Submolecular Tuning of Ligand Size and Spacing for Dynamic Macrophage Modulation.

Cell adhesion occurs when integrin recognizes and binds to Arg-Gly-Asp (RGD) ligands present in fibronectin. Herein, submolecular ligand size and spacing is tuned via the template-mediated in situ growth of nanoparticles for dynamic macrophage modulation. To tune liganded GNP size and spacing from 3 to 20 nm, in situ localized assembly of gold nanoparticle (GNP) arrays on nano-magnetite templates are engineered. 3 nm-spaced ligands stimulate the binding of integrin that mediates macrophage adhesion-assisted pro-regenerative polarization as compared to the 20 nm-spaced ligands, which can be dynamically anchored to the substrate for stabilizing integrin binding and facilitating dynamic macrophage adhesion. Increasing the ligand size from 7 to 20 nm only slightly promotes macrophage adhesion, not observed with 13 nm-sized ligands. Increasing the ligand spacing from 3 to 17 nm significantly hinders macrophage adhesion that induces inflammatory polarization. Submolecular tuning of ligand spacing can dominantly modulate host macrophages. This article is protected by copyright. All rights reserved.