Team Develops a New Tool to Foster Cardiovascular Tissue Transplantation Research

Alicia Allen

Alicia Allen, a fourth-year graduate student advised by Dr. Janet Zoldan, uses a relatively simple technique called electrospinning to create aligned polymer fibers that generate aligned cell sheets necessary for engineering tissues that generate a strong contractile force, such as cardiac muscle.

In a new paper published in Biomaterials Science, researchers advised by Janet Zoldan, an assistant professor of biomedical engineering at The University of Texas at Austin, have developed a more affordable, less resource-intensive way to create aligned cell sheets beneficial for tissue engineering purposes, specifically for engineering tissues that are anisotropic in function, such as cardiac muscle, nervous tissue, blood vessels, or cartilage.

Researchers interested in engineering tissue transplants have been working on ways to create thick, more three-dimensional cell constructs because they accurately mimic tissue architecture and function. For cardiac tissue in particular, more cells are needed to generate a greater contractile force. Stacking single-layer cell sheets together can achieve thicker cell constructs, and if cells within cell sheets are induced to align, function can be improved.

However, it is challenging and resource-intensive to generate aligned cell sheets. Often, a clean room is needed to develop this technology. Zoldan’s team, led by first author and graduate student Alicia Allen, may have found a simpler technique to create aligned cell sheets. 

Allen has created a platform combining a thermosensitive polymer combined with a second polymer that promotes cellular attachment. Using a common and inexpensive biomaterial fabrication technique called electrospinning, she’s combined these polymers to create aligned polymer fibers that can be seeded with cells and then dissolved by lowering the temperature to generate aligned cell sheets.

Allen’s findings provide for a scalable solution that will further the Zoldan Lab’s research efforts in cardiac tissue engineering. Additionally, other scientists working in the area of tissue engineering have access to a less expensive, less resource-intensive method to create a cell microenvironment that promotes the cell sheet alignment necessary for generating functional tissue-engineered transplants. 

Cell sheet diagram

Researchers combined two polymers—thermosensitive PNIPAAM with poly(caprolactone) (PCL), which promotes cellular attachment—to create aligned fibers. They found that ultimately they could create aligned cell sheets, which have the potential to better recapitulate anisotropic architecture to achieve proper tissue function.