Researchers grow liver cells from tonsil-derived stem cells on 3-D scaffold

Last Updated: 2014-10-06

By Will Boggs MD

NEW YORK (Reuters Health) - A new polypeptide thermogel system can provide a 3-dimensional scaffold for differentiating liver cells from tonsil-derived mesenchymal stem cells, researchers from Korea report.

Dr. Byeongmoon Jeong from Ewha Womans University, Seoul, Korea and colleagues investigated PEG-L-PA thermogel as a potential 3D culture system of tonsil-derived mesenchymal stem cells to induce the differentiation of stem cells into hepatocytes.

Mesenchymal stem cells have been shown to have the capacity for hepatic differentiation, but most studies have used conventional 2-dimensional cell culture systems that fail to mimic the 3D environments of living biological systems, according to the authors.

Tonsil-derived mesenchymal stem cells were encapsulated in the thermogel by using sol-to-gel transition of the cell-suspended polymer aqueous solution.

Unlike cells grown in culture, which developed a broadened flattened shape, the cells grown in the thermogel developed into spherical aggregates in the presence of hepatogenic growth factors, the researchers reported September 5 online in ACS Applied Materials & Interfaces online report.

Cells grown in this environment showed typical hepatogenic biomarker expression, including albumin and alpha-fetoprotein production.

Critical to this process, the researchers say, is careful selection of the combination of growth factors, cytokines, and chemicals to maximize hepatogenic differentiation of the stem cells.

"Therefore," they conclude, "further studies are needed to optimize the current thermogel as a 3D culture system of tonsil-derived mesenchymal stem cells (TMSCs). In addition, in vivo studies are also needed to confirm efficiency of cell therapy and biocompatibility of the TMSC/PEG-L-PA thermogel."

In email to Reuters Health, Dr. Jeong said, "A simple injection of a system consisting of stem cells, factors, polymer aqueous solution will lead to formation of the scaffold in situ at a target site, where the system provides a happy microenvironment for the stem cells and cells, and replace the damaged tissue."

To improve the system, Dr. Jeong continued, "we will improve the polymeric scaffold, and study the incorporation of cytokines, which provides the stem cell with long-term supply of the cytokines to induce the differentiation into the target cells. Currently we are interested in liver, cartilage, and neural tissue recovery by using the injectable tissue engineering system."

Dr. Jeong sees this system being used eventually as a nonsurgical treatment for patients otherwise needing liver transplantation for non-recoverable liver damage.

Dr. Takanori Takebe from Yokohama University's Department of Regenerative Medicine, Yokohama, Japan told Reuters Health by email, "This kind of gel is interesting to examine in the context of transplantation procedures. More specifically, combining with dispersed cells, gels support the stabilization of the transplanted cells by implanting into ectopic sites if the gels are optimized."

"If that system works well in terms of function after transplantation (although not tested), that will potentially help to support (patients with) chronic/acute liver failure, and bridge some time to liver transplantation," Dr. Takebe said.

SOURCE: http://bit.ly/YsBMS6

ACS Applied Materials Interfaces 2014.