Post-surgery infections are considered the most challenging complication in the orthopedic and dental field.

Calcium phosphates are of great interest for biomedical applications such as bone tissue engineering, bone fillers, drug and gene delivery, and orthopedic and dental implant coating. Here, the first electrochemically driven coating of medical implants using hydroxyapatite (HAp) nanoparticles (NPs) as building blocks is reported. This uncommon combination offers a simple, straightforward, and economic process with well controllable, pure, single‐phase HAp. Crystalline, pure HAp NPs are formed by precipitation reaction. The HAp NPs are dispersed by either citrate or poly(acrylic acid) to form pH sensitive dispersion. Controllable and homogeneous coating of medical implants is accomplished by altering the pH on the surface upon applying either a constant potential or current. The process involves protonation of the carboxylic acid moieties, which causes the irreversible aggregation of the HAp NPs due to diminishing the repulsive forces between the particles. Deposition is further demonstrated on a commercial dental implant. Moreover, the adhesion of the coating satisfies FDA and international standard requirements. A porous interconnected network of bone‐like HAp layer is formed during soaking in a simulated body fluid for 30 d and is similar to bone generation, and it therefore holds promise for further in vivo testing.

Overcoming postimplantation infections is considered as a major challenge in medicine, where continuous efforts have been invested in developing bactericidal functional coatings. The synergic combination of hydroxyapatite (HAp) and ZnO holds beneficial properties, such as excellent bioactivity that is reinforced with its antibacterial nature. Here, highly phase tunable pure ZnO-HAp nanocomposite coatings were fabricated via electrophoretic deposition. HAp and ZnO nanoparticles were synthesized separately, dispersed simultaneously, and coelectrophoretically deposited onto a titanium substrate. By manipulating the deposition potentials, a single-stage graded-coating of ZnO-HAp was successfully obtained. In addition, by controlling the composition of the nanomaterials in the dispersions, we managed to precisely tailor composite coatings with a dictated phase ratio between ZnO and HAp. In vitro studies, bioactivity, cytotoxicity, and antibacterial tests, showed excellent performance by enhancing the mineralization of the coating and improving cells proliferation while successfully eradicating E. coli bacteria.

Hybrid electrodes, which are made of a physical (electrical double layer) storage component and a chemical (battery-type) material, have shown great potential in battery–supercapacitor hybrid (BSH) devices. Here, we present an approach which is based on electrophoretic deposition (EPD) as a means of assembling a binder-free, high-performance BSH device. Ketjenblack (KB) used as the physical storage material and NiCo2O4 (NCO) as the chemical storage compound were dispersed in the presence of Ni2+. The latter assisted in positively charging the surface of both materials and thus resulted in similar deposition rates by EPD on nickel foam (NF). This enabled us to nicely control the NCO to KB ratio in the hybrid electrode and optimize its performance. In this binder-free hybrid electrode, the KB chains served as a fast electron path providing high conductivity for the NCO electroactive material. More importantly, the KB chains could remain in contact with NCO coping with the mechanical stress during the electrochemical reaction. As a result, the optimized hybrid electrode showed high specific capacity (460 C g–1 at 1 A g–1) and excellent cycling performance (82.5% retention after 15 000 cycles). The BSH device was assembled with the hybrid electrode (NF/NCO-KB) as positive and activated carbon as negative electrodes, and exhibited high energy density of 53.0 Wh kg–1 at power density of 746 W kg–1 and outstanding cycling performance of 88.6% retention after 10 000 cycles.

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