Biodegradable Metallic Materials for Temporary Medical Implants

2017 ◽  
Vol 891 ◽  
pp. 395-399 ◽  
Author(s):  
Dalibor Vojtěch ◽  
Jiří Kubásek ◽  
Jaroslav Čapek ◽  
Iva Pospíšilová
Keyword(s):  
Blood Vessels ◽  
Corrosion Behavior ◽  
Mechanical Performance ◽  
Metallic Materials ◽  
Medical Implants ◽  
Advantages And Disadvantages ◽  
Fe Alloys

Biodegradable Mg, Zn and Fe alloys are currently studied as prospective biomaterials for temporary medical implants like stents for repairing damaged blood vessels and devices (screws and plates) for fixing fractured bones. In the present paper, novel Mg-, Zn- and Fe-biodegradable alloys are proposed. Advantages and disadvantages of the three kinds of alloys are demonstrated regarding the mechanical performance, in vitro corrosion behavior and biocompatibility.

Corrosion and Mechanical Behavior of Biodegradable Metallic Biomaterials

2015 ◽  
Vol 227 ◽  
pp. 431-434 ◽  
Author(s):  
Dalibor Vojtěch ◽  
Jiří Kubásek ◽  
Jaroslav Capek ◽  
Alena Michalcova ◽  
Iva Pospíšilová
Keyword(s):  
Mechanical Behavior ◽  
Corrosion Behavior ◽  
Mechanical Performance ◽  
Point Of View ◽  
Medical Implants ◽  
Advantages And Disadvantages ◽  
Metallic Biomaterials ◽  
Biodegradable Metals ◽  
Fixation Devices

Biodegradable alloys are currently studied as prospective biomaterials for temporary medical implants like stents and fixation devices for fractured bones. Among biodegradable metals, only magnesium, zinc and iron meet general requirements of biocompatibility and relative non-toxicity. In the present paper, Mg-, Zn- and Fe-based biodegradable alloys are compared. Advantages and disadvantages of the three kinds of alloying systems are demonstrated regarding the corrosion behavior, mechanical performance and biocompatibility. From the corrosion behavior point of view, Zn- and Fe-based alloys appear as promising alternatives to Mg-based alloys.

scholarly journals Elastomeric Electrospun Scaffolds of a Biodegradable Aliphatic Copolyester Containing PEG-Like Sequences for Dynamic Culture of Human Endothelial Cells

Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1620
Author(s):  
Luca Fusaro ◽  
Chiara Gualandi ◽  
Diego Antonioli ◽  
Michelina Soccio ◽  
Anna Liguori ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Vascular Tissue ◽  
Mechanical Performance ◽  
Thrombus Formation ◽  
Cell Activity ◽  
Mechanical Tests ◽  
Cyclic Stretch ◽  
Biological Characterization ◽  
The Right

In the field of artificial prostheses for damaged vessel replacement, polymeric scaffolds showing the right combination of mechanical performance, biocompatibility, and biodegradability are still demanded. In the present work, poly(butylene-co-triethylene trans-1,4-cyclohexanedicarboxylate), a biodegradable random aliphatic copolyester, has been synthesized and electrospun in form of aligned and random fibers properly designed for vascular applications. The obtained materials were analyzed through tensile and dynamic-mechanical tests, the latter performed under conditions simulating the mechanical contraction of vascular tissue. Furthermore, the in vitro biological characterization, in terms of hemocompatibility and cytocompatibility in static and dynamic conditions, was also carried out. The mechanical properties of the investigated scaffolds fit within the range of physiological properties for medium- and small-caliber blood vessels, and the aligned scaffolds displayed a strain-stiffening behavior typical of the blood vessels. Furthermore, all the produced scaffolds showed constant storage and loss moduli in the investigated timeframe (24 h), demonstrating the stability of the scaffolds under the applied conditions of mechanical deformation. The biological characterization highlighted that the mats showed high hemocompatibility and low probability of thrombus formation; finally, the cytocompatibility tests demonstrated that cyclic stretch of electrospun fibers increased endothelial cell activity and proliferation, in particular on aligned scaffolds.

