Biomedical Engineering Reference
In-Depth Information
(A)
(B)
(C)
FIGURE 17.9
ECM mineralization on different samples after 2 weeks culturing of MSCs. (A) Flat Ti control, (B) 25 nm NTs,
and (C) 80 nm NTs.
Reprinted with permission from Ref.
[2]
.
BIC
100
80
60
*
*
**
*
*
Machined
30 nm
70 nm
100 nm
**
**
**
**
**
**
40
20
0
**
*
*
**
Week 3
Week 5
Week 8
Time after operation
FIGURE 17.10
Values of BIC for all implant surfaces at 3, 5 and 8 weeks after implantation. Asterisk (*) shows significant
difference in comparison with machined implant (
0.05). Double asterisks (**) show a significant
difference in comparison with all other groups in experiment (
P
,
P
,
0.05).
Reprinted with permission from Ref.
[16]
.
compared to the pristine Ti controls
[15]
. The bone morphogenetic protein 2 (BMP-2) expression
within the 50, 70, and 100 nm groups is statistically different compared to the control group. In
addition, a significant difference is found from the osteocalcin expression in the 70 nm group.
Wang et al.
[16]
have investigated the effects of the NTs with different diameters of 30, 70, and
100 nm on the biological attachment mechanism of implants to bone in vivo. When comparing to
machined Ti implants, a significant increase in BIC (
Figure 17.10
) and gene expression level is
found in the bone attached to implants with the NTs, especially with the 70 nm diameter ones. The
evidence demonstrates the strong ability of the NTs to induce better osseointegration, and the NTs
with a size of about 70 nm may be the optimal ones for osseointegration.
17.5
Drug-loading NTs for better bioactivity and antibacterial properties
The nanotubular structure of the NTs provide space for drug loading, thereby opening the possibil-
ity of endowing the implant surface with extra properties by loading targeted agents. Desai's group
