Biophysical Society Thematic Meeting

- 43 -

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

University of South Carolina, Columbia, SC, USA,

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.