Epigallocatechin Gallate-Modified Silver Nanoparticles Show Antiviral Activity against Herpes Simplex Type 1 and 2.

(1) Background: Epigallocatechin gallate (EGCG) has been recognized as a flavonoid showing antiviral activity against various types of DNA and RNA viruses. In this work, we tested if EGCG-modified silver nanoparticles (EGCG-AgNPs) can become novel microbicides with additional adjuvant properties to treat herpes infections. (2) Methods: The anti-HSV and cytotoxic activities of EGCG-AgNPs were tested in human HaCaT and VK-2-E6/E7 keratinocytes. HSV-1/2 titers and immune responses after treatment with EGCG-AgNPs were tested in murine models of intranasal HSV-1 infection and genital HSV-2 infection. (3) Results: EGCG-AgNPs inhibited attachment and entry of HSV-1 and HSV-2 in human HaCaT and VK-2-E6/E7 keratinocytes much better than EGCG at the same concentration. Infected mice treated intranasally (HSV-1) or intravaginally (HSV-2) with EGCG-AgNPs showed lower virus titers in comparison to treatment with EGCG alone. After EGCG-AgNPs treatment, mucosal tissues showed a significant infiltration in dendritic cells and monocytes in comparison to NaCl-treated group, followed by significantly better infiltration of CD8+ T cells, NK cells and increased expression of IFN-α, IFN-γ, CXCL9 and CXCL10. (4) Conclusions: Our findings show that EGCG-AgNPs can become an effective novel antiviral microbicide with adjuvant properties to be applied upon the mucosal tissues.

Anti-HSV Activity of Metallic Nanoparticles Functionalized with Sulfonates vs. Polyphenols.

Metallic nanoparticles exhibit broad-spectrum activity against bacteria, fungi, and viruses. The antiviral activity of nanoparticles results from the multivalent interactions of nanoparticles with viral surface components, which result from the nanometer size of the material and the presence of functional compounds adsorbed on the nanomaterial surface. A critical step in the virus infection process is docking and entry of the virus into the host cell. This stage of the infection can be influenced by functional nanomaterials that exhibit high affinity to the virus surface and hence can disrupt the infection process. The affinity of the virus to the nanomaterial surface can be tuned by the specific surface functionalization of the nanomaterial. The main purpose of this work was to determine the influence of the ligand type present on nanomaterial on the antiviral properties against herpes simplex virus type 1 and 2. We investigated the metallic nanoparticles (gold and silver) with different sizes (5 nm and 30 nm), coated either with polyphenol (tannic acid) or sulfonates (ligands with terminated sulfonate groups). We found that the antiviral activity of nano-conjugates depends significantly on the ligand type present on the nanoparticle surface.

Functionalized Noble Metal Nanoparticles for the Treatment of Herpesvirus Infection.

Neuroinfections caused by herpesviruses, mainly by HHV-1, represent a significant problem for modern medicine due to the small number of therapeutic substances available in the pharmaceutical sector. Furthermore, HHV-1 infection has been linked to neurodegenerative processes such as Alzheimer's disease, which justifies the search for new effective therapies. The development of nanotechnology opens up new possibilities for the treatment of neuroinflammation. Gold and silver nanoparticles are gaining popularity, and the number of clinical trials involving metallic nanoparticles is constantly increasing. This paper reviews the research on gold and silver nanoparticles and their potential use in the treatment of herpesvirus neuroinfection.

Fly Ash from Lignite Combustion as a Filler for Rubber Mixes-Part II: Chemical Valorisation of Fly Ash.

