogens, increasing drug resistance, changes in living environments and lifestyles, and the aging population. Despite rapid advancements in mechanistic research and drug development for these diseases, current treatments often have limited efficacy and notable side effects, necessitating the development of more effective and targeted anti-inflammatory therapies. In recent years, the rapid development of nanotechnology has provided crucial technological support for the prevention, treatment, and detection of inflammation-associated diseases. Various types of nanoparticles (NPs) play significant roles, serving as vaccine vehicles to enhance immunogenicity and as drug carriers to improve targeting and bioavailability. NPs can also directly combat pathogens and inflammation. In addition, nanotechnology has facilitated the development of biosensors for pathogen detection and imaging techniques for inflammatory diseases. This review categorizes and characterizes different types of NPs, summarizes their applications in the prevention, treatment, and detection of infectious and inflammatory diseases. It also discusses the challenges associated with clinical translation in this field and explores the latest developments and prospects. In conclusion, nanotechnology opens up new possibilities for the comprehensive management of infectious and inflammatory diseases.

Core-Shell Type Lipidic and Polymeric Nanocapsules: the Transformative Multifaceted Delivery Systems

Amongst the several nano-drug delivery systems, lipid or polymer-based core-shell nanocapsules (NCs) have garnered much attention of researchers owing to its multidisciplinary properties and wide application. NCs are structured core-shell systems in which the core is an aqueous or oily phase protecting the encapsulated drug from environmental conditions, whereas the shell can be lipidic or polymeric. The core is stabilized by surfactant/lipids/polymers, which control the release of the drug. The presence of a plethora of biocompatible lipids and polymers with the provision of amicable surface modifications makes NCs an ideal choice for precise drug delivery. In the present article, multiple lipidic and polymeric NC (LNCs and PNCs) systems are described with an emphasis on fabrication methods and characterization techniques. Far-reaching applications as a carrier or delivery system are demonstrated for oral, parenteral, nasal, and transdermal routes of administration to enhance the bioavailability of hard-to-formulate drugs and to achieve sustained and targeted delivery. This review provide in depth understanding on core-shell NC's mechanism of absorption, surface modification, size tuning, and toxicity moderation which overshadows the drawbacks of conventional approaches. Additionally, the review shines a spotlight on the current challenges associated with core-shell NCs and applications in the foreseeable future.

Progress on Applying Carbon Dots for Inhibition of RNA Virus Infection

Viral infection is a globally leading health issue. Annually, new lethal RNA viruses unexpectedly emerged and mutated threatening health and safety. Meanwhile, it is urgent to explore novel antiviral agents, which, however, takes years to be clinically available. Nonetheless, the development of carbon dots (CDs) in the past 20 years has exhibited their vast application potentials and revealed their promising capacity as future antiviral agents considering their versatile properties and significant antiviral responses. Thus, CDs have been widely investigated as an alternative of traditional chemotherapy for inhibiting viral infection and replication in vitro. Meanwhile, attempts to apply CDs to in vivo systems are in high demand. In this review, recent developments of CDs-based antiviral therapies are systematically summarized. Furthermore, the role of CDs in photodynamic inactivation to kill viruses or bacteria is briefly discussed.

Allium sativum derived carbon dots as a potential theranostic agent to combat the COVID-19 crisis

Coronavirus disease 2019 (COVID-19) is one of the worst pandemics to have hit the humanity. The manifestations are quite varied, ranging from severe lung infections to being asymptomatic. Hence, there is an urgent need to champion new tools to accelerate the end of this pandemic. Compromised immunity is a primary feature of COVID-19. Allium sativum (AS) is an effective dietary supplement known for its immune-modulatory, antibacterial, anti-inflammatory, anticancer, antifungal, and anti-viral properties. In this paper, it is hypothesized that carbon dots (CDs) derived from AS (AS-CDs) may possess the potential to downregulate the expression of pro-inflammatory cytokines and revert the immunological aberrations to normal in case of COVID-19. CDs have already been explored in the world of nanobiomedicine as a promising theranostic candidates for bioimaging and drug/gene delivery. The antifibrotic and antioxidant effects of AS are elaborated, as demonstrated in several studies. It is found that the most active constituent of AS, allicin has a highly potent antioxidant and reactive oxygen species (ROS) scavenging effect. The antibacterial, antifungal, and anti-viral effects along with their capability of negating inflammatory effects and cytokine storm are discussed. The synthesis of theranostic CDs from AS may provide a novel weapon in the therapeutic armamentarium for the management of COVID-19 infection and, at the same time, could act as a diagnostic agent for COVID-19.

