Bone tissue engineering: Attaching proteins for better regeneration

Current treatments for bone defects and bone tissue regeneration have significant limitations. Now a new method that immobilises a fusion protein in a hybrid collagen-polymer supportive scaffold shows promise for bone tissue engineering.

Guoping Chen, Yoshihiro Ito and researchers at the Tissue Regeneration Materials Unit, International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science, RIKEN, the Immuno-Biological Laboratories Co., Ltd, and the National Institute for Child Health and Development, Tokyo, added a collagen-binding domain from fibronectin to BMP4, a protein that promotes bone regeneration.

The new fusion protein, BMP4-CBD, was used in a scaffold of natural collagen sponge and a strong synthetic polymer, poly(lactic-co-glycolic acid) (PLGA). The scaffold provides space and support for the bone cell growth.

The researchers investigated the BMP4-CBD immobilized on the collagen-PLGA scaffold cultured in vivo for four weeks. They compared the approach with a range of controls including scaffolds with wild-type BMP4 without the collagen-binding domain and scaffolds with just the collagen-binding domain. The expression of specific and non-specific osteogenetic markers used as indicators of bone tissue regeneration was much higher for BMP4-CBD. Using BMP4-CBD also initiated calcification.

“These effects should be attributed to the retention of more effective molecules due to the specific binding of the fusion BMP4 to the collagen,” say the authors. The stimulation effect of the protein promoting the bone regeneration is thus maintained over a longer period. The research may benefit patients suffering from bone defects in the future.

Further information

Publications and Affiliation:

Hongxu Lu1, Naoki Kawazoe1, Takashi Kitajima2, Yuka Myoken3, Masahiro Tomita 3, Akihiro Umezawa4, Guoping Chen1*, Yoshihiro Ito2* Spatial immobilization of bone morphogenetic protein-4 in a collagen-PLGA hybrid scaffold for enhanced osteoinductivity. Biomaterials, 33, 6140–6146, (2012).

1. Tissue Regeneration Materials Unit, International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
2. Nano Medical Engineering Laboratory, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako 351-0198, Japan
3. Neosilk Laboratory, Immuno-Biological Laboratories Co., Ltd., 3-13-60 Kagamiyama, Higashihiroshima, Hiroshima 739-0046, Japan
4. National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo 157-8535, Japan

* Corresponding authors

Contact details

International Center for Materials Nanoarchitectonics(WPI-MANA)
1-1 Namiki, Tsukuba-shi Ibaraki, 305-0044 Japan
Email: Guoping Chen, Ph.D Guoping.CHENnims.go.jp
Telephone: +81-29-860-4496