Mimicking cell membrane-like structures on alkylated silicon surfaces by peptide amphiphiles

We present a new strategy for flexible attachment of peptide amphiphiles on functionalized silicon surfaces. This method involves the production of an alkylated surface on which a lipidated peptide can then be attached through hydrophobic interaction. We applied this to two derivatives of amphiphilic peptide molecules with the same amino acid sequence (A-A-A-A-G-G-G-E-R-G-D) but different in alkyl chain lengths (palmitic acid, undecanoic acid). The basis of this work was to develop substrates which are more biocompatible and bioactive. The ultra-thin peptide amphiphile films were characterized using electrical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (ATR-FTIR) spectroscopy. The results demonstrated that the length of the alkyl chain in the peptide amphiphile affects the packing and coverage of the peptides on the silicon surface.

► Lipidated peptide amphiphiles were hydrophobically attached onto an alkylated surface. ► Morphology of nanofibres of the peptide amphiles depended on the acyl chain length. ► We show that extended 2D analogues of the nanofibre surface can be constructed. ► Peptide amphiphiles with shorter acyl chains formed more homogeneous layers.