Relation between fiber orientation and mechanical properties of nano-engineered poly(vinylidene fluoride) electrospun composite fiber mats

Abstract

Biomaterials processed in the form of electrospun fiber mats have already been explored to mimic different types of extracellular matrix in the human body once human body shows both aligned and randomly oriented cell/tissues. Knowing that numerous cell functions are regulated by mechanical signals, it is of key importance to quantitatively taken into account the influence of the fiber alignment on the tensile properties of such biomaterials as they will determine suitability of the materials for specific applications. In this way, this work reports on the development of nano-engineered poly(vinylidene fluoride) (PVDF) aligned and randomly oriented fibers and in the influence of fiber orientation on their mechanical properties. It was found that the Young's modulus depends significantly on the angle between the stretch direction and the fiber direction (225 MPa, 27 MPa and 23 MPa for the 0°, 45° and 90° angles, respectively), being independent of the deformation direction on the randomly oriented fibers. Nevertheless, with the applied stress, all samples undergo a reorientation of the fibers towards the stretching direction and a decrease of the fiber diameter. The addition of CoFe2O4 magnetostrictive nanoparticles, that induces the magnetoelectric response on the composite fiber mats and opens large application potential for non-contact tissue engineering strategies, slightly changed the Young's Modulus of the fibers (increased to 308,71 MPa for the sample with 10 wt% of CoFe2O4). All the features allied with the non-cytotoxicity of the developed composite fibers makes them good candidates for scaffold in tissue engineering applications.