Tailoring the biological response of zirconium implants using zirconia bioceramic coatings: A systematic review

Characterization and investigation of biological properties of silver nanoparticle-doped hydroxyapatite-based surfaces on zirconium

The infections leading to failed implants can be controlled mainly by metal and metal oxide-based nanoparticles. In this work, the randomly distributed AgNPs-doped onto hydroxyapatite-based surfaces were produced on zirconium by micro arc oxidation (MAO) and electrochemical deposition processes. The surfaces were characterized by XRD, SEM, EDX mapping and EDX area and contact angle goniometer. AgNPs-doped MAO surfaces, which is beneficial for bone tissue growth exhibited hydrophilic behaviors. The bioactivity of the AgNPs-doped MAO surfaces is improved compared to bare Zr substrate under SBF conditions. Importantly, the AgNPs-doped MAO surfaces exhibited antimicrobial activity for E. coli and S. aureus compared to control samples.

Injectable, Self-Healing and Multiple Responsive Histamine Modified Hyaluronic Acid Hydrogels with Potentialities in Drug Delivery, Antibacterial and Tissue Engineering

Hydrogels are 3D network structures composed of physically or chemically crosslinked, hydrophilic molecules. Compared with conventional hydrogels with static and permanent network structures, injectable and responsive hydrogels generated from dynamic networks, have attracted increasing attention from various disciplines due to their wide-ranging applications in tissue engineering, drug delivery, soft robotics, etc. Herein, an injectable self-healing and multiple-responsive hyaluronic acid (HA)- histamine (His)/metal hydrogel is developed by modifying His onto HA and the subsequent, dynamic coordination between imidazole and metal ions. The pH-responsive and mechanical behaviors exhibited by the HA-His/metal hydrogels are tunable with the kinds and the concentrations of metal ions. The HA-His/Zr⁴⁺ hydrogels demonstrate a moldable capability at a neutral pH and a multi-stimulus-responsive capability when exposed to a weak alkaline environment and hyaluronidase, which inhibits bacterial growth and biofilm formation. Biocompatibilities and accelerated wound healing are demonstrated in vitro and in vivo and are thoroughly investigated and well characterized. The HA-His/Zr⁴⁺ hydrogel has great potential in various biomedical applications, such as pH- and hyaluronidase-responsive sustained release, antibacterial, and implantable materials for tissue engineering.

Plasma Electrolytic Oxidation Ceramic Coatings on Zirconium (Zr) and Zr-Alloys: Part-II: Properties and Applications

A plasma electrolytic oxidation (PEO) is an electrochemical and eco-friendly process where the surface features of the metal substrate are changed remarkably by electrochemical reactions accompanied by plasma micro-discharges. A stiff, adhesive, and conformal oxide layer on the Zr and Zr-alloy substrates can be formed by applying the PEO process. The review describes recent progress on various applications and functionality of PEO coatings in light of increasing industrial, medical, and optoelectronic demands for the production of advanced coatings. Besides, it explains how the PEO coating can address concerns about employing protective and long-lasting coatings with a remarkable biocompatibility and a broad excitation and absorption range of photoluminescence. A general overview of the process parameters of coatings is provided, accompanied by some information related to the biological conditions, under which, coatings are expected to function. The focus is to explain how the biocompatibility of coatings can be improved by tailoring the coating process. After that, corrosion and wear performance of PEO coatings are described in light of recognizing parameters that lead to the formation of coatings with outstanding performance in extreme loading conditions and corrosive environments. Finally, a future outlook and suggested research areas are outlined. The emerging applications derived from paramount features of the coating are considered in light of practical properties of coatings in areas including biocompatibility and bioactivity, corrosion and wear protection, and photoluminescence of coatings