Enhanced cellular adhesion on titanium by silk functionalized with titanium binding and RGD peptides

Abstract

Soft tissue adhesion on titanium represents a challenge for implantable materials. In order to improve adhesion at the cell/material interface we used a new approach based on the molecular recognition of titanium by specific peptides. Silk fibroin protein was chemically grafted with titanium binding peptide (TiBP) to increase adsorption of these chimeric proteins to the metal surface. Quartz Crystal Microbalance was used to quantify the specific adsorption of TiBP-functionalized silk and an increase in protein deposition by more than 35% was demonstrated due to the presence of the binding peptide. A silk protein grafted with TiBP and fibronectin-derived RGD peptide was then prepared. The adherence of fibroblasts on the titanium surface modified with the multifunctional silk coating demonstrated an increase in the number of adhering cells by 60%. The improved adhesion was demonstrated by Scanning Electron Microscopy and immunocytochemical staining of focal contact points. Chick embryo organotypic culture also revealed strong adhesion of endothelial cells expanding on the multifunctional silk-peptide coating. These results demonstrated that silk functionalized with TiBP and RGD represents a promising approach to modify cell-biomaterial interfaces, opening new perspectives for implantable medical devices, especially when reendothelialization is required.

Extracellular matrix as an inductive scaffold for functional tissue reconstruction

“…31,54–58 The Arg-Gly-Asp peptide has been used to promote cell adhesion to synthetic substrates. 59–63 Thus, an additional advantage of the use of an ECM-based biomaterial is that it acts not only as a reservoir of structural and functional proteins, but also as a degradable substrate with an additional reserve of “hidden” bioactive peptides released during context-dependent degradation processes.…”

Electrodeposited Gels Prepared from Protein Alloys

“…Re-endothelialization is a crucial aspect of wound healing after vascular injury and similarly after stenting [26]. Furthermore, cellular binding domains as well as other specific biofunctional motifs can be easily integrated into the assembled gels through genetic engineering techniques [30,31]. The electrodeposited protein alloy coatings, as a versatile biomaterial platform, could serve as building blocks of nanoparticle-based drug carriers.…”

Adding Functions to Biomaterial Surfaces through Protein Incorporation

“…[277] Amongst peptides of interest the cell adhesion properties of the RGD peptide have been particularly exploited in material functionalization. RGD is the smallest fibronectin-derived sequence that retains its cell-binding ability and is recognized by multiple cell-bound integrins, [278] leading to enhanced cellular adhesion on functionalized surfaces, [279] a reduced foreign body response [280] and, in some cases, increased cellular migration. RGD has been utilized to seed a poly(methylpentene) membrane with lung endothelial cells to create a bioartificial lung [281] and to promote short-term adhesion, proliferation and differentiation of neural stem cells on polyester materials, albeit less effectively than (laminin-derived) IKVAV in the latter case.…”