scholarly journals Application of Zr and Ti-Based Bulk Metallic Glasses for Orthopaedic and Dental Device Materials

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 203 ◽  
Author(s):  
Kazuhiro Imai ◽  
Xiao Zhou ◽  
Xiaoxuan Liu
Keyword(s):  
Mechanical Properties ◽  
Metallic Glasses ◽  
Amorphous Alloys ◽  
Bulk Metallic Glasses ◽  
In Vivo Studies ◽  
Metallic Materials ◽  
Failure Resistance ◽  
Cobalt Chrome

Conventional orthopaedic and dental device materials are made of metallic materials such as stainless steel (SUS316L), titanium alloy (Ti-6Al-4V), and cobalt-chrome (Co-Cr). Those materials have the disadvantage of mechanical properties and anti-corrosion behavior. Bulk metallic glasses (BMGs), which are also called amorphous alloys, are metallic materials with metastable glassy states and have a higher strength, higher elasticity, higher failure resistance, and lower Young’s modulus compared with crystalline alloys. There are several types of BMGs. Among them, Zr-based BMGs and Ti-based BMGs have excellent mechanical properties. In addition, they have good corrosion resistance and are promising for orthopaedic and dental device materials. In this review article, in vitro and in vivo studies regarding Zr and Ti-based BMGs applications as biomaterials, especially in orthopaedic and dental device materials, are reviewed.

scholarly journals Microstructure and Mechanical Properties of PU/PLDL Sponges Intended for Grafting Injured Spinal Cord

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2693
Author(s):  
Anna Lis-Bartos ◽  
Dariusz Szarek ◽  
Małgorzata Krok-Borkowicz ◽  
Krzysztof Marycz ◽  
Włodzimierz Jarmundowicz ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Spinal Cord ◽  
Young Modulus ◽  
In Vivo Studies ◽  
Polymer Composition ◽  
In Vitro Toxicity ◽  
Injured Spinal Cord ◽  
Degradation Rates

Highly porous, elastic, and degradable polyurethane and polyurethane/polylactide (PU/PLDL) sponges, in various shapes and sizes, with open interconnected pores, and porosity up to 90% have been manufactured. They have been intended for gap filling in the injured spinal cord. The porosity of the sponges depended on the content of polylactide, i.e., it decreased with the increase of polylactide content. The rise of polylactide content caused an increase of Young modulus and rigidity as well as a more complex morphology of the polyurethane/polylactide blends. The mechanical properties, in vitro toxicity, and degradation in artificial cerebrospinal fluid were tested. Sponges underwent continuous degradation with varying degradation rates depending on the polymer composition. In vitro cell studies with fibroblast cultures proved the biocompatibility of the polymers. Based on the obtained results, the designed PU/PLDL sponges appeared to be promising candidates for bridging gaps within injured spinal cord in further in vitro and in vivo studies.

In vitro and in vivo studies on ultrafine-grained biodegradable pure Mg, Mg–Ca alloy and Mg–Sr alloy processed by high-pressure torsion

2020 ◽  
Vol 8 (18) ◽  
pp. 5071-5087
Author(s):  
Wenting Li ◽  
Xiao Liu ◽  
Yufeng Zheng ◽  
Wenhao Wang ◽  
Wei Qiao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
High Pressure Torsion ◽  
In Vivo Studies ◽  
Ultrafine Grained

High-pressure torsion processing is an effective way to significantly refine the microstructure and consequently modify the mechanical properties, biodegradable behaviors and biocompatibility of pure Mg, Mg–1Ca and Mg–2Sr alloys.

Long-term safety and performance of a novel conical bioresorbable vascular scaffold: insights from in-vitro and in-vivo studies

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Q Ma ◽  
Y Du ◽  
J.L Wang ◽  
S.J Wu ◽  
Y.X Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Coronary Angiography ◽  
Quantitative Coronary Angiography ◽  
In Vivo Studies ◽  
Histopathological Analysis ◽  
Rotational Axis ◽  
Bioresorbable Vascular Scaffold

