Drug-encapsulated carbon (DECON): A novel platform for enhanced drug delivery

Development of silk fibroin/collagen film containing GI-20 peptide-loaded PLGA nanoparticles against corneal herpes simplex virus-1

Herpes simplex virus-1 (HSV-1) is the primary cause of infectious blindness. Despite impressive therapeutic outcomes of conventional treatments, HSV-1 drug resistance can be easily developed. Thus, more constructive strategies should be implemented. Led by this inspiration, this work describes the potential utility of a biodegradable silk fibroin/collagen (SF/Col) film combined with GI-20-loaded poly lactic-co-glycolic acid (PLGA) nanoparticle to provide efficient and sustained delivery platform for synthetic GI-20 peptide against HSV-1. A non-irritant film containing 90 % SF and 10 % Col incorporated with mentioned nanodrug showed some optimum physicochemical properties including loading efficiency (74.15 % ± 1.12), tensile strength (3.16 ± 0.67 MPa), water uptake ability (∼73 %), cytocompatibility (viable up to 35 µg/mL of GI-20), and sustained release paradigm (∼90 % within 14 days). Also, GI-20 peptide at concentration of 35 µg/mL could prophylactically attenuate viral titration by 5 log10 units. In addition, the corneal uptake was improved without vascular irritation. In accordance with in vitro results, no hallmarks of keratitis and significant neovascularization along with ignorable inflammatory responses were obtained. Taken together, these results could guarantee the potential of mentioned multifunctional biomaterial in the healing of infected corneal tissue.

Activated Charcoal-Alginate Platform for Simultaneous Local Delivery of Bioactive Agents: At the Nexus of Antimicrobial and Cytotoxic Activity of Zn2+ Ions

Antimicrobial resistance (AMR) is a global public health threat that affects cancer patients more than the general population. In this work, a composite system based on Zn-alginate hydrogel and activated charcoal (AC) particles that, upon contact with physiological fluids, simultaneously releases bioactive agents (Zn2+ and AC particles impregnated with povidone-iodine) was designed to locally address specific problems characteristic for malignant wounds (MWs). This composite was comprehensively investigated in vitro regarding its morphology (field-emission scanning electron microscopy), Zn2+ release (flame atomic absorption spectrometry), iodine adsorption and desorption from AC particles (energy dispersive X-ray analysis and UV-visible spectroscopy) as well as its antimicrobial and antitumor activity. With respect to the ongoing AMR crises, antimicrobial activity was tested against a wide range of wild multi-drug resistant bacterial and yeast strains, all isolated from patient wounds. Since Zn2+ ions proved to be selectors of resistant strains of bacteria, the synergistic activity of AC particles and adsorbed iodine was shown to be crucial for excellent antibacterial activity. On the other hand, the synergy of AC particles and Zn2+ ions showed an equally strong antifungal effect. In addition, antimicrobial concentrations of Zn2+ ions showed cytotoxic activity against two cancer cell lines derived from cancers affecting skin either as metastatic cancer (breast cancer MDA-MB-453 cell line) or primary cancer of the skin (malignant melanoma Fem-X cell line), which enables Zn2+ ions to be further investigated as potent local agents targeting malignant cells.

Emerging drugs for the treatment of herpetic keratitis

INTRODUCTION

Herpes simplex keratitis stands as a prominent factor contributing to infectious blindness among developed nations. On a global scale, over 60% of the population tests positive for herpes simplex virus type-1 (HSV-1). Despite these statistics, there is currently no vaccine available for the virus. Moreover, the conventional nucleoside drugs prescribed to patients are proving ineffective in addressing issues related to drug resistance, recurrence, latency, and the escalating risk of vision loss. Hence, it is imperative to continually explore all potential avenues to restrict the virus. This review article centers on the present treatment methods for HSV-1 keratitis (HSK), highlighting the ongoing clinical trials. It delves into the emerging drugs, their mode-of-action and future therapeutics.

AREAS COVERED

The review focuses on the significance of a variety of small molecules targeting HSV-1 lifecycle at multiple steps. Peer-reviewed articles and abstracts were searched in MEDLINE, PubMed, Embase, and clinical trial websites.

EXPERT OPINION

The exploration of small molecules that target specific pathways within the herpes lifecycle holds the potential for substantial impact on the antiviral pharmaceutical market. Simultaneously, the pursuit of disease-specific biomarkers has the capacity to usher in a transformative era in diagnostics within the field.

