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

2021 ◽  
Author(s):  
David David ◽  
Matt Dargusch ◽  
Nan Yang ◽  
Jeffrey Venezuela ◽  
Nagasivamuni Balasubramani ◽  
...  
Keyword(s):  
Magnesium Alloys ◽  
Hydrogen Gas ◽  
Alloy Content ◽  
In Vivo Degradation

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

2022 ◽  
Author(s):  
Seong Ryoung Kim ◽  
Keon Mo Lee ◽  
Jin Hong Kim ◽  
Young Jin Choi ◽  
Han Ick Park ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
High Purity ◽  
Histopathological Examination ◽  
Hydrogen Gas ◽  
X Rays ◽  
Inflammatory Reactions ◽  
Paravertebral Muscles ◽  
Femur Condyle

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.

scholarly journals Long-term in vivo degradation behavior and near-implant distribution of resorbed elements for magnesium alloys WZ21 and ZX50

2016 ◽  
Vol 42 ◽  
pp. 440-450 ◽  
Author(s):  
F. Amerstorfer ◽  
S.F. Fischerauer ◽  
L. Fischer ◽  
J. Eichler ◽  
J. Draxler ◽  
...  
Keyword(s):  
Magnesium Alloys ◽  
Degradation Behavior ◽  
In Vivo Degradation

In vivo degradation of binary magnesium alloys – a long-term study

2016 ◽  
Vol 17 (3-4) ◽  
Author(s):  
Anastasia Myrissa ◽  
Elisabeth Martinelli ◽  
Gábor Szakács ◽  
Leopold Berger ◽  
Johannes Eichler ◽  
...  
Keyword(s):  
Magnesium Alloys ◽  
Degradation Behavior ◽  
Sprague Dawley ◽  
Term Study ◽  
Bone Implant ◽  
Long Term Study ◽  
Interface Mechanics ◽  
In Vivo Degradation

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

scholarly journals In Vitro and In Vivo Biosafety Analysis of Resorbable Polyglycolic Acid-Polylactic Acid Block Copolymer Composites for Spinal Fixation

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 29
Author(s):  
Seung Kyun Yoon ◽  
Jin Ho Yang ◽  
Hyun Tae Lim ◽  
Young-Wook Chang ◽  
Muhammad Ayyoob ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Animal Experiments ◽  
Polymeric Materials ◽  
Polyglycolic Acid ◽  
Poly Lactic Acid ◽  
Skin Sensitization ◽  
Spinal Fixation ◽  
In Vivo Degradation

Herein, spinal fixation implants were constructed using degradable polymeric materials such as PGA–PLA block copolymers (poly(glycolic acid-b-lactic acid)). These materials were reinforced by blending with HA-g-PLA (hydroxyapatite-graft-poly lactic acid) and PGA fiber before being tested to confirm its biocompatibility via in vitro (MTT assay) and in vivo animal experiments (i.e., skin sensitization, intradermal intracutaneous reaction, and in vivo degradation tests). Every specimen exhibited suitable biocompatibility and biodegradability for use as resorbable spinal fixation materials.

scholarly journals In-Vivo Degradation Behavior and Osseointegration of 3D Powder-Printed Calcium Magnesium Phosphate Cement Scaffolds

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 946
Author(s):  
Katharina Kowalewicz ◽  
Elke Vorndran ◽  
Franziska Feichtner ◽  
Anja-Christina Waselau ◽  
Manuel Brueckner ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Bone Substitutes ◽  
Magnesium Phosphate ◽  
Degradation Behavior ◽  
Micro Computed Tomography ◽  
Calcium Magnesium ◽  
Interest In Research ◽  
In Vivo Degradation ◽  
Volume Decrease

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.

In vitro and in vivo degradation of silk fibers degummed with various sodium carbonate concentrations

2021 ◽  
Vol 27 ◽  
pp. 102369
Author(s):  
Shijun Lu ◽  
Xiaochen Tang ◽  
Qingqing Lu ◽  
Jiwei Huang ◽  
Xinran You ◽  
...  
Keyword(s):  
Sodium Carbonate ◽  
Silk Fibers ◽  
In Vivo Degradation

scholarly journals Optimizing the Reaction Conditions for the Formation of Fumarate via Trans-Hydrogenation

2021 ◽  
Author(s):  
Laura Wienands ◽  
Franziska Theiß ◽  
James Eills ◽  
Lorenz Rösler ◽  
Stephan Knecht ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Thermal Equilibrium ◽  
Reaction Rate ◽  
Low Cost ◽  
Hydrogen Gas ◽  
Metabolic Imaging ◽  
Reaction Conditions ◽  
Precursor Molecule ◽  
Solution Preparation

AbstractParahydrogen-induced polarization is a hyperpolarization method for enhancing nuclear magnetic resonance signals by chemical reactions/interactions involving the para spin isomer of hydrogen gas. This method has allowed for biomolecules to be hyperpolarized to such a level that they can be used for real time in vivo metabolic imaging. One particularly promising example is fumarate, which can be rapidly and efficiently hyperpolarized at low cost by hydrogenating an acetylene dicarboxylate precursor molecule using parahydrogen. The reaction is relatively slow compared to the timescale on which the hyperpolarization relaxes back to thermal equilibrium, and an undesirable 2nd hydrogenation step can convert the fumarate into succinate. To date, the hydrogenation chemistry has not been thoroughly investigated, so previous work has been inconsistent in the chosen reaction conditions in the search for ever-higher reaction rate and yield. In this work we investigate the solution preparation protocols and the reaction conditions on the rate and yield of fumarate formation. We report conditions to reproducibly yield over 100 mM fumarate on a short timescale, and discuss aspects of the protocol that hinder the formation of fumarate or lead to irreproducible results. We also provide experimental procedures and recommendations for performing reproducible kinetics experiments in which hydrogen gas is repeatedly bubbled into an aqueous solution, overcoming challenges related to the viscosity and surface tension of the water.

scholarly journals Poly(ethylene glycol)-b-poly(1,3-trimethylene carbonate) Amphiphilic Copolymers for Long-Acting Injectables: Synthesis, Non-Acylating Performance and In Vivo Degradation

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1438
Author(s):  
Silvio Curia ◽  
Feifei Ng ◽  
Marie-Emérentienne Cagnon ◽  
Victor Nicoulin ◽  
Adolfo Lopez-Noriega
Keyword(s):  
Ethylene Glycol ◽  
Ring Opening ◽  
Gel Chromatography ◽  
Amphiphilic Copolymers ◽  
Trimethylene Carbonate ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene ◽  
Long Acting ◽  
In Vivo Degradation

This article presents the evaluation of diblock and triblock poly(ethylene glycol)-b-poly(1,3-trimethylene carbonate) amphiphilic copolymers (PEG-PTMCs) as excipients for the formulation of long-acting injectables (LAIs). Copolymers were successfully synthesised through bulk ring-opening polymerisation. The concomitant formation of PTMC homopolymer could not be avoided irrespective of the catalyst amount, but the by-product could easily be removed by gel chromatography. Pure PEG-PTMCs undergo faster erosion in vivo than their corresponding homopolymer. Furthermore, these copolymers show outstanding stability compared to their polyester analogues when formulated with amine-containing reactive drugs, which makes them particularly suitable as LAIs for the sustained release of drugs susceptible to acylation.

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