Abstract Background The phenomenon of size-mismatches between cylindrical stents and tapered vessels is not uncommon in current endovascular interventions which is associated with poor clinical outcomes. Purpose The aim of the present study was to evaluate the mechanical properties of the novel conic BRS and to validate its performance with the support of optical coherence tomography (OCT), quantitative coronary angiography (QCA) and histology up to 2 years in a porcine model. Methods We produced the conical BRS with the four-axis 3D printing system, with a computer-controlled rotational axis (the 4th axis) in addition to the 3 axes of traditional 3D printing systems. Mechanical properties were evaluated by recoil and radial strength, cyclic fatigability testing. Twelve swine that received 12 conic BRS were evaluated by OCT, QCA and histology post-implantation and at 12 and 24 months. Results The in vitro study showed no fractures after accelerated cycle testing over time (at 3.8×108 cycles). The recoil rate of the scaffolds after plate compress test was 14.3±0.61%. There was no significant peri-operative complications. By OCT, 60±21 struts per BRS were recognizable by 2 years. Quantitative coronary angiography showed late luminal loss and percent diameter stenosis were 0.02±0.52 mm and 0.50±16.90% at 2-year follow-up. Histopathological analysis demonstrated mild vessel injuries, inflammatory cell infiltration around struts at 1 and 2 years follow ups. Conclusions The conical BRS showed optimal performance and has the potential to improve clinical outcome. OCT and histological images Funding Acknowledgement Type of funding source: None

Additively manufactured titanium alloys and effect of hydroxyapatite coating for biomedical applications: A review

2020 ◽  
Vol 234 (11) ◽  
pp. 1450-1460
Author(s):  
Franklin Anene ◽  
Jaafar Aiza ◽  
Ismail Zainol ◽  
Azmah Hanim ◽  
Mohd Tahir Suraya
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Titanium Alloys ◽  
Biomedical Applications ◽  
Hydroxyapatite Coating ◽  
In Vivo Studies ◽  
Processing Technologies ◽  
Treatment Processes

Metallic implants are extensively used to treat a spectrum of orthopaedic related disorders. Among the metals, titanium and its alloys are considered most excellent and indispensable material for the production of orthopaedic implants regarding their sterling mechanical properties and exceptional biocompatibility. Recently, rapid progress in developing non-toxic titanium-based alloys with modulus similar to that of human bone has inspired researchers globally. Thus, many studies have focused on titanium alloys, their heat treatment processes and several processing technologies. Additive manufacturing has been designed to enhance their mechanical properties tailored towards biomedical applications. Inarguably, the need to further improve on the implant’s biocompatibility with bodily environment for optimum service life is of great importance. Hence, hydroxyapatite coating provides an improvement as demonstrated by in vitro as well as in vivo studies. The present article critically reviews, based on recent scientific literatures, the progress made thus far in the development of titanium-based alloys, additive manufacturing processes and their heat and surface treatments tailored towards biomedical applications.

scholarly journals New Ti-Alloys and Surface Modifications to Improve the Mechanical Properties and the Biological Response to Orthopedic and Dental Implants: A Review

2016 ◽  
Vol 2016 ◽  
pp. 1-21 ◽  
Author(s):  
Yvoni Kirmanidou ◽  
Margarita Sidira ◽  
Maria-Eleni Drosou ◽  
Vincent Bennani ◽  
Athina Bakopoulou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Survival Rates ◽  
Biological Response ◽  
Surface Treatments ◽  
Titanium Implants ◽  
In Vivo Studies ◽  
Advantages And Disadvantages ◽  
Ti Alloys

Titanium implants are widely used in the orthopedic and dentistry fields for many decades, for joint arthroplasties, spinal and maxillofacial reconstructions, and dental prostheses. However, despite the quite satisfactory survival rates failures still exist. New Ti-alloys and surface treatments have been developed, in an attempt to overcome those failures. This review provides information about new Ti-alloys that provide better mechanical properties to the implants, such as superelasticity, mechanical strength, and corrosion resistance. Furthermore, in vitro and in vivo studies, which investigate the biocompatibility and cytotoxicity of these new biomaterials, are introduced. In addition, data regarding the bioactivity of new surface treatments and surface topographies on Ti-implants is provided. The aim of this paper is to discuss the current trends, advantages, and disadvantages of new titanium-based biomaterials, fabricated to enhance the quality of life of many patients around the world.

scholarly journals Mechanical Considerations of Electrospun Scaffolds for Myocardial Tissue and Regenerative Engineering

