Fabrication of Thermo-Responsive Molecular Layers from Self-Assembling Elastin-Like Oligopeptides Containing Cell-Binding Domain for Tissue Engineering

Tomoyuki Koga,Tomoo Matsuoka,Koji Odawara,Kazuhiro Nakamoto,Nobuyuki Higashi

doi:10.3390/polym7010134

Abstract

Novel thermo-responsive elastin-like oligopeptides containing cell-binding epitope (Arg-Gly-Asp-Ser sequence); arginine-glycine-aspartic acid-serine (RGDS)-elastin-like peptides (ELP) and RGDS-deg-ELP; were newly prepared as building blocks of self-assembled molecular layer for artificial extra cellular matrix. A detailed analysis of the conformation of the oligo(ELP)s in water and their self-assembling behavior onto hydrophobic surfaces were performed by using circular dichroism, Fourier transform infrared spectroscopy (FTIR), atomic force microscopy and water contact angle measurements. The experimental results revealed that both oligo(ELP)s self-assembled onto hydrophobic surfaces and formed molecular layers based on their thermo-responsive conformational change from hydrous random coil to dehydrated β-turn structure. Effective cell adhesion and spreading behaviors were observed on these self-assembled oligo(ELP) layers. In addition, attached cells were found to be recovered successfully as a cell-sheet by temperature-induced disassembly of oligo(ELP) layer. This achievement provides an important insight to construct novel oligopeptide-based nano-surfaces for the design of smart artificial extra-cellular matrix.

Highlights

An important challenge in tissue engineering and regenerative medicine is the design of novel scaffolds for cell adhesion, spreading and proliferation that mimic the natural extra-cellular matrix (ECM) [1,2]
We have shown that poly(ethylene glycol) (PEG)-modified oligo(ELP)s perform self-assembly into spherical micelle-like aggregates in water in response to the conformational switches of oligo(ELP) segment [27]
20-residual oligo(ELP) with (VPGVG)4 sequence was connected to cell-binding Ruoslahti found that the arginine-glycine-aspartic acid-serine (RGDS) epitope directly or through flexible diethylenglycol(deg) linker, were designed and employed as building blocks of self-assembled molecular layer for artificial ECM (Figure 1)

Summary

Introduction

An important challenge in tissue engineering and regenerative medicine is the design of novel scaffolds for cell adhesion, spreading and proliferation that mimic the natural extra-cellular matrix (ECM) [1,2]. An attractive strategy to engineer the ECM-mimicking surface of synthetic functional materials is the use of polymer and such short peptide-epitopes, since polymeric materials can be engineered to have an appropriate mechanical strength, biocompatibility and stimuli-responsiveness. The ELPs potentially offer several advantages over PNIPAM such as biocompatibility and biodegradablility characters Based on such interesting properties, ELPs have already been employed as useful molecular tools for biological applications such as protein purification, drug delivery and artificial ECM [17,18,19,20,21,22,23,24,25,26]. Cell attachment and recovery experiments were carried out by using the resultant thermo-responsive peptide layers These studies should provide simple and essential strategy for the design of novel oligopeptide-based smart surface

Peptide Preparation

Cell Attachment

Results and Discussion

Conclusions