Electrovectorial effect of polarized hydroxyapatite on quasi-epitaxial growth at nano-interfaces

Manipulation of bacterial adhesion and proliferation by surface charges of electrically polarized hydroxyapatite

“…Ueshima et al demonstrated the direct observation of Ca distribution on the N-and P-surfaces in SBF using confocal laser scanning microscopy, indicating a higher concentration of Ca near the N-surface and a lower concentration of Ca near the P-surface. 3 In order to clarify proliferation mechanisms, further study is needed relative to the interaction between the stimulus caused by the electrostatic force and bacterial activation.…”

“…1 In vitro experiments have shown that apatite overgrowth is accelerated on the N-surface while it is decelerated on the P-surface of HAp ceramics in a simulated body fluid (SBF). 2,3 Cultivation experiments of osteoblastlike cells (MC3T3-E1 cells) on polarized HAp surfaces have demonstrated that both cell adhesion and the precipitation of porous apatite tissues are accelerated on the N-surface and decelerated on the P-surface compared to that on the 0-surface. 4 The present research concerning bacterial adhesion is expected to have a great significance in a large variety of fields with regard to different aspects of nature and human life, such as environmental science and the biomedical field.…”

Formation of calcite thin films by cooperation of polyacrylic acid and self-generating electric field due to aligned dipoles of polarized substrates

“…These powders were calcined at 850 • C for 2 h, and then compressed into pellets 10 mm in diameter and 0.7 mm thickness. Dense HAp ceramic substrates were obtained by sintering the HAp pellets at 1250 • C for 2 h under a water vapor steam in order not to dehydrate lattice OH − ions from the HAp structure [24]. The crushed powders of sintered pellets were analyzed by X-ray diffraction (XRD) and Fourier transform infrared analysis (FTIR).…”

“…Recently, we have indicated that the hydroxyapatite (HAp) electret had a strong electric field at its surface due to the aligned dipoles throughout its structure and that this electric field acted on only a given local spot and controlled the crystallization of hydroxyapatite. In addition, we have also suggested that a dipole-induced electric field was expected to influence crystallization more than the electric field by the localized surface charges on organic membranes [22][23][24]. An electret is a material that has a permanent macroscopic electric field at its surface; this field can arise form a net orientation of polar groups in the material, or form a net, macroscopic electrostatic charge on the material, and parallels a magnet on magnetism.…”

Change in the morphology of hydroxyapatite nanocrystals in the presence of bioaffinitive polymeric species under the application of electrical field

“…As for the application of the external electrical field to HAP ceramics, one of the directions is poling treatment to improve the bioaffinity, mainly by using cell cultivation methods [3,4].…”