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.

scholarly journals Mg-Zn-Ca Alloys for Hemostasis Clips for Vessel Ligation: In Vitro and In Vivo Studies of Their Degradation and Response

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3039 ◽  
Author(s):  
Yen-Hao Chang ◽  
Chun Chieh Tseng ◽  
Chih-Yeh Chao ◽  
Chung-Hwan Chen ◽  
Sung-Yen Lin ◽  
...  
Keyword(s):  
Degradation Rate ◽  
Protective Layer ◽  
Dip Coating ◽  
In Vivo Studies ◽  
Surface Measurement ◽  
In Vivo Experiments ◽  
Degradation Rates ◽  
And Behavior

To control the degradation rate of magnesium (Mg) alloys, chitosan (CHI) and L-glutamic acid (LGA) were used as coatings on Mg-Zn-Ca alloys via dip coating. In this study, either two or seven CHI/LGA layers were applied as a coating on Mg-2.8Zn-0.8Ca alloy (ZX31) and Mg-2.8Zn-0.8Ca hemostasis clips (ZX31 clips). The morphologies, compositions, and surface roughness of the specimens were characterized via scanning electron microscopy, Fourier transform infrared spectroscopy, and surface measurement devices. The degradation rates and behavior of the specimens were evaluated by immersing them in simulated body fluids and by applying these ZX31 clips on rabbits’ uterine tubes for five weeks. The specimen with seven layers (ZX31(CHI/LGA)7) exhibited improved corrosion behavior when compared with ZX31 or ZX31(CHI/LGA)2, with a reduced degradation rate of the Mg alloy in a simulated body environment. In vivo experiments showed that ZX31 clips exhibited good biocompatibilities in each group but could not maintain the clamping function for five weeks. The weight loss of ZX31(CHI/LGA)7 was significantly lower than that of the other groups. Consequently, it was verified that CHI can be used as a protective layer on a magnesium alloy surface via in vitro and in vivo experiments.

Microdialysis of galanin in rat spinal cord: in vitro and in vivo studies

2001 ◽  
Vol 139 (3) ◽  
pp. 354-358 ◽  
Author(s):  
Hygge Blakeman ◽  
Z. Wiesenfeld-Hallin ◽  
P. Alster
Keyword(s):  
Spinal Cord ◽  
In Vivo Studies ◽  
Rat Spinal Cord

scholarly journals Spinal Cord Injury as a Model of Bone-Muscle Interactions: Therapeutic Implications From in vitro and in vivo Studies

2020 ◽  
Vol 11 ◽  
Author(s):  
Marco Invernizzi ◽  
Alessandro de Sire ◽  
Filippo Renò ◽  
Carlo Cisari ◽  
Letterio Runza ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
In Vivo Studies ◽  
Therapeutic Implications ◽  
Cord Injury

scholarly journals Toxicity of Zero- and One-Dimensional Carbon Nanomaterials

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1214 ◽  
Author(s):  
Iruthayapandi Selestin Raja ◽  
Su-Jin Song ◽  
Moon Sung Kang ◽  
Yu Bin Lee ◽  
Bongju Kim ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Carbon Nanomaterials ◽  
Volume Ratio ◽  
In Vivo Studies ◽  
In Vitro Toxicity ◽  
One Dimensional ◽  
Multi Walled Carbon Nanotubes ◽  
Living Organisms

The zero (0-D) and one-dimensional (1-D) carbon nanomaterials have gained attention among researchers because they exhibit a larger surface area to volume ratio, and a smaller size. Furthermore, carbon is ubiquitously present in all living organisms. However, toxicity is a major concern while utilizing carbon nanomaterials for biomedical applications such as drug delivery, biosensing, and tissue regeneration. In the present review, we have summarized some of the recent findings of cellular and animal level toxicity studies of 0-D (carbon quantum dot, graphene quantum dot, nanodiamond, and carbon black) and 1-D (single-walled and multi-walled carbon nanotubes) carbon nanomaterials. The in vitro toxicity of carbon nanomaterials was exemplified in normal and cancer cell lines including fibroblasts, osteoblasts, macrophages, epithelial and endothelial cells of different sources. Similarly, the in vivo studies were illustrated in several animal species such as rats, mice, zebrafish, planktons and, guinea pigs, at various concentrations, route of administrations and exposure of nanoparticles. In addition, we have described the unique properties and commercial usage, as well as the similarities and differences among the nanoparticles. The aim of the current review is not only to signify the importance of studying the toxicity of 0-D and 1-D carbon nanomaterials, but also to emphasize the perspectives, future challenges and possible directions in the field.

