“Osteoinductive biomimetic calcium phosphate bone substitute for bone regeneration” is the title of the outstanding study for which Yuelian Liu, Research Group Leader at the Academic Centre for Dentistry at the University of Amsterdam (ACTA), Netherlands, received the Prize for Basic Research in Implant Dentistry at the EAO Annual Congress in September 2014 in Rome.
Yuelian Liu, who collaborated on this project with researchers from the University of Berne, Switzerland, and Zhejiang University, China, prevailed over a large number of excellent international competitors, and was excited to receive the prize. “It is wonderful to see that our research and the hard work has been recognized in this way”, she said after the awards ceremony.
Developing an alternative to autogenous bone grafts
When presenting her research at the Basic Research Session of the EAO Congress, Yuelian Liu explained that the aim of her research was “to develop osteoinductive bone substitutes that can be used as an alternative to autogenous grafts in bone regeneration”.
To achieve this goal, she and her collaborators have developed a Biomimetic Calcium Phosphate (BioCaP) with two different delivery methods for the growth factor BMP-2: an internally incorporated and a coating-incorporated method.
They compared the two delivery methods with each other as well as with other materials and delivery methods, first in a subcutaneous ectopic bone induction model in rats, and then in a second study in critical-sized defects in sheep.
Incorporation of BMP-2 in biomaterial better than adsorption
In the rat model, in which the materials were implanted subcutaneously, the volume of bone, bone marrow, and blood vessel was significantly higher in samples in which BMP-2 was incorporated internally or in the coating, compared to granules with absorbed growth factor.
It is known that the adsorption of BMP-2 on materials is always associated with a high-dose burst release, which results in a poor osteoinduction – an effect that was also observed by Yuelian Liu and her co-workers in the rat model. The incorporation of BMP-2 in the biomaterials leads to visibly better bone formation than adsorption.
“Autogenous bone transplantation will not be needed anymore”
In the sheep model, both delivery methods accelerated bone formation and showed efficacy equal to that of autologous bone. In addition, it was observed that BioCaP with the coating-incorporated BMP-2 was degraded more slowly.
Based on these findings, the researchers concluded that both delivery methods of BMP-2 enhance bone formation. “Benefiting from these two delivery modes, BioCaP can be a promising alternative to autografts for bone regeneration”, said Yuelian Liu stated in her presentation.
“An osteoinductive BioCaP bone substitute”, she added, “is ideal for bone tissue augmentation and critical-sized bone-defect repair. Autologous bone transplantation will not be needed anymore.”
“At home” in the Osteology Foundation
Yuelian Liu also thanked the Osteology Foundation for its support of the project. Immediately following the awards ceremony, she rushed to the Osteology booth at the exhibition to share her excitement about the prize. “I feel at home in the Osteology Foundation”, Yuelian Liu said.
Among the first to congratulate her was Reinhard Gruber, Board Member of the Osteology Foundation. “The competition for the Basic Research Prize was very tough”, he said, “and it was really not easy to win. The researchers have done great work, and the study definitely deserves to win”.
- Liu Y, et al.: Biomimetic coatings for bone tissue engineering of critical-sized defects. J R Soc Interface 2010; 7 Suppl. 5: S631-47.
- Wu G, et al.: Functionalization of deproteinized bovine bone with a coating-incorporated depot of BMP-2 renders the material efficiently osteoinductive and suppresses foreign-body reactivity. Bone 2011: 49: 1323-30.
- Hunziker EB, et al.: Osseointegration: The slow delivery of BMP-2 enhances osteoinductivity. Bone 2012; 51; 98-106.
- Liu T, et al.: Deproteinized bovine bone functionalized with the slow delivery of BMP-2 for the repair of critical-sized bonedefects in sheep. Bone 2013; 56: 110-18.