Nanofiber membranes as biomimetic and mechanically stable surface coatings.

ABSTRACT

Elastomers have been extensively exploited to study cell physiology in fields such as mechanobiology, however, their intrinsic high hydrophobicity renders their surfaces incompatible for prolonged cell adhesion and proliferation. Electrospun fiber networks on the other side provide a promising environment for enhanced cell adhesion and growth due to their architecture closely mimicking the structure of the extracellular matrix present within tissues of the human body. Here, we explored the stable integration of electrospun fibers onto the surfaces of elastomeric materials to promote cytocompatibility of these composites. Elastomers based on room temperature vulcanizing silicone (RTV), polydimethylsiloxane (PDMS) as well as functionalized PDMS-based materials were chosen as wafer substrates for attachment of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDFhfp) fibers, a well-known antithrombotic polymer. Electrospinning the fibers onto uncured interfaces acted as bonding agents on the wafers, enabling penetration and formation of a stable bond between the fibers surfaces and the elastomers after curing the interface. Dimensional analysis revealed a relationship between peeling force, intrusion depth and the elastic modulus of the wafers. A design parameter Πα was extrapolated to be used as a predictive tool of the peeling force when intrusion depth of PVDFhfp fibers and elastic modulus of the wafers are known. Cultivating fibroblasts on these hybrid membranes showed cell attachment and growth over 7 days regardless of the composition of the substrate, confirming high cytocompatibility for all composite materials. The presented approach opens avenues to establish nanofiber morphologies as a novel, stable surface texturing tool for tissue engineering, cell biology, medical devices and textiles.