Fabrication of Large Pores in Electrospun Nanofibrous Scaffolds for Cellular Infiltration: A Review

Abstract

In the past decade, considerable effort has been made to construct biomimetic scaffolds from electrospun nanofibers for engineering different tissues. However, one of the major concerns with electrospun nanofibrous scaffolds is that the densely arranged architecture of fibers and small pores or voids between fibers hinder efficient cellular infiltration or prevent three dimensional (3D) cellular integration with host tissue in vivo after implantation. To overcome this problem, many concepts or strategies applicable during the electrospinning or post-electrospinning procedures have been proposed to enlarge pore size of electrospun scaffolds. This article addresses the issues of pore geometry and cellular infiltration of electrospun scaffolds, and first reviews the fabrication solutions/approaches applied to achieve larger micropores in electrospun mats. The evidence and potential for fostering cellular infiltration using these improved porous scaffolds are then discussed. Finally, it is hoped that this will enable us to better exploit viable technologies or develop new ones for constructing ideal nanofibrous architecture for fulfilling specific tissue engineering needs.

Bone Tissue Engineering with Multilayered Scaffolds—Part I: An Approach for Vascularizing Engineered Constructs In Vivo

“…The major criticism against the use of electrospun polymeric nanofibers in tissue engineering is their small pore size and thereby the fish-net effect, which restricts the infiltration of cells and vasculature. 25,26 However, wafers of functional cells in microscale thickness (50-100 mm, the stretchable length of a cell) can be successfully developed using biodegradable nanofibrous wafer discs and appropriate cell seeding strategy. Similarly, porous microfibrous and ceramic discs can be developed in microscale thickness by appropriate methods and can be used as suitable platform for tissue/vessel ingrowth after appropriate bioengineering.…”

Study of polycaprolactone wet electrospinning process

“…To produce bulky and fluffy material using the common electrospinning method is a tricky matter. This task could be achieved either using special collectors [3] or by the usage of porogen particles, that is, chemical blowing agents, imbedded in between the nanofibers [4]. Wet electrospinning is a relatively simple and effective method to produce three dimensional (sponge-like) materials without sophisticated devices and without special chemical additives.…”

A review of electrospinning manipulation techniques to direct fiber deposition and maximize pore size

“…Laser ablation involves rapid precise, intense heating of electrospun scaffolds to create controlled patterns and pores [151]. Variations and patterns can be created by controlling power, pulse, and orientation of ablation, which can be then optimized for cell infiltration [150,[152][153][154]. Cell infiltration can be significantly enhanced using a method of electrospinning that spins a polymer around a needle array as opposed to a solid or hollow mandrel and creates a focused, low density, uncompressed three-dimensional electrospun nanofibrous scaffold [155].…”