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A new piezoelectric actuator induces bone formation in vivo: a preliminary study.

Reis J, Frias C, Canto e Castro C, Botelho ML, Marques AT, Simões JA, Capela e Silva F, Potes J - J. Biomed. Biotechnol. (2012)

Bottom Line: After one-month implantation, total bone area and new bone area were significantly higher around actuators when compared to static controls.Bone deposition rate was also significantly higher in the mechanically stimulated areas.The present in vivo study suggests that piezoelectric materials and the converse piezoelectric effect may be used to effectively stimulate bone growth.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Medicina Veterinária, Universidade de Évora, 7002-554 Évora, Portugal.

ABSTRACT
This in vivo study presents the preliminary results of the use of a novel piezoelectric actuator for orthopedic application. The innovative use of the converse piezoelectric effect to mechanically stimulate bone was achieved with polyvinylidene fluoride actuators implanted in osteotomy cuts in sheep femur and tibia. The biological response around the osteotomies was assessed through histology and histomorphometry in nondecalcified sections and histochemistry and immunohistochemistry in decalcified sections, namely, through Masson's trichrome, and labeling of osteopontin, proliferating cell nuclear antigen, and tartrate-resistant acid phosphatase. After one-month implantation, total bone area and new bone area were significantly higher around actuators when compared to static controls. Bone deposition rate was also significantly higher in the mechanically stimulated areas. In these areas, osteopontin increased expression was observed. The present in vivo study suggests that piezoelectric materials and the converse piezoelectric effect may be used to effectively stimulate bone growth.

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Low-magnification picture of histological section where it is evident the fibrous tissue around the implant (arrows). Scale bar represents 4 mm.
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fig3: Low-magnification picture of histological section where it is evident the fibrous tissue around the implant (arrows). Scale bar represents 4 mm.

Mentions: Specimens were dehydrated through an ascending ethanol series. Soft tissues (local lymph nodes and samples of the fibrous capsule surrounding the implants) were routinely processed and embedded in paraffin. Undecalcified bone samples of each of the implants were included in resin (Technovit 9100, Heraeus Kulzer, Germany) according to the manufacturer's instructions and 80 μm thick sections cut with a saw microtome (Leica 1600, Germany) parallel to the piezoelectric film long axis. A minimum of five sections of each resin block was cut. Sections were then appropriately processed for routine staining (Giemsa Eosin), mounted for fluorescence microscopy. The prepared slides were evaluated qualitatively. For histomorphometric studies, the interface between the bone and implant was divided in four distinct areas: Z1, Z2, Z3, and Z4, from cortical towards bone surrounding the free extremity of the piezoelectric film (Figure 1(b)). Pictures were taken from the bone surrounding both sides of the film in areas Z1 to Z3 and Z4, using a 40x magnification (Figure 3).


A new piezoelectric actuator induces bone formation in vivo: a preliminary study.

Reis J, Frias C, Canto e Castro C, Botelho ML, Marques AT, Simões JA, Capela e Silva F, Potes J - J. Biomed. Biotechnol. (2012)

Low-magnification picture of histological section where it is evident the fibrous tissue around the implant (arrows). Scale bar represents 4 mm.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3369535&req=5

fig3: Low-magnification picture of histological section where it is evident the fibrous tissue around the implant (arrows). Scale bar represents 4 mm.
Mentions: Specimens were dehydrated through an ascending ethanol series. Soft tissues (local lymph nodes and samples of the fibrous capsule surrounding the implants) were routinely processed and embedded in paraffin. Undecalcified bone samples of each of the implants were included in resin (Technovit 9100, Heraeus Kulzer, Germany) according to the manufacturer's instructions and 80 μm thick sections cut with a saw microtome (Leica 1600, Germany) parallel to the piezoelectric film long axis. A minimum of five sections of each resin block was cut. Sections were then appropriately processed for routine staining (Giemsa Eosin), mounted for fluorescence microscopy. The prepared slides were evaluated qualitatively. For histomorphometric studies, the interface between the bone and implant was divided in four distinct areas: Z1, Z2, Z3, and Z4, from cortical towards bone surrounding the free extremity of the piezoelectric film (Figure 1(b)). Pictures were taken from the bone surrounding both sides of the film in areas Z1 to Z3 and Z4, using a 40x magnification (Figure 3).

Bottom Line: After one-month implantation, total bone area and new bone area were significantly higher around actuators when compared to static controls.Bone deposition rate was also significantly higher in the mechanically stimulated areas.The present in vivo study suggests that piezoelectric materials and the converse piezoelectric effect may be used to effectively stimulate bone growth.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Medicina Veterinária, Universidade de Évora, 7002-554 Évora, Portugal.

ABSTRACT
This in vivo study presents the preliminary results of the use of a novel piezoelectric actuator for orthopedic application. The innovative use of the converse piezoelectric effect to mechanically stimulate bone was achieved with polyvinylidene fluoride actuators implanted in osteotomy cuts in sheep femur and tibia. The biological response around the osteotomies was assessed through histology and histomorphometry in nondecalcified sections and histochemistry and immunohistochemistry in decalcified sections, namely, through Masson's trichrome, and labeling of osteopontin, proliferating cell nuclear antigen, and tartrate-resistant acid phosphatase. After one-month implantation, total bone area and new bone area were significantly higher around actuators when compared to static controls. Bone deposition rate was also significantly higher in the mechanically stimulated areas. In these areas, osteopontin increased expression was observed. The present in vivo study suggests that piezoelectric materials and the converse piezoelectric effect may be used to effectively stimulate bone growth.

Show MeSH
Related in: MedlinePlus