Biomedical engineers from the University of California, San Diego have created a stem cell based tissue that mimics the human liver. This model could be used for patient-specific drug screening and disease modeling. The complex micro-architecture of a liver utilized a hexagonal pattern of stem cells and human liver tissue. Autologous stem cells were taken from the patient’s own skin cells to act as supporting cells. Because the method used 3D printing, the entire structure—a 3 × 3 millimeter square, 200 micrometers thick—takes just seconds to print on demand.
As reported in a recent article in the New York Times, researchers from the National Cancer Institute have developed an immune system treatment for a woman afflicted with cholangiocarcinoma (bile-duct cancer) utilizing her own stem cells. The scientists, led by Dr. Steven A Rosenberg, identified T-cells in the woman’s immune system that specifically attacked the cancerous cells in her body. They then used her stem cells to grow billions of these T-cells in a laboratory, and then infused the T-cells back into her bloodstream. After 18 months of the treatment, known as adoptive cell therapy, the woman experienced considerable reduction of tumor size and quantity.
Researchers at King’s County Hospital, London, have found that co-culturing hepatocytes [liver cells] with human mesenchymal stem cells [The same type found in Dental Stem Cells] improves hepatocyte survival and function. They found that in the presence of hepatocytes, the MSCs produced pro-survival factors, which supported the growth of the hepatocyte culture.
Researchers at Yokohama City University in Japan created tiny human livers utilizing human stem cells. The rudimentary livers [which were transplanted into mice] grew, made human liver proteins, and metabolized drugs as human livers do. And while the liver buds, as they are called, did not turn into complete livers, the study represents an important step in developing methodologies for growing large, complex organs.
Researchers all around the world are working towards utilizing stem cells to grow replacement organs. While once thought to be a futuristic concept, it is now very real. Doctors and researchers have successfully transplanted lab grown bladders, blood vessels, tear ducts, arteries and windpipes. Now, research teams around the world are growing urethras, bile ducts, larynxes, bones, livers, kidneys, and even hearts.
"Ninety percent of the patients on the transplant list are actually waiting for a kidney. Patients are dying every day because we don't have enough of those organs to go around," explained Anthony Atala, a leading stem cell researcher from Wake Forest during a TED talk. Given this acute need for organs, researchers around the world are racing to develop techniques to grow organs and tissue with stem cells.
Stem cell biologist Takanori Takebe of Yokohama City University in Japan successfully grew a small rudimentary liver while at the RIKEN Center for Developmental Biology in Kobe, researcher Yoshiki Sasai and his colleagues directed “retinal precursor cells” to develop into an the optic cup of the eye. Takebe said “a more developed version of the liver could eventually be used for long-term organ replacement, as well as serving as a short-term graft for patients whose damaged native livers are expected to recover.” Both the liver research and the optical tissue regeneration are examples of how advances in directing cells to differentiate will accelerate the application of stem cell treatments.