ABSTRACT
Rute Nunes,a,b,c Carole Sousa,b Bruno Sarmento, PhD,a,b,c and José das Neves, PhDa,b,caCESPU, Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde, Gandra, PortugalbINEB-Instituto de Engenharia Biomédica, Universidade do Porto, Porto, PortugalcInstituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal Keywords: HIV/AIDS, pre-exposure prophylaxis, vaginal drug delivery, dendrimers, polymeric nanocarriers, mucoadhesion, rectal microbicides
beneficial [7-11]. These last may possess intrinsic antiviral activity or act as active agents carriers. For example, the dendrimer-based vaginal gel VivaGel® (Holdings (SPL7013 or astodrimer sodium) from Starpharma Holdings Ltd., Melbourne, Australia) showed promising results both in vitro and in vivo and is at present in an advanced stage of the development pipeline [12]. Even so, most of the research is now focusing on nanotechnology-based antiretroviral (ARV) drug carriers, in particular polymeric nanoparticles (NPs), rather than on nanosystems possessing intrinsic antiviral activity, such as the case of the SPL7013 dendrimer included in VivaGel®. Possible benefits of polymeric NPs for the vaginal delivery of ARV agents have been shown to include the enhancement of epithelial penetration, possibility of drug targeting, modulation of adhesion/diffusion through cervicovaginal mucus, and effective distribution throughout the genital tract [13-17]. Even if the potential of nanotechnology is valid for both vaginal and rectal microbicides, most research has been conducted toward the development of the first. Nonetheless, rectal transmission is well recognized as an important route for human immunodeficiency virus (HIV) dissemination in both male and female populations engaged in receptive anal intercourse (RAI), thus justifying the concurrent development of rectal nanotechnology-based microbicides. This chapter provides an overview of the possibilities and achievements in the field of nanotechnology-based microbicides for the prevention of sexual HIV transmission and, potentially, other pathogens (e.g., herpes simplex virus [HSV]). Parts of this chapter have been previously published by our group in different review articles [18-20].
