Electrospinning uses electric fields to manipulate nanoscale and microscale fibers. The technique is well-developed but time-intensive and costly. A new method was developed to create customizable nanofibers for growing cell cultures that cuts time spent removing toxic solvents and chemicals.
Nanofibers are used as scaffolds, made up of strands and pockets, that can grow cells. Making customizable scaffolds is surprisingly simple, especially when compared to the laborious casting and additive processes typically used to produce scaffolds suitable for electrospinning. The cells align without applying anything externally such as an electric field.
When spun in an electric field — imagine a cotton candy machine — the self-aligning cells follow the strand-and-pocket pattern of the underlying nanofibers. Varying electric field strengths results in different pocket sizes. At 18 kilovolts, the fibers align. At 19 kilovolts, small pockets form that are ideal for cardiac myoblasts. At 20 kilovolts, honeycombs of pockets expand in the fibers. Bone cells prefer the pockets formed at 21 kilovolts; dermal cells prefer the spacious rooms that grow at 22 kilovolts.
A variety of polymer mixes were tested. Some of the most common materials remain tried-and-true. The two-polymer blend allowed researchers to manipulate the nanofiber pocket size; a three-polymer blend made tweaking the mechanical properties possible. The polymers include polycaprolactone (PCL) that is biodegradable and easy to shape, and conductive polyaniline (PANI). Together, they made a two-polymer blend that could be combined with polyvinylidene difluoride (PVDF).
Being able to use the same materials to create different nanofiber characteristics means eliminating chemical and physical variables.