Mesoporous zinc oxide-based drug delivery system offers an antifungal and immunoregulatory strategy for treating keratitis

Fungal keratitis is a refractory eye disease that is prone to causing blindness. Fungal virulence and inflammatory responses are two major factors that accelerate the course of fungal keratitis. However, the current antifungal drugs used for treatment usually possess transient residence time on the ocular surface and low bioavailability deficiencies, which limit their therapeutic efficacy. In this work, natamycin (NATA)-loaded mesoporous zinc oxide (Meso-ZnO) was synthesized for treating Aspergillus fumigatus keratitis with excellent drug-loading and sustained drug release capacities. In addition to being a carrier for drug delivery, Meso-ZnO could restrict fungal growth in a concentration-dependent manner, and the transcriptome analysis of fungal hyphae indicated that it inhibited the mycotoxin biosynthesis, oxidoreductase activity and fungal cell wall formation. Meso-ZnO also promoted cell migration and exhibited anti-inflammatory role during fungal infection by promoting the activation of autophagy. In mouse models of fungal keratitis, Meso-ZnO/NATA greatly reduced corneal fungal survival, alleviated tissue inflammatory damage, and reduced neutrophils accumulation and cytokines expression. This study suggests that Meso-ZnO/NATA can be a novel and effective treatment strategy for fungal keratitis.

The Interplay of Genital Herpes with Cellular Processes: A Pathogenesis and Therapeutic Perspective

Genital herpes, primarily caused by herpes simplex virus-2 (HSV-2), remains a pressing global health concern. Its remarkable ability to intertwine with cellular processes, from harnessing host machinery for replication to subverting antiviral defenses like autophagy and programmed cell death, exemplifies the intricate interplay at the heart of its pathogenesis. While the biomedical community has extensively researched antiviral interventions, the efficiency of these strategies in managing HSV-2 remains suboptimal. Recognizing this, attention has shifted toward leveraging host cellular components to regulate HSV-2 replication and influence the cell cycle. Furthermore, innovative interventional strategies-including drug repurposing, microbivacs, connecting the host microbiome, and exploiting natural secondary metabolites-are emerging as potential game changers. This review summarizes the key steps in HSV-2 pathogenesis and newly discovered cellular interactions, presenting the latest developments in the field, highlighting existing challenges, and offering a fresh perspective on HSV-2's pathogenesis and the potential avenues for its treatment by targeting cellular proteins and pathways.

Synthetic Heparanase Inhibitors Can Prevent Herpes Simplex Viral Spread

Herpes simplex virus (HSV-1) employs heparan sulfate (HS) as receptor for cell attachment and entry. During late-stage infection, the virus induces the upregulation of human heparanase (Hpse) to remove cell surface HS allowing viral spread. We hypothesized that inhibition of Hpse will prevent viral release thereby representing a new therapeutic strategy for HSV-1. A range of HS-oligosaccharides was prepared to examine the importance of chain length and 2-O-sulfation of iduronic moieties for Hpse inhibition. It was found that hexa- and octasaccharides potently inhibited the enzyme and that 2-O-sulfation of iduronic acid is tolerated. Computational studies provided a rationale for the observed structure-activity relationship. Treatment of human corneal epithelial cells (HCEs) infected with HSV-1 with the hexa- and octasaccharide blocked viral induced shedding of HS which significantly reduced spread of virions. The compounds also inhibited migration and proliferation of immortalized HCEs thereby providing additional therapeutic properties.

An insight on ophthalmic drug delivery systems: Focus on polymeric biomaterials-based carriers

Presently, different types of eye diseases, such as glaucoma, myopia, infection, and dry eyes are treated with topical eye drops. However, due to ocular surface barriers, eye drops require multiple administrations, which may cause several risks, thereby necessitating additional strategies. Some of the key characteristics of an ideal ocular drug delivery system are as follows: (a) good penetration into cornea, (b) high drug retention in the ocular tissues, (c) targetability to the desired regions of the eye, and (d) good bioavailability. It is worthy to note that the corneal epithelial tight junctions hinder the permeation of therapeutics through the cornea. Therefore, it is necessary to design nanocarriers that can overcome these barriers and enhance drug penetration into the inner parts of the eye. Moreover, intelligent multifunctional nanocarriers can be designed to include cavities, which may help encapsulate sufficient amount of the drug. In addition, nanocarriers can be modified with the targeting moieties. Different types of nanocarriers have been developed for ocular drug delivery applications, including emulsions, liposomes, micelles, and nanoparticles. However, these formulations may be rapidly cleared from the eye. The therapeutic use of the nanoparticles (NPs) is also hindered by the non-specific adsorption of proteins on NPs, which may limit their interaction with the cellular moieties or other targeted biological factors. Functional drug delivery systems (DDS), which can offer targeted ocular drug delivery while avoiding the non-specific protein adsorption could exhibit great potential. This could be further realized by the on-demand DDS, which can respond to the stimuli in a spatio-temporal fashion. The cell-mediated DDS offer another valuable platform for ophthalmological drug delivery.

