Nanotubes Functionalized with BMP2 Knuckle Peptide Improve the Osseointegration of Titanium Implants in Rabbits.
To determine the effects of surface modification on implant osseointegration in vivo, we first immobilized polydopamine onto 70-nm diameter TiO2 nanotubes as an intermediate layer, and then conjugated a 21 amino acid peptide sequence (the so-called "knuckle peptide") of bone morphogenetic protein-2 (BMP-2) onto the nanotubes created by electrochemical anodization. We inserted these implants into the tibiae of rabbits and measured the gene expression and bone formation around them. The successful fabrication of BMP-2 knuckle peptide was confirmed by contact angle measurement, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The histological features and the amount of bone fluorescence around the implants on non-decalcified sections were investigated at 3, 5, 8, and 12 weeks after implantation using traditional light and fluorescence microscopy, and the gene expression of alkaline phosphatase, osterix, collagen-I, and tartrate-resistant acid phosphatase was examined by real-time PCR at 1, 2, 3, 4, and 5 weeks after implantation. The results demonstrated a significant increase in bone-implant contact, quantity of fluorescence, and gene expression levels of the bone attached to implants with immobilized BMP-2 knuckle peptide compared with the other two control groups. In conclusion, the surface functionalization of TiO2 nanotubes with BMP-2 knuckle peptide was beneficial for osseointegration and this approach could be further developed to improve Ti-based implants for various applications.
Yuanping
Y
Ma
Zhenting
Z
Zhang
Yiran
Y
Liu
Hongyi
H
Li
Na
N
Wang
Wenwen
W
Liu
Wenjun
W
Li
Lingling
L
Jin
Jinshu
J
Wang
Su
S
Chen
D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000737:chemistry / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000494:pharmacology*; D043942:Nanotubes; D016348:Osseointegration / Q000187:drug effects*; D010006:Osteoblasts / Q000187:drug effects / Q000502:physiology; D010012:Osteogenesis / Q000187:drug effects; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D019736:Prostheses and Implants; D011817:Rabbits; D013499:Surface Properties; D013977:Tibia / Q000601:surgery; D014025:Titanium
D055396:Bone Morphogenetic Protein 2; D020099:Coated Materials, Biocompatible; D010446:Peptide Fragments; C009495:titanium dioxide; D014025:Titanium