Topical microbicides to stop sexually transmitted diseases, such as herpes simplex virus type 2 (HSV-2), are urgently needed. The emerging field of nanotechnology offers novel suitable tools for addressing this challenge. Our objective was to study, in vitro and in vivo, antiherpetic effect and antiviral mechanisms of several polyanionic carbosilane dendrimers with anti-HIV-1 activity to establish new potential microbicide candidates against sexually transmitted diseases. Plaque reduction assay on Vero cells proved that G2-S16, G1-S4, and G3-S16 are the dendrimers with the highest inhibitory response against HSV-2 infection. We also demonstrated that our dendrimers inhibit viral infection at the first steps of HSV-2 lifecycle: binding/entry-mediated events. G1-S4 and G3-S16 bind directly on the HSV-2, inactivating it, whereas G2-S16 adheres to host cell-surface proteins. Molecular modeling showed that G1-S4 binds better at binding sites on gB surface than G2-S16. Significantly better binding properties of G1-S4 than G2-S16 were found in an important position for affecting transition of gB trimer from G1-S4 prefusion to final postfusion state and in several positions where G1-S4 could interfere with gB/gH-gL interaction. We demonstrated that these polyanionic carbosilan dendrimers have a synergistic activity with acyclovir and tenofovir against HSV-2, in vitro. Topical vaginal or rectal administration of G1-S4 or G2-S16 prevents HSV-2 transmission in BALB/c mice in values close to 100%. This research represents the first demonstration that transmission of HSV-2 can be blocked by vaginal/rectal application of G1-S4 or G2-S16, providing a step forward to prevent HSV-2 transmission in humans.

Faculty of Science J E Purkinje University Ústí nad Labem Czech Republic

Molecular Immunobiology Laboratory General Universitary Hospital Gregorio Marañon Health Research Institute Gregorio Marañon Spanish HIV HGM BioBank Networking Research Center on Bioengineering Biomaterials and Nanomedicine Madrid Spain

Molecular Immunobiology Laboratory General Universitary Hospital Gregorio Marañon Health Research Institute Gregorio Marañon Spanish HIV HGM BioBank Networking Research Center on Bioengineering Biomaterials and Nanomedicine Madrid Spain; Viral and Immune Infection Unit Center Institute of Health Carlos 3 Majadahonda Campus Molecular Immunobiology Laboratory General Universitary Hospital Gregorio Marañon Madrid Spain

Organic and Inorganic Chemistry Department Alcala University University Campus Alcala de Heneras Networking Research Center on Bioengineering Biomaterials and Nanomedicine Madrid Spain

See more in PubMed

Looker KJ, Magaret AS, Turner KM, Vickerman P, Gottlieb SL, Newman LM. Global estimates of prevalent and incident herpes simplex virus type 2 infections in 2012. PLoS One. 2015;10(1):e114989. PubMed PMC

Gupta R, Warren T, Wald A. Genital herpes. Lancet. 2007;370(9605):2127–2137. PubMed

Wagner EK, Flanagan WM, Devi-Rao G, et al. The herpes simplex virus latency-associated transcript is spliced during the latent phase of infection. J Virol. 1988;62(12):4577–4585. PubMed PMC

Johnston C, Saracino M, Kuntz S, et al. Standard-dose and high-dose daily antiviral therapy for short episodes of genital HSV-2 reactivation: three randomised, open-label, cross-over trials. Lancet. 2012;379(9816):641–647. PubMed PMC

Johnston C, Koelle DM, Wald A. Current status and prospects for development of an HSV vaccine. Vaccine. 2014;32(14):1553–1560. PubMed PMC

Freeman EE, Weiss HA, Glynn JR, Cross PL, Whitworth JA, Hayes RJ. Herpes simplex virus 2 infection increases HIV acquisition in men and women: systematic review and meta-analysis of longitudinal studies. AIDS. 2006;20(1):73–83. PubMed

Briz V, Sepulveda-Crespo D, Diniz AR, et al. Development of water-soluble polyanionic carbosilane dendrimers as novel and highly potent topical anti-HIV-2 microbicides. Nanoscale. 2015;7(35):14669–14683. PubMed