Activated Carbon-Enriched Electrospun-Produced Scaffolds for Drug Delivery/Release in Biological Systems

To vectorize drug delivery from electrospun-produced scaffolds, we introduce a thin outer drug retention layer produced by electrospinning from activated carbon nanoparticles (ACNs)-enriched polycaprolacton (PCL) suspension. Homogeneous or coaxial fibers filled with ACNs were produced by electrospinning from different PCL-based suspensions. Stable ACN suspensions were selected by sorting through solvents, stabilizers and auxiliary components. The ACN-enriched scaffolds produced were characterized for fiber diameter, porosity, pore size and mechanical properties. The scaffold structure was analyzed by scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that ACNs were mainly coated with a polymer layer for both homogeneous and coaxial fibers. Drug binding and release from the scaffolds were tested using tritium-labeled sirolimus. We showed that the kinetics of sirolimus binding/release by ACN-enriched scaffolds was determined by the fiber composition and differed from that obtained with a free ACN. ACN-enriched scaffolds with coaxial and homogeneous fibers had a biocompatibility close to scaffold-free AC, as was shown by the cultivation of human gingival fibroblasts and umbilical vein cells on scaffolds. The data obtained demonstrated that ACN-enriched scaffolds had good physico-chemical properties and biocompatibility and, thus, could be used as a retaining layer for vectored drug delivery.

Assessment of antimicrobial, cytotoxicity, and antiviral impact of a green zinc oxide/activated carbon nanocomposite

This work deals with the synthesis of zinc oxide nanoparticles/activated carbon (ZnO NPs/AC) nanocomposites with different weight ratios (3:1, 1:1, and 1:3), where the antimicrobial, antiviral, and cytotoxicity impact of the formulated nanocomposites were evaluated versus the crude ZnO and AC samples. The formula (3:1; designated Z3C1) exhibited the utmost bactericidal effect against Gram positive group, unicellular and filamentous fungi. Regarding Gram negative group, the sample (Z3C1) was remarkably effective against Klebsiella pneumonia, unlike the case of Escherichia coli. Moreover, the whole samples showed negligible cytotoxicity against the human WI38 cell line, where the most brutality (4%) was exerted by 1000 µg/mL of the formula (Z1C3). Whilst, the formula (Z3C1) exerted the apical inhibition impact against Herpes simplex (HSV1) virus. Consequently, the synthesized (Z3C1) nanocomposite was sorted out to be fully characterized via different physicochemical techniques including FTIR, XRD, SEM, TEM, Zeta potential, TGA, and BET. XRD indicated a predominance of the crystalline pattern of ZnO NPs over the amorphous AC, while the FTIR chart confirmed an immense combination between the ZnO NPs and AC. SEM, TEM, and size distribution images illustrated that the fabricated ZnO NPs/AC was in the nanoscale size swung from 30 to 70 nm. The distinctive surface area of composite material, recording 66.27 m²/g, clearly disclosed its bioactivity toward different bacterial, fungal, and virus species.

Drug-loaded mesoporous carbon with sustained drug release capacity and enhanced antifungal activity to treat fungal keratitis

Fungal keratitis is a severe infectious corneal disease with a high rate of incidence and blindness. Since traditional treatments natamycin (NATA) eye drops, exhibit poor dissolution and bioavailability, and the efficacy of current therapeutic approaches remains limited. In this study, we innovatively utilized mesoporous carbon (Meso-C) and microporous carbon (Micro-C) as nanocarriers loaded with the antifungal drug NATA and silver nanoparticles (Ag-NPs). Porous carbon loaded with NATA and Ag-NPs has not previously been studied in fungal keratitis. Due to the mesoporous structure, high surface area and larger pore volume of Meso-C, it displayed greater superiority in sustained drug release and drug dispersity than Micro-C. Moreover, Meso-C could adsorb inflammatory cytokines during fungal infection. In vitro, Meso-C/NATA/Ag showed excellent antifungal effects. In vivo, compared with pure NATA treatment, Meso-C/NATA/Ag exhibited significantly improved therapeutic effects and reduced dosing frequency when treating fungal keratitis. Our study is the first to report the sustained drug release and improved drug dispersity of Meso-C/NATA and demonstrates that NATA and Ag-NPs-loaded Meso-C has therapeutic effects against fungal keratitis.

Safety, efficacy and delivery of multiple nucleoside analogs via drug encapsulated carbon (DECON) based sustained drug release platform

Acyclovir and similar nucleoside analogs form an essential frontline treatment for various herpesvirus infections of the eye. However, these drugs have low ocular retention when delivered topically and need to be administered several times every day. We have previously demonstrated that acyclovir loaded into activated carbon can be used to significantly decrease dosage frequency in a murine model of ocular infection. In this study, we demonstrate that other nucleoside analogs such as ganciclovir, penciclovir and famciclovir have excellent loading and release profile similar to acyclovir. Similarly we also demonstrate that nucleoside analog loaded carbons termed DECON are effective at very low concentrations in treating active viral infection of human corneal epithelial cells. In this study, using a variety of techniques to evaluate corneal dryness, nerve sensitivity, intraocular pressure, corneal thickness, and somatic inflammation, we report that DECON is well tolerated after administration three times daily over the course of four weeks.

