Biocompatibility Evaluation of PEO-treated Magnesium Alloy Implants Placed in Rabbit Femur Condyle Notches and Paravertebral Muscles

Abstract Background: Magnesium alloys have been receiving much attention for use in biodegradable metal implants because of their excellent mechanical properties and biocompatibility. However, their rapid breakdown and low bioactivity can cause the implant to lose mechanical integrity before the bone is completely healed. Moreover, hydrogen gas released during degradation can significantly delay the tissue regeneration process. To solve the instability of magnesium alloys, Zn and Ca can be added to improve the mechanical properties and biocompatibility. One other way to improve the mechanical properties of Mg is plasma electrolytic oxidation (PEO), which provides a dense, thick ceramic-like coating on the Mg surface. In this study, high-purity Mg was selected as the control, and Mg-1wt%Zn-0.1wt%Ca alloy and PEO-treated Mg-1wt%Zn-0.1wt%Ca alloy were selected as the test materials; the results of radiographic and histological analyses of their biocompatibility are reported herein. Materials and method: Nineteen New Zealand white rabbits were used in the study. Rod-bars (Ø2.7x13.6mm) were placed on both paravertebral muscles, and cannulated screws (Ø2.7x10mm) were placed on both femur condyle notches. Each animal was implanted in all four sites. X-rays were taken at 0, 2, 4, 8, and 12 weeks, micro-CT, and live-CT were taken at 4, 8, and 12 weeks. At weeks 4, 8, and 12, individuals representing each group were selected and sacrificed to prepare specimens for histopathological examination. Result: The results confirm that in vivo, Mg-1wt%Zn-0.1wt%Ca alloy had higher corrosion resistance than high-purity Mg and safely degraded over time without causing possible side effects (foreign body or inflammatory reactions, etc.). In addition, PEO treatment of Mg-1wt%Zn-0.1wt%Ca alloy had a positive effect on fracture recovery by increasing the bonding area with bone. Conclusion: Our results suggest that PEO treatment of Mg-1wt%Zn-0.1wt%Ca alloy can be a promising biomaterials in the field of various clinical situations such as orthopedic and maxillofacial surgerys.

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The in vivo and in vitro corrosion of high-purity magnesium and magnesium alloys WZ21 and AZ91

Corrosion Science ◽

10.1016/j.corsci.2013.06.019 ◽

2013 ◽

Vol 75 ◽

pp. 354-366 ◽

Cited By ~ 127

Author(s):

Nor Ishida Zainal Abidin ◽

Barbara Rolfe ◽

Helen Owen ◽

Julian Malisano ◽

Darren Martin ◽

...

Keyword(s):

Magnesium Alloys ◽

High Purity

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Recent advances in research on magnesium alloys and magnesium–calcium phosphate composites as biodegradable implant materials

Journal of Biomaterials Applications ◽

10.1177/0885328216657271 ◽

2016 ◽

Vol 31 (6) ◽

pp. 878-900 ◽

Cited By ~ 26

Author(s):

Katarzyna Kuśnierczyk ◽

Michał Basista

Keyword(s):

Mechanical Properties ◽

Metal Matrix Composites ◽

Magnesium Alloys ◽

Metal Matrix ◽

Calcium Phosphates ◽

Second Phase ◽

Matrix Composites ◽

Alloy Matrix ◽

Biodegradable Implant

Magnesium alloys are modern biocompatible materials suitable for orthopaedic implants due to their biodegradability in biological environment. Many studies indicate that there is a high demand to design magnesium alloys with controllable in vivo corrosion rates and required mechanical properties. A solution to this challenge can be sought in the development of metal matrix composites based on magnesium alloys with addition of relevant alloying elements and bioceramic particles. In this study, the corrosion mechanisms along with corrosion protection methods in magnesium alloys are discussed. The recently developed magnesium alloys for biomedical applications are reviewed. Special attention is given to the newest research results in metal matrix composites composed of magnesium alloy matrix and calcium phosphates, especially hydroxyapatite or tricalcium phosphate, as the second phase with emphasis on the biodegradation behavior, microstructure and mechanical properties in view of potential application of these materials in bone implants.

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In-vivo Degradation and Hydrogen Gas Development in Low Alloy Content Magnesium Alloys

10.26226/morressier.60993d920d0b548838eef46b ◽

2021 ◽

Author(s):

David David ◽

Matt Dargusch ◽

Nan Yang ◽

Jeffrey Venezuela ◽

Nagasivamuni Balasubramani ◽

...

