Bone Mechanical Stimulation with Piezoelectric Materials - Natural Polymers, Biopolymers, Biomaterials, and Their Composites, Blends, and IPNs - page 291

Figure 9. Microphotograph of decalcified sections, DAB immunohistochemistry staining for
osteocalcin, respectively. Picture shows A3 areas of actuator (on the left) and static control (on the
right), evidencing more extensive osteocalcin labelling around actuator. Scale bar represents 20 µm.

The results are very clear in evidencing qualitative and quantitative statistically
significant differences when comparing static and actuated films but it would be nec-
essary to enlarge the animal study. However, considering the limitations evidenced
by the material itself, we feel this could be ethically questionable unless alternative
electrodes and materials with piezoelectric properties are developed.

CoNClusioN
The huge potential of piezoelectric materials as a mean to produce direct mechanical
stimulation lies also on the possibility of producing stimuli at a high range of frequen-
cies and in multiple combinations, in order to avoid routine loading accommodation.
The use of piezoelectric material based actuators to produce bone mechanical
stimulation seems promising in theory and the present in vitro and in vivo studies were
a first step towards the validation of the concept.
Taking into account what is already known on bone physiology, and particularly,
bone mechanotransduction, developing materials for bone regeneration that are able
to respect bone electrophysiology seems like a logical move towards better clinical
results whenever treatment of bone defects is being considered.

KeyWords

• actuator device

• Nitric oxide

• osteoblasts

• osteocytes

• Piezoelectric effect

• Polymeric piezoelectric films