Fly ash (FA) fractions with a particle size of 63 µm < FA < 250 µm obtained by sieve fractionation were used as a partial carbon black (CB) replacement in a rubber mixture based on styrene-butadiene rubber (SBR). In order to improve the interactions at the interface between rubber and fractionated ash, at the stage of preparing the rubber mixtures, two different vinyl silanes were added to the system: Vinyltrimethoxysilane (U-611) or Vinyl-tris (2-methoxy-ethoxy) silane (LUVOMAXX VTMOEO DL50), silane with epoxy groups: 3-(glycidoxypropyl)trimethoxysilane (U-50) or sulfur functionalized silanes: containing sulfide bridges: Bis(triethoxysilylpropyl)polysulfide silane (Si-266) or mercapto groups: Mercaptopropyltrimethoxysilane (Dynaslan MTMO). The conducted research confirmed the effectiveness of silanization with selected functional silanes, from the point of view of improving the processing and operational properties of vulcanizates, in which CB is partially replaced with the finest fractions of fly ash. The silanization generally increased the interaction at the rubber−ash interface, while improving the degree of filler dispersion in the rubber mixture. The results of TGA and FTIR analyses confirmed the presence of silanes chemically bonded to the surface of fly ash particles. SEM tests and determination of the bound rubber (BdR) content show that the introduction of the silanes to the mixture increases the degree of ash dispersion (DI) and the Payne effect, which is the greatest when mercaptosilane was used for modification. The highest increase in torque, which was recorded in the case of rubber mixtures containing sulfur silanes and silane with epoxy groups, may be due to their participation in the vulcanization process, which is confirmed by the results of vulcametric studies. The lowest values of mechanical strength, elongation at break, and the highest hardness of vulcanizates obtained in this case may be the result of the over-crosslinking of the rubber. The addition of sulfur-containing silanes significantly slowed down the vulcanization process, which is particularly visible (up to three times extension of the t90 parameter, compared to mixtures without silane) in the case of Si-266. The addition of silanes, except for Si-266 (with a polysulfide fragment), generally improved the abrasion resistance of vulcanizates. The Dynaslan MTMO silane (with mercapto groups) performs best in this respect. Proper selection of silane for the finest fraction of fly ash in the rubber mixtures tested allows for an increase in the mechanical strength of their vulcanizates from 9.1 to 17 MPa, elongation at break from 290 to 500%, hardness from 68 to 74 °ShA, and reduction in abrasion from 171 to 147 mm3.

Lactoferrin-Conjugated Nanoparticles as New Antivirals.

Lactoferrin is an iron-binding glycoprotein with multiple functions in the body. Its activity against a broad spectrum of both DNA and RNA viruses as well as the ability to modulate immune responses have made it of interest in the pharmaceutical and food industries. The mechanisms of its antiviral activity include direct binding to the viruses or its receptors or the upregulation of antiviral responses by the immune system. Recently, much effort has been devoted to the use of nanotechnology in the development of new antivirals. In this review, we focus on describing the antiviral mechanisms of lactoferrin and the possible use of nanotechnology to construct safe and effective new antiviral drugs.

Plasmonic heating of protected silver nanowires for anti-frosting superhydrophobic coating.

Atmospheric frosting and icing pose significant problems for critical and common-use infrastructures. Passive anti-frosting and anti-icing strategies that require no energy input have been actively sought, with no viable and permanent solutions known yet. Bioinspired superhydrophobic (SH) materials have been considered promising path to explore; however, the outcome has been less than compelling because of their low resistance to atmospheric humidity. In most cases, condensing water on an SH surface eventually leads to mechanical locking of ice instead of ice removal. Hybrid strategies involving some form of limited energy input are being increasingly considered, each with its own challenges. Here, we propose the application of plasmonic heating of silver nanowires (AgNWs) for remote frost removal, utilizing an SH hybrid passive-active system. This novel system comprises a durable nanocomposite covered with a hydrophobized mesh of AgNWs, protected against environmental degradation by a tin oxide (SnO2) shell. We demonstrate the frost removal ability at -10 °C and 30% RH, achieved by a combination of plasmonic heating of AgNWs with a non-sticking behavior of submicrometric droplets of molten frost on the SH surface. Heating was realized by illuminating the mesh with low-power blue laser light. Adjustment of the nanowire (NW) and shell dimensions allows the generation of surface plasmon resonance in illuminated NWs at a wavelength overlapping the emission maximum of the light used. In environmental stability tests, the nanostructures exhibited high atmospheric, mechanical, and thermal stability. The narrow-wavelength absorption of the structure in the blue light range and the reflective properties in the infrared range were designed to prevent protected surfaces from overheating in direct sunlight.

