Page 262 - Advances in Biomechanics and Tissue Regeneration

13.4 MAGNETIC, MAGNETOMECHANIC, AND MAGNETOELECTRIC MATERIALS 259

TABLE 13.1 Cells, Applied Stimuli (Electrical and/or Mechanical) and Material Used for Specific Representative Biomedical
Applications—cont’d
Stimuli
Tissue Cells Electric Mechanical Material Reference
Rat bone marrow stromal cells 0.35V/cm for 4h PPy films [108]

human adipose-derived 200μA (DC) for PPY/PCL scaffold [109]
mesenchymal stem cells 4h/day
BMSC and MC3T3-E1 500mV, 1kHz Self-doped sulfonated polyaniline-based [110]
interdigitated electrodes
SaOS-2 osteoblast-like cell 20–60mV Twice a day for 10s P(VDF-TrFE)/BNNTs film [111]
culture
Wound NIH 3T3 cells (mouse embryo Intermittent deformation of Polyurethane/PVDF fibers [112]
healing fibroblasts) 8% at 0.5Hz for 24h
Skin fibroblasts 100mV/mm, PPy on the surface of polyethylene [113]
10s stimulation terephthalate (PET) substrates
within a period of
1200s or
300s stimulation
within a period of
600s
Blood Human umbilical vein 400mV/cm PANI-coated PCL fibers [114]
vessels endothelial cells 30min/day

high electroactive properties, including piezoelectric, pyroelectric, and ferroelectric properties [64]. Materials com-
posed by these polymers develop voltage when a mechanical stress is applied, thus promoting the adhesion and pro-
liferation of different types of cells [5].
PVDF, in particular, is a semicrystalline biocompatible polymer possessing high mechanical strength, thermal sta-
bility, chemical resistance, and hydrophobic properties [41, 45, 65, 66]. It is biocompatible, being, therefore, a promising
material for biomedical applications, which showed to influence cellular response when both the phase and polariza-
tion of the material were evaluated [65, 67]. Thus the polarization of PVDF influenced the adsorption of fibronectin,
being, therefore, an important factor to consider in further studies. The influence of polymer surface charge on MC3T3-
E1 preosteoblasts cultivated under static and dynamic conditions was also studied [41], and it was concluded that
positively charged PVDF films promote higher osteoblast adhesion and proliferation, which further increased under
dynamic stimulation. The application of this polymer is not only confined to academic research. Due to its stability,
strength, and biocompatibility, PVDF has been approved by the FDA, and it has been used in surgical mesh form for
human implants and surgery [68].

13.4 MAGNETIC, MAGNETOMECHANIC, AND MAGNETOELECTRIC MATERIALS

Another strategy able to induce the mechanotransduction effect on cells is the application of magnetic stimuli on
magnetic responsive materials. The use of magnetic materials in biomedicine has been widely explored; many
applications are based on the possibility of preparing nanoscaled magnets. These materials possess important
properties that have allowed applications in different medical areas including neurology [115],ophthalmology
[116],dentistry [117],and cardiology [118]. In fact the size of these magnetic nanomaterials has been playing a
key role, imparting unique properties to the material. Specific interactions with cells, viruses, and proteins, which

II. MECHANOBIOLOGY AND TISSUE REGENERATION