
Fluorescence shows how cells, the little blue dots, prefer the pockets made within the green-colored nanofibers. Credit: Smitha Rao
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 Michigan Technological 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. Their work is published in Elsevier’s Materialia (DOI: 10.1016/j.mtla.2019.100296).
Smitha Rao, assistant professor of biomedical engineering at Michigan Tech, 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,” Rao 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?”
Nanofiber Strands and Pockets
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, Rao’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,” Rao 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. Rao’s team, including lead author and PhD student Samerender Nagam Hanumantharao and master’s student Carolynn Que, 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.
Multi-strand Nanofibers
Rao’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 (PCL), biodegradable and easy to shape, and conductive polyaniline (PANI), which together made a two-polymer blend, which could be combined with polyvinylidene difluoride (PVDF).
“Because polyaniline is conducting in nature, people can throw it into the fiber matrix to get conductive scaffolds for cells such as neurons,” Rao 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. Rao 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?” Rao said. “This is our basic building block; this is the two-by-two Lego. And you can build whatever you want from there.”
Learn more: Engineers Craft the Basic Building Block for Electrospun Nanofibers
The Latest on: Electrospun nanofibers
via Google News
The Latest on: Electrospun nanofibers
- ASTM International F3502-21 Compliant Mask Technology Opens Doors Letting Teachers and Kids Get 'Back to School'on February 22, 2021 at 5:39 am
The growing debate strengthens as teachers stand their ground against going back to school prior to getting vaccinated.
- Smart composite nanofiber mats with thermal management functionalityon February 19, 2021 at 5:20 am
The white colour of the nanofiber mats (Fig. 1) and also the fiber forms were maintained after PCM addition. The SEM observations from the electrospun PAN/PCM composite nanofiber mats revealed that ...
- Engineering multifunctional bactericidal nanofibers for abdominal hernia repairon February 19, 2021 at 4:59 am
Afewerki et al. employ integrated electrospinning, plasma treatment and direct surface modification strategy to engineer multifunctional bactericidal nanofibers for use in hernia repair. In a mouse ...
- Rational Design of Nanofiber Scaffolds for Orthopedic Tissue Repair and Regenerationon February 17, 2021 at 4:00 pm
It then illustrates that rationally designed scaffolds made up of electrospun nanofibers could be a promising solution to overcome the problems that current approaches encounter. The article also ...
- Polyacrylonitrile/polybenzoxazine-based [email protected] nanofibers: hierarchical porous structure and magnetic adsorption propertyon February 11, 2021 at 4:05 am
comprising of graphitic nanofibers and embedded Fe3O4 nanocrystals were prepared by using electrospun polyacrylonitrile/ polybenzoxazine (PBZ) nanofibers as composite carbon precursor. By the ...
- Current Projectson February 9, 2021 at 9:01 pm
These materials will be electrospun into tissue engineering scaffolds ... Membranes made of polymeric nanofiber scaffolds are being explored to serve as the next generation materials for chemical ...
- Nanofiber-hydrogel composite–mediated angiogenesis for soft tissue reconstructionon February 4, 2021 at 4:00 pm
Here, we report a nanofiber-hydrogel composite that addresses these issues. By incorporating interfacial bonding between electrospun poly(ε-caprolactone) fibers and a hyaluronic acid hydrogel network, ...
- Scott Sell, Ph.D.on February 4, 2021 at 12:02 pm
Sell conducts research in the areas of tissue engineering and regenerative medicine, particularly focusing on the potential for electrospinning to create extracellular matrix analogue scaffolds for ...
- This Spider-Man bandage gun sprays onto wound, heals with nanofiberson January 5, 2021 at 8:06 pm
explains are "polymeric electrospun healing fibers". Digital Trends explains that "Electrospinning, which creates nanofibers using electricity, has been deployed in the medical field for years.
- Electrospun nitrogen and carbon co-doped porous TiO2 nanofibers with high visible light photocatalytic activityon December 25, 2020 at 4:32 am
Nitrogen and carbon co-doped porous TiO2 nanofibers (NCPTNs) were exploited by a combination of electrospinning and controlled calcination technologies. Polyvinyl pyrrolidone (PVP) was employed both ...
via Bing News