Biomedical Engineering Reference
In-Depth Information
can influence bone cell (osteoblast) attachment
[21-24]
. There are three major ways
[25]
to modify
titanium implant surfaces, which are:
1.
morphological
2.
physicochemical
3.
biochemical.
6.2.1
Morphological Modification of Titanium Surface
Alteration in titanium surface morphology has been used to influence osteoblast attachment, differ-
entiation, proliferation, and migration. The most prominent fabrication methods to produce macro-,
micro-, and nanoscale surface topographies include mechanical methods like plasma spraying
[26,27]
,
particle blasting
[28]
, micromachining
[29-31]
, grinding, polishing
[32]
, and chemical methods like
acid etching
[33,34]
, alkali etching
[35,36]
, and anodization
[37,38]
(
Table 6.1
). Electrochemical
micromachining of titanium through laser-patterned oxide film has also been reported
[39,40]
.
6.2.2
Physicochemical Modification of Titanium Surface
Physicochemical characteristics like surface-free energy, surface charge, chemical composition, and
surface wettability are fundamental parameters that influence osteoblast attachment. Physicochemical
properties of titanium substrates can be altered primarily through manufacturing processes
[41,42]
.
This is often combined with biochemical modification of titanium surface. This recent trend in tita-
nium surface engineering is aimed to design biologically inspired surfaces that have the potential
to mimic natural bone architecture and stimulate osteoblast adhesion, differentiation, proliferation,
Table 6.1
Titanium Surface Modification Techniques
Type of Surface Modification
Methods
Morphological and physicochemical
modification
l
Plasma spraying
l
Particle blasting
l
Micromachining
l
Grinding
l
Polishing
l
Chemical methods like:
l
Acid etching
l
Alkali etching
l
Anodization
Biochemical modification
l
Osteoinductive biomolecular cues (cell-adhesive proteins and
growth factors like BMP-2)
l
Microscale and nanoscale coating of HA/calcium phosphate/
alumina coatings with bioactive molecular cues, osteoinductive
growth factors, and antibacterial drugs
l
Organic nanoscale SAMs
l
Bioactive, biodegradable hydrogels
l
Antibacterial agents or antibacterial drug delivery directly from
titanium surface