Keyword(s):

Magnesium Alloys ◽

Hydrogen Gas ◽

Alloy Content ◽

In Vivo Degradation

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In Vivo Response of Growth Plate to Biodegradable Mg-Ca-Zn Alloys Depending on the Surface Modification

International Journal of Molecular Sciences ◽

10.3390/ijms20153761 ◽

2019 ◽

Vol 20 (15) ◽

pp. 3761

Author(s):

Mi Hyun Song ◽

Won Joon Yoo ◽

Tae-Joon Cho ◽

Yong Koo Park ◽

Wang-Jae Lee ◽

...

Keyword(s):

Surface Modification ◽

Growth Plate ◽

Rabbit Model ◽

Hydrogen Gas ◽

Inflammatory Reactions ◽

Bone Bridge ◽

Plasma Electrolyte ◽

Tissue Reactions ◽

Zn Alloys

Because Mg-Ca-Zn alloys are biodegradable and obviate secondary implant removal, they are especially beneficial for pediatric patients. We examined the degradation performance of Mg-Ca-Zn alloys depending on the surface modification and investigated the in vivo effects on the growth plate in a skeletally immature rabbit model. Either plasma electrolyte oxidation (PEO)-coated (n = 18) or non-coated (n = 18) Mg-Ca-Zn alloy was inserted at the distal femoral physis. We measured the degradation performance and femoral segment lengths using micro-CT. In addition, we analyzed the histomorphometric and histopathologic characteristics of the growth plate. Although there were no acute, chronic inflammatory reactions in either group, they differed significantly in the tissue reactions to their degradation performance and physeal responses. Compared to non-coated alloys, PEO-coated alloys degraded significantly slowly with diminished hydrogen gas formation. Depending on the degradation rate, large bone bridge formation and premature physeal arrest occurred primarily in the non-coated group, whereas only a small-sized bone bridge formed in the PEO-coated group. This difference ultimately led to significant shortening of the femoral segment in the non-coated group. This study suggests that optimal degradation could be achieved with PEO-coated Mg-Ca-Zn alloys, making them promising and safe biodegradable materials with no growth plate damage.

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Novel Mg-0.5Ca-xMn Biodegradable Alloys Intended for Orthopedic Application: An In Vitro and In Vivo Study

Materials ◽

10.3390/ma14237262 ◽

2021 ◽

Vol 14 (23) ◽

pp. 7262

Author(s):

Corneliu Munteanu ◽

Daniela Maria Vlad ◽

Eusebiu-Viorel Sindilar ◽

Bogdan Istrate ◽

Maria Butnaru ◽

...

Keyword(s):

Medical Application ◽

Ionic Concentration ◽

Hydrogen Gas ◽

Point Of View ◽

X Rays ◽

Body Regions ◽

Materials Used ◽

The Right

Mg-based biodegradable materials, used for medical applications, have been extensively studied in the past decades. The in vitro cytocompatibility study showed that the proliferation and viability (as assessed by quantitative MTT-assay—3-(4,5-dimethyltiazol-2-yl)-2,5-diphenyl tetrazolium bromide) were not negatively affected with time by the addition of Mn as an alloying element. In this sense, it should be put forward that the studied alloys don’t have a cytotoxic effect according to the standard ISO 10993-5, i.e., the level of the cells’ viability (cultured with the studied experimental alloys) attained both after 1 day and 5 days was over 82% (i.e., 82, 43–89, 65%). Furthermore, the fibroblastic cells showed variable morphology (evidenced by fluorescence microscopy) related to the alloy sample’s proximity (i.e., related to the variation on the Ca, Mg, and Mn ionic concentration as a result of alloy degradation). It should be mentioned that the cells presented a polygonal morphology with large cytoplasmic processes in the vicinity of the alloy’s samples, and a bipolar morphology in the remote region of the wells. Moreover, the in vitro results seem to indicate that only 0.5% Mn is sufficient to improve the chemical stability, and thus the cytocompatibility; from this point of view, it could provide some flexibility in choosing the right alloy for a specific medical application, depending on the specific parameters of each alloy, such as its mechanical properties and corrosion resistance. In order to assess the in vivo compatibility of each concentration of alloy, the pieces were implanted in four rats, in two distinct body regions, i.e., the lumbar and thigh. The body’s reaction was followed over time, 60 days, both by general clinical examinations considering macroscopic changes, and by laboratory examinations, which revealed macroscopic and microscopic changes using X-rays, CT(Computed Tomography), histology exams and SEM (Scanning Electron Microscopy). In both anatomical regions, for each of the tested alloys, deformations were observed, i.e., a local reaction of different intensities, starting the day after surgery. The release of hydrogen gas that forms during Mg alloy degradation occurred immediately after implantation in all five of the groups examined, which did not affect the normal functionality of the tissues surrounding the implants. Imaging examinations (radiological and CT) revealed the presence of the alloy and the volume of hydrogen gas in the lumbar and femoral region in varying amounts. The biodegradable alloys in the Mg-Ca-Mn system have great potential to be used in orthopedic applications.

