The repair of articular cartilage not only owns a huge market, but also is a classic academic problem. One of the mainstream clinical treatments is autologous chondrocyte transplantation (ACI). In order to obtain sufficient chondrocytes, autologous chondrocytes need to go through expansion several times in vitro. However, chondrocytes are easy to dedifferentiate during culturing, and lose their ability to form normal cartilage after implanting. So it is very meaningful to elucidate the cues to regulate the dedifferentiation of chondrocytes during in vitro culture.

Ding’s group developed a unique micropatterning technic to fabricate RGD microislands on persistently non-fouling PEG background, by which single chondrocytes could be well localized. Using these micropatterns, they made the first study of the effects of the size and shape of cells on the influence of chondrocyte dedifferentiation. They found that chondrocytes derived from joint cartilage of SD rats are more likely going dedifferentiation when incubated in a more spread and elongated condition in the examined cell geometry range, whatever in the normoxia or hypoxia condition. This trend is not conclusive without the usage of their group’s polymer material technic to exclude the interference of other factors.

The paper with Bin Cao, a PhD student supervised by Professor Ding as the first author was published in Biomaterials. See details：Bin Cao, Rong Peng, Zhenhua Li, Jiandong Ding*, Effects of spreading areas and aspect ratios of single cells on dedifferentiation of chondrocytes, Biomaterials, 2014, 35, 6871-6881. Links：http://www.sciencedirect.com/science/article/pii/S0142961214005201#

Fluorescence micrographs of single chondrocytes on microislands with different diameters (A) and aspect ratios (B). The dashed lines indicate the positions of the cell-adhesive microislands. The cell staining was made after 10-day culture in growth medium under the normoxia condition. Red: F-actin, green: vinculin, blue: nuclei. Scale bar: 10 um.