Novel Bioresorbable Alloy Could Lead to Temporary Implants

Implants made of a material that minimizes inflammation and does not need to be removed after healing could save patients from a lot of unnecessary pain and risk.

Material scientists from Russia’s National University of Science and Technology (NUST) MISIS in Moscow and the University of Western Australia in Perth published their findings in the Journal of Magnesium and Alloys.

In the article, “Gallium-containing magnesium alloy for potential use as temporary implants in osteosynthesis,” the team describes several alloys that they tested. The composition of their chosen alloy is mostly magnesium with 4% by weight of each gallium and zinc.

Head of Hybrid Nanostructured Materials Laboratory at NUST MISIS and co-author of the publication, Alexander Komissarov, Ph.D., said “We have chosen gallium as an alloying element due to its unique properties.” Gallium typically inhibits bone resorption and is often used to treat disorders due to accelerated bone loss. The element also plays a role in the bone regeneration process leading to increased thickness, strength, and mineral content.

Finally, it also has antibacterial properties. The alloy decomposes slowly with little biocorrosion and “has a unique profile of characteristics for use in bone implants due to the optimal combination of mechanical properties and corrosion rate,” concluded Komissarov.

Magnesium alloys have been studied for some time for use as resorbable medical devices. The first commercially available magnesium alloy approved for medical implants is known as Magnezix^® and made by Germany-based Syntellix AG. Magnezix contains zinc and calculum, in addition to magnesium and is used to make pins and screws for orthopedic applications.

Current resorbable implants are primarily made from polymers of lactic acid. Spine plates, such as Medtronic’s Mystique were intended to provide fixation while fusion took place, and to dissolve leaving no trace of the implant. Some studies showed that clinical outcomes were similar to titanium plates, but rates of pseudoarthrosis were significantly higher. These observations leave the door open for newer resorbable materials.

A recent review, “Biodegradable Magnesium‐Based Implants in Orthopedics—A General Review and Perspectives,” published in Advanced Science discusses the many potential benefits of magnesium alloys for spine and orthopedic use. For example, despite its high strength, it has a Young’s modulus close to that of bone. Mismatches in this measure of elasticity is a predictor of subsidence.

Additionally, as the fourth most prevalent mineral in the body and an essential element in biochemical processes, ions released through degradation are easily taken up by the body, and excess excreted.

Lastly, the review presented evidence that magnesium promotes osteogenic differentiation, enhances angiogenesis, inhibits osteoclastogenesis, and modulates osteoimmunological responses. All of these effects promote the growth of new and healthy bone.

The gallium-containing magnesium alloy, as well as others in development, have the potential to make an impact in the spine and orthopedic device market that has been dominated by PEEK and titanium for decades.