16 Exploring the Nanotechnology-Based Drug Delivery Systems for AIDS Treatment Flávia Chiva Carvalho 1 , Rubiana Mara Mainardes 2 and Maria Palmira Daflon Gremião 1 1 School of Pharmaceutical Sciences, State University of São Paulo, UNESP, Araraquara, 2 State University of West-Center, UNICENTRO, Guarapuava, Brazil 1. Introduction The Acquired Immunodeficiency Syndrome (AIDS) and Human Immunodeficiency Virus (HIV) infection are a worldwide public health challenge. The emergence of antiretroviral therapy agents has significantly increased the life expectancy and the patient´s quality of life. In the 1990’s, there was a great improvement in the knowledge of the disease, enlargement of therapeutic resources, a rise in life expectancy and the epidemiologic profile. Since the mid-1990’s, the advancement of pharmacology studies and the arrival of protease inhibitor antiretroviral have given rise to a new era of anti-HIV agents, known as Highly Active Antiretroviral Therapy (HAART) (Geocze et al., 2010, Richman et al., 2009). The HAART’s adhesion improved the clinical results, the control of the advancement of the disease and decreased the mortality rate, which resulted in an improvement of the patient’s life quality. Despite the successful administration of HAART, latently infected cells can escape the viral immune response and persist for long periods of time (Alexaki et al., 2008). In addition, the HAART presents several collateral effects, such as fatigue, nausea, sickness, diarrhea and lipodystrophy. These symptoms contribute to a lack of treatment adhesion in the patient, resulting in a rise in the blood viral load and a decline in CD4+ T cells count, as well as an increased tolerance of anti-HIV drugs, treatment failure, increased opportunistic infections and in wasted investments (Geocze et al., 2010). Moreover, many antiretroviral drugs undergo extensive pre-systemic metabolism and instability in the gastrointestinal environment, resulting in inadequate and erratic oral absorption as well as low bioavailability. The half-life for most anti-HIV drugs is short, and thus, it requires frequent dosage administrations, leading to a decrease in patient compliance. Also, some antiretroviral classes present poor solubility, low absorption and limited bioavailability. Another limitation of the current HAART is the inefficiency of the regimens to eradicate HIV from various anatomical reservoirs (e.g., central nervous system (CNS) and gastrointestinal tract) and intracellular sites (e.g., macrophages, hepatocytes, dendritic cells and Langerhans cells) (Ojewole et al., 2008, Saksena & Haddad, 2003). Large concentrations are essential for eliminating HIV from these reservoirs to achieve the desired therapeutic effect, but these large doses contribute to severe side effects associated with anti-HIV therapy (Ojewole et al., 2008). Because drug development in the HIV field has slowed