Recent Progress on Biomaterials Fighting against Viruses

Viruses not only pose severe threats to public health, but also influence the development of society. Over the past decade, rapid advances have been seen in the application of nanomaterials to virus research. As an interdisciplinary field, nanotechnology offers powerful functions because the structures of nanomaterials are unique, with remarkable physicochemical properties and excellent biocompatibility. Nanomaterials have been developed for virus detection and tracking and for antiviral strategies, to better understand viruses and reduce viral infections, implying a bright future for this field. Herein, the recent advances are systematically summarized regarding the nanomaterials used in viral studies. Representative applications of nanomaterials to viral detection and tracking are described. The antiviral effects achieved with nanomaterials based on different mechanisms are also described, including entry inhibition, inhibition of viral replication, and immunological enhancement. The current challenges and future opportunities in this promising field are also discussed.

Nanotechnology for virus treatment

The continued emergence of novel viruses poses a significant threat to global health. Uncontrolled outbreaks can result in pandemics that have the potential to overburden our healthcare and economic systems. While vaccination is a conventional modality that can be employed to promote herd immunity, antiviral vaccines can only be applied prophylactically and do little to help patients who have already contracted viral infections. During the early stages of a disease outbreak when vaccines are unavailable, therapeutic antiviral drugs can be used as a stopgap solution. However, these treatments do not always work against emerging viral strains and can be accompanied by adverse effects that sometimes outweigh the benefits. Nanotechnology has the potential to overcome many of the challenges facing current antiviral therapies. For example, nanodelivery vehicles can be employed to drastically improve the pharmacokinetic profile of antiviral drugs while reducing their systemic toxicity. Other unique nanomaterials can be leveraged for their virucidal or virus-neutralizing properties. In this review, we discuss recent developments in antiviral nanotherapeutics and provide a perspective on the application of nanotechnology to the SARS-CoV-2 outbreak and future virus pandemics.

Carbon-based antiviral nanomaterials: graphene, C-dots, and fullerenes. A perspective

The appearance of new and lethal viruses and their potential threat urgently requires innovative antiviral systems. In addition to the most common and proven pharmacological methods, nanomaterials can represent alternative resources to fight viruses at different stages of infection, by selective action or in a broad spectrum. A fundamental requirement is non-toxicity. However, biocompatible nanomaterials have very often little or no antiviral activity, preventing their practical use. Carbon-based nanomaterials have displayed encouraging results and can present the required mix of biocompatibility and antiviral properties. In the present review, the main candidates for future carbon nanometric antiviral systems, namely graphene, carbon dots and fullerenes, have been critically analysed. In general, different carbon nanostructures allow several strategies to be applied. Some of the materials have peculiar antiviral properties, such as singlet oxygen emission, or the capacity to interfere with virus enzymes. In other cases, nanomaterials have been used as a platform for functional molecules able to capture and inhibit viral activity. The use of carbon-based biocompatible nanomaterials as antivirals is still an almost unexplored field, while the published results show promising prospects.

Functional Carbon Quantum Dots as Medical Countermeasures to Human Coronavirus

Therapeutic options for the highly pathogenic human coronavirus (HCoV) infections are urgently needed. Anticoronavirus therapy is however challenging, as coronaviruses are biologically diverse and rapidly mutating. In this work, the antiviral activity of seven different carbon quantum dots (CQDs) for the treatment of human coronavirus HCoV-229E infections was investigated. The first generation of antiviral CQDs was derived from hydrothermal carbonization of ethylenediamine/citric acid as carbon precursors and postmodified with boronic acid ligands. These nanostructures showed a concentration-dependent virus inactivation with an estimated EC50 of 52 ± 8 μg mL-1. CQDs derived from 4-aminophenylboronic acid without any further modification resulted in the second-generation of anti-HCoV nanomaterials with an EC50 lowered to 5.2 ± 0.7 μg mL-1. The underlying mechanism of action of these CQDs was revealed to be inhibition of HCoV-229E entry that could be due to interaction of the functional groups of the CQDs with HCoV-229E entry receptors; surprisingly, an equally large inhibition activity was observed at the viral replication step.

Nanoformulations: A Valuable Tool in the Therapy of Viral Diseases Attacking Humans and Animals