Antioxidant enzymes immobilized on gold and silver nanoparticles enhance DNA repairing systems of rat skin after exposure to ultraviolet radiation.

The aim of the study was to investigate in vivo whether the application of immobilized superoxide dismutase (SOD) and catalase (CAT) could enhance DNA repairing systems and reduce level of CPD (cyclobutane pyrimidine dimers) and 6-4PP ((6-4) pyrimidine-pyrimidone photoproducts), and whether the immobilization on gold (AuNPs) and silver (AgNPs) nanoparticles affects the outcome. The study presents secondary analysis of our previous research. Three-day application of SOD and CAT in all forms of solution decreased the levels of CPD and 6-4PP boosted by UV irradiation. The mRNA expression level of the nucleotide excision repair (NER) system genes (XPA, XPC, ERCC1, ERCC2, ERCC3, LIG1) increased after application of immobilized and free enzymes. Increased by UV irradiation, p53 mRNA expression level normalized with the enzyme application. In conclusion, application of free and immobilized antioxidant enzymes accelerates removal of harmful effects of UV radiation in the rat skin by increasing expression level of NER genes.

Silver Nanowires and Silanes in Hybrid Functionalization of Aramid Fabrics.

New functionalization methods of meta- and para-aramid fabrics with silver nanowires (AgNWs) and two silanes (3-aminopropyltriethoxysilane (APTES)) and diethoxydimethylsilane (DEDMS) were developed: a one-step method (mixture) with AgNWs dispersed in the silane mixture and a two-step method (layer-by-layer) in which the silanes mixture was applied to the previously deposited AgNWs layer. The fabrics were pre-treated in a low-pressure air radio frequency (RF) plasma and subsequently coated with polydopamine. The modified fabrics acquired hydrophobic properties (contact angle ΘW of 112-125°). The surface free energy for both modified fabrics was approximately 29 mJ/m2, while for reference, meta- and para-aramid fabrics have a free energy of 53 mJ/m2 and 40 mJ/m2, respectively. The electrical surface resistance (Rs) was on the order of 102 Ω and 104 Ω for the two-step and one-step method, respectively. The electrical volume resistance (Rv) for both modified fabrics was on the order of 102 Ω. After UV irradiation, the Rs did not change for the two-step method, and for the one-step method, it increased to the order of 1010 Ω. The specific strength values were higher by 71% and 63% for the meta-aramid fabric and by 102% and 110% for the para-aramid fabric for the two-step and one-step method, respectively, compared to the unmodified fabrics after UV radiation.

Lactoferrin-Functionalized Noble Metal Nanoparticles as New Antivirals for HSV-2 Infection.

(1) Background: Lactoferrin has been recognized as a potent inhibitor of human herpetic viruses, such as herpes simplex type 1 (HSV-1) and 2 (HSV-2). In this work, we tested if silver and gold nanoparticles modified with lactoferrin (LF-Ag/AuNPs) can become novel microbicides with additional adjuvant properties to treat genital herpes infection. (2) Methods: The antiviral and cytotoxic activities of LF-Ag/AuNPs were tested in human skin HaCaT and vaginal VK-2-E6/E7 keratinocytes. Viral titers and immune responses after treatment with LF-Ag/AuNPs were tested in murine vaginal HSV-2 infection. (3) Results: LF-Ag/AuNPs inhibited attachment and entry of HSV-2 in human keratinocytes much better than lactoferrin. Furthermore, pretreatment with LF-AgNPs led to protection from infection. Infected mice treated intravaginally with LF-Ag/AuNPs showed lower virus titers in the vaginal tissues and spinal cords in comparison to treatment with lactoferrin. Following treatment, vaginal tissues showed a significant increase in CD8+/granzyme B + T cells, NK cells and dendritic cells in comparison to NaCl-treated group. LF-Ag/AuNPs-treated animals also showed significantly better expression of IFN-γ, CXCL9, CXCL10, and IL-1ß in the vaginal tissues. (4) Conclusions: Our findings show that LF-Ag/AuNPs could become effective novel antiviral microbicides with immune-stimulant properties to be applied upon the mucosal tissues.