Non-Cavitation Targeted Microbubble-Mediated Single-Cell Sonoporation

Sonoporation employs ultrasound accompanied by microbubble (MB) cavitation to induce the reversible disruption of cell membranes and has been exploited as a promising intracellular macromolecular delivery strategy. Due to the damage to cells resulting from strong cavitation, it is difficult to balance efficient delivery and high survival rates. In this paper, a traveling surface acoustic wave (TSAW) device, consisting of a TSAW chip and a polydimethylsiloxane (PDMS) channel, was designed to explore single-cell sonoporation using targeted microbubbles (TMBs) in a non-cavitation regime. A TSAW was applied to precisely manipulate the movement of the TMBs attached to MDA-MB-231 cells, leading to sonoporation at a single-cell level. The impact of input voltage and the number of TMBs on cell sonoporation was investigated. In addition, the physical mechanisms of bubble cavitation or the acoustic radiation force (ARF) for cell sonoporation were analyzed. The TMBs excited by an ARF directly propelled cell membrane deformation, leading to reversible perforation in the cell membrane. When two TMBs adhered to the cell surface and the input voltage was 350 mVpp, the cell sonoporation efficiency went up to 83%.

BX795-Organic Acid Coevaporates: Evaluation of Solid-State Characteristics, In Vitro Cytocompatibility and In Vitro Activity against HSV-1 and HSV-2

BX795 is a TANK binding kinase-1 inhibitor that has shown excellent therapeutic activity in murine models of genital and ocular herpes infections on topical delivery. Currently, only the BX795 free base and its hydrochloride salt are available commercially. Here, we evaluate the ability of various organic acids suitable for vaginal and/or ocular delivery to form BX795 salts/cocrystals/co-amorphous systems with the aim of facilitating pharmaceutical development of BX795. We characterized BX795-organic acid coevaporates using powder X-ray diffractometry, Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy, ¹H-nuclear magnetic resonance spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) to elucidate the interaction between BX795 and various organic acids such as taurine, maleic acid, fumaric acid, tartaric acid, and citric acid. Furthermore, using human corneal epithelial cells and HeLa cells, we evaluated BX795-organic acid coevaporates for in vitro cytocompatibility and in vitro antiviral activity against herpes simplex virus-type 1 (HSV-1) and type-2 (HSV-2). Our studies indicate that BX795 forms co-amorphous systems with tartaric acid and citric acid. Interestingly, the association of organic acids with BX795 improved its thermal stability. Our in vitro cytocompatibility and in vitro antiviral studies to screen suitable BX795-organic acid coevaporates for further development show that all BX795-organic acid systems, at a concentration equivalent to 10 µM BX795, retained antiviral activity against HSV-1 and HSV-2 but showed differential cytocompatibility. Further, dose-dependent in vitro cytocompatibility and antiviral activity studies on the BX795-fumaric acid system, BX795-tartaric acid co-amorphous system, and BX795-citric acid co-amorphous system show similar antiviral activity against HSV-1 and HSV-2 compared to BX795, whereas only the BX795-citric acid co-amorphous system showed higher in vitro cytocompatibility compared to BX795.

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.

Prophylactic treatment with BX795 blocks activation of AKT and its downstream targets to protect vaginal keratinocytes and vaginal epithelium from HSV-2 infection

Genital herpes infections in humans are usually caused by herpes simplex virus type-2 (HSV-2), which result in recurrent lesions in the anogenital region. Past studies have shown that a viral protein translation inhibitor, BX795 is capable of mitigating HSV-2 infection both in vitro and in vivo when dosed therapeutically. However, any preventative benefits of this compound against HSV-2 infection remain poorly understood. In this study, we show that BX795 when added prophylactically to human vaginal keratinocytes generates strong preventative effects against a future HSV-2 infection. As a possible mechanism for this action, we found that BX795 efficiently reduces phosphorylation of AKT and its downstream targets p70S6K and 4EBP1. Our in-silico protein docking studies support our immunoblotting results and provide further credence to the proposed mechanism. Using a murine model of vaginal infection, we show that prior treatment with BX795 is also protective in vivo and leads to lower viral replication in the vaginal tissue.

