Human Infra-patellar Fat Pad-Derived Stromal Cells Show Great Cartilage-Making Potential, Which is Enhanced By Connective Tissue Components

With age and overuse, our knees wear out and we sometimes need an artificial one. The cartilage shock absorber at the ends of our bones simply does not regenerate very well, and this results in large problems when we get older.

Is there an effective way to regenerate cartilage? Stem cells do have the ability to make cartilage, but finding the right stem cell and delivering enough of them to make a difference remains a challenge.

To that end, Tang-Yuan Chu and his colleagues from Tzu Chi University and the Buddhist Tzu Chi General Hospital in Hualien, Taiwan have discovered that stem cells from the fat pad that surrounds the knee appear to be one of the best sources of cartilage-making cells for the knee.

The infra-patellar fat pad or IFP contains a stem cell population called infra-patellar fat pad-derived stromal cells or IFPSCs. These IFPSCs were isolated by Chu and his colleagues from patients who were undergoing arthroscopic surgery. When Chu and others grew these cells in culture, the IFPSCs grew robustly for two weeks. The culture protocol was a standard one and no special requirements were required. In fact, after two weeks, the IFPSCs grew to more than 10 million cells on the third passage.

When the ability of IFPSCs to form cartilage-making cells (chondrocytes) were compared with mesenchymal stem cells from bone marrow, fat and umbilical cord connective tissue (Wharton’s jelly), the IFPSCs showed a clear superiority to these other cells types, and differentiated into chondrocytes quite effectively.

Next, Chu and his crew cultured the IFPSCs on a material called hyaluronic acid (HA). HA is a common component of the synovial fluid that helps lubricate our larger joints and in connective tissue, and basement membranes upon which epithelial cells sit.

Hyaluronic Acid

When grown on 25% HA, the IFPSCs were better at making bone or fat than IFPSCs grown on no HA. Furthermore, when grown on 25% HA, IFPSCs showed a four-fold increase in their ability to form chondrocytes. The HA also did not affect the ability of the cells to divide.

In conclusions, these IFPSCs seem to possess a strong potential to differentiate into chondrocytes and regenerate cartilage. Also, this ability is augmented in a growth environment of 25% HA. Certainly some preclinical trials with laboratory animal are due. Wouldn’t you say?

Source: Dah-Ching Ding; Kun-Chi Wu; Hsiang-Lan Chou; Wei-Ting Hung; Hwan-Wun Liu; Tang-Yuan Chu. Human infra-patellar fat pad-derived stromal cells have more potent differentiation capacity than other mesenchymal cells and can be enhanced by hyaluronan.  Cell Transplantation,


Published by


Professor of Biochemistry at Spring Arbor University (SAU) in Spring Arbor, MI. Have been at SAU since 1999. Author of The Stem Cell Epistles. Before that I was a postdoctoral research fellow at the University of Pennsylvania in Philadelphia, PA (1997-1999), and Sussex University, Falmer, UK (1994-1997). I studied Cell and Developmental Biology at UC Irvine (PhD 1994), and Microbiology at UC Davis (MA 1986, BS 1984).