Biofabrication of Tissue Scaffolds - Advances in Biomaterials Science and Biomedical Applications - page 318

Nanofibrous architectures are known to modulate effects on a wide variety of cell behaviors.
Nanofibrous architectures can positively affect cell binding and spreading compared to mi‐
cropore and microfibrous architectures (Figure 2). Nanofibrous scaffold architectures have
larger surface areas to adsorb proteins than micro-architectures, presenting more binding
sites to cell membrane receptors [25]. The exposure of additional cryptic binding sites may
also be affected by adsorbed proteins. Furthermore, cells growing in a 3D nanofibrous struc‐
tural environment are able to exchange nutrients and utilize receptors throughout their sur‐
face, while cells in flat culture conditions are limited to nutrient exchange on only one side.
Electrospinning techniques have been widely employed to fabricate porous scaffolds with
nanofibrous architectures that can mimic the structure and biological functions of the natu‐
ral extracellular matrix [26]. This technique is able to generate fibers with diameters ranging
from 2 nm to several micrometers using solutions of both natural and synthetic polymers,
with small pore sizes and high surface area to volume ratios. A typical electrospinning setup
includes three parts: a syringe pump containing the polymeric materials, a high voltage
source to generate high electric field for spinning, and a collector to collect the fibers [27]
(Figure 3). During scaffold fabrication, the following electrospinning parameters are very
important with respect to the fiber morphology: polymer solution parameters (viscosity,
molecular weight of polymer, polymer conductivity, surface tension), processing parameters
(applied voltage, distance between tip and collector, flow rate), and environment parame‐
ters (humidity, temperature). Nanofibers with high surface area to volume ratios are most
suitable for tissue engineering applications [28].
Figure 2. Scaffold architecture affects cell binding and spreading. (Modified from [25])