Various viruses can be considered as one of the most frequent causes of human diseases, from mild illnesses to really serious sicknesses that end fatally. Numerous viruses are also pathogenic to animals and plants, and many of them, mutating, become pathogenic also to humans. Several cases of affecting humans by originally animal viruses have been confirmed. Viral infections cause significant morbidity and mortality in humans, the increase of which is caused by general immunosuppression of the world population, changes in climate, and overall globalization. In spite of the fact that the pharmaceutical industry pays great attention to human viral infections, many of clinically used antivirals demonstrate also increased toxicity against human cells, limited bioavailability, and thus, not entirely suitable therapeutic profile. In addition, due to resistance, a combination of antivirals is needed for life-threatening infections. Thus, the development of new antiviral agents is of great importance for the control of virus spread. On the other hand, the discovery and development of structurally new antivirals represent risks. Therefore, another strategy is being developed, namely the reformulation of existing antivirals into nanoformulations and investigation of various metal and metalloid nanoparticles with respect to their diagnostic, prophylactic, and therapeutic antiviral applications. This chapter is focused on nanoscale materials/formulations with the potential to be used for the treatment or inhibition of the spread of viral diseases caused by human immunodeficiency virus, influenza A viruses (subtypes H3N2 and H1N1), avian influenza and swine influenza viruses, respiratory syncytial virus, herpes simplex virus, hepatitis B and C viruses, Ebola and Marburg viruses, Newcastle disease virus, dengue and Zika viruses, and pseudorabies virus. Effective antiviral long-lasting and target-selective nanoformulations developed for oral, intravenous, intramuscular, intranasal, intrarectal, intravaginal, and intradermal applications are discussed. Benefits of nanoparticle-based vaccination formulations with the potential to secure cross protection against divergent viruses are outlined as well.

Evolution of efficacious pangenotypic hepatitis C virus therapies

Hepatitis C compromises the quality of life of more than 350 million individuals worldwide. Over the last decade, therapeutic regimens for treating hepatitis C virus (HCV) infections have undergone rapid advancements. Initially, structure-based drug design was used to develop molecules that inhibit viral enzymes. Subsequently, establishment of cell-based replicon systems enabled investigations into various stages of HCV life cycle including its entry, replication, translation, and assembly, as well as role of host proteins. Collectively, these approaches have facilitated identification of important molecules that are deemed essential for HCV life cycle. The expanded set of putative virus and host-encoded targets has brought us one step closer to developing robust strategies for efficacious, pangenotypic, and well-tolerated medicines against HCV. Herein, we provide an overview of the development of various classes of virus and host-directed therapies that are currently in use along with others that are undergoing clinical evaluation.

Glutathione-Capped Ag2S Nanoclusters Inhibit Coronavirus Proliferation through Blockage of Viral RNA Synthesis and Budding

Development of novel antiviral reagents is of great importance for the control of virus spread. Here, Ag₂S nanoclusters (NCs) were proved for the first time to possess highly efficient antiviral activity by using porcine epidemic diarrhea virus (PEDV) as a model of coronavirus. Analyses of virus titers showed that Ag₂S NCs significantly suppressed the infection of PEDV by about 3 orders of magnitude at the noncytotoxic concentration at 12 h postinfection, which was further confirmed by the expression of viral proteins. Mechanism investigations indicated that Ag₂S NCs treatment inhibits the synthesis of viral negative-strand RNA and viral budding. Ag₂S NCs treatment was also found to positively regulate the generation of IFN-stimulating genes (ISGs) and the expression of proinflammation cytokines, which might prevent PEDV infection. This study suggest the novel underlying of Ag₂S NCs as a promising therapeutic drug for coronavirus.

Nanotechnology in Glycomics: Applications in Diagnostics, Therapy, Imaging, and Separation Processes

This review comprehensively covers the most recent achievements (from 2013) in the successful integration of nanomaterials in the field of glycomics. The first part of the paper addresses the beneficial properties of nanomaterials for the construction of biosensors, bioanalytical devices, and protocols for the detection of various analytes, including viruses and whole cells, together with their key characteristics. The second part of the review focuses on the application of nanomaterials integrated with glycans for various biomedical applications, that is, vaccines against viral and bacterial infections and cancer cells, as therapeutic agents, for in vivo imaging and nuclear magnetic resonance imaging, and for selective drug delivery. The final part of the review describes various ways in which glycan enrichment can be effectively done using nanomaterials, molecularly imprinted polymers with polymer thickness controlled at the nanoscale, with a subsequent analysis of glycans by mass spectrometry. A short section describing an active glycoprofiling by microengines (microrockets) is covered as well.

Nanoparticles in Antiviral Therapy

In addition to general unavailability of specific antiviral therapeutics for a variety of viral diseases, usage of most antiviral drugs is linked to their limited solubility in aqueous media, short half-life time, and inadequate penetration to specified anatomic compartments. Accordingly, there is continuous effort to improve physicochemical characteristics of existing antiviral drugs. Since nanomaterials display remarkable physical and chemical properties, high surface area to volume ratio, and increased reactivity, new approaches for antiviral therapies include combinations of nanomaterials and current antiviral agents. Multivalent nanostructures, polymers, dendrimers, and liposomes can establish multivalent binding interactions with many biological systems and thus can target pathogenic interactions. There are reports about anitiviral activities of different metal nanoparticles, especially silver nanoparticles and their potential for treatment, prophylaxis, and control of viral infections. Integration of classic antiviral drugs, in the form of multiple ligands, onto nanostructures provides the advantages by creating a high local concentration of active molecules. This article will summarize the antiviral activity of different nanoparticle-based approaches currently available for the treatment of viral infections, and it will discuss metal nanoparticles as possible future antiviral drugs.