Novel Trends in the Development of Metallic Materials for Medical Implants

2015 ◽  
Vol 647 ◽  
pp. 59-65
Author(s):  
Dalibor Vojtěch ◽  
Jiří Kubásek ◽  
Jaroslav Čapek ◽  
Iva Pospíšilová
Keyword(s):  
Human Population ◽  
Mechanical Performance ◽  
Functional Performance ◽  
Biodegradable Materials ◽  
Metallic Materials ◽  
Medical Implants ◽  
Metallic Biomaterials ◽  
Fixation Devices ◽  
New Directions ◽  
Porous Biomaterials

Metallic biomaterials are currently used in medicine for fabrication of various kinds of implants like joint and bone replacements, dental implants, stents, fixation devices for fractured bones etc. Their advantages over polymeric or ceramic biomaterials are in higher strength, fracture toughness and fatigue life. In addition, metals can be simply processed by established technologies known for centuries. Due to the increasing average age of human population, there are growing requirements for mechanical and functional performance of implants. Therefore, extensive research and development activities are focused on new directions in this area including new surface treatments and alloys with improved biocompatibility and mechanical performance, porous biomaterials, biodegradable metallic materials. Biodegradable materials are explored as alternatives for fabrication of temporary medical implants like stents and fixation devices (screws, plates, nails) for fractured bones. The present paper focuses on new Mg-and Zn-biodegradable alloys. Advantages of these materials are characterized with respect to mechanical performance and corrosion behavior.

scholarly journals Corrosion Modeling of Magnesium and Its Alloys for Biomedical Applications: Review

2020 ◽  
Vol 1 (2) ◽  
pp. 219-248
Author(s):  
Moataz Abdalla ◽  
Alexander Joplin ◽  
Mohammad Elahinia ◽  
Hamdy Ibrahim
Keyword(s):  
Corrosion Behavior ◽  
Biomedical Applications ◽  
Numerical Models ◽  
Research Effort ◽  
Degradation Process ◽  
Medical Implants ◽  
Biodegradable Metals ◽  
Significant Research

Biodegradable metals have been under significant research as promising alternatives to the currently in-use nonbiodegradable materials in the field of supportive medical implants. In this scope, magnesium and its alloys were widely investigated due to their superior biocompatibility over other metals. Most of the research effort in the literature has been focused on assuring the biocompatibility, improving mechanical properties, and tailoring the corrosion rate of magnesium-based implants. Furthermore, considerable research was done to develop numerical models towards an inexpensive and fast designing tools capable of simulating the degradation/corrosion behavior of magnesium-based implants. Due to the complexity of the degradation process and the various factors that can be involved, several hypotheses were introduced to provide a realistic simulation of the corrosion behavior in vitro and in vivo. A review of the current literature hypothesis and different modeling constitutive equations for modeling the corrosion of magnesium alloys along with a summary of the supplementary experimental methods is provided in this paper.

3D-printing of Urethane-based Photoelastomers for Vascular Tissue Regeneration

2009 ◽  
Vol 1239 ◽  
Author(s):  
Stefan Baudis ◽  
Thomas Pulka ◽  
Bernhard Steyrer ◽  
Harald Wilhelm ◽  
Guenter Weigel ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Blood Vessels ◽  
Vascular Tissue ◽  
Mechanical Performance ◽  
In Vitro Tests ◽  
Layer By Layer ◽  
Digital Light Processing ◽  
Tissue Replacement ◽  
Tear Resistance

AbstractThe mechanical properties of materials designated for vascular tissue replacement are of crucial importance. The elastic modulus, the tensile strength as well as the suture tear resistance have to be adjusted. Our approach is to use photopolymers for artificial vascular grafts. Via the layer-by-layer photopolymerization of suitable resin formulations as performed in additive manufacturing (AM) very complex structures are realizable. Hence AM offer the possibility to create cellular structures within the artificial grafts that might favor the ingrowth of new tissue. Commercially available urethane acrylates (UA) were chosen as base monomers since urethane groups are known to have good cell-adhesion behavior and poly-UAs show adequate mechanical performance. The mechanical properties of the photoelastomers can be tailored by addition of reactive diluents (e.g. 2-hydroxyethyl acrylate, HEA) and thiols (e.g. 3,6 dioxa-1,8-octane-dithiol) as chain transfer agents to comply with the mechanical properties of natural blood vessels. To examine the suture tear resistance a new testing method has been developed. Finally, a formulation containing 30 wt% UA and 70 wt% HEA complies with the mechanical properties of natural blood vessels, shows good biocompatibility in in-vitro tests and was successfully 3D-printed with digital light processing AM.