Antiviral Drug Delivery System for Enhanced Bioactivity, Better Metabolism and Pharmacokinetic Characteristics

Antiviral drugs (AvDs) are the primary resource in the global battle against viruses, including the recent fight against corona virus disease 2019 (COVID-19). Most AvDs require multiple medications, and their use frequently leads to drug resistance, since they have poor oral bioavailability and low efficacy due to their low solubility/low permeability. Characterizing the in vivo metabolism and pharmacokinetic characteristics of AvDs may help to solve the problems associated with AvDs and enhance their efficacy. In this review of AvDs, we systematically investigated their structure-based metabolic reactions and related enzymes, their cellular pharmacology, and the effects of metabolism on AvD pharmacodynamics and pharmacokinetics. We further assessed how delivery systems achieve better metabolism and pharmacology of AvDs. This review suggests that suitable nanosystems may help to achieve better pharmacological activity and pharmacokinetic behavior of AvDs by altering drug metabolism through the utilization of advanced nanotechnology and appropriate administration routes. Notably, such AvDs as ribavirin, remdesivir, favipiravir, chloroquine, lopinavir and ritonavir have been confirmed to bind to the severe acute respiratory syndrome-like coronavirus (SARS-CoV-2) receptor and thus may represent anti-COVID-19 treatments. Elucidating the metabolic and pharmacokinetic characteristics of AvDs may help pharmacologists to identify new formulations with high bioavailability and efficacy and help physicians to better treat virus-related diseases, including COVID-19.

SARS-CoV-2 and its new variants: a comprehensive review on nanotechnological application insights into potential approaches

SARS-CoV-2 (COVID-19) spreads and develops quickly worldwide as a new global crisis which has left deep socio-economic damage and massive human mortality. This virus accounts for the ongoing outbreak and forces an urgent need to improve antiviral therapeutics and targeted diagnosing tools. Researchers have been working to find a new drug to combat the virus since the outbreak started in late 2019, but there are currently no successful drugs to control the SARS-CoV-2, which makes the situation riskier. Very recently, new variant of SARS-CoV-2 is identified in many countries which make the situation very critical. No successful treatment has yet been shown although enormous international commitment to combat this pandemic and the start of different clinical trials. Nanomedicine has outstanding potential to solve several specific health issues, like viruses, which are regarded a significant medical issue. In this review, we presented an up-to-date drug design strategy against SARS-CoV-2, including the development of novel drugs and repurposed product potentials were useful, and successful drugs discovery is a constant requirement. The use of nanomaterials in treatment against SARS-CoV-2 and their use as carriers for the transport of the most frequently used antiviral therapeutics are discussed systematically here. We also addressed the possibilities of practical applications of nanoparticles to give the status of COVID-19 antiviral systems.

Applications of Nanoparticles for Herpes Simplex Virus (HSV) and Human Immunodeficiency Virus (HIV) Treatment

In recent years, the growing studies focused on the immunotherapy of hepatocellular carcinoma and proved the preclinical and clinical promises of host antitumor immune response. However, there were still various obstacles in meeting satisfactory clinic need, such as low response rate, primary resistance and secondary resistance to immunotherapy. Tackling these barriers required a deeper understanding of immune underpinnings and a broader understanding of advanced technology. This review described immune microenvironment of liver and HCC which naturally decided the complexity of immunotherapy, and summarized recent immunotherapy focusing on different points. The ever-growing clues indicated that the instant killing of tumor cell and the subsequent relive of immunosuppressive microenvironment were both indis- pensables. The nanotechnology applied in immunotherapy and the combination with intervention technology was also discussed.

The 3-O-sulfation of heparan sulfate modulates protein binding and lyase degradation

Humans express seven heparan sulfate (HS) 3-O-sulfotransferases that differ in substrate specificity and tissue expression. Although genetic studies have indicated that 3-O-sulfated HS modulates many biological processes, ligand requirements for proteins engaging with HS modified by 3-O-sulfate (3-OS) have been difficult to determine. In particular, the context in which the 3-OS group needs to be presented for binding is largely unknown. We describe herein a modular synthetic approach that can provide structurally diverse HS oligosaccharides with and without 3-OS. The methodology was employed to prepare 27 hexasaccharides that were printed as a glycan microarray to examine ligand requirements of a wide range of HS-binding proteins. The binding selectivity of antithrombin-III (AT-III) compared well with anti-Factor Xa activity supporting robustness of the array technology. Many of the other examined HS-binding proteins required an IdoA2S-GlcNS3S6S sequon for binding but exhibited variable dependence for the 2-OS and 6-OS moieties, and a GlcA or IdoA2S residue neighboring the central GlcNS3S. The HS oligosaccharides were also examined as inhibitors of cell entry by herpes simplex virus type 1, which, surprisingly, showed a lack of dependence of 3-OS, indicating that, instead of glycoprotein D (gD), they competitively bind to gB and gC. The compounds were also used to examine substrate specificities of heparin lyases, which are enzymes used for depolymerization of HS/heparin for sequence determination and production of therapeutic heparins. It was found that cleavage by lyase II is influenced by 3-OS, while digestion by lyase I is only affected by 2-OS. Lyase III exhibited sensitivity to both 3-OS and 2-OS.

