Liposomes as nanocarriers for anti-HIV therapy.

Globally, in the last three decades of medical research, the use of liposomes as carrier for anti-HIV/AIDS drugs is gaining prominence. These potential anti-HIV nanocarriers are concentric lipid bilayers which can be fabricated to protect molecules and to target the drugs to specific sites, which is the reason behind their popularity in the antiretroviral drug delivery. The development of an effective drug delivery system such as liposomes presents an opportunity to circumvent the many challenges associated with antiretroviral drug therapy. The physiochemical properties of liposomes such as size, charge, and lipid composition significantly affect the liposomal efficiency. These nanocarriers offer advantages such as drug loading both in aqueous region and within the bilayer of the vesicles, act as solubilizing agents, protect drug from degradation in the body, allow modification of the pharmacokinetic and tissue distribution patterns of the drug, provide drug targeting, and have low immunogenicity, biocompatibility, and cell specificity. Different types of liposome-based delivery systems, such as cationic, anionic, sterically stabilized, and immunoliposomes, have been studied for the anti-HIV/AIDS drug delivery. Liposomes, however, face challenges with regard to their use in antiretroviral drug delivery such as limited hydrophilic drug-loading capacity, issues related to physical and biologic stability, poor scale-up, cost, short shelf life, and toxicity. Numerous patented strategies have been granted in the USA and around the world related to these anti-HIV nanocarriers. In the present article, we have discussed the general physiological aspects of the HIV infection, relevance of the nanocarrier, liposomes, in the treatment of this disease and some recently awarded US patents and patent applications of these liposomal delivery systems for anti-HIV drugs.