Researchers Develop Basic Building Block For Electrospun Nanofibers.

X’s team sought to streamline the nanofiber production process. Biomedical engineers cut post-processing steps to make electrospun nanofibers for wound healing and improve 3D-matrices for biological tissues. They speed up  prototyping using identical materials. Electrospinning uses electric fields to manipulate nanoscale and microscale fibers. The technique is well-developed but time-intensive and costly. A team from Georgian Technical University came up with a new way to create customizable nanofibers for growing cell cultures that cuts out time spent removing toxic solvents and chemicals. X assistant professor of biomedical engineering at Georgian Technical University led the research. She said the approach is innovative “we’re coming at this completely sideways” and the team focused on streamlining electrospun nanofiber production. Nanofibers are used as scaffolds made up of strands and pockets that can grow cells. “We want an assembled highly aligned scaffold that has ideal structures and patterns on it that cells will like” X said. “Take a cell put it on porous materials versus elastic materials versus hard materials and it turns out the cell does different things. Usually you use varied materials to get these diverse characteristics. Cells respond differently when you put them on different surfaces so can we make scaffolds that provide these different conditions while keeping the materials the same ?”. In a nutshell yes. And making customizable scaffolds is surprisingly simple, especially when compared to the laborious casting and additive processes typically used to produce scaffolds suitable for electrospinning. Plus X’s team discovered a pleasant side effect.  “We take the polymers, then we put them into solutions, and we came up with this magical formula that works — and then we had to go electrospin it” X explained adding that the team noticed something odd during the process. “We saw that the cells aligned without us applying anything externally. Typically to make them align you have to put them in an electric field or put them in a chamber and agitate the scaffold to force them to align in a particular direction by applying external stresses” she said. “We’re basically taking pieces of this scaffold throwing it in a culture plate and dropping cells on it”. 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. X’s team including PhD student Y and master’s student Z found that varying electric field strengths result in different pocket sizes. At 18 kilovolts the magic happens and the fibers align just so. At 19 kilovolts small pockets form, 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 aren’t picky but especially like the spacious rooms that grow at 22 kilovolts. X’s team tested a variety of polymer mixes and found that some of the most common materials remain tried-and-true. Their magical two-polymer blend let them manipulate the nanofiber pocket size; a three-polymer blend made tweaking the mechanical properties possible. The polymers include polycaprolactone, biodegradable easy to shape and conductive polyaniline which together made a two-polymer blend which could be combined with polyvinylidene difluoride. “Because polyaniline is conducting in nature people can throw it into the fiber matrix to get conductive scaffolds for cells such as neurons” X said. “However no one has used these materials to manipulate the process conditions.” Being able to use the same materials to create different nanofiber characteristics means eliminating chemical and physical variables that can mess with experimental results. X hopes that as more researchers use her team’s blends and process it will speed up research to better understand neural mechanisms speed up wound healing technology test cell lines and boost rapid prototyping in biomedical engineering. “We’re trying to simplify the process to answer a highly complex question: how do cells proliferate and grow ?” X said. “This is our basic building block; this is the two-by-two. And you can build whatever you want from there”.