Green synthesis of graphite from CO2 without graphitization process of amorphous carbon

Environmentally benign synthesis of graphite at low temperatures is a great challenge in the absence of transition metal catalysts. Herein, we report a green and efficient approach of synthesizing graphite from carbon dioxide at ultralow temperatures in the absence of transition metal catalysts. Carbon dioxide is converted into graphite submicroflakes in the seconds timescale via reacting with lithium aluminum hydride as the mixture of carbon dioxide and lithium aluminum hydride is heated to as low as 126 °C. Gas pressure-dependent kinetic barriers for synthesizing graphite is demonstrated to be the major reason for our synthesis of graphite without the graphitization process of amorphous carbon. When serving as lithium storage materials, graphite submicroflakes exhibit excellent rate capability and cycling performance with a reversible capacity of ~320 mAh g^–1 after 1500 cycles at 1.0 A g^–1. This study provides an avenue to synthesize graphite from greenhouse gases at low temperatures.

Green synthesis of graphite is a great challenge in the absence of the graphitization of amorphous carbon at high temperatures. Here, the authors report a green approach of synthesizing graphite from carbon dioxide at low temperature in seconds timescale.

Standalone or combinatorial phenylbutyrate therapy shows excellent antiviral activity and mimics CREB3 silencing

Herpesviruses are ubiquitous human pathogens that tightly regulate many cellular pathways including the unfolded protein response to endoplasmic reticulum (ER) stress. Pharmacological modulation of this pathway results in the inhibition of viral replication. In this study, we tested 4-phenylbutyrate (PBA), a chemical chaperone-based potent alleviator of ER stress, for its effects on herpes simplex virus (HSV) type 1 infection. Through in vitro studies, we observed that application of PBA to HSV-infected cells results in the down-regulation of a proviral, ER-localized host protein CREB3 and a resultant inhibition of viral protein synthesis. PBA treatment caused viral inhibition in cultured human corneas and human skin grafts as well as murine models of ocular and genital HSV infection. Thus, we propose that this drug can provide an alternative to current antivirals to treat both ocular HSV-1 and genital HSV-2 infections and may be a strong candidate for human trials.

Pharmaceutically Acceptable Carboxylic Acid-Terminated Polymers Show Activity and Selectivity against HSV-1 and HSV-2 and Synergy with Antiviral Drugs

Polyanionic macromolecules including carboxylate-terminated polymers (polycarboxylates) are capable of inhibiting sexually transmitted viruses such as human immunodeficiency virus (HIV) and herpes simplex virus (HSV). Cellulose acetate phthalate (CAP), a pharmaceutically acceptable pH-sensitive polycarboxylate polymer, showed promising prophylactic activity against HIV and HSV, but the instability of CAP in an aqueous environment prevented its clinical development. Interestingly, several pharmaceutically acceptable polycarboxylates have features similar to CAP with an aqueous stability significantly higher than that of CAP. However, their activity against sexually transmitted viruses remains unexplored. Here, we evaluate the activity of various polycarboxylates such as polyvinyl acetate phthalate (PVAP), various grades of hydroxypropyl methylcellulose phthalate (HPMCP-50, HPMCP-55, and HPMCP-55S), and various grades of methacrylic acid copolymers (Eudragit L100-55, Eudragit L100, Eudragit S100, and Kollicoat MAE 100P) against HSV. We, for the first time, demonstrate that PVAP, HPMCP-55S, and Eudragit S100 have activity and selectivity against HSV-1 and HSV-2. Further, we report that polycarboxylates can be easily transformed into nanoparticles (NPs) and in the nanoparticulate form, they show similar or enhanced activity against HSV. Finally, using PVAP NPs, as a model, we demonstrate using in vitro HSV therapy studies that polycarboxylate NPs are capable of synergizing with antiviral drugs such as acyclovir (ACV), tenofovir, and tenofovir disoproxil fumarate. Thus, pharmaceutically acceptable carboxylic acid-terminated polymers and their NPs have the potential to be developed into topical formulations for the prevention and treatment of HSV infection.

In Vitro and In Vivo Activity, Tolerability, and Mechanism of Action of BX795 as an Antiviral against Herpes Simplex Virus 2 Genital Infection

Herpes simplex virus type 2 (HSV-2) causes recurrent lesions in the anogenital area that may be transmitted through sexual encounters. Nucleoside analogs, such as acyclovir (ACV), are currently prescribed clinically to curb this infection. However, in some cases, reduced efficacy has been observed due to the emergence of resistance against these drugs. In our previous study, we reported the discovery of a novel anti-HSV-1 small molecule, BX795, which was originally used as an inhibitor of TANK-binding kinase 1 (TBK1). In this study, we report the antiviral efficacy of BX795 on HSV-2 infection in vaginal epithelial cells in vitro at 10 μM and in vivo at 50 μM. Additionally, through biochemical assays in vitro and histopathology in vivo, we show the tolerability of BX795 in vaginal epithelial cells at concentrations as high as 80 μM. Our investigations also revealed that the mechanism of action of BX795 antiviral activity stems from the reduction of viral protein translation via inhibition of protein kinase B phosphorylation. Finally, using a murine model of vaginal infection, we show that topical therapy using 50 μM BX795 is well tolerated and efficacious in controlling HSV-2 replication.

