Surface immobilization of fibronectin derived peptide fragments: the electrostatics and hydrophobic play for triggering angiogenesis processes

The guidance of angiogenesis processes is very intriguing for new and efficient therapies, which rely on the control of proliferation, migration, and differentiation of endothelial cells [1]. The PHSRN sequence is located in the contiguous domain of the first recognition site of fibronectin, the well-known RGD epitope. We have previously demonstrated, by adsorbing PHSRN on hydrophilic or hydrophobic surfaces, that the surface free energy plays a critical role for the cellular response, which in turn can be related to different peptide arrangements [2]. We report here on the surface immobilization of homologous peptide sequences, having a single-point mutation with respect to PHSRN fragment, in order to tune the interaction at the biointeface simply by changing the overall charge/hydrophobic character of the biomolecule. The peptide immobilization process by weak adsorption has been scrutinized by the QCM-D technique, in terms of mass uptake and viscoelastic properties at the biointerface, and by SFG spectroscopy, which allows determining the structure, orientation, and dynamics of the substrate-adsorbed peptides. Endothelial cell cultures on the so characterized, peptide coated supports, in the presence and absence of relevant angiogenic cofactors, evidenced that both cell adhesion and proliferation processes are significantly influenced by the different peptide arrangements at the interface. (1) DG Anderson et al, Science (2004). (2) C Satriano et al, JCIS (2010).