Direct Writing Electrospinning of Scaffolds with Multidimensional Fiber Architecture for Hierarchical Tissue Engineering

Abstract

Nanofibrous structures have long been used as scaffolds for tissue engineering (TE) applications, due to their favorable characteristics, such as high porosity, flexibility, high cell attachment and enhanced proliferation, and overall resemblance to native extracellular matrix (ECM). Such scaffolds can be easily produced at a low cost via electrospinning (ESP), but generally cannot be fabricated with a regular and/or complex geometry, characterized by macropores and uniform thickness. We present here a novel technique for direct writing (DW) with solution ESP to produce complex three-dimensional (3D) multiscale and ultrathin (∼1 μm) fibrous scaffolds with desirable patterns and geometries. This technique was simply achieved via manipulating technological conditions, such as spinning solution, ambient conditions, and processing parameters. Three different regimes in fiber morphologies were observed, including bundle with dispersed fibers, bundle with a core of aligned fibers, and single fibers. The transition between these regimes depended on tip to collector distance (Wd) and applied voltage (V), which could be simplified as the ratio V/Wd. Using this technique, a scaffold mimicking the zonal organization of articular cartilage was further fabricated as a proof of concept, demonstrating the ability to better mimic native tissue organization. The DW scaffolds directed tissue organization and fibril matrix orientation in a zone-dependent way. Comparative expression of chondrogenic markers revealed a substantial upregulation of Sox9 and aggrecan (ACAN) on these structures compared to conventional electrospun meshes. Our novel method provides a simple way to produce customized 3D ultrathin fibrous scaffolds, with great potential for TE applications, in particular those for which anisotropy is of importance.

Characterization of Polydioxanone in Near-Field Electrospinning

“…Our results suggest that PDO is a reliable biodegradable polymer for the creation of NFES written fibers. The trends reported in our characterization of the major NFES processing parameters for PDO align with other reported NFES polymers [24][25][26][27][28][29][30]. These parameter trends are also consistent with TES parameter trends, except for the applied voltage.…”

Simple fabrication of inner chitosan‐coated alginate hollow microfiber with higher stability

“…Recently, fiber‐based techniques have been widely used as bottom–up scaffolds to form hierarchical structures in numerous tissue engineering applications . Electrospinning, microfluidic extruding, and interface complexation are commonly used techniques to produce microfibers . Compared with other techniques, microfluidic systems, with the ability to handle liquids in the microscale, provide an effective way to flexibly manipulate microfluid and thus produce microscale fibers with various morphologies (e.g., tubular, flat, grooved, porous, and hybrid fibers), without the use of complicated devices or facilities .…”

Retinal cell regeneration using tissue engineered polymeric scaffolds

“…could generate nanofibrous networks displaying a topography that promotes cell adhesion, proliferation, and differentiation. Indeed, this specific structure is expected to allow more effective exchange of nutrients and metabolites across the nanofibers [97]. The fabrication of nanofibrous scaffold comprising silk fibroin and poly(Llactic-co-ε-caprolactone) has potential application for retinal progenitor cells [98].…”