Nanomaterials and Nanotechnology-Associated Innovations against Viral Infections with a Focus on Coronaviruses

Viral infections have recently emerged not only as a health threat to people but rapidly became the cause of universal fatality on a large scale. Nanomaterials comprising functionalized nanoparticles (NPs) and quantum dots and nanotechnology-associated innovative detection methods, vaccine design, and nanodrug production have shown immense promise for interfacing with pathogenic viruses and restricting their entrance into cells. These viruses have been scrutinized using rapid diagnostic detection and therapeutic interventional options against the caused infections including vaccine development for prevention and control. Coronaviruses, namely SARS-CoV, MERS-CoV, and SARS-CoV-2, have endangered human life, and the COVID-19 (caused by SARS-CoV-2) outbreak has become a perilous challenge to public health globally with huge accompanying morbidity rates. Thus, it is imperative to expedite the drug and vaccine development efforts that would help mitigate this pandemic. In this regard, smart and innovative nano-based technologies and approaches encompassing applications of green nanomedicine, bio-inspired methods, multifunctional bioengineered nanomaterials, and biomimetic drug delivery systems/carriers can help resolve the critical issues regarding detection, prevention, and treatment of viral infections. This perspective review expounds recent nanoscience advancements for the detection and treatment of viral infections with focus on coronaviruses and encompasses nano-based formulations and delivery platforms, nanovaccines, and promising methods for clinical diagnosis, especially regarding SARS-CoV-2.

Herpes Simplex Virus: The Hostile Guest That Takes Over Your Home

Alpha (α)-herpesviruses (HSV-1 and HSV-2), like other viruses, are obligate intracellular parasites. They hijack the cellular machinery to survive and replicate through evading the defensive responses by the host. The viral genome of herpes simplex viruses (HSVs) contains viral genes, the products of which are destined to exploit the host apparatus for their own existence. Cellular modulations begin from the entry point itself. The two main gateways that the virus has to penetrate are the cell membrane and the nuclear membrane. Changes in the cell membrane are triggered when the glycoproteins of HSV interact with the surface receptors of the host cell, and from here, the components of the cytoskeleton take over. The rearrangement in the cytoskeleton components help the virus to enter as well as transport to the nucleus and back to the cell membrane to spread out to the other cells. The entire carriage process is also mediated by the motor proteins of the kinesin and dynein superfamily and is directed by the viral tegument proteins. Also, the virus captures the cell’s most efficient cargo carrying system, the endoplasmic reticulum (ER)–Golgi vesicular transport machinery for egress to the cell membrane. For these reasons, the host cell has its own checkpoints where the normal functions are halted once a danger is sensed. However, a cell may be prepared for the adversities from an invading virus, and it is simply commendable that the virus has the antidote to these cellular strategies as well. The HSV viral proteins are capable of limiting the use of the transcriptional and translational tools for the cell itself, so that its own transcription and translation pathways remain unhindered. HSV prefers to constrain any self-destruction process of the cell—be it autophagy in the lysosome or apoptosis by the mitochondria, so that it can continue to parasitize the cell for its own survival. This review gives a detailed account of the significance of compartmentalization during HSV pathogenesis. It also highlights the undiscovered areas in the HSV cell biology research which demand attention for devising improved therapeutics against the infection.

BX795 demonstrates potent antiviral benefits against herpes simplex Virus-1 infection of human cell lines

Herpes simplex virus-1 (HSV-1) infection is known to cause skin blisters, keratitis as well as deadly cases of encephalitis in some situations. Only a few therapeutic modalities are available for this globally prevalent infection. Very recently, a small molecule BX795 was identified as an inhibitor of HSV-1 protein synthesis in an ocular model of infection. In order to demonstrate its broader antiviral benefits, this study was aimed at evaluating the antiviral efficacy, mode-of-action, and toxicity of BX795 against HSV-1 infection of three human cell lines: HeLa, HEK, and HCE. Several different assays, including cell survival analysis, imaging, plaque analysis, Immunoblotting, and qRT-PCR, were performed. In all cases, BX795 demonstrated low toxicity at therapeutic concentration and showed strong antiviral benefits. Quite interestingly, cell line-dependent differences in the mechanism of antiviral action and cytokine response to infection were seen upon BX795 treatment. Taken together, our results suggest that BX795 may exert its antiviral benefits via cell-line specific mechanisms.

Synthesis of a Porous C3N-Derived Framework with High Yield by Gallic Acid Cross-Linking Using Salt Melts

Porous carbon/nitrogen frameworks are an emerging class of noble organic materials with a wide range of potential applications. However, the design and controlled synthesis of those materials are still a challenge. Herein, we present the rational design of such a system with high microporosity, specific surface areas of up to 946 m² g^-1, and excellent condensation yields. The obtained noble frameworks were used for the delivery of larger organic molecules and changed the melting behavior of some daily drug molecules along their highly polarizable surfaces.

