Immobilisation of linear and cyclic RGD-peptides on titanium surfaces and their impact on endothelial cell adhesion and proliferation

• Main Authors: PW Kämmerer, M Heller, J Brieger, MO Klein, B Al-Nawas, M Gabriel
• Format: Article
• Language: English
• Published: AO Research Institute Davos 2011-04-01
• Series: European Cells & Materials
• Subjects: RGD modification; titanium; immobilisation; linear; cyclic; endothelial cells
• Online Access: http://www.ecmjournal.org/journal/papers/vol021/pdf/v021a27.pdf

Functional coatings on titanium vascular stents and endosseous dental implants could probably enhance endothelial cell (EC) adhesion and activity with a shortening of the wound healing time and an increase of peri-implant angiogenesis during early bone formation. Therefore, the role of the structure of linear and cyclic cell adhesive peptides Arg-Gly-Asp (l-RGD and c-RGD) on differently pre-treated titanium (Ti) surfaces (untreated, silanised vs. functionalised with l- and c-RGD peptides) on EC cell coverage and proliferation was evaluated. After 24 h and after 3 d, surface coverage of adherent cells was quantified and an alamarBlue® proliferation assay was conducted. After 24 h, l-RGD modified surfaces showed a significantly better coverage of adhered cells than untreated titanium (p=0.01). Differences between l-RGD surfaces and silanised Ti (p=0.066) as well as between l-RGD and c-RGD surfaces (p=0.191) were not significant. After 3 d, c-RGD surfaces showed a significantly higher cell coverage than untreated Ti, silanised and l-RGD titanium surfaces (all p<0.0001). After 24 h, c-RGD modified surfaces showed significant higher cell proliferation compared to untreated Ti (p=0.003). However, there were no differences in proliferation between c-RGD and l-RGD (p=0.126) or c-RGD and silanised titanium (p=0.196). After 3 d, proliferation on c-RGD surfaces outranged significantly untreated titanium (p=0.004), silanised (p=0.001) and l-RGD surfaces (p=0.023), whereas no significant difference could be found between untreated Ti and l-RGD surfaces (p=0.54). According to these results, the biomimetic coating of c-RGD peptides on conventional titanium surfaces showed a positive effect on EC cell coverage and proliferation. We were able to show that modifications of titanium surfaces with c-RGD are a promising approach in promoting endothelial cell growth.