Investigation of cellular response to covalent immobilization of peptide and hydrophobic attachment of peptide amphiphiles on substrates

Abstract

An overall investigation was made of the cell morphology, adhesion, viability, and proliferation of human fibroblast cells on surfaces functionalized with peptide and peptide amphiphiles. We compared surfaces in which the RGD peptide was immobilized covalently onto silicon with those in which lipidated versions of the RGD peptide were hydrophobically attached to the alkylated silicon surfaces. The hydrophobically attached peptide amphiphile on alkylated silicon surfaces produce structures that are somewhat akin to the structure of a cell membrane. Scanning electron microscopy (SEM) and Laser scanning confocal microscopy (LSCM) were used to characterize the seeding human fibroblast cells on all prepared surfaces. Surfaces were also evaluated with a methyl tetrazole sulfate (MTS) assay to compare the proliferation ability. Cell-substrate interactions were examined through cell adhesion assay. Peptide-amphiphile modified surfaces exhibited substantially superior cellular responses compared to those on the covalently immobilized peptide. It was also shown that the length of alkyl tail in lipidated peptides may influence cellular response. Hydrophobically attached peptide amphiphiles on alkylated silicon surfaces may suggest new biomimetic platforms for further studies of the interaction between cells and extracellular matrix.