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Nano-microbicides are the Solution to the HIV Pandemic

explanatory Essay
2454 words
2454 words
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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 ...

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...omes Alive. PNAS, 102:12294-12295

Ø MALLIPEDDI, R. & ROHAN, L.C. 2010. Progress in Antiretroviral Drug Delivery Using Technology. International Journal of Nanomedicine, 5:533-547

Ø NDESENDO, V.M.K., PILLAY, V., CHOONARA, Y.E., BUCHMANN, E., BAYEVER, D.N. & MEYER, L.C.R. 2008. A Review of Current Intra-vaginal Drug Delivery Approaches Employed for the Prophylaxis of HIV/AIDS and Prevention of Sexually Transmitted Infections. American Association of Pharmaceutical Scientists, 9:505-520

Ø VAN DE WIJGERT, J. & COGGINS, C. 2002. Microbicides to Prevent Heterosexual Transmission of HIV: Ten Years Down the Road, 2:1-10

Ø VANGELISTA, L., SECCHI, M., LIU, X.,BACHI, A., JIA, L., XU, Q. & LUSSO, P. 2010. Engineering of Lactobacillus jensenii To Secrete RANTES and a CCR5 Antagonist Analogue as Live HIV-1 Blockers. Antimicrobial Agents and Chemotherapy , 54:2994-3001

In this essay, the author

  • Opines that the availability of microbicides would empower women to protect themselves, as well as their partners against infection.
  • Explains that the lack of effective vaccines against pathogens has stimulated the interest in the development of a topical microbicide.
  • Explains that hiv infects the cd4 cells in the body where the dendritic cells and macrophages are the primary target for infection.
  • Explains the need for 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.
  • Explains that microbicides are compounds or substances that can be used to reduce the infectivity of microbes, such as viruses and bacteria.
  • Explains that nano-microbicides are composed of atoms and molecules with the use of nanotechnology. they use nanocarriers to achieve more effective drug delivery.
  • Explains that nanocarriers are being investigated to overcome typical drug delivery challenges such as conformational stability, physiochemical stability and enhanced cellular uptake of poorly permeable drugs.
  • Explains that mucus has a negative charge due to carboxyl- and sulphate groups, so nanoparticles must have positive charges in order to penetrate the mucous barrier.
  • Explains that the small size of these molecules causes difficulty in control of drug release kinetics. the large surface area to volume ratio of the molecule leads to stability issues like aggregation.
  • Explains that microbicides are divided into four categories: products that kill or inactivate the infectious pathogens, such as compounds that disrupt the lipid cell membranes or increase the membrane porosity.
  • Explains that microbicides take the form of gels, creams and suppositories and is usually spermicidal. lactobacillus binds to the vaginal epithelium, produces lactic acid and hydrogen peroxide.
  • Explains that a study of lactobacillus jensenii to secrete rantes and ccr5 antagonists as live hiv blockers is currently being investigated.
  • Explains that live nano-microbicides, where a commensal bacterium is engineered to secrete an anti-hiv peptide, is one of the developing technologies in nanomedicine.
  • Explains that a gel-like molecular condom is an anti-hiv vaginal gel, which spreads and converts to gel when applied intra-vaginally.
  • Explains that the vagina consists of a thin walled, collapsed fibro-mucosal tube comprised of distinct anatomical regions.
  • Explains that polymeric nano-particles have desirable features, including stability and sustained drug release. they can be tailored to meet dosing requirements and can therefore be hydrophilic or hydrophobic.
  • Explains the potential toxicity and cytotoxic effect of inorganic nano-particles, which are highly effective in the fight against hiv.
  • Explains that silver nano-particles are an example of protein-conjugated noble metal nanos. they undergo specific interaction with hiv via prevential binding with the gp120 subunit of the viral envelope glycoprotein.
  • Explains that polystyrene nanospheres capture hiv particles on their surface and trigger an immune response against these particles, which causes a release of anti-hiv iga antibodies.
  • Explains that dendrimers differ from conventional polymers in that they have multi-branched three-dimensional architecture with minimal poly-dispersity and high functionality.
  • Opines that nanotechnology is causing concern in developing countries because of political pressure to prove its efficacy. the beneficial properties of nanomedicine are parallel with the health risks they entail.
  • Explains that nano-microbicides are the solution to the hiv pandemic, but is far from being perfected in both medicinal and safety aspects.
  • Explains that nano-microbicides: challenge in drug delivery, patient ethics and intellectual property in the war against hiv/aids.
  • Explains that mallipeddi, r., and rohan, l.c. progress in antiretroviral drug delivery utilizing technology.
  • Describes ndesendo, pillay, choonara, buchmann, bayever, d.n., and meyer, l.c.r.
  • Cites van de wijgert, j., and coggins, c. 2002. microbicides to prevent heterosexual transmission of hiv.
  • Explains that lactobacillus jensenii secretes rantes and a ccr5 antagonist analogue as live hiv-1 blockers.
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