Electrostatic flocking of salt-treated microfibers and nanofiber yarns for regenerative engineering

Abstract

Electrostatic flocking is a textile technology that employs a Coulombic driving force to launch short fibers from a charging source towards an adhesive-covered substrate, resulting in a dense array of aligned fibers perpendicular to the substrate. However, electrostatic flocking of insulative polymeric fibers remains a challenge due to their insufficient charge accumulation. We report a facile method to flock electrostatically insulative poly(ε-caprolactone) (PCL) microfibers (MFs) and electrospun PCL nanofiber yarns (NFYs) by incorporating NaCl during pre-flock processing. Both MF and NFY were evaluated for flock functionality, mechanical properties, and biological responses. To demonstrate this platform's diverse applications, standalone flocked NFY and MF scaffolds were synthesized and evaluated as scaffold for cell growth. Employing the same methodology, scaffolds made from poly(glycolide-co- l -lactide) (PGLA) (90:10) MFs were evaluated for their wound healing capacity in a diabetic mouse model. Further, a flock-reinforced polydimethylsiloxane (PDMS) disc was fabricated to create an anisotropic artificial vertebral disc (AVD) replacement potentially used as a treatment for lumbar degenerative disc disease. Overall, a salt-based flocking method is described with MFs and NFYs, with wound healing and AVD repair applications presented.

Repair Strategies and Bioactive Functional Materials for Intervertebral Disc

“…Furthermore, they fabricated an anisotropic artificial IVD based on a flock-reinforced polydimethylsiloxane disc, which consumes more energy, has a higher equilibrium modulus, and maintains the shape recovery of elastomers after compression with 100 supraphysiological loads (Figure 4f-h). [76] Yang et al created an articular IVD-like implant that contained a hierarchically organized AF and NP based on type II collagen using an optimized micropattern screening microchip to produce micropatterned bacterial cellulose nanofibers. Long-term (3-month) experiments implanting the artificial IVD in rats demonstrated their excellent structural and functional performance (Figure 4i,j).…”

“…h) Analysis of scaffolds for wound healing. Reproduced with permission [76]. Copyright 2021, Elsevier.…”

Elastic Fibers in the Intervertebral Disc: From Form to Function and toward Regeneration

“…The most common strategy has been the assembly of individually prepared cell-seeded AF and NP [ 127 , 128 , 129 ]. The most advanced IVD-like construct consists of a circular fibrous structure with or without angle-ply architecture using electrospinning or fiber deposition and then the addition of a hydrogel at the core of the ring for the NP [ 130 , 131 , 132 , 133 , 134 ]. The electrospinning approach is capable of developing a lamellar structure to resemble the organization of native AF, which is important for modeling the mechanical properties and formation of oriented ECM.…”

Production of Modified Composite Nanofiber Yarns with Functional Particles

“…Composite yarns are used primarily in the production of filtration products as well as in the health sector , and the textile industry for the production of clothing. , However, they can be further modified so as to enhance their application potential, particularly via their combination with other high-surface-area components such as activated carbon (so as to increase their filtration properties). , For filter applications, it is possible to use, for example, the widely used polyamide , or polyvinyl butyral . Their potential application in the health sector includes the creation of nanofibrous surgical suture sheaths enriched with antibiotic particles aimed at preventing the spread of microorganisms due to, for example, anastomotic leakage. , Yarns can be modified via either the grafting of specific molecules onto the fibers or the addition of functional particles directly to the spinning solution, the main disadvantage of which is that the particles may not be spun together with the polymer solution and that the spun particles become encapsulated within the polymer fiber. , Moreover, the incorporation of particles into the fiber surface involves the risk that the particles may stick to the surface of the yarn and may come loose.…”

“…Composite yarns are used primarily in the production of filtration products as well as in the health sector 15 , 16 and the textile industry for the production of clothing. 17 , 18 However, they can be further modified so as to enhance their application potential, 19 particularly via their combination with other high-surface-area components such as activated carbon (so as to increase their filtration properties).…”