Abstracts Book - IMRC 2018

• SB6-O026
LINKING ARM EFFECT ON THE BIOLOGICAL PERFORMANCE OF A
CD31 PEPTIDE DIRECTLY GRAFTED ON L605 CoCr ALLOY BY A
PLASMA BASED MULTI-STEP STRATEGY
Sergio Diaz Rodriguez 1 , Pascale Chevallier 1 , Caroline Loy 1 , Diego Mantovani 1
1 Université Laval, Laboratoire de Biomatériaux et de Bioingénierie, Canada.
Atherosclerosis is a cardiovascular disease characterized by the formation of a
narrowing plaque on the artery, blocking the blood flow and leading to heart
strokes. Stents are implanted in the blocked zone to open and support the artery
from collapsing. Complications post-implantation exist, and the risk of
restenosis is latent. Therefore, enhancing biological properties with bioactive
molecule are mandatory for clinics, but also long-term stability is also required.
Thus, a novel multi-step plasma-based approach that allows to functionalize
directly the metallic surfaces of CoCr alloys with amine groups (-NH2) to further
graft bioactive molecules has been developed.
In this study, the impact on the biological performance by using different linking
arms (LA) on a CD31 peptide (P23) with pro-endothelialization and antithrombotic
properties was assessed: Glutaric anhydride (GA), a short spacer and
polyethylene glycol (PEG) with antifouling properties. These molecules were
covalently grafted using the novel approach.
Electropolished L605 specimens were functionalized using a MW-plasma reactor
fed with N2/H2 in a two-step procedure for surface amination. These samples
reacted with one LA, followed by the terminal-COOH activation with EDC and the
P23 grafting. Characterization of the surface was followed by XPS and ToF-SIMS.
For re-endothelialization, Endothelial cell (EC) adhesion and proliferation was
assessed using a 2 well culture-insert. For hemocompatibility, hemoglobin-free
colorimetric assay was performed.
Characterization by XPS and ToF-SIMS confirmed functionalization of the surface
and the grafting efficiency of the LA and P23. Regarding the biological
performance, grafting the peptide promoted cell adhesion and proliferation
compared to EP. Moreover, after three days EC formed a complete monolayer
preventing the blood clot formation.