Carnauba wax nanoparticles enhance strong systemic and mucosal cellular and humoral immune responses to HIV-gp140 antigen

Induction of humoral responses to HIV at mucosal compartments without inflammation is important for vaccine design. We developed charged wax nanoparticles that efficiently adsorb protein antigens and are internalized by DC in the absence of inflammation. HIV-gp140-adsorbed nanoparticles induced stronger in vitro T-cell proliferation responses than antigen alone. Such responses were greatly enhanced when antigen was co-adsorbed with TLR ligands. Immunogenicity studies in mice showed that intradermal vaccination with HIV-gp140 antigen-adsorbed nanoparticles induced high levels of specific IgG. Importantly, intranasal immunization with HIV-gp140-adsorbed nanoparticles greatly enhanced serum and vaginal IgG and IgA responses. Our results show that HIV-gp140-carrying wax nanoparticles can induce strong cellular/humoral immune responses without inflammation and may be of potential use as effective mucosal adjuvants for HIV vaccine candidates

Concentrations of Dapivirine in the Rhesus Macaque and Rabbit following Once Daily Intravaginal Administration of a Gel

Dapivirine is a nonnucleoside reverse transcriptase inhibitor being developed as a topical microbicide for the prevention of human immunodeficiency virus infection. The distribution of radioactivity and drug in plasma and in vaginal, cervical, and draining lymph node tissues was investigated after daily application of a vaginal gel formulation of [14C]dapivirine to rhesus macaques. This was preceded by a preliminary study with rabbits. Following the intravaginal administration of [14C]dapivirine (0.1 mg/ml [15 Ci/ml]) to rabbits (0.5 ml/day) and macaques (1 ml/day) for 7 days, the dapivirine levels associated with vaginal and cervical tissue samples 1 h after the final dose were high (quantities of g/g of tissue) and remained detectable at 24 h (mean,>2.5 ng/g in rabbits) and 48 h (mean,>80 ng/g in macaques). Radioactivity levels were low in the plasma and very low or unquantifiable in the draining lymph nodes of the macaques. Microautoradiography identified drug-related material (DRM) on the surfaces of the vaginal and cervical tissues of the rabbits and macaques. Although DRM was primarily associated with the outermost layer of shedding cells in rabbits, two animals showed some evidence of small quantities in the mucosal epithelium of the cervix. In macaques, DRM was seen within the keratinized layer of the vaginal epithelium and and was found to extend into the superficial cellular layers, and in at least one animal it appeared to be present in the deepest (germinal) layer of the epithelium and in submucosal tissues. The persistence of biologically significant concentrations of dapivirine in vagina

Non-aqueous silicone elastomer gels as a vaginal microbicide delivery system for the HIV-1 entry inhibitor maraviroc

Aqueous semi-solid polymeric gels, such as those based on hydroxyethylcellulose (HEC) and polyacrylic acid (e.g. Carbopol®), have a long history of use in vaginal drug delivery. However, despite their ubiquity, they often provide sub-optimal clinical performance, due to poor mucosal retention and limited solubility for poorly water-soluble actives. These issues are particularly pertinent for vaginal HIV microbicides, since many lead candidates are poorly water-soluble and where a major goal is the development of a coitally independent, once daily gel product. In this study, we report the use of a non-aqueous silicone elastomer gel for vaginal delivery of the HIV-1 entry inhibitor maraviroc. In vitro rheological, syringeability and retention studies demonstrated enhanced performance for silicone gels compared with a conventional aqueous HEC gel, while testing of the gels in the slug model confirmed a lack of mucosal irritancy. Pharmacokinetic studies following single dose vaginal administration of a maraviroc silicone gel in rhesus macaques showed higher and sustained MVC levels in vaginal fluid, vaginal tissue and plasma compared with a HEC gel containing the same maraviroc loading. The results demonstrate that non-aqueous silicone gels have potential as a formulation platform for coitally independent vaginal HIV microbicides