Sacrificial Core-Based Electrospinning: A Facile and Versatile Approach to Fabricate Devices for Potential Cell and Tissue Encapsulation Applications

Abstract

Electrospinning uses an electric field to produce fine fibers of nano and micron scale diameters from polymer solutions. Despite innovation in jet initiation, jet path control and fiber collection, it is common to only fabricate planar and tubular-shaped electrospun products. For applications that encapsulate cells and tissues inside a porous container, it is useful to develop biocompatible hollow core-containing devices. To this end, by introducing a 3D-printed framework containing a sodium chloride pellet (sacrificial core) as the collector and through post-electrospinning dissolution of the sacrificial core, we demonstrate that hollow core containing polyamide 66 (nylon 66) devices can be easily fabricated for use as cell encapsulation systems. ATR-FTIR and TG/DTA studies were used to verify that the bulk properties of the electrospun device were not altered by contact with the salt pellet during fiber collection. Protein diffusion investigations demonstrated that the capsule allowed free diffusion of model biomolecules (insulin, albumin and Ig G). Cell encapsulation studies with model cell types (fibroblasts and lymphocytes) revealed that the capsule supports the viability of encapsulated cells inside the capsule whilst compartmentalizing immune cells outside of the capsule. Taken together, the use of a salt pellet as a sacrificial core within a 3D printed framework to support fiber collection, as well as the ability to easily remove this core using aqueous dissolution, results in a biocompatible device that can be tailored for use in cell and tissue encapsulation applications.

Strategies to Tune Electrospun Scaffold Porosity for Effective Cell Response in Tissue Engineering

“…Both approaches have been explored in different contexts and the resultant matrices were used in diverse fields [13]. For instance, they have been explored as filters for volatile organic compounds, nanoparticles, and airborne bacterial contaminates [14], as substrates for enzyme immobilization in fine chemistry, biomedicine, and biosensor [15,16], and as scaffolds for cell adhesion and growth in tissue engineering and regenerative medicine [17,18].…”

The Relationships between Process Parameters and Polymeric Nanofibers Fabricated Using a Modified Coaxial Electrospinning

“…But on the other hand, the conversion is a very complicated process with many uncertain and changeable factors, involving several disciplines such as electrostatic dynamics, hydrodynamics, and polymeric rheology [12,13,14,15,16]. Thus, it is not strange that although numerous publications have reported the potential applications of electrospun nanofibers in a wide variety of fields, such as energy [17,18,19], environment [20,21,22,23], medicine [24,25,26,27], food engineering [28,29,30] and tissue engineering [31,32,33], no uniform theories about this process have been put forward. Often, a mathematical model that is built on a certain working fluid fails to predict another type of working fluid.…”

Combination of 3D Printing and Electrospinning Techniques for Biofabrication

“…Reproduced with permission. [ 31 ] Copyright 2018, MDPI. h) Depositing electrospun fibers onto a bifurcated tubular mandrel.…”

“…The liquid photopolymer resin was cured by a laser in a 3D printer to construct the framework comprising a thick external skeleton and a thin internal lattice to form a luminal space (Figure 2g). [ 31 ] The printed framework packed with sodium chloride was used as the collecting unit of the electrospinning apparatus, which was placed directly in front of a grounded metal plate and connected to a direct current motor. [ 31 ] To control the packing density and fiber diameter, the motor was at a constant speed rotation during the preparation of capsules.…”

“…[ 30 ] Based on different applications, 3D‐printed scaffolds and electrospun fibers have been combined in various ways to meet the requirements, in which the application of sacrificial materials brings new insight for the fiber fabrication process. [ 22,31 ]…”