Negative Hamaker Coefficients: Application to the Human Immunodeficiency Virus (HIV) – Blood Interactions in Antiretroviral Drug Media

Abstract

Negative Hamaker coefficients approach was used as a thermodynamic tool in determining the HIV-blood interactions in the presence of antiretroviral drugs. Expressions required for the computation of the Negative Hamaker coefficients were obtained using the Lifshitz theory which is a function of the absorbance of the interacting systems. The methodology involved the serial dilution of the five different antiretroviral drugs (two HAART/FDC and three single drugs) and the subsequent incubation with the blood samples collected from ten HIV infected persons. Absorbance measurements were performed using a digital Ultraviolet Visible MetaSpecAE1405031Pro Spectrophotometer. The MATLAB software tools were employed in the mathematical analysis of the very large body of data generated from the experiments. The Hamaker constants A11, A22, A33 and hence the combined Hamaker coefficients A132 were derived. The absolute values for the combined Hamaker coefficient, A132abs obtained for each of the five antiretroviral drugs interacting with infected lymphocytes varied from -0.02481×10-21Joule for drug D4 to -0.05845×10-21Joule for D3. The negative senses of the absolute combined Hamaker coefficients imply net negative van der Waals forces indicating a possible repulsion or blocking of the invading virus by the administered drug which is assumed to coat the lymphocytes. Such repulsion will in principle suggest that contact might not occur between the virus and the lymphocyte and hence possibly, the virus will not penetrate into the lymphocyte. This may result in reduction of viral load and increase of CD4 counts. The findings of this work may be useful to Pharmaceutical industries in drug design.