Influence of Modified Epoxy Resins on Peroxide Curing, Mechanical Properties and Adhesion of SBR, NBR and XNBR to Silver Wires-Part II: Application of Carboxy-Containing Peroxy Oligomer (CPO).

This research was aimed at verifying the effect of carboxy-containing peroxy oligomer (CPO) addition on the possibility of rubber crosslinking and a subsequent adhesion of the modified rubber to silver wires. Three commonly industrially used rubbers were selected for the study: styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR) and carboxylated acrylonitrile-butadiene rubber (XNBR), together with carboxy-containing peroxy oligomer (CPO). An improvement in the adhesion of rubbers to silver wires was observed when applying the oligomeric peroxide with functional groups, with no deterioration of mechanical properties of the vulcanizates. Crosslinking synergy between dicumyl peroxide (DCP) and the modifier could hardly be observed. Nevertheless, the studies demonstrated, that to a small extent, even the CPO itself can crosslink NBR and especially XNBR, resulting in a material of notable elasticity and adhesion to silver wires.

Influence of Modified Epoxy Resins on Peroxide Curing, Mechanical Properties and Adhesion of SBR, NBR and XNBR to Silver Wires. Part I: Application of Monoperoxy Derivative of Epoxy Resin (PO).

The research was aimed at checking the effect of monoperoxy derivative of epoxy resin (PO) on the possibility of rubber crosslinking and a subsequent adhesion of the modified rubber to silver wires. Three of the commonly industrially used rubbers were selected for the study: styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR) and carboxylated acrylonitrile-butadiene rubber (XNBR), together with the popular, commercially available Epidian 6 epoxy resin, subjected to the functionalization. An improvement in the adhesion of rubbers to silver wires was observed when using the modified resin. In some cases, an improvement in the mechanical properties of the rubber was observed, especially when the resin was used for crosslinking together with dicumyl peroxide (DCP). Crosslinking synergy between dicumyl peroxide and the modified resin could be observed especially in the case of PO applied for peroxide curing of SBR and NBR.

A SnO2 shell for high environmental stability of Ag nanowires applied for thermal management.

Since silver nanowires (AgNWs) show high infrared reflectance many studies present their applicability as thermal management products for various wearable textiles. However, their use for practical purposes is only partially evaluated, without focusing on improving their low atmospheric and liquid stability. This report describes a new approach for the topic and proposes a facile method of Ag nanowire passivation with a SnO2 layer for high environmental stability and retention of high infrared reflectance. The one-step passivation process of AgNWs was carried out in the presence of sodium stannate in an aqueous solution at 100 °C, and resulted in the formation of core/shell Ag/SnO2 nanowires. This study presents the morphological, chemical, and structural properties of Ag/SnO2NWs formed with a 14 nm thick SnO2 shell, consisting of 7 nm rutile-type crystals, covering the silver metallic core. The optical properties of the AgNWs changed significantly after shell formation, and the longitudinal and transverse modes in the surface plasmon resonance spectrum were red shifted as a result of the surrounding media dielectric constant changes. The passivation process protected the AgNWs from decomposition in air for over 4 months, and from dissolution in a KCN solution at concentrations up to 0.1 wt%. Moreover, the report shows the microwave irradiation effect on the shell synthesis and previously synthesised Ag/SnO2NWs. The post-synthesis irradiation, as well as the SnO2 shell obtained by microwave assistance, did not allow long-term stability to be achieved. The microwave-assisted synthesis process was also not fast enough to inhibit the formation of prismatic silver structures from the nanowires. The Ag/SnO2NWs with a shell obtained by a simple hydrolysis process, apart from showing high infra-red reflectance on the para-aramid fabric, are highly environmentally stable. The presented SnO2 shell preparation method can protect the AgNW's surface from dissolution or decomposition and facilitate the designing of durable smart wearable thermal materials for various conditions.

