Biophysical Society Thematic Meeting - October 25-30, 2015

Polymers and Self Assembly: From Biology to Nanomaterials Poster Session I

2-POS Board 2 A Theoretical Study of Micellar Ligand-Receptor Binding Regulations: The Effect of Receptors Density on The Binding to A Distinctive Ligand Ebtisam A. Aldaais 1,2 , Mark J. Uline 1 . 1 University of South Carolina, Columbia, SC, USA, 2 University of Dammam, Dammam, Eastern Province, Saudi Arabia. A variety of interactions between drug delivery devices, and local cells and tissues, impact clinical outcomes in terms of both therapeutic action and biological response. The further development of design objective micelles for drug delivery applications is associated with understanding the competitions of interactions in the system. The mean-field approximation is used in this study to generalize a molecular theory that determine the competition between electrostatic, van der Waals and steric interaction, and consequently, determining the ligand- receptor binding protocols. The micelles are designed to target cancer cells primarily through electrostatic binding as several cancers are known to flip negatively charged lipids to the outer- leaflet [1, 2]. Cancer cells and healthy cells have the same kinds of receptors, however some of these receptors are overexpressed in cancer cells, such as epidermal growth factor receptors (EGFR). Thus, the developed theory considers the influence of different receptor densities on the ligand-receptor binding. The molecular reorganization on the surface of the micelle is a design variable that needs to be considered for enhanced targeting. We show that size (curvature) is strongly coupled to the way polymers express ligands to the surface, and our molecular theory platform is uniquely suited to address these issues. According to the theory, charge regulation stabilizes polybases on micelles at the cost of chemical free energy and gaining in the van der Waals attractive interactions. As a result, the bonds formation between ligands and receptors with different densities are affected by the proper choice of temperature, ligand-polybases density and spacer. The developed theory should enable the prediction of a design guideline for the creation of therapeutic micelles.

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