A Comprehensive Review on Surface Modifications of Biodegradable Magnesium-Based Implant Alloy: Polymer Coatings Opportunities and Challenges

Abstract

The development of biodegradable implants is certainly intriguing, and magnesium and its alloys are considered significant among the various biodegradable materials. Nevertheless, the fast degradation, the generation of a significant amount of hydrogen gas, and the escalation in the pH value of the body solution are significant barriers to their use as an implant material. The appropriate approach is able to solve this issue, resulting in a decrease the rate of Mg degradation, which can be accomplished by alloying, surface adjustment, and mechanical treatment. Surface modification is a practical option because it not only improves corrosion resistance but also prepares a treated surface to improve bone regeneration and cell attachment. Metal coatings, ceramic coatings, and permanent polymers were shown to minimize degradation rates, but inflammation and foreign body responses were also suggested. In contrast to permanent materials, the bioabsorbable polymers normally show the desired biocompatibility. In order to improve the performance of drugs, they are generally encapsulated in biodegradable polymers. This study summarized the most recent advancements in manufacturing polymeric coatings on Mg alloys. The related corrosion resistance enhancement strategies and future potentials are discussed. Ultimately, the major challenges and difficulties are presented with aim of the development of polymer-coated Mg-based implant materials.

Progress in bioactive surface coatings on biodegradable Mg alloys: A critical review towards clinical translation

“…The accumulation of H 2 under polymeric layer makes them grow and ultimately burst with prolonged immersion [ 150 ]. Additionally, polymeric layers are prone to swelling and subsequent delamination in the presence of physiological media [ 151 ]. Therefore, recent studies are oriented to address the challenges related to polymeric top-coats for MAO pore sealing.…”

Advances in Barrier Membranes for Guided Bone Regeneration Techniques

“…Modification of magnesium alloys can be achieved by adding alloying elements as well as surface modification. Physical modification, such as modifying microstructural features, can effectively slow down the degradation of magnesium alloy in vitro and in vivo , reduce local hydrogen evolution and pH raise, which ulteriorly improves its biocompatibility ( Wu et al, 2019 ; Saberi et al, 2021 ). Magnesium alloys can be modified by integrating with other materials such as collagen.…”

Recent Progress in Surface Modification of Mg Alloys for Biodegradable Orthopedic Applications

“…The composition of such a layer can be easily tuned for imparting degradation resistance and better tissue implant interaction (Wang et al, 2012). The majority of these coatings reported are composed of CaPbased ceramic materials or biodegradable polymeric material (Saberi et al, 2021). The coating material is physically deposited on the Mg-substrate as schematically represented in Figure 5, and these coatings have better control on the degradation rate and bioactivity.…”