Influence of Low-Pressure RF Plasma Treatment on Aramid Yarns Properties.

The aim of the study was to modify the surface free energy (SFE) of meta- (mAr) and para-aramid (pAr) yarns by their activation in low-pressure air radio frequency (RF) (40 kHz) plasma and assessment of its impact on the properties of the yarns. After 10 and 90 min of activation, the SFE value increased, respectively, by 14% and 37% for mAr, and by 10% and 37% for pAr. The value of the polar component increased, respectively by 22% and 57% for mAr and 20% and 62% for pAr. The value of the dispersion component for mAr and pAr increased respectively by 9% and 25%. The weight loss decreased from 49% to 46% for mAr and 62% to 50% for pAr after 90 min of activation. After 90 min, the specific strength for mAr did not change and for pAr it decreased by 40%. For both yarns, the 10 min activation in plasma is sufficient to prepare their surface for planned nanomodification.

Polyphenol-Conjugated Bimetallic Au@AgNPs for Improved Wound Healing.

BACKGROUND: Polyphenols possess antioxidant, anti-inflammatory and antimicrobial properties and have been used in the treatment of skin wounds and burns. We previously showed that tannic acid-modified AgNPs sized >26 nm promote wound healing, while tannic acid-modified AgNPs sized 13 nm can elicit strong local inflammatory response. In this study, we tested bimetallic Au@AgNPs sized 30 nm modified with selected flavonoid and non-flavonoid compounds for wound healing applications. METHODS: Bimetallic Au@AgNPs were obtained by growing an Ag layer on AuNPs and further modified with selected polyphenols. After toxicity tests and in vitro scratch assay in HaCaT cells, modified lymph node assay as well as the mouse splint wound model were further used to access the wound healing potential of selected non-toxic modifications. RESULTS: Tannic acid, gallic acid, polydatin, resveratrol, catechin, epicatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate and procyanidin B2 used to modify Au@AgNPs exhibited good toxicological profiles in HaCaT cells. Au@AgNPs modified with 15 µM tannic acid, 200 µM resveratrol, 200 µM epicatechin gallate, 1000 µM gallic acid and 200 µM procyanidin B2 induced wound healing in vivo and did not lead to the local irritation or inflammation. Tannic acid-modified Au@AgNPs induced epithelial-to-mesenchymal transition (EMT) - like re-epithelialization, while other polyphenol modifications of Au@AgNPs acted through proliferation and wound closure. CONCLUSION: Bimetallic Au@AgNPs can be used as a basis for modification with selected polyphenols for topical uses. In addition, we have demonstrated that particular polyphenols used to modify bimetallic nanoparticles may show different effects upon different stages of wound healing.

Combined effect of silver nanoparticles and aluminium chloride, butylparaben or diethylphthalate on the malignancy of MDA-MB-231 breast cancer cells and tumor-specific immune responses of human macrophages and monocyte-derived dendritic cells.