2020 ◽  
Vol 7 (4) ◽  
pp. 122 ◽  
Author(s):  
Michael Nguyen-Truong ◽  
Yan Vivian Li ◽  
Zhijie Wang
Keyword(s):  
Mechanical Properties ◽  
Cardiac Tissue ◽  
In Vivo Studies ◽  
Myocardial Tissue ◽  
Future Perspectives ◽  
Electrospun Scaffolds ◽  
Nanofibrous Scaffolds ◽  
Therapeutic Development

Biomaterials to facilitate the restoration of cardiac tissue is of emerging importance. While there are many aspects to consider in the design of biomaterials, mechanical properties can be of particular importance in this dynamically remodeling tissue. This review focuses on one specific processing method, electrospinning, that is employed to generate materials with a fibrous microstructure that can be combined with material properties to achieve the desired mechanical behavior. Current methods used to fabricate mechanically relevant micro-/nanofibrous scaffolds, in vivo studies using these scaffolds as therapeutics, and common techniques to characterize the mechanical properties of the scaffolds are covered. We also discuss the discrepancies in the reported elastic modulus for physiological and pathological myocardium in the literature, as well as the emerging area of in vitro mechanobiology studies to investigate the mechanical regulation in cardiac tissue engineering. Lastly, future perspectives and recommendations are offered in order to enhance the understanding of cardiac mechanobiology and foster therapeutic development in myocardial regenerative medicine.

In vitro and in vivo studies of new cationic Zn(II)‐benzonaphthoporphyrazines as photosensitizers for PDT

2001 ◽  
Vol 5 (8) ◽  
pp. 645-651
Author(s):  
M. Peeva ◽  
M. Shopova ◽  
U. Michelsen ◽  
D. Wöhrle ◽  
G. Petrov ◽  
...  
Keyword(s):  
In Vivo Studies

Effect of caffeine on theophyliine on cerebral blood flow response to brain activation: In vitro and in vivo studies

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S198-S198
Author(s):  
Joseph R Meno ◽  
Thien-son K Nguyen ◽  
Elise M Jensen ◽  
G Alexander West ◽  
Leonid Groysman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Activation ◽  
In Vivo Studies ◽  
Blood Flow Response ◽  
Flow Response

Effects of Unfractionated and Low Molecular Weight Heparins on Platelet Thromboxane Biosynthesis “In Vivo”

1994 ◽  
Vol 72 (06) ◽  
pp. 942-946 ◽  
Author(s):  
Raffaele Landolfi ◽  
Erica De Candia ◽  
Bianca Rocca ◽  
Giovanni Ciabattoni ◽  
Armando Antinori ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Unfractionated Heparin ◽  
Low Molecular Weight Heparin ◽  
Primary Source ◽  
In Vivo Studies ◽  
Low Molecular Weight ◽  
Heparin Administration ◽  
To Receive

SummarySeveral “in vitro” and “in vivo” studies indicate that heparin administration may affect platelet function. In this study we investigated the effects of prophylactic heparin on thromboxane (Tx)A2 biosynthesis “in vivo”, as assessed by the urinary excretion of major enzymatic metabolites 11-dehydro-TxB2 and 2,3-dinor-TxB2. Twenty-four patients who were candidates for cholecystectomy because of uncomplicated lithiasis were randomly assigned to receive placebo, unfractionated heparin, low molecular weight heparin or unfractionaed heparin plus 100 mg aspirin. Measurements of daily excretion of Tx metabolites were performed before and during the treatment. In the groups assigned to placebo and to low molecular weight heparin there was no statistically significant modification of Tx metabolite excretion while patients receiving unfractionated heparin had a significant increase of both metabolites (11-dehydro-TxB2: 3844 ± 1388 vs 2092 ±777, p <0.05; 2,3-dinor-TxB2: 2737 ± 808 vs 1535 ± 771 pg/mg creatinine, p <0.05). In patients randomized to receive low-dose aspirin plus unfractionated heparin the excretion of the two metabolites was largely suppressed thus suggesting that platelets are the primary source of enhanced thromboxane biosynthesis associated with heparin administration. These data indicate that unfractionated heparin causes platelet activation “in vivo” and suggest that the use of low molecular weight heparin may avoid this complication.

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