Kinetic limitations of cooperativity based drug delivery systems

TL;DR

This paper presents a theoretical study of a novel drug delivery system that uses cooperative binding to target cancer cells, revealing kinetic limitations and proposing ways to enhance specificity by adjusting bond strength.

Contribution

It introduces a kinetic model of cooperative binding in dendrimer-based drug delivery, highlighting limitations and strategies to improve cell specificity.

Findings

Cooperative binding enhances cell specificity but is kinetically limited.

Weaker individual bonds can increase overall cooperativity and targeting precision.

Theoretical and in-vitro analysis support the proposed optimization strategies.

Abstract

We study theoretically a novel drug delivery system that utilizes the overexpression of certain proteins in cancerous cells for cell specific chemotherapy. The system consists of dendrimers conjugated with "keys" (ex: folic acid) which "key-lock" bind to particular cell membrane proteins (ex: folate receptor). The increased concentration of "locks" on the surface leads to a longer residence time for the dendrimer and greater incorporation into the cell. Cooperative binding of the nanocomplexes leads to an enhancement of cell specificity. However, both our theory and detailed analysis of in-vitro experiments indicate that the degree of cooperativity is kinetically limited. We demonstrate that cooperativity and hence the specificity to particular cell type can be increased by making the strength of individual bonds weaker, and suggest a particular implementation of this idea. The implications of the work for optimizing the design of drug delivery vehicles are discussed.