European Cells and Materials Vol. NN. Suppl. N, 20xx (page htu)
ISSN 1473-2262
Biofunctionalization of patterned PLLA surfaces with RGD, REDV and YIGSR
peptides to promote endothelial cells adhesion and migration
R Schieber1,2,3, D Moreno1,2, C Mas-Moruno1,2, FJ Gil1,2, F Mücklich3, M Pegueroles1,2
1
Biomaterials, Biomechanics and Tissue Engineering Group, Technical University of Catalonia,
Spain. 2 Centre for Research in Nano Engineering, Technical University of Catalonia, Spain.
3
Chair of Functional Materials, Saarland University, Germany
INTRODUCTION: Angioplasty and stent
implantation open the blocked artery and restore
proper blood flow after atherosclerosis disease.
Despite their utility, intracoronary stents induce
two types of complications: in-stent restenosis and
thrombosis. Recently, biodegradable poly-L-lactic
acid (PLLA) stents have been inserted to restore
the healed artery, reabsorb and consequently avoid
late stent thrombosis [1]. Moreover, rapid stent
endothelialisation is one of the main goals in order
to heal the damaged tissue and decrease in-stent
restenosis [2]. The present work combines
topographical
modification
and
peptide
functionalization of PLLA surfaces to increase
endothelial cells adhesion and migration, and thus
enhance endothelialization.
METHODS: PLLA films were obtained by
solvent casting with a solution of PLLA (PL65
from Purasorb) in chloroform (3.7%v/v). Linear
topography pattern was done by hot stamping at
180ºC with PDMS stamps (periodicity: 10 µm,
depth: 1 µm). RGD, REDV and YIGSR lineal
peptides with and without a terminal
carboxyfluorescein
molecule
(CF)
were
synthesized by solid-phase and covalently attached
to the surfaces using EDC/NHS. Planar and/or
non-functionalized surfaces were used as control.
Crystallinity, thermal degradation and topography
were evaluated by DSC, TGA and interferometry
respectively. HUVEC adhesion was characterized
by immunofluorescence. HUVEC migration was
performed through a wound healing assay.
RESULTS: Homogeneous linear nanopatterned
surface were successfully obtained with ~900 nm
depth and ~10 µm periodicity. As expected, DSC
indicated that hot stamping reduced crystallinity
from 26,2% to 10,0%. TGA measured degradation
temperature of PLLA films was 360ºC, higher than
the temperature of the hot stamping process.
Visualization of the immobilized CF-peptides by
fluorescent microscopy shows a successful and
similar adhesion of RGD, REDV and YIGSR
peptides on PLLA films. Cell adhesion studies
indicated higher number of adhered HUVECs onto
RGD and YIGSR surfaces compared to REDV and
non-functionalized films. The effect of linear
topography was clear showing an elongation and
alignment of the adhered cells following the
pattern channels. HUVEC cells on the combined
functionalized with YIGSR and patterned surfaces
induced an accelerated HUVECs migration.
Fig. 1: HUVEC migration at initial point (H0) and
after 16h (H16) of flat (F), patterned (P) and
patterned and functionalized with YIGSR (PYIGSR) PLLA films.
DISCUSSION & CONCLUSIONS: PLLA
surfaces with linear patterning and functionalized
with RGD, REDV and YIGSR peptides were
successfully obtained. Topography induces cell
orientation parallel to the linear pattern.
Biofunctionalization with RGD and YIGSR
peptides enhances cell adhesion compared to
REDV
and
non-functionalized
surfaces.
Furthermore, functionalization and patterning
accelerate HUVEC migration in the pattern
direction. Overall, patterned PLLA functionalized
with RGD or YIGSR may be excellent candidates
to improve PLLA stent endothelialization.
REFERENCES: 1 N. Soji, et al (2012)
Circulation 19: 2343-2352. 2 D.B. Schneider, et al
(2012) Circulation 95: 308-310.
ACKNOWLEDGEMENTS: R.S. would like to
thank the Erasmus Mundus Doctoral Programme
for funding through a DocMASE Scholars.
http://www.ecmjournal.org