Surface potential and roughness controlled cell adhesion and collagen formation in electrospun PCL fibers for bone regeneration

Surface potential of biomaterials is a key factor regulating cell responses, driving their adhesion and signaling in tissue regeneration. In this study we compared the surface and zeta potential of smooth and porous electrospun polycaprolactone (PCL) fibers, as well as PCL films, to evaluate their significance in bone regeneration. The ' surface potential of the fibers was controlled by applying positive and negative voltage polarities during the electrospinning. The surface properties of the different PCL fibers and films were measured using X-ray photoelectron spectroscopy (XPS) and Kelvin probe force microscopy (KPFM), and the zeta potential was measured using the electrokinetic technique. The effect of surface potential on the morphology of bone cells was examined using advanced microcopy, including 3D reconstruction based on a scanning electron microscope with a focused ion beam (FIB-SEM). Initial cell adhesion and collagen formation were studied using fluorescence microscopy and Sirius Red assay respectively, while calcium mineralization was confirmed with energy-dispersive x-ray (EDX) and Alzarin Red staining. These studies revealed that cell adhesion is driven by both the surface potential and morphology of PCL fibers. Furthermore, the ability to tune the surface potential of electrospun PCL scaffolds provides an essential electrostatic handle to enhance cell-material interaction and cellular activity, leading to controllable morphological changes

Hierarchical Composite Meshes of Electrospun PS Microfibers with PA6 Nanofibers for Regenerative Medicine

One of the most frequently applied polymers in regenerative medicine is polystyrene (PS), which is commonly used as a flat surface and requires surface modifications for cell culture study. Here, hierarchical composite meshes were fabricated via electrospinning PS with nylon 6 (PA6) to obtain enhanced cell proliferation, development, and integration with nondegradable polymer fibers. The biomimetic approach of designed meshes was verified with a scanning electron microscope (SEM) and MTS assay up to 7 days of cell culture. In particular, adding PA6 nanofibers changes the fibroblast attachment to meshes and their development, which can be observed by cell flattening, filopodia formation, and spreading. The proposed single-step manufacturing of meshes controlled the surface properties and roughness of produced composites, allowing governing cell behavior. Within this study, we show the alternative engineering of nondegradable meshes without post-treatment steps, which can be used in various applications in regenerative medicine

Accelerated wound closure rate by hyaluronic acid release from coated PHBV electrospun fiber scaffolds

The enormous potential of electrospun polymer fibers allows for their development in the field of biomaterials for tissue engineering and wound healing. Electrospun fibers based on biodegradable polymers such as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) are an ideal material for the production of a biocompatible cell scaffold supporting wound closure and skin regeneration. The aim of this research was to create a fibrous PHBV scaffold supporting the 3D environment for anchoring and proliferation of keratinocytes. Moreover, hyaluronic acid (HA) has been used as a coating on PHBV fibers to improve the wound closure processes. ATR-FTIR results indicated the presence of HA in the PHBV scaffolds and UV-Vis analysis confirmed the release of HA from the fibers over 24h test. Importantly, this release of HA increase keratinocyte activity as well their proliferation leading to accelerated wound closure rate in the scratch tests. The designed HA-coated PHBV scaffolds demonstrate the great potential of surface-modified electrospun polymer fibers for wound healing