Phenolic Modified Ceramic Coating on Biodegradable Mg Alloy: The Improved Corrosion Resistance and Osteoblast-Like Cell Activity

Abstract

Magnesium alloys have great potential for developing orthopedic implants due to their biodegradability and mechanical properties, but the rapid corrosion rate of the currently-available alloys limits their clinical applications. To increase the corrosion resistance of the substrate, a protective ceramic coating is constructed by a micro-arc oxidation (MAO) process on ZK60 magnesium alloy. The porous ceramic coating is mainly composed of magnesium oxide and magnesium silicate, and the results from cell cultures show it can stimulate osteoblastic cell growth and proliferation. Moreover, gallic acid, a phenolic compound, was successfully introduced onto the MAO coating by grafting on hydrated oxide and chelating with magnesium ions. The gallic acid and rough surface of MAO altered the cell attachment behavior, making it difficult for fibroblasts to adhere to the MAO coating. The viability tests showed that gallic acid could suppress fibroblast growth and stimulate osteoblastic cell proliferation. Overall, the porous MAO coating combined with gallic acid offered a novel strategy for increasing osteocompatibility.

Porous Alumina Ceramics Obtained by Particles Self-Assembly Combing Freeze Drying Method

“…Porous ceramics have attracted considerable attention for their excellent thermal shock resistance, low density, low thermal conductivity, high refractoriness, high permeability, high specific surface area, constant filter quality and longer lifetime [1,2,3],thus they are extensively employed in industrial applications including gas filters [4], fluid filtration, sensors, bioreactors, catalytic substrates, bone substitute, insulating lining, random materials, light weight components [5] and so on. All those outstanding performances are closely related to the size, distribution and morphology of the pores, as well as their interconnectivity.…”

Development of a Novel Degradation-Controlled Magnesium-Based Regeneration Membrane for Future Guided Bone Regeneration (GBR) Therapy

“…Moreover, the significant change in current slope suggests that the ARRm-H380 microstructures had the passivation behavior, which indicates that a protective oxide film formed on the surface [24]. This protective oxide film can inhibit aggressive ions from penetrating and reacting with the inner metal surface, thereby reducing the risk of forming hydrogen cavities and releasing highly-concentrated alkali ions [25]. Both the cathodic and anodic current densities were significantly reduced in the presence of the MgF 2 coating; in particular, ARRm-H380-F24 h offered the highest corrosion resistance and lowest anodic current density, and featured a wide passivation window (E break − E corr ), indicating that the solid-solution heat treatment could further trigger better coating quality, performance and the overall anti-corrosion ability.…”

Bioactive Glass and Silicate-Based Ceramic Coatings on Metallic Implants: Open Challenge or Outdated Topic?

“…Beside non-resorbable metals, magnesium (Mg) and Mg alloys are being employed as well in orthopedics [9,10,11], but due to their rapid biodegradability [12] they are not good candidates for dental implant applications.…”