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Strain rate effects on the mechanical properties of high-purity α-titanium

DYMAT 2009 - 9th International Conferences on the Mechanical and Physical Behaviour of Materials under Dynamic Loading ◽

10.1051/dymat/2009162 ◽

2009 ◽

Cited By ~ 1

Author(s):

M. E. Nixon ◽

O. Cazacu ◽

J. House

Keyword(s):

Mechanical Properties ◽

Strain Rate ◽

High Purity ◽

Strain Rate Effects ◽

Rate Effects

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Comparison of High Purity Factor IX Concentrates and a Prothrombin Complex Concentrate in a Canine Model of Thrombogenicity

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646468 ◽

1991 ◽

Vol 66 (05) ◽

pp. 609-613 ◽

Cited By ~ 14

Author(s):

I R MacGregor ◽

J M Ferguson ◽

L F McLaughlin ◽

T Burnouf ◽

C V Prowse

Keyword(s):

High Purity ◽

Time Course ◽

Prothrombin Complex Concentrate ◽

Degradation Products ◽

Canine Model ◽

Factor Ix ◽

In Vitro Tests ◽

Albumin Infusion

SummaryA non-stasis canine model of thrombogenicity has been used to evaluate batches of high purity factor IX concentrates from 4 manufacturers and a conventional prothrombin complex concentrate (PCC). Platelets, activated partial thromboplastin time (APTT), fibrinogen, fibrin(ogen) degradation products and fibrinopeptide A (FPA) were monitored before and after infusion of concentrate. Changes in FPA were found to be the most sensitive and reproducible indicator of thrombogenicity after infusion of batches of the PCC at doses of between 60 and 180 IU/kg, with a dose related delayed increase in FPA occurring. Total FPA generated after 100-120 IU/kg of 3 batches of PCC over the 3 h time course was 9-12 times that generated after albumin infusion. In contrast the amounts of FPA generated after 200 IU/kg of the 4 high purity factor IX products were in all cases similar to albumin infusion. It was noted that some batches of high purity concentrates had short NAPTTs indicating that current in vitro tests for potential thrombogenicity may be misleading in predicting the effects of these concentrates in vivo.

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Hemostatic wound dressings: Predicting their effects by in vitro tests

Journal of Biomaterials Applications ◽

10.1177/0885328219831095 ◽

2019 ◽

Vol 33 (9) ◽

pp. 1285-1297 ◽

Cited By ~ 2

Author(s):

Cornelia Wiegand ◽

Martin Abel ◽

Uta-Christina Hipler ◽

Peter Elsner ◽

Michael Zieger ◽

...

Keyword(s):

Blood Clot ◽

Wound Dressings ◽

In Vitro Tests ◽

Regenerated Cellulose ◽

Oxidized Regenerated Cellulose ◽

Inflammatory Reactions ◽

In Vitro Techniques ◽

Cotton Gauze

Background Application of controlled in vitro techniques can be used as a screening tool for the development of new hemostatic agents allowing quantitative assessment of overall hemostatic potential. Materials and methods Several tests were selected to evaluate the efficacy of cotton gauze, collagen, and oxidized regenerated cellulose for enhancing blood clotting, coagulation, and platelet activation. Results Visual inspection of dressings after blood contact proved the formation of blood clots. Scanning electron microscopy demonstrated the adsorption of blood cells and plasma proteins. Significantly enhanced blood clot formation was observed for collagen together with β-thromboglobulin increase and platelet count reduction. Oxidized regenerated cellulose demonstrated slower clotting rates not yielding any thrombin generation; yet, led to significantly increased thrombin-anti-thrombin-III complex levels compared to the other dressings. As hemostyptica ought to function without triggering any adverse events, induction of hemolysis, instigation of inflammatory reactions, and initiation of the innate complement system were also tested. Here, cotton gauze provoked high PMN elastase and elevated SC5b-9 concentrations. Conclusions A range of tests for desired and undesired effects of materials need to be combined to gain some degree of predictability of the in vivo situation. Collagen-based dressings demonstrated the highest hemostyptic properties with lowest adverse reactions whereas gauze did not induce high coagulation activation but rather activated leukocytes and complement.

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