High-resolution ex vivo analysis of the degradation and osseointegration of Mg-xGd implant screws in 3D

• Biodegradable magnesium (Mg) alloys can revolutionize osteosynthesis, because they have mechanical properties similar to those of the bone, and degrade over time, avoiding the need of removal surgery. However, they are not yet routinely applied because their degradation behavior is not fully understood. In this study we have investigated and quantified the degradation and osseointegration behavior of two biodegradable Mg alloys based on gadolinium (Gd) at high resolution. Mg-5Gd and Mg-10Gd screws were inserted in rat tibia for 4, 8 and 12 weeks. Afterward, the degradation rate and degradation homogeneity, as well as bone-to-implant interface, were studied with synchrotron radiation micro computed tomography and histology. Titanium (Ti) and polyether ether ketone (PEEK) were used as controls material to evaluate osseointegration. Our results showed that Mg-5Gd degraded faster and less homogeneously than Mg-10Gd. Both alloys gradually form a stable degradation layer at the interface and were surrounded by new bone tissue. The results were correlated to in vitro data obtained from the same material and shape. The average bone-to-implant contact of the Mg-xGd implants was comparable to that of Ti and higher than for PEEK. The results suggest that both Mg-xGd alloys are suitable as materials for bone implants.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Odontologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Dentistry (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinsk bioteknologi -- Biomaterialvetenskap (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Medical Biotechnology -- Biomaterials Science (hsv//eng)

Keyword

Magnesium alloys

Biodegradable implant

Micro-computed tomography

degradation rate

Degradation homogeneity

Ex vivo imaging

Ex vivo

histology

Histology vs. tomography

in-vivo

magnesium alloys

rare-earth

bone

vitro

accumulation

biomaterials

gadolinium

corrosion

strength

Engineering

Materials Science

Biomedical Engineering

Hälsa och samhälle

Ex vivo histology

Micro-computed tomography degradation rate

Publication and Content Type

ref (subject category)

art (subject category)