Review: unraveling the less explored flocking technology for tissue engineering scaffolds

Abstract

Clinical translation of the scaffold-based tissue engineering (TE) therapy still faces multitude challenges despite intense investigations and advancement over the years. In order to circumvent clinical barriers, it is important to analyze the current technical challenges in constructing a clinically efficacious scaffold and subsequent issues relating to tissue repair. The major limitations of current scaffolds are lack of sufficient vascularisation, mechanical strength and issues related to the osseointegration of the scaffold in case of bone tissue engineering. Hence, this review accentuates the main challenges hampering widespread clinical translation of scaffold-based TE, with a focus on novel scaffolds fabricated using flocking technology. Flock technology is a well known method used in textile industry. Flocking application for scaffold fabrication is less explored yet they offer promising solutions for creating anisotropic scaffolds with high compressive strength despite of high porosity. Critical insights on the current researches of the fabricated flock scaffold and future directions for advancing flocking to next-generation TE scaffolds into the clinical realm are discussed. This review will serve as a one stop arrangement for understanding the vital pre-requisite properties of scaffolds, principle as well as factors governing flocking of scaffolds and the improved properties of flock scaffolds. Further, this will promulgate flocking technology as a plausible candidate to spearhead TE scaffold fabrication.

Electrostatic Flocking of Insulative and Biodegradable Polymer Microfibers for Biomedical Applications

“…To demonstrate how this flocking mechanism is fundamentally different than each of those previously reported (utilizing fiber finishes or inherently semiconductive materials), we flocked 0.5% AgNP/PCL fibers and surface-finished Rayon fibers after incubating at a different relative humidity (RH) for 24 h (Figure S2, Supporting Information). [1][2][3][4][5][6][7][8][16][17][18][19][20][21] Rayon fibers Theoretical cross-section view of PCL microfibers at different AgNP concentrations, (middle) photograph of microfibers with increasing (left to right) concentration of AgNPs, and (bottom) different concentration AgNP microfibers after cutting. b) Estimated conductivities using the Percolation Theory model for PCL microfibers loaded with 70 nm diameter AgNPs (conductivity threshold for flocking indicated with red arrow).…”

“…Electrostatic flocking, a textile engineering technique that consists of three main components (flock fibers, an adhesive, and a substrate) uses an electrostatic field to launch short microfibers (flock fibers) toward an adhesive-covered substrate, creating a layer of vertically-aligned fibers perpendicular to the substrate. [1,2] Generally, flocking can be regarded as a surface modification technique used to decorate object surfaces or planar textiles. Application of flock fibers (short polymeric microfibers with proprietary electrostatic surface finishes) to an object increases regional mechanical strength, generates anisotropic surfaces with high surface areas and porosities, and allows for surface functionalization based on the type of fiber used.…”

Factors affecting the mechanical and geometrical properties of electrostatically flocked pure chitosan fiber scaffolds

“…17,18 Moreover, electrostatic flocking technology has been used for the preparation of three-dimensional anisotropic scaffolds, featuring a columnar fiber orientation to enhance the biomechanical properties under compression. [19][20][21][22][23] Gossla and colleagues recently prepared flocked scaffolds consisting of chitosan only, ensuring full biodegradability. 24 It was found that these scaffolds were suitable for the proliferation of hMSC and Saos-2 cell lines, hence they were proposed as a promising candidate for articular cartilage TE applications.…”

Development of a Bioinspired, Self‐Adhering, and Drug‐Eluting Laryngotracheal Patch

“…These composites can potentially provide improved, reversible adhesion compared to traditional bio‐polymers 18,19 . Originally envisioned as adhesive tapes or as stability mechanisms in robotic climbers, they can also function as scaffolds in tissue engineering 20 …”

“…18,19 Originally envisioned as adhesive tapes or as stability mechanisms in robotic climbers, they can also function as scaffolds in tissue engineering. 20 The design of a base layer for tissue sealants requires materials capable of conforming to the gross anatomy that control fluid permeability while maintaining biocompatibility. Electrospinning is the preferred technique for creating fibrous mats in controlled, designed architectures.…”