scholarly journals Poly(lactide- co -glycolide) porous scaffolds for tissue engineering and regenerative medicine

2012 ◽  
Vol 2 (3) ◽  
pp. 366-377 ◽  
Author(s):  
Zhen Pan ◽  
Jiandong Ding
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Regenerative Medicine ◽  
Porous Scaffolds ◽  
Plga Scaffold ◽  
Degradation Rates ◽  
Long Time ◽  
Facile Fabrication

Porous scaffolds fabricated from biocompatible and biodegradable polymers play vital roles in tissue engineering and regenerative medicine. Among various scaffold matrix materials, poly(lactide- co -glycolide) (PLGA) is a very popular and an important biodegradable polyester owing to its tunable degradation rates, good mechanical properties and processibility, etc. This review highlights the progress on PLGA scaffolds. In the latest decade, some facile fabrication approaches at room temperature were put forward; more appropriate pore structures were designed and achieved; the mechanical properties were investigated both for dry and wet scaffolds; a long time biodegradation of the PLGA scaffold was observed and a three-stage model was established; even the effects of pore size and porosity on in vitro biodegradation were revealed; the PLGA scaffolds have also been implanted into animals, and some tissues have been regenerated in vivo after loading cells including stem cells.

173. Neural Precursor Cells Produce Trophic Factors In Vitro and Following In Vivo Transplantation into the Injured Spinal Cord

2008 ◽  
Vol 8 (5) ◽  
pp. 88S
Author(s):  
Gregory Hawryluk ◽  
Eftekhar Eftekharpour ◽  
Soheila Karimi-Abdolrezaee ◽  
Michael Fehlings
Keyword(s):  
Spinal Cord ◽  
Precursor Cells ◽  
Neural Precursor Cells ◽  
Trophic Factors ◽  
Neural Precursor ◽  
Injured Spinal Cord

scholarly journals Ancient and Modern Cereals as Ingredients of the Gluten-Free Diet: Are They Safe Enough for Celiac Consumers?

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 906
Author(s):  
Francesca Colombo ◽  
Chiara Di Lorenzo ◽  
Simone Biella ◽  
Corinne Bani ◽  
Patrizia Restani
Keyword(s):  
Celiac Disease ◽  
Autoimmune Disorder ◽  
Gluten Free Diet ◽  
In Vivo Studies ◽  
In Vitro Toxicity ◽  
Gluten Free ◽  
Wide Variability

Celiac disease is an autoimmune disorder that occurs in genetically predisposed individuals after consuming prolamins from some cereals. Although the products available for celiac subjects have increased significantly in quality and quantity over the last few decades, research still focuses on identifying new ingredients to improve the nutritional, sensorial and functional qualities of gluten-free products. In terms of toxicity for people with celiac disease, there is a wide variability between ancient and modern grains. The most contradictory results are related to the role of oats in the gluten-free diet. In order to clarify the role of minor cereals (such as oat) and ancient grains in the diets of celiac patients, this review discusses recent in vitro and in vivo studies performed on those cereals for which the toxicity for celiac subjects is still controversial. According to in vivo studies, selected oat varieties could be tolerated by celiac patients. On the other hands, although some wheat-ancient grains (Triticum monococcum, Triticum aestivum ssp. spelta and Kamut®) showed a reduced in vitro toxicity, to date, these grains are still considered toxic for celiac patients. Contradictory results underline the importance of studying the safety of “unusual” cereals in more detail.

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

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