Viscoelastic Testing Methodologies for Tissue Engineered Blood Vessels

2005 ◽  
Vol 127 (7) ◽  
pp. 1176-1184 ◽  
Author(s):  
Joseph D. Berglund ◽  
Robert M. Nerem ◽  
Athanassios Sambanis
Keyword(s):  
Blood Vessels ◽  
Mechanical Performance ◽  
Uniaxial Tensile ◽  
Collagen Gels ◽  
Uniaxial Tensile Testing ◽  
Modeling Systems ◽  
Tissue Engineered Blood Vessels ◽  
Linear Viscoelastic

In order to function in vivo, tissue engineered blood vessels (TEBVs) must encumber pulsatile blood flow and withstand hemodynamic pressures for long periods of time. To date TEBV mechanical assessment has typically relied on single time point burst and/or uniaxial tensile testing to gauge the strengths of the constructs. This study extends this analysis to include creep and stepwise stress relaxation viscoelastic testing methodologies. TEBV models exhibiting diverse mechanical behaviors as a result of different architectures ranging from reconstituted collagen gels to hybrid constructs reinforced with either untreated or glutaraldhyde-crosslinked collagen supports were evaluated after 8 and 23 days of in vitro culturing. Data were modeled using three and four-parameter linear viscoelastic mathematical representations and compared to porcine carotid arteries. While glutaraldhyde-treated hybrid TEBVs exhibited the largest overall strengths and toughness, uncrosslinked hybrid samples exhibited time-dependent behaviors most similar to native arteries. These findings emphasize the importance of viscoelastic characterization when evaluating the mechanical performance of TEBVs. Limits of testing methods and modeling systems are presented and discussed.

Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

1982 ◽  
Vol 40 ◽  
pp. 520-521
Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Saline Solution ◽  
Saturated Calomel Electrode ◽  
Physiological Saline ◽  
X Ray ◽  
Physiological Saline Solution ◽  
Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

Persistence of Fibrinolytic Activity in Fragments of Human Veins Cultured in Vitro

1970 ◽  
Vol 24 (01/02) ◽  
pp. 043-047 ◽  
Author(s):  
M Pandolfi
Keyword(s):  
Blood Vessels ◽  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Vasa Vasorum ◽  
Adult Human ◽  
Slide Technique

SummaryExplants from 5 adult human veins were cultured in a fibrinolytically inactive medium for 3 weeks and assayed for the presence of plasminogen activator by the fibrin slide technique. The explants from 3 veins showed fibrinolytic activity confined to their vasa vasorum for the whole duration of the culture; no decrease of activity was seen. The finding suggests that small blood vessels are able to synthesize plasminogen activator.

PERFUSION OF OVARIES IN VITRO AND IN VIVO

1972 ◽  
Vol 68 (2_Supplb) ◽  
pp. S285-S309 ◽  
Author(s):  
Kurt Ahrén ◽  
Per Olof Janson ◽  
Gunnar Selstam
Keyword(s):  
Perfusion System ◽  
Perfusion Technique ◽  
Preliminary Results ◽  
Advantages And Disadvantages

ABSTRACT This paper discusses in vivo and in vitro ovarian perfusion systems described so far in the literature. The interest is not focussed primarily on the results of these studies but rather on the advantages and disadvantages of the techniques and methods used. Another part of the paper summarizes the points which are most important, in our opinion, to take into consideration when developing an in vitro perfusion technique of the ovary. The last part of the paper gives a description of and some preliminary results from an in vitro perfusion system of the rabbit ovary which is under development in this laboratory.

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