The application of nanogenerators and piezoelectricity in osteogenesis

Abstract

Bone is a complex organ possessing both physicomechanical and bioelectrochemical properties. In the view of Wolff's Law, bone can respond to mechanical loading and is subsequently reinforced in the areas of stress. Piezoelectricity is one of several mechanical responses of the bone matrix that allows osteocytes, osteoblasts, osteoclasts, and osteoprogenitors to react to changes in their environment. The present review details how osteocytes convert external mechanical stimuli into internal bioelectrical signals and the induction of intercellular cytokines from the standpoint of piezoelectricity. In addition, this review introduces piezoelectric and triboelectric materials used as self-powered electrical generators to promote osteogenic proliferation and differentiation due to their electromechanical properties, which could promote the development of promising applications in tissue engineering and bone regeneration. ARTICLE HISTORY

Nanostructured Biomaterials for Bone Regeneration

“…Piezoelectricity is observed when a mechanical deformation causes the formation of a net dipole moment and subsequent Maeder et al, 2004;Boccaccini and Blaker, 2005;Opoku et al, 2015;Panda and Sahoo, 2015;Rocca et al, 2015;Fernandes et al, 2016;Zhang et al, 2016;Bramhill et al, 2017;Damaraju et al, 2017;Ribeiro et al, 2017;Tajbakhsh and Hajiali, 2017;Ehterami et al, 2018;Kao et al, 2019 Piezoelectric Non-degradability Questions/concerns regarding biocompatibility and long-term safety Otero et al, 2012;Bitounis et al, 2013;Liu et al, 2013;Nurunnabi et al, 2015;Sridhar et al, 2015;Assaf et al, 2017;Kim J.W. et al, 2017;Silva et al, 2017;Wang et al, 2017;Zhou et al, 2017;Chan et al, 2018; Häfeli et al, 2009;Huang et al, 2009;Bock et al, 2010;Wu et al, 2010b;Wu Y. et al, 2010;Wei et al, 2011;Zhu et al, 2011;Panseri et al, 2012;Tampieri et al, 2012;Alarifi et al, 2014;Singh R.K. et al, 2014;Shen et al, 2015;Ribeiro et al, 2016;Yun et al, 2016 polarization of the material (Tichý, 2010).…”

“…Typically fabricated either as films, rods, or tubes/fibers (Ribeiro et al, 2015b), they exhibit sound mechanical properties, including superior strength and impact resistance when compared to inorganic materials. Biocompatibility, piezoelectric activity, and significant osteogenic capacity have also been demonstrated both in vitro and in vivo (Zhang et al, 2016;Damaraju et al, 2017;Ribeiro et al, 2017;Kao et al, 2019). Among these, PVDF [poly(vinylidene fluoride)] and its copolymers, PLLA, and PHBV (poly-3-hydroxybutyrate-3-hydroxy valerate) are the most studied.…”

“…Nanopiezoceramic materials investigated for bone regeneration applications include barium titanate (BT), boron nitride (BN), and zinc oxide (ZnO). While these materials possess a high piezoelectric coefficient, some of them display lower biocompatibility at high doses, which can represent a major limitation for their use in tissue engineering applications ( Maeder et al, 2004 ; Opoku et al, 2015 ; Panda and Sahoo, 2015 ; Kao et al, 2019 ). Nevertheless, each of these piezoceramics has shown osteoinductive capabilities in vitro , supporting their use in the development of bone regenerative biomaterials, where they are often incorporated in a variety of ways into 3D scaffolds in order to impart piezoelectric characteristics to augment bone formation.…”

“…For example, BT nanoparticles have been shown to enhance the osteogenic differentiation of MSCs, and osteoblastic cells demonstrated superior adhesion, proliferation, and migration into the pores of scaffolds comprised of BT, while BN nanotubes (BNNTs) demonstrate high protein adsorption ability and promotion of enhanced MSC attachment, proliferation, and osteogenic differentiation ( Rocca et al, 2015 ; Li X. et al, 2016 ; Tajbakhsh and Hajiali, 2017 ; Ehterami et al, 2018 ). Finally, the incorporation of ZnO nanoparticles has proven capable of enhancing both the bioactivity and even the mechanical properties of such composite materials ( Shalumon et al, 2011 ; Feng et al, 2014 ; Kao et al, 2019 ).…”

Respiration‐driven triboelectric nanogenerators for biomedical applications

“…Stimulation and activation of certain cells, organs and systems in human body by low-dose electricity have long been demonstrated. [102][103][104][105][106][107] The periodic biphasic pulselike electrical signals generated from TENG were also found capable of modulating cell activities, such as accelerating proliferation, adjusting orientation, stimulating motility, and improving differentiation. 32,108 Therefore, the all-time accessible respiration energy guarantees a continuous operation of TENG to provide consistent electric pulses for therapeutic electrostimulation.…”