Electrophoretic deposition (EPD) is attracting increasing attention as an effective technique for the processing of biomaterials, specifically bioactive coatings and biomedical nanostructures. The well-known advantages of EPD for the production of a wide range of microstructures and nanostructures as well as unique and complex material combinations are being exploited, starting from well-dispersed suspensions of biomaterials in particulate form (microsized and nanoscale particles, nanotubes, nanoplatelets). EPD of biological entities such as enzymes, bacteria and cells is also being investigated. The review presents a comprehensive summary and discussion of relevant recent work on EPD describing the specific application of the technique in the processing of several biomaterials, focusing on (i) conventional bioactive (inorganic) coatings, e.g. hydroxyapatite or bioactive glass coatings on orthopaedic implants, and (ii) biomedical nanostructures, including biopolymer–ceramic nanocomposites, carbon nanotube coatings, tissue engineering scaffolds, deposition of proteins and other biological entities for sensors and advanced functional coatings. It is the intention to inform the reader on how EPD has become an important tool in advanced biomaterials processing, as a convenient alternative to conventional methods, and to present the potential of the technique to manipulate and control the deposition of a range of nanomaterials of interest in the biomedical and biotechnology fields.

https://royalsocietypublishing.org/doi/pdf/10.1098/rsif.2010.0156.focus

Electrophoretic deposition of biomaterials

https://hal.archives-ouvertes.fr/hal-00835892/document

Accurate characterization of pure silicon-substituted hydroxyapatite powders synthesized by a new precipitation route

In-vitro bioactivity, biocorrosion and antibacterial activity of silicon integrated hydroxyapatite/chitosan composite coating on 316 L stainless steel implants.

Hydroxyapatite powders were prepared by a chemical precipitation method and electrophoretically deposited on pure Ti surgical substrates. The powders were suspended in dimethylformamide (DMF). The zeta potential, electromobility and the conductivity of the HA suspension was characterized at various pH values to identify the most stable dispersion conditions. The effect of applied voltage and deposition time on deposition rate, deposition thickness and coating morphology were studied. The coating morphology and composition were characterized by scanning electron microscopy (SEM). The crystalline phase of HA before and after electrophoretic deposition was examined using X- ray diffraction (XRD). Transition electron microscope (TEM) indicated that HA consisted of needle-shaped crystallites.

Electrophoretic deposition of hydroxyapatite coatings on titanium from dimethylformamide suspensions

Aerosol deposition of silicon-substituted hydroxyapatite coatings for biomedical applications

Silicon Substituted Hydroxyapatite (Si-HA) coatings were prepared on titanium substrates by electrophoretic deposition (EPD). The stability of Si-HA suspension in n-butanol and chloroform mixture has been studied by electricity conductivity and sedimentation test. The microstructure, shear strength and bioactivity in vitro has been tested. The stability of Si-HA suspension containing n-butanol and chloroform mixture as medium is better than that of pure n-butanol as medium. The good adhesion of the particles with the substrate and good cohesion between the particles were obtained in n-butanol and chloroform mixture. Adding triethanolamine (TEA) as additive into the suspension is in favor of the formation of uniform and compact Si-HA coatings on the titanium substrates by EPD. The shear strength of the coatings can reach 20.43 MPa after sintering at 700 °C for 2 h, when the volume ratio of n-butanol: chloroform is 2:1 and the concentration of TEA is 15 ml/L. Titanium substrates etched in H2O2/NH3 solution help to improve the shear strength of the coatings. After immersion in simulated body fluid for 7 days, Si-HA coatings have the ability to induce the bone-like apatite formation.

Rong Fang Liu

Papers

Electrophoretic deposition of silicon substituted hydroxyapatite coatings from n-butanol–chloroform mixture