Interfacial Self-Assembly to Spatially Organize Graphene Oxide Into Hierarchical and Bioactive Structures

Anna Majkowska,Egle Solito,Jose Carlos Rodriguez-Cabello,Mariel Gonzalez,Estelle C Collin,Armando E Del Rio Hernandez,Carlos Redondo-Gómez,Alistair Rice,Alvaro Mata,Karla E Inostroza-Brito

doi:10.3389/fmats.2020.00167

Abstract

Multicomponent self-assembly holds great promise for the generation of complex and functional biomaterials with hierarchical microstructure. Here, we describe the use of supramolecular co-assembly between an elastin-like recombinamer (ELR5) and a peptide amphiphile (PA) to organise graphene oxide (GO) flakes into bioactive structures across multiple scales. The process takes advantage of a reaction – diffusion mechanism to enable the incorporation and spatial organization of GO within multiple ELR5/PA layers. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and ImageJ software were used to demonstrate the hierarchical organisation of GO flakes within the ELR5/PA layers and the distribution profiles of GO throughout the ELR5/PA membranes. Furthermore,atomic force microscopy (AFM) revealed improved Young’s moduli of the ELR5/PA/GOmembranes compared to the ELR5/PA membranes. Lastly, we investigated biocompatibility of the ELR5/PA/GO membrane via various cell culture methods.

Highlights

Self-assembly, the process by which multiple smaller components autonomously interact and organize into larger well-defined structures, plays a crucial role in the way nature creates structure and functionality (Whitesides and Grzybowski, 2002)
Cells grown on ELR5/PAK2-K4 and ELR5/PAK2-K4/graphene oxide (GO) membranes displayed a much less spread morphology and formed fewer connections with neighboring cell. These results suggest that ELR5/PAK3 membranes support better cell adhesion compared to ELR5/PAK2-K4 membranes regardless of the GO content
We report the ability of the ELR5/peptide amphiphile (PA) selfassembling system to manipulate, localize, and organize GO flakes into hierarchical structures

Summary

Introduction

Self-assembly, the process by which multiple smaller components autonomously interact and organize into larger well-defined structures, plays a crucial role in the way nature creates structure and functionality (Whitesides and Grzybowski, 2002). In an attempt to emulate biological systems, molecular self-assembly is being used to design bioinspired materials with a spectrum of exciting properties such as well-defined nanostructure (Zhang, 2003; Gazit, 2007), precise display of bioactive signals (Webber et al, 2010; Azevedo, 2019), temporal control of signaling (Kumar et al, 2018), and tuneable mechanical properties (Pashuck et al, 2010). The co-assembly of peptide amphiphiles (PAs) bearing either host or guest moieties has been recently used to develop hydrogels with enhanced mechanical properties (Redondo-Gómez et al, 2019). Taking advantage of hydrodynamic forces generated during additive manufacturing, Hedegaard et al (2018) developed biocompatible hydrogel constructs with well-defined ordered or randomly oriented nanofibers, surface microtopographies, distinct microgeometries, and macroscopic assemblies

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Results

Conclusion