A hierarchically ordered compacted coil scaffold for tissue regeneration

Abstract

Hierarchically ordered scaffold has a great impact on cell patterning and tissue engineering. The introduction of controllable coils into a scaffold offers an additional unique structural feature compared to conventional linear patterned scaffolds and can greatly increase interior complexity and versatility. In this work, 3D coil compacted scaffolds with hierarchically ordered patterns and tunable coil densities created using speed-programmed melt electrospinning writing (sMEW) successfully led to in vitro cell growth in patterns with tunable cell density. Subcutaneous implantation in mice showed great in vivo biocompatibility, as evidenced by no significant increase in tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) levels in mouse serum. In addition, a lumbar vertebra was successfully printed for mesenchymal stem cells to grow in the desired pattern. A long-range patterned matrix composed of programmable short-range compacted coils enabled the design of complex structures, e.g., for tailored implants, by readily depositing short-range coil-compacted secondary architectures along with customized primary design.

3D Electrospun Synthetic Extracellular Matrix for Tissue Regeneration

“…[112] The scaffold shape can also be designed to match specific bones, such as the lumbar vertebra, as described by Su and coworkers. [54] In vitro, 3D electrospun scaffolds support cell development. Human osteosarcoma cells cultured on piezoelectric hydrophilic electrospun PVDF scaffolds showed well-defined actin stress fibers crossing the cell (Figure 9A), and the scaffold was found to generate a local electric field that activated the osteoblasts (Figure 9B).…”

“…[ 51 ] As evaporation of solvents may affect the precision of the fiber deposition, [ 52 ] solvent‐free electrospinning was introduced to the field of NFE in 2008, creating the emerging melt electrospinning writing (MEW) technology. [ 53 ] Although MEW makes it possible to achieve high‐resolution nanostructures with tunable coil densities [ 54 ] and precise deposition of single fibers, [ 49 ] it cannot achieve wide‐range regulation in height. This challenge must be overcome before MEW is fully applicable in the construction of artificial organs.…”

“…3D electrospun scaffolds can help fabricate highly porous structures with biomaterials mimicking the natural 3D extracellular microenvironment for improved cell adhesion, proliferation, and differentiation. [ 54,63 ] 3D electrospun scaffolds display strong potential in tissue regeneration through their biochemical cues from natural, synthetic, or hybrid biomaterial selections and physical cues from the mechanical, topographical, and geometrical features of the fiber constructs [38b,64] . Most recent studies have focused on producing 3D bioactive and biocompatible scaffolds with potential applications in fields such as neural, cardiac tissue, and bone tissue regeneration [63c,65] .…”

“…[ 112 ] The scaffold shape can also be designed to match specific bones, such as the lumbar vertebra, as described by Su and coworkers. [ 54 ]…”

A Charge-Based Mechanistic Study into the Effects of Process Parameters on Fiber Accumulating Geometry for a Melt Electrohydrodynamic Process

“…Melt electrowriting processes, as an emergent technology utilizing the principle of electro-hydrodynamics and additive manufacturing [1,2], have aroused wide interest due to its ability to produce polymeric scaffold with tunable microarchitecture [3][4][5][6] and morphology [7][8][9][10][11]. Moreover, the solvent-free characteristic of the process makes it amenable for a broad application scope for engineered tissues [12][13][14][15][16][17][18]. However, the printing fidelity of the engineered scaffold notably deteriorates when the printing toolpath is designed for larger layering dimensions [19] or smaller feature pore sizes [20].…”