In vitro corrosion resistance and cytocompatibility of nano-hydroxyapatite reinforced Mg–Zn–Zr composites

Abstract

Due to good biocompatibility and mechanical properties, magnesium (Mg) and its alloys are considered promising degradable materials for orthopedic applications. In this work, a Mg metal matrix composite (MMC) was fabricated using Mg-2.9Zn-0.7Zr alloy as the matrix and 1 wt% nano-hydroxyapatite (n-HA) particles as reinforcements. In vitro corrosion behavior and cytocompatibility of a Mg-Zn-Zr/n-HA composite and a Mg-Zn-Zr alloy were investigated. In contrast with the Mg-Zn-Zr alloy, the MMC has better properties. The average corrosion rate of MMC is 0.75 mm/yr after immersion in simulated body fluid (SBF) for 20 days, and the surface of MMC is covered with white Ca-P precipitates. The electrochemical test results show that the corrosion potential (E(corr)) of MMC increases to -1.615 V and its polarization resistance (R(p)) is 2.56 KOmega with the addition of n-HA particles. The co-cultivation of MMC with osteoblasts results in the adhesion and proliferation of cells on the surface of the composite. The maximum cell density is calculated to be (1.85+/-0.15) x 10(4)/l after 5 days of co-culture with osteoblasts. The average cell numbers for two groups after culturing for 3 and 5 days (P<0.05) are significantly different. All the results demonstrate that the Mg-Zn-Zr/n-HA composite can be potentially used as biodegradable bone fixation material.

Effect of calcium content on the microstructure, hardness and in-vitro corrosion behavior of biodegradable Mg-Ca binary alloy

“…It can be seen from Figures 6a-c that no considerable amount of bio-corrosion products was formed on the surface of Mg-Ca alloys containing 0.7 to 2% Ca, respectively. It is believed that Mg(DH) 2 film initially forms on the surface of the alloys as a result of magnesium dissolution in SBF 18 . Afterwards, this film gradually transforms to the hydrate state (Mg(DH) 2 .nH 2 D) while being soaked in the solution.…”

Introductory Chapter: Multi-Aspect Bibliographic Analysis of the Synergy of Technical, Biological and Medical Sciences Concerning Materials and Technologies Used for Medical and Dental Implantable Devices

“…A human organism well tolerates these alloys [362,363] mainly with coatings adapted to bioresorbable implants [364][365][366][367]. Reinforcements of magnesium MMCs usually include, notably, HA [368][369][370][371][372][373], FA [374], calcium polyphosphate [375], and calcium [374] and well affect biocompatibility. Mg and its alloys can be used for non-biodegradable scaffolds [372].…”

Effect of Alloying Elements on Properties of Biodegradable Magnesium Composite for Implant Application

“…In addition, these metallic materials as implants are not biodegradable and require a second surgery in order to remove the metals implant from the body causing more pain to patient [4]. Consequently, it not only increases the hospitalization time and cost but also elevates chances of infection and complications.…”