The aim of this study was to assess whether silver nanoparticles (AgNP) or selected cosmetic ingredients may modify functions of various immunocompetent cell populations. To this end, the effect of two AgNP (size of 15 nm or 45 nm), alone and in combination with aluminium chloride, butyl paraben, di-n-butyl phthalate or diethyl phthalate was assessed on: (1) migration and invasion of MDA-MB-231 human breast cancer cells; (2) M1/M2 polarization of phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 macrophages (M0) and (3) activation/maturation of monocyte-derived dendritic cells (DCs). The results of this study showed that neither any of the test chemicals alone nor the mixtures significantly changed the migration or invasion ability of MDA-MB-231 cells following, both 72-h and 21-day exposure. Analysis of the expression of marker genes for both M1 (IL-1B, CXCL9, TNF) and M2 (DCSIGN, MRC1) polarization revealed that the chemicals/mixtures did not activate M1/M2 differentiation of the M0 macrophages. In addition, no significant changes were observed in the expression of CD86, HLA-DR and CD54 surface markers and phagocytic activity of DCs following 48-h exposure to AgNP alone or in combination with test compounds. Our study suggests that AgNP alone or in combination with tested cosmetic ingredients do not alter function of immunocompetent cells studied.

Facile synthesis of SnO2 shell followed by microwave treatment for high environmental stability of Ag nanoparticles.

This study describes a new method for passivating Ag nanoparticles (AgNPs) with SnO2 layer and their further treatment by microwave irradiation. The one-step process of SnO2 layer formation was carried out by adding sodium stannate to the boiling aqueous AgNPs solution, which resulted in the formation of core@shell Ag@SnO2 nanoparticles. The coating formation was a tunable process, making it possible to obtain an SnO2 layer thickness in the range from 2 to 13 nm. The morphology, size, zeta-potential, and optical properties of the Ag@SnO2NPs were studied. The microwave irradiation significantly improved the environmental resistance of Ag@SnO2NPs, which remained stable in different biological solutions such as NaCl at 150 mM and 0.1 M, Tris-buffered saline buffer at 0.1 M, and phosphate buffer at pH 5.6, 7.0, and 8.0. Ag@SnO2NPs after microwave irradiation were also stable at biologically relevant pH values, both highly acidic (1.4) and alkaline (13.2). Moreover, AgNPs covered with a 13 nm-thick SnO2 layer were resistant to cyanide up to 0.1 wt%. The microwave-treated SnO2 shell can facilitate the introduction of AgNPs in various solutions and extend their potential application in biological environments by protecting the metal nanostructures from dissolution and aggregation.

The effect of immobilized antioxidant enzymes on the oxidative stress in UV-irradiated rat skin.

Aim: Superoxide dismutase (SOD) and catalase (CAT) immobilized on gold nanoparticles (AuNP) and silver nanoparticles (AgNP) nanoparticles were used to reduce UV radiation-induced oxidative stress in rat skin. Materials & methods: The antioxidant influence of the enzymes was investigated on level of malondialdehyde, 8-hydroksy-2'deoksyguanozine, myeloperoxidase, total antioxidant capacity, SOD2 and CAT activity and expression, and glutathione and glutathione peroxidase activity. Results: The application of immobilized SOD and CAT on UV-irradiated skin reduced malondialdehyde and 8-hydroksy-2'deoksyguanozine levels also SOD and CAT activity and expression increased. The tested enzymes influence glutathione peroxidase activity and level of total antioxidant capacity and glutathione. Conclusion: Immobilized enzymes increased the antioxidative potential of skin following UV irradiation.

The synthesis of monodisperse silver nanoparticles with plant extracts.

