  As part of applications dealing with cardiovascular tissue engineering,
drop-cast polyvinylidene fluoride (PVDF) scaffolds have been treated by cold
plasma to enhance their adherence to cardiac cells. The scaffolds were treated
in a dielectric barrier device where cold plasma was generated in a gaseous
environment combining a carrier gas (helium or argon) with/without a reactive
gas (molecular nitrogen). We show that an Ar-N2 plasma treatment of 10 min
results in significant hydrophilization of the scaffolds, with contact angles
as low as 52.4{\deg} instead of 132.2{\deg} for native PVDF scaffolds.
Correlation between optical emission spectroscopy and X-ray photoelectron
spectroscopy shows that OH radicals from the plasma phase can functionalize the
surface scaffolds, resulting in improved wettability. For all plasma-treated
PVDF scaffolds, the adhesion and maturation of primary cardiomyocytes is
increased, showing a well-organized sarcomeric structure ({\alpha}-actinin
immunostaining). The efficacy of plasma treatment was also supported by
real-time PCR analysis to demonstrate an increased expression of the genes
related to adhesion and cardiomyocyte function. Finally, the biocompatibility
of the PVDF scaffolds was studied in a cardiac environment, after implantation
of acellular scaffolds on the surface of the heart of healthy mice. Seven and
28 days after implantation, no exuberant fibrosis and no multinucleated giant
cells were visible in the grafted area, hence demonstrating the absence of
foreign body reaction and the biocompatibility of these scaffolds.
