In vivo degradation behavior of Ca-deficient hydroxyapatite coated Mg–Zn–Ca alloy for bone implant application

2011 ◽  
Vol 88 (1) ◽  
pp. 254-259 ◽  
Author(s):  
Huanxin Wang ◽  
Shaokang Guan ◽  
Yisheng Wang ◽  
Hongjian Liu ◽  
Haitao Wang ◽  
...  
2016 ◽  
Vol 17 (3-4) ◽  
Author(s):  
Anastasia Myrissa ◽  
Elisabeth Martinelli ◽  
Gábor Szakács ◽  
Leopold Berger ◽  
Johannes Eichler ◽  
...  

AbstractBioresorbable magnesium materials are widely investigated because of their promising properties as orthopedic devices. Pure magnesium (99.99%) and two binary magnesium alloys (Mg2Ag and Mg10Gd) were used to investigate the degradation behavior, the bone adherence and bone-implant interface mechanics of these materials in growing Sprague-Dawley


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 946
Author(s):  
Katharina Kowalewicz ◽  
Elke Vorndran ◽  
Franziska Feichtner ◽  
Anja-Christina Waselau ◽  
Manuel Brueckner ◽  
...  

Calcium magnesium phosphate cements (CMPCs) are promising bone substitutes and experience great interest in research. Therefore, in-vivo degradation behavior, osseointegration and biocompatibility of three-dimensional (3D) powder-printed CMPC scaffolds were investigated in the present study. The materials Mg225 (Ca0.75Mg2.25(PO4)2) and Mg225d (Mg225 treated with diammonium hydrogen phosphate (DAHP)) were implanted as cylindrical scaffolds (h = 5 mm, Ø = 3.8 mm) in both lateral femoral condyles in rabbits and compared with tricalcium phosphate (TCP). Treatment with DAHP results in the precipitation of struvite, thus reducing pore size and overall porosity and increasing pressure stability. Over 6 weeks, the scaffolds were evaluated clinically, radiologically, with Micro-Computed Tomography (µCT) and histological examinations. All scaffolds showed excellent biocompatibility. X-ray and in-vivo µCT examinations showed a volume decrease and increasing osseointegration over time. Structure loss and volume decrease were most evident in Mg225. Histologically, all scaffolds degraded centripetally and were completely traversed by new bone, in which the remaining scaffold material was embedded. While after 6 weeks, Mg225d and TCP were still visible as a network, only individual particles of Mg225 were present. Based on these results, Mg225 and Mg225d appear to be promising bone substitutes for various loading situations that should be investigated further.


2010 ◽  
Vol 638-642 ◽  
pp. 742-747 ◽  
Author(s):  
Nina von der Höh ◽  
Dirk Bormann ◽  
Arne Lucas ◽  
Fritz Thorey ◽  
Andrea Meyer-Lindenberg

Resorbable magnesium alloy implants for osteosynthetic surgery would be advantageous to common implants of titanium or surgical steel as a second surgery for implant removal would become unnecessary. To influence the degradation progress, surface modifications are sensible. As plates and screws were used to stabilize fractures, the degradation behavior of threaded cylinders is of particular interest. Therefore each eight solid MgCa0.8 alloy cylinders (3 x 5 mm) with smooth and sandblasted surface, respectively, and eight screw-shaped, threaded MgCa0.8 cylinders (thread pitch 1.25 mm, length 5 mm) were inserted into the medial femoral condyle of adult New Zealand White rabbits. Implantation periods were three and six months, within which the animals were examined daily. To evaluate a possible gas generation radiographs were taken weekly. After euthanasia the bone-implant-compound was scanned in a µ-computed tomograph (µCT80, ScancoMedical). All implants were well tolerated. Smooth implants degraded slowly. The cross sectional area did not reduce obviously after three months implantation duration and only mildly after six months. Sandblasted implants showed the fastest degradation progress after both implantation periods with the most obvious generation of gas. Threaded cylinders revealed pitting corrosion at the thread pitches. They degrade faster than smooth implants but slower than sandblasted cylinders. In summary, surface modification influences the degradation behavior of resorbable magnesium alloy implants. Contrary to common materials, smooth surfaces seem to be favorable. Thread pitches of screw-shaped implants show pitting corrosion. To what extend this result affects future applications of resorbable screws has to be examined in further investigations.


2006 ◽  
Vol 7 (1) ◽  
pp. 365-372 ◽  
Author(s):  
Brian G. Amsden ◽  
M. Yat Tse ◽  
Norma D. Turner ◽  
Darryl K. Knight ◽  
Stephen C. Pang

2018 ◽  
Vol 41 (11) ◽  
pp. 772-778 ◽  
Author(s):  
Sara R Knigge ◽  
Birgit Glasmacher

A lot of research has been done in the field of magnesium-based implant material. This study is focused on finding an explanation for the large disparity in results from similar experiments in literature. The hypothesis is that many different measurement protocols are used to quantify magnesium degradation and this leads to inconsistent results. Cylindrical, pure magnesium samples were used for this study. The degradation took place in revised simulated body fluid at 37°C. Hydrogen evolution was measured to quantify the degradation. Two commonly used experimental protocols were examined: static conditions and a fluid changing method. For static testing, the samples stayed in fluid. For the fluid changing method, the fluid was changed after 2 and 5 days of immersion. In addition, a new method with continuous fluid flow was established. After an initial phase, the results confirm that for all three methods, the degradation behavior differs strongly. The static condition results in a very slow degradation rate. The fluid change method leads to a similar behavior like the static condition except that the degradation was speeded up after the fluid changes. The continuous degradation is linear for a long period after the initial phase. In comparison with in vivo degradation behavior, the degradation process in continuous flow shows the best fitting. The accumulation of degradation products, especially the increasing pH value, has a strong inhibiting effect. This cannot be observed in vivo so that a constant experimental environment realizable by continuous flow is more suitable for magnesium-based implant material testing.


2016 ◽  
Vol 113 ◽  
pp. 183-187 ◽  
Author(s):  
Jialin Niu ◽  
Meiping Xiong ◽  
Xingmin Guan ◽  
Jian Zhang ◽  
Hua Huang ◽  
...  

2009 ◽  
Vol 1190 ◽  
Author(s):  
Bernhard Hiebl ◽  
Karl Kratz ◽  
Rosemarie Fuhrmann ◽  
Friedrich Jung ◽  
Andres Lendlein ◽  
...  

AbstractThe degradation behavior of biodegradable multiblock copolymers (PDC) containing poly(p-dioxanone) hard segments (PPDO) and crystallizable poly(epsilon-caprolactone) switching segments (PCL) synthesized via co-condensation of two oligomeric macrodiols with an aliphatic diisocyanate as junction unit was explored in in vivo and in vitro experiments. The in vitro experiments for enzymatic degradation resulted that the poly(epsilon-caprolactone) segments are degraded faster, than the poly(p-dioxanone) segments. During degradation the outer layer of the test specimen becomes porous. Finally non-soluble degradation products in form of particles were found at the surface. This observation is in good agreement with the in vivo studies, where the non-soluble degradation products in the periimplantary tissues showed a diameter of 1 – 3 micron.


Materials ◽  
2011 ◽  
Vol 4 (12) ◽  
pp. 2197-2218 ◽  
Author(s):  
Berit Ullmann ◽  
Janin Reifenrath ◽  
Dina Dziuba ◽  
Jan-Marten Seitz ◽  
Dirk Bormann ◽  
...  

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