HIV spreads at alarming rates in developing countries, especially in resource pour settings and therefore the availability of microbicides would greatly empower women to protect themselves, as well as their partners against infection. The use of microbicides by women can easily be controlled and does not need the cooperation, consent or knowledge of their partners (DU TOIT et. al., 2009).
The lack of effective vaccines against pathogens has stimulated the interest in the development of a topical microbicide. Microbicides are designed to inhibit HIV infection by directly inactivating the virus or interrupting the attachment of the virus to the host cells and replication thereof. To be able to develop an effective microbicide, one has to understand the means by which HIV infiltrates the genital mucosa, the role of dendritic cells, as well as the process of transportation of the virus to the lymph nodes (DU TOIT et. al., 2009).
HIV infects the CD4 cells in the body where the dendritic cells and the macrophages are the primary target for infection. These cells are present in the sub-epithelial layers of the vaginal- and cervical mucosa. HIV transmission occurs at the mucosal surface by means of body fluids, which penetrate the spuamous epithelium of the ectocervix and the columnar epithelium of the endocervix to reach the target cells. Fusion of the viral HIV envelope glycoprotein (gp120) interacts with the CD4-receptors, followed by interaction with CCR5 that initiates target cell fusion. Envelope fusion with the target cell is the first step of infection, where the viral RNA genome of the infectious cell is released into the target cell, where it undergoes reverse transcription followed by integration of pro-viral DNA into the host chromosome. Assembly of the viral proteins with the cell membrane generates a mature virus capable of infecting other cells (MALLIPEDDI & ROHAN, 2010).
There is need for the development of pharmaceutical formulations that can be conveniently administered to patients and display an acceptable shelf-life and general stability. Challenges in drug delivery are targeting and biocompatibility (DU TOIT et. al., 2009).
Microbicides are any compounds or substances that can be used to reduce the infectivity of microbes, such as viruses and bacteria and in this case they are compounds that can be applied intra-vaginally or intra-rectal to protect against HIV (DU TOIT et. al., 2009).
Nano-microbicides are microbicides composed of atoms and molecules with the use of nanotechnology, where nanotechnology can be defined as the study of manipulating matter on an atomic and molecular scale. Nanotechnology is very diverse (DU TOIT et. al., 2009). It makes use of nanocarriers to achieve more effective drug delivery. Popular nanocarriers are nanoparticles like polymeric-, inorganic- and solid lipids, liposomes and dendrimers. An advantage of nanocarriers is the protection of drugs against degradation by enzymes, such as...