Accelerating Cell Migration along Radially Aligned Nanofibers through the Addition of Electrosprayed Nanoparticles in a Radial Density Gradient

Abstract

by directing the migration of fibroblasts to the wound site for the re-establishment of dermis, [10] and the regeneration of dura mater requires the migration of cells from the periphery toward the center to cover the defected dura. [11] As another example, newborn cortical neurons in the developing cortex migrate along radial glial fibers toward the cortical plate to form the layered structure. [8,12] In addition, enhanced recruitment of endogenous neural stem cells from the central canal region to the lesion site is necessary for the repair of spinal cord injury to re-establish neural connectivity. [13] As such, it is of great importance to promote tissue regeneration by developing a scaffold capable of effectively guiding the radial migration of cells and directing their organization for the formation of functional tissue.Cell migration can be directed by different means, such as topographic and haptotactic cues. [8,14,15] When designing a scaffold, these beneficial cues should be integrated to maximize their impact on cell migration. Despite major progress, it remains a major challenge to develop scaffolds that recapitulate the complex structure and microenvironment of native tissues. Among various types of scaffolding materials, electrospun fibers show great promises owing to their capability to mimic some structural and compositional features of the extracellular matrix (ECM) and the feasibility to combine both topographic and haptotactic cues in the same scaffold. [16][17][18][19] As reported in the literature, scaffolds comprised of radially aligned nanofibers could provide a topographic cue to guide and accelerate cell migration along the radial direction, promoting wound closure. [11] 3D scaffolds consisting of radially aligned nanofibers could also promote diabetic wound healing. [10] Furthermore, radially aligned nanofibers could direct the growth of retinal ganglion cell axons radially, mimicking the radial axon paths in the retina. [20,21] In addition to the topographic cue, gradients represent another important type of cue in regulating the migration and assembly of cells. [1,22] A variety of strategies have been developed for incorporating radial gradients into the surface of a solid substrate. [23][24][25] For example, surface engineering through asymmetric chemical modification or geometrical patterning has been applied to generate graded features on a solid substrate such as silicon wafer or glass slide. [26,27] These methods Scaffolds capable of promoting cell migration from the periphery toward the center along with the radial direction hold promises for tissue regeneration.Here a simple and general method is reported based on masked electrospray for the fabrication of such scaffolds by depositing collagen nanoparticles on radially aligned nanofibers in a radial density gradient. Placed between the metallic needle and the collector, an aperture with tunable opening sizes serves as the mask. By increasing the size of the opening at a fixed speed, the electrosprayed particles take a radial dens...

Micro- and Nanostructured Fibrous Composites via Electro-Fluid Dynamics: Design and Applications for Brain

“…Beyond mimicking the peculiar architecture of the ECM, it has been demonstrated that the addition of bioactive cues via nanoparticles can promote cell differentiation, so guiding the regeneration process [ 69 ]. From this perspective, micro- or nanoparticles have been widely used to support brain regeneration through the use of nanoparticles, including specific chemical (e.g., growth factors [ 70 ]) or topological signals [ 71 ].…”

“…More recently, a fiber scaffold decorated with collagen nanoparticles with a density gradient was fabricated by electrospraying of collagen onto aligned fibers of PCL [ 102 ]. In detail, collagen nanoparticles with a density gradient were collected onto radially aligned fibers via electrospraying by the use of a size-tunable aperture working as a mask between the needle and the grounded collector [ 71 ]. Once the hole was gradually opened, particles tended to be distributed onto more extended portions of the surrounding substrates, thus altering the particle density in time, from the center to the periphery.…”

Hereditary Optic Neuropathies: A Systematic Review on the Interplay between Biomaterials and Induced Pluripotent Stem Cells

“…In this regard, PCL shows promise [96]. Electrospray and fiber structures in these polymers have been proven to be very effective in guiding cell proliferation [97]. Moreover, polyester biomaterials with a fiber structure, such as PCL either alone or mixed with poly(glycerol sebacate) (PGS) or with poly-l-lactide (PLL) or PLGA, have been used as supports for retinal progenitor cells (RPCs) to promote their attachment and expansion [10].…”

3D‐printed electrospun fibres for wound healing

“…Drug delivery via electrospray microspheres is also a viable strategy. Electrospraying makes it easy to build up a density gradient to achieve gradient distribution of active ingredients 112 . In particular, EHD equipment can work in the mode of electrostatic spray by changing operating parameters.…”