Assembling Surfactants-Mucoadhesive Polymer Nanomicelles (ASMP-Nano) for Ocular Delivery of Cyclosporine-A

The physiological protective mechanisms of the eye reduce the bioavailability of topically administered drugs above all for those with high molecular weight and /or lipophilic characteristics, such as Cyclosporine A (CyA). The combined strategy based on the association of nanomicelles and mucoadhesive polymer seems promising since a limited number of commercial products containing CyA have been recently approved. The scope of this investigation was the design of Assembling Surfactants-Mucoadhesive Polymer Nanomicelles (ASMP-Nano), based on a binary system of two surfactants in combination with hyaluronic acid, and their biopharmaceutical evaluation. The optimisation of the ASMP-Nano in term of the amount of surfactants, CyA-loading and size determined the selection of the clear and stable Nano1HAB-CyA formulation containing 0.105% w/w CyA loaded-nanomicelles with a size of 14.41 nm. The nanostructured system had a protective effect towards epithelial corneal cells with a cell viability of more than 80%. It interacted with cellular barriers favouring the uptake and the accumulation of CyA into the cells as evidenced by fluorescent probe distribution, by hindering CyA permeation through reconstituted corneal epithelial tissue. In pharmacokinetics study on rabbits, the nanomicellar carrier prolonged the CyA retention time in the precorneal area mainly in presence of hyaluronic acid (HA), a mucoadhesive polymer.

Nanomaterials Designed for Antiviral Drug Delivery Transport across Biological Barriers

Viral infections are a major global health problem, representing a significant cause of mortality with an unfavorable continuously amplified socio-economic impact. The increased drug resistance and constant viral replication have been the trigger for important studies regarding the use of nanotechnology in antiviral therapies. Nanomaterials offer unique physico-chemical properties that have linked benefits for drug delivery as ideal tools for viral treatment. Currently, different types of nanomaterials namely nanoparticles, liposomes, nanospheres, nanogels, nanosuspensions and nanoemulsions were studied either in vitro or in vivo for drug delivery of antiviral agents with prospects to be translated in clinical practice. This review highlights the drug delivery nanosystems incorporating the major antiviral classes and their transport across specific barriers at cellular and intracellular level. Important reflections on nanomedicines currently approved or undergoing investigations for the treatment of viral infections are also discussed. Finally, the authors present an overview on the requirements for the design of antiviral nanotherapeutics.

Prior inhibition of AKT phosphorylation by BX795 can define a safer strategy to prevent herpes simplex virus-1 infection of the eye

PURPOSE

To evaluate the prophylactic antiviral efficacy, corneal tolerance and toxicity of topically dosed BX795, a non-nucleoside small-molecule inhibitor of herpes simplex virus type-1 (HSV-1).

METHODS

Prophylactic treatment with BX795 was performed both in-vitro on human corneal epithelial cells and in-vivo on mice prior to HSV-1 challenge. Viral burden was evaluated using a standard plaque assay. In a separate experiment, mice were treated topically 3-times daily for 4-weeks with BX795 to evaluate corneal tolerance and toxicity. Phenol-red thread measurements, fluorescein staining and optical coherence tomography (OCT) were used to evaluate tear production, dryness and corneal structural changes. Corneal sensitivity and intraocular pressure were measured using esthesiometery and tonometery respectively.

RESULTS

Both in-vitro and in-vivo results showed a robust suppression of HSV-1 infection when treated prophylactically with BX795. The fluorescein stain and phenol-red results for the BX795-treated eyes did not show signs of corneal surface dryness when compared to trifluridine (TFT), an FDA-approved topical antiviral. The OCT measurements showed no signs of structural changes to the cornea suggesting that BX795 treatment was well tolerated without any apparent signs of toxicity or inflammation. The corneal sensitivity of BX795-treated eyes was not significantly different from TFT-treated eyes. No significant increase in the intraocular pressure of BX795-treated mice was observed.

CONCLUSIONS

Prophylactic treatment with BX795 protects corneal cells from HSV-1 infection. The antiviral is well-tolerated on murine corneas without any detectable toxicity.

Current and Emerging Therapies for Ocular Herpes Simplex Virus Type-1 Infections

Herpes simplex virus type-1 (HSV-1) is a neurotropic, double-stranded DNA virus that can cause a wide variety of diseases, including many ocular pathologies. It is one of the leading causes of infectious blindness in the United States. Because of its ubiquitous nature and its potential to cause serious ocular maladies, there is a significant need for more effective antiviral therapies against ocular HSV-1. In this review, we discuss the lifecycle of HSV-1 as it pertains to corneal infections and the clinically approved as well as emerging treatments to combat HSV-1 infections. We also highlight some newly identified host targets for the antiviral drug development.