Two closely related {4-[(N-substituted amino)(diethoxyphosphoryl)methyl]phenyl}boronic acids

Organic phosphonic acids and organic phosphonic acid esters have been of much interest due to their applications in the fields of medicine, agriculture and industrial chemistry. Boronic acids can act as synthetic intermediates and building blocks and are used in sensing, protein manipulation, therapeutics, biological labelling and separation. The additional introduction of an aminophosphonic acid group into a boronic acid may give new opportunities for application. To study the structure of such multifunctional compounds, we prepared two new derivatives which can be easily converted to the corresponding phosphonic acids. In the title compounds, {4-[(butylamino)(diethoxyphosphoryl)methyl]phenyl}boronic acid monohydrate, C₁₅H₂₇BNO₅P·H₂O, (I), and {4-[(diethoxyphosphoryl)(4-nitroanilino)methyl]phenyl}boronic acid, C₁₇H₂₂BN₂O₇P, (II), three different substituents are attached to a central C-H group, namely 4-boronophenyl, diethoxyphosphoryl and amine. Compound (I) crystallizes as a monohydrate and O_B-H...N hydrogen bonds link neighbouring molecules into chains along the [001] direction. The solvent water molecule connects two such chains running in opposite directions. Compound (II) crystallizes as an ansolvate and classical hydrogen bonds result in a layer structure in the (001) plane.

High Efficiency of Functional Carbon Nanodots as Entry Inhibitors of Herpes Simplex Virus Type 1

Nanostructures have been lately identified as an efficient therapeutic strategy to modulate viral attachment and entry. The high concentrations of ligands present on nanostructures can considerably enhance affinities toward biological receptors. We demonstrate here the potential of carbon nanodots (C-dots) surface-functionalized with boronic acid or amine functions to interfere with the entry of herpes simplex virus type 1 (HSV-1). C-dots formed from 4-aminophenylboronic acid hydrochloride (4-AB/C-dots) using a modified hydrothermal carbonization are shown to prevent HSV-1 infection in the nanograms per milliliter concentration range (EC50 = 80 and 145 ng mL(-1) on Vero and A549 cells, respectively), whereas the corresponding C-dots formed from phenylboronic acid (B/C-dots) have no effects even at high concentrations. Some of the presented results also suggest that C-dots are specifically acting on the early stage of virus entry through an interaction with the virus and probably the cells at the same time.

Entry inhibitors: New advances in HCV treatment

Hepatitis C virus (HCV) infection affects approximately 3% of the world's population and causes chronic liver diseases, including liver fibrosis, cirrhosis, and hepatocellular carcinoma. Although current antiviral therapy comprising direct-acting antivirals (DAAs) can achieve a quite satisfying sustained virological response (SVR) rate, it is still limited by viral resistance, long treatment duration, combined adverse reactions, and high costs. Moreover, the currently marketed antivirals fail to prevent graft reinfections in HCV patients who receive liver transplantations, probably due to the cell-to-cell transmission of the virus, which is also one of the main reasons behind treatment failure. HCV entry is a highly orchestrated process involving initial attachment and binding, post-binding interactions with host cell factors, internalization, and fusion between the virion and the host cell membrane. Together, these processes provide multiple novel and promising targets for antiviral therapy. Most entry inhibitors target host cell components with high genetic barriers and eliminate viral infection from the very beginning of the viral life cycle. In future, the addition of entry inhibitors to a combination of treatment regimens might optimize and widen the prevention and treatment of HCV infection. This review summarizes the molecular mechanisms and prospects of the current preclinical and clinical development of antiviral agents targeting HCV entry.

Nanostructures for the Inhibition of Viral Infections

Multivalent interactions are omnipresent in biology and confer biological systems with dramatically enhanced affinities towards different receptors. Such multivalent binding interactions have lately been considered for the development of new therapeutic strategies against bacterial and viral infections. Multivalent polymers, dendrimers, and liposomes have successfully targeted pathogenic interactions. While a high synthetic effort was often needed for the development of such therapeutics, the integration of multiple ligands onto nanostructures turned to be a viable alternative. Particles modified with multiple ligands have the additional advantage of creating a high local concentration of binding molecules. This review article will summarize the different nanoparticle-based approaches currently available for the treatment of viral infections.