Plant extracts are known for their antihyperglycemic, antioxidant, antimutagenic, antifungal, anti-inflammatory, antiviral and antibacterial properties. These biological properties make plant extracts interesting surface modifiers of nanoparticles (NPs), which are also known for their unique features. Plant extracts can play a multifunctional role in the synthesis of NPs (i.e. can act as a reducing agent, stabiliser and bioactive compound), which gives additional properties to the final hybrid material. The combination of an extract of natural origin with NPs results in bioconjugates with unique final properties that often may not be obvious. The properties of a bioconjugate depend on both the plant extract (chemical composition, amount, a method of conjugation to NP surface, etc.) and the NPs (type, size, shape, polydispersity, etc.). Syntheses of NPs with plant extract usually lead to polydisperse particles with heterogeneous properties that are difficult to control from a biological point of view. In this paper, we present a synthesis protocol to obtain monodisperse silver nanoparticles (AgNPs) with plant extract. Cacao beans and grape seed extracts were selected as natural sources of polyphenols having biomedical importance (e.g. catechin, tannic acid, epicatechin gallate) and used to synthesise using a chemical reduction method. Syntheses were carried out with different molar ratios of reagents to find the best conditions for obtaining AgNPs that are homogeneous in size and shape. The colloids obtained were characterised with ultraviolet-visible (UV-Vis) spectroscopy, scanning transmission electron microscopy (STEM) and dynamic light scattering (DLS). It was found that syntheses carried out only with plant extract resulted in unstable colloids containing polydisperse nanoparticles. Stable colloids containing spherical monomodal particles were obtained by the incorporation of sodium citrate as an additional reagent in the synthesis mixture. The results obtained clearly indicate the crucial role of sodium citrate in the synthesis of spherical AgNPs of controlled size using plant extracts for biological applications.

A Study of the Activity of Recombinant Mn-Superoxide Dismutase in the Presence of Gold and Silver Nanoparticles.

Superoxide dismutase (SOD) is one of the best characterized enzyme maintaining the redox state in the cell. A bacterial expression system was used to produce human recombinant manganese SOD with a His-tag on the C-end of the protein for better purification. In addition, gold and silver nanoparticles were chemically synthesized in a variety of sizes, and then mixed with the enzyme for immobilization. Analysis by dynamic light scattering and scanning transmission electron microscopy revealed no aggregates or agglomerates of the obtained colloids. After immobilization of the protein on AuNPs and AgNPs, the conjugates were analyzed by SDS-PAGE. It was determined that SOD was adsorbed only on the gold nanoparticles. Enzyme activity was analyzed in colloids of the gold and silver nanoparticles bearing SOD. The presence of a nanoparticle did not affect enzyme activity; however, the amount of protein and size of the gold nanoparticle did influence the enzymatic activity of the conjugate. Our findings confirm that active recombinant human superoxide dismutase can be produced using a bacterial expression system, and that the enzyme can be immobilized on metal nanoparticles. The interaction between enzymes and metal nanoparticles requires further investigation.

Antiviral Activity of Tannic Acid Modified Silver Nanoparticles: Potential to Activate Immune Response in Herpes Genitalis.

(1) Background: Tannic acid is a plant-derived polyphenol showing antiviral activity mainly because of an interference with the viral adsorption. In this work, we tested whether the modification of silver nanoparticles with tannic acid (TA-AgNPs) can provide a microbicide with additional adjuvant properties to treat genital herpes infection. (2) Methods: The mouse model of the vaginal herpes simplex virus 2 (HSV-2) infection was used to test immune responses after treatment of the primary infection with TA-AgNPs, and later, after a re-challenge with the virus. (3) Results: The mice treated intravaginally with TA-AgNPs showed better clinical scores and lower virus titers in the vaginal tissues soon after treatment. Following a re-challenge, the vaginal tissues treated with TA-AgNPs showed a significant increase in the percentages of IFN-gamma+ CD8+ T-cells, activated B cells, and plasma cells, while the spleens contained significantly higher percentages of IFN-gamma+ NK cells and effector-memory CD8+ T cells in comparison to NaCl-treated group. TA-AgNPs-treated animals also showed significantly better titers of anti-HSV-2 neutralization antibodies in sera; and (4) Conclusions: Our findings suggest that TA-AgNPs sized 33 nm can be an effective anti-viral microbicide to be applied upon the mucosal tissues with additional adjuvant properties enhancing an anti-HSV-2 immune response following secondary challenge.