Chonco L, Pion M, Vacas E, et al. Carbosilane dendrimer nanotechnology outlines of the broad HIV blocker profile. J Control Release. 2012;161(3):949–958. PubMed

Cordoba EV, Arnaiz E, De La Mata FJ, et al. Synergistic activity of carbosilane dendrimers in combination with maraviroc against HIV in vitro. AIDS. 2013;27(13):2053–2058. PubMed

Galan M, Sanchez Rodriguez J, Jimenez JL, et al. Synthesis of new anionic carbosilane dendrimers via thiol-ene chemistry and their antiviral behaviour. Org Biomol Chem. 2014;12(20):3222–3237. PubMed

Sepulveda-Crespo D, Serramia MJ, Tager AM, et al. Prevention vaginally of HIV-1 transmission in humanized BLT mice and mode of antiviral action of polyanionic carbosilane dendrimer G2-S16. Nanomedicine. 2015;11(6):1299–1308. PubMed

Bourne N, Stanberry LR, Kern ER, Holan G, Matthews B, Bernstein DI. Dendrimers, a new class of candidate topical microbicides with activity against herpes simplex virus infection. Antimicrob Agents Chemother. 2000;44(9):2471–2474. PubMed PMC

Tyssen D, Henderson SA, Johnson A, et al. Structure activity relationship of dendrimer microbicides with dual action antiviral activity. PLoS One. 2010;5(8):e12309. PubMed PMC

Sepulveda-Crespo D, Lorente R, Leal M, et al. Synergistic activity profile of carbosilane dendrimer G2-STE16 in combination with other dendrimers and antiretrovirals as topical anti-HIV-1 microbicide. Nanomedicine. 2014;10(3):609–618. PubMed

Cordoba EV, Bastida H, Pion M, et al. HIV-Antigens charged on phosphorus dendrimers as tools for tolerogenic dendritic cells-based immunotherapy. Curr Med Chem. 2013;21(16):1898–1909. PubMed

Gong E, Matthews B, McCarthy T, et al. Evaluation of dendrimer SPL7013, a lead microbicide candidate against herpes simplex viruses. Antiviral Res. 2005;68(3):139–146. PubMed

Vacas Cordoba E, Arnaiz E, Relloso M, et al. Development of sulphated and naphthylsulphonated carbosilane dendrimers as topical microbicides to prevent HIV-1 sexual transmission. AIDS. 2013;27(8):1219–1229. PubMed

Bayly CI, Cieplak P, Cornell WD, Kollman PA. A well-behaved electrostatic potential based method using charge restraints for deriving atomic charges – the resp model. J Phys Chem. 1993;97(40):10269–10280.

Dupradeau FY, Pigache A, Zaffran T, et al. The R.ED. tools: advances in RESP and ESP charge derivation and force field library building. Phys Chem Chem Phys. 2010;12(28):7821–7839. PubMed PMC

Schmidt MW, Baldridge KK, Boatz JA, et al. General atomic and molecular electronic-structure system. J Comput Chem. 1993;14(11):1347–1363.

Case DA, Babin V, Berryman JT, et al. AMBER 14. University of California; San Francisco: 2014.

Maurer UE, Zeev-Ben-Mordehai T, Pandurangan AP, et al. The structure of herpesvirus fusion glycoprotein B-bilayer complex reveals the protein-membrane and lateral protein-protein interaction. Structure. 2013;21(8):1396–1405. PubMed PMC

Pettersen EF, Goddard TD, Huang CC, et al. UCSF chimera – a visualization system for exploratory research and analysis. J Comput Chem. 2004;25(13):1605–1612. PubMed

Jorgensen WL, Chandrasekhar J, Madura JD, Impey RW, Klein ML. Comparison of simple potential functions for simulating liquid water. J Chem Phys. 1983;79(2):926–935.

Wu X, Brooks BR. Self-guided Langevin dynamics simulation method. Chem Phys Lett. 2003;381(3–4):512–518.

