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.

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 In Vitro and In Vivo Studies of BMP-2-Loaded PCL–Gelatin–BCP Electrospun Scaffolds

2014 ◽  
Vol 20 (23-24) ◽  
pp. 3279-3289 ◽  
Author(s):  
Bo-Ram Kim ◽  
Thuy Ba Linh Nguyen ◽  
Young-Ki Min ◽  
Byong-Taek Lee
Keyword(s):  
In Vivo Studies ◽  
Electrospun Scaffolds

Cell Sheet-Based Vascularized Myocardial Tissue Fabrication

2018 ◽  
Vol 59 (3-4) ◽  
pp. 276-285 ◽  
Author(s):  
Hyoe Komae ◽  
Minoru Ono ◽  
Tatsuya Shimizu
Keyword(s):  
Regenerative Medicine ◽  
Cardiac Tissue ◽  
Cell Sheet ◽  
Myocardial Tissue ◽  
Engineering Technology ◽  
Cell Sheet Engineering ◽  
Human Cardiomyocytes ◽  
Whole Heart

Background: The development of regenerative medicine in recent years has been remarkable as tissue engineering technology and stem cell research have advanced. The ultimate goal of regenerative medicine is to fabricate human organs artificially. If fabricated organs can be transplanted medically, it will be the innovative treatment of diseases for which only donor organ transplantation is the definitive therapeutic method at present. Summary: Our group has reported successful fabrication of thick functional myocardial tissue in vivo and in vitro by using cell sheet engineering technology which requires no scaffolds. Thick myocardial tissue can be fabricated by stacking cardiomyocyte sheets on the vascular bed every 24 h, so that a vascular network can be formed within the myocardial graft. We call this procedure a multi-step transplantation procedure. After human-induced pluripotent stem cells were discovered and human cardiomyocytes became available, a thick, macroscopically pulsate human myocardial tissue was successfully constructed by using a multi-step transplantation procedure. Furthermore, our group succeeded in fabricating functional human myocardial tissue which can generate pressure. Here, we present our way of fabricating human myocardial tissue by means of cell sheet engineering technology. Key Messages: Our group succeeded in fabricating thick, functional human myocardium which can generate pulse pressure. However, there are still a few problems to be solved until clinically functional human cardiac tissue or a whole heart can be fabricated. Research on myocardial regeneration progresses at such a pace that we believe the products of this research will save many lives in the near future.

Radiation Effect on Poly(ε-Caprolactone) Nanofibrous Scaffold

2007 ◽  
Vol 119 ◽  
pp. 95-98
Author(s):  
Youn Mook Lim ◽  
Joon Pyo Jeun ◽  
Chan Hee Jung ◽  
Jae Hak Choi ◽  
Phil Hyun Kang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Radiation Effect ◽  
Average Diameter ◽  
Nanofibrous Scaffolds ◽  
Biomimetic Scaffolds ◽  
Biodegradable Poly ◽  
Γ Ray

Nano- to micro-structured biodegradable poly(ε-caprolactone) nanofibrous scaffolds (PCL NFSs) were prepared by an electrospinning. Electrospinning has recently emerged as a leading technique for generating the biomimetic scaffolds for tissue engineering applications. The average diameter of the electrospun PCL NFSs ranged from 0.5 to 2 ㎛ depending on the solvent/nonsolvent mixture. PCL NFSs were irradiated using γ-ray and their mechanical properties and biodegradability were measured. In vitro/vivo degradation studies of the scaffolds as a function of the radiation dose were performed. The scaffolds were degraded more slowly in vitro than in vivo.

scholarly journals Interaction of Radiofrequency Radiation with Biological Systems A Comprehensive Update on Recent Challenges

2019 ◽  
Vol 4 (2) ◽  
pp. 83-90 ◽  
Author(s):  
Saurabh Verma ◽  
Asheesh Gupta ◽  
Bhuvnesh Kumar
Keyword(s):  
Risk Assessment ◽  
Thermal Effects ◽  
Biological Effect ◽  
Biological Systems ◽  
The Body ◽  
In Vivo Studies ◽  
Future Perspectives ◽  
Energy Interaction

Rapid advancement of radiofrequency (RF)-driven technologies has greatly affected our everyday lives. Increasing evidence led by in-vitro, in-vivo studies, epidemiological and clinical trials indicates that RF interacts considerably well with biological systems in various ways depending on different exposure parameters and properties of biological materials. Besides their innumerable benefits in different sectors of commercial and military fields, they can induce alterations in many physiological functions of the body, which may culminate into adverse human health consequences. The present article explicitly addresses the RF-based technologies and their applications, fundamentals of RF energy interaction with biological systems, exposure parameters, and dosimetry studies along with thermal and non-thermal effects on different vital organs at molecular and cellular levels. Further, this article outlines the limitations of RF-induced biological effect studies, status of risk assessment, safety levels and its future perspectives.

scholarly journals Thrombogenic Risk Induced by Intravascular Mesenchymal Stem Cell Therapy: Current Status and Future Perspectives

Cells ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1160 ◽  
Author(s):  
Louise Coppin ◽  
Etienne Sokal ◽  
Xavier Stéphenne
Keyword(s):  
Clinical Trials ◽  
In Vivo Studies ◽  
Current Status ◽  
Future Perspectives ◽  
Complement Pathway ◽  
Mesenchymal Stem Cell Therapy ◽  
Dual Activation

Mesenchymal stem cells (MSCs) are currently studied and used in numerous clinical trials. Nevertheless, some concerns have been raised regarding the safety of these infusions and the thrombogenic risk they induce. MSCs express procoagulant activity (PCA) linked to the expression of tissue factor (TF) that, when in contact with blood, initiates coagulation. Some even describe a dual activation of both the coagulation and the complement pathway, called Instant Blood-Mediated Inflammatory Reaction (IBMIR), explaining the disappointing results and low engraftment rates in clinical trials. However, nowadays, different approaches to modulate the PCA of MSCs and thus control the thrombogenic risk after cell infusion are being studied. This review summarizes both in vitro and in vivo studies on the PCA of MSC of various origins. It further emphasizes the crucial role of TF linked to the PCA of MSCs. Furthermore, optimization of MSC therapy protocols using different methods to control the PCA of MSCs are described.

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.

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