Deposition of Thiol-Rich Coatings on Nanofibrous Scaffolds Via Atmospheric Pressure DBD Plasma for Tissue Engineering Applications

Tissue engineering is a rapidly emerging aiming at overcoming the limitations of conventional transplantation methods through development of substitute structures so-called scaffolds for the restoration of damaged tissues. One of the promising approaches towards a successful tissue repair is fabrication of a scaffold mimicking the fibrous structure of the extracellular matrix (ECM) that governs a wide range of crucial cellular performances such as adhesion and proliferation.
Electrospinning can be used as a simple, versatile and cost-effective biofabrication technique able to produce polymeric fibrous meshes simulating the ECM morphology. Several biodegradable polymers have been employed in the generation of scaffolds with polycaprolactone (PCL) being by far the most considered material due to its non-toxicity and history of safe clinical use. Despite the afore-mentioned advantages, PCL is a hydrophobic material that does not exhibit desirable bio-chemical properties promoting cell-surface interactions. Therefore, a surface modification putting into effect appropriate biochemical properties can solve the issue. The generation of thiolated surfaces is gaining a huge popularity in TE applications since thiol groups (-SH) are known to serve as highly selective anchoring sites for the subsequent covalent immobilization of biomolecules. This was previously done via self-assembly approaches that ahave some drawbacks such as the use of organic solvents, the long reaction times and the multi-step procedure. As an alternative, plasma-assisted polymerization of thiol-containing precursors can be employed to deposit thiol-rich coatings onto the scaffolds in a fast, solvent-free and eco-friendly way.
In this research, PCL nanofibers are first using electrospinning. A plasma polymerization process was then performed to deposit a thiol-rich coatings on the electrospun fibers using a dielectric barrier discharge (DBD) with 1-propanethiol as precursor. An optimization of the process was carried out via an extensive parametric study involving the discharge power, gas flow rate, treatment time and pressure inside the DBD chamber.