Nguyen H, Roe DR, Simmerling C. Improved Generalized Born Solvent Model Parameters for Protein Simulations. J Chem Theory Comput. 2013;9(4):2020–2034. PubMed PMC

Gotz AW, Williamson MJ, Xu D, Poole D, Le Grand S, Walker RC. Routine microsecond molecular dynamics simulations with amber on GPUs. 1. Generalized born. J Chem Theory Comput. 2012;8(5):1542–1555. PubMed PMC

Miller BR, McGee TD, Swails JM, Homeyer N, Gohlke H, Roitberg AE. MMPBSA.py: an efficient program for end-state free energy calculations. J Chem Theory Comput. 2012;8(9):3314–3321. PubMed

Baker NA, Sept D, Joseph S, Holst MJ, McCammon JA. Electrostatics of nanosystems: application to microtubules and the ribosome. Proc Natl Acad Sci U S A. 2001;98(18):10037–10041. PubMed PMC

Hawkins GD, Cramer CJ, Truhlar DG. Parametrized models of aqueous free energies of solvation based on pairwise descreening of solute atomic charges from a dielectric medium. J Phys Chem. 1996;100(51):19824–19839.

Sepulveda-Crespo D, Sanchez-Rodriguez J, Serramia MJ, et al. Triple combination of carbosilane dendrimers, tenofovir and maraviroc as potential microbicide to prevent HIV-1 sexual transmission. Nanomedicine (Lond) 2015;10(6):899–914. PubMed

Parr MB, Kepple L, McDermott MR, Drew MD, Bozzola JJ, Parr EL. A mouse model for studies of mucosal immunity to vaginal infection by herpes simplex virus type 2. Lab Invest. 1994;70(3):369–380. PubMed

Cutler B, Justman J. Vaginal microbicides and the prevention of HIV transmission. Lancet Infect Dis. 2008;8(11):685–697. PubMed PMC

Basha SH, Talluri D, Raminni NP. Computational repositioning of ethno medicine elucidated gB-gH-gL complex as novel anti herpes drug target. BMC Complement Altern Med. 2013;13 PubMed PMC

Cusini M, Ghislanzoni M. The importance of diagnosing genital herpes. J Antimicrob Chemother. 2001;47(Suppl T1):9–16. PubMed

Rasines B, Sanchez-Nieves J, Maiolo M, et al. Synthesis, structure and molecular modelling of anionic carbosilane dendrimers. Dalton Trans. 2012;41(41):12733–12748. PubMed

Akhtar J, Shukla D. Viral entry mechanisms: cellular and viral mediators of herpes simplex virus entry. FEBS J. 2009;276(24):7228–7236. PubMed PMC

Xiao F, Fofana I, Thumann C, et al. Synergy of entry inhibitors with direct-acting antivirals uncovers novel combinations for prevention and treatment of hepatitis C. Gut. 2015;64(3):483–494. PubMed PMC

Andrei G, Lisco A, Vanpouille C, et al. Topical tenofovir, a microbicide effective against HIV, inhibits herpes simplex virus-2 replication. Cell Host Microbe. 2011;10(4):379–389. PubMed PMC

Van Damme L, Govinden R, Mirembe FM, et al. Lack of effectiveness of cellulose sulfate gel for the prevention of vaginal HIV transmission. N Engl J Med. 2008;359(5):463–472. PubMed

Cottrell ML, Kashuba AD. Topical microbicides and HIV prevention in the female genital tract. J Clin Pharmacol. 2014;54(6):603–615. PubMed PMC

Ishikawa T, Yamada H, Oyamada A, Goshima F, Nishiyama Y, Yoshikai Y. Protective role of Fas-FasL signaling in lethal infection with herpes simplex virus type 2 in mice. J Virol. 2009;83(22):11777–11783. PubMed PMC

McConville C, Boyd P, Major I. Efficacy of tenofovir 1% vaginal gel in reducing the risk of HIV-1 and HSV-2 infection. Clin Med Insights Womens Health. 2014;7:1–8. PubMed PMC

Tanaka E, Noguchi T, Nagai K, Akashi Y, Kawahara K, Shimada T. Morphology of the epithelium of the lower rectum and the anal canal in the adult human. Med Mol Morphol. 2012;45(2):72–79. PubMed