Mg-based porous metals as cancellous bone analogous material: A review

2015 ◽  
Vol 231 (6) ◽  
pp. 544-556 ◽  
Author(s):  
N Jasmawati ◽  
SJ Fatihhi ◽  
AMS Putra ◽  
Ardiyansyah Syahrom ◽  
MN Harun ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cancellous Bone ◽  
Mechanical Performance ◽  
Cost Effective ◽  
Biodegradable Materials ◽  
Manufacturing Processes ◽  
Porous Metals ◽  
Research Focus ◽  
The Past ◽  
Porous Magnesium

Interest in cancellous bone analogous materials is driven by the development of tissue engineering and biomaterials. For the past decade, the research focus has been centered on biodegradable materials, in which the ability of the material to safely degrade in the human body while retaining sufficient qualities during service is conveniently cost-effective and less morbid. Among others, magnesium and its alloys have presented the best qualities especially as load-bearing biomaterials. In this article, the promising details of porous magnesium and its alloys as a cancellous bone analogous material developed during the past 10 years are highlighted. The manufacturing processes, mechanical performance, and biocompatibility of porous magnesium and its alloys are discussed. The Achilles’ heel of current evaluation was identified. Further, a few prospective developments of porous magnesium and its alloys are put forward with advanced desirable qualities as a cancellous bone analogous material.

scholarly journals Polylactide, Processed by a Foaming Method Using Compressed Freon R134a, for Tissue Engineering

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3453
Author(s):  
María Aguado ◽  
Laura Saldaña ◽  
Eduardo Pérez del Río ◽  
Judith Guasch ◽  
Marc Parera ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Human Mesenchymal Stem Cells ◽  
Total Porosity ◽  
Cost Effective ◽  
Polymer Matrices ◽  
Porous Polymer ◽  
Manufacturing Processes ◽  
Dense Matrix ◽  
Polymeric Scaffolds ◽  
Gas Foaming

Fabricating polymeric scaffolds using cost-effective manufacturing processes is still challenging. Gas foaming techniques using supercritical carbon dioxide (scCO2) have attracted attention for producing synthetic polymer matrices; however, the high-pressure requirements are often a technological barrier for its widespread use. Compressed 1,1,1,2-tetrafluoroethane, known as Freon R134a, offers advantages over CO2 in manufacturing processes in terms of lower pressure and temperature conditions and the use of low-cost equipment. Here, we report for the first time the use of Freon R134a for generating porous polymer matrices, specifically polylactide (PLA). PLA scaffolds processed with Freon R134a exhibited larger pore sizes, and total porosity, and appropriate mechanical properties compared with those achieved by scCO2 processing. PLGA scaffolds processed with Freon R134a were highly porous and showed a relatively fragile structure. Human mesenchymal stem cells (MSCs) attached to PLA scaffolds processed with Freon R134a, and their metabolic activity increased during culturing. In addition, MSCs displayed spread morphology on the PLA scaffolds processed with Freon R134a, with a well-organized actin cytoskeleton and a dense matrix of fibronectin fibrils. Functionalization of Freon R134a-processed PLA scaffolds with protein nanoparticles, used as bioactive factors, enhanced the scaffolds’ cytocompatibility. These findings indicate that gas foaming using compressed Freon R134a could represent a cost-effective and environmentally friendly fabrication technology to produce polymeric scaffolds for tissue engineering approaches.

Additive manufacturing of hydroxyapatite and its composite materials: A review

2020 ◽  
Vol 05 (03) ◽  
pp. 2030002
Author(s):  
Chunze Yan ◽  
Gao Ma ◽  
Annan Chen ◽  
Ying Chen ◽  
Jiamin Wu ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Additive Manufacturing ◽  
Composite Materials ◽  
Computer Aided Design ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Research Field ◽  
Manufacturing Processes ◽  
Layer By Layer ◽  
Tissue Engineering Scaffolds

Hydroxyapatite (HA) is a promising biomaterial for tissue engineering scaffolds due to its similar performance and composition to natural bone. However, the brittleness and poor toughness of pure HA limit its clinical application. Therefore, a lot of HA composites have been prepared to improve their mechanical performance. Fabricating complex and customized tissue engineering HA scaffolds have a very high requirement for manufacturing processes. It is difficult to fabricate ideal HA porous structures for artificial bone implants using traditional manufacturing processes, such as plasma spraying–sintering, and injection forming. Additive manufacturing (AM) could make three-dimensional physical parts with complex structures directly from computer-aided-design (CAD) models in a layer-by-layer way, and therefore show unique advantages in fabricating bone tissue engineering scaffolds with complex external shape and internal microporous structures. This paper reviews the state of the art for the preparation and AM process of HA and its composite materials, and raises the prospects for this research field.

Regulatory and sustainability initiatives lead to improved polyaminopolyamide epichlorohydrin (PAE) wet-strength resins and paper products

TAPPI Journal ◽  
2018 ◽  
Vol 17 (09) ◽  
pp. 519-532 ◽  
Author(s):  
Mark Crisp ◽  
Richard Riehle
Keyword(s):  
Health And Safety ◽  
Cost Effective ◽  
Worker Safety ◽  
Regulatory Requirements ◽  
Wet Strength ◽  
The Past ◽  
Consumer Safety ◽  
Federal Institute ◽  
Sustainability Initiatives ◽  
The Impact

Polyaminopolyamide-epichlorohydrin (PAE) resins are the predominant commercial products used to manufacture wet-strengthened paper products for grades requiring wet-strength permanence. Since their development in the late 1950s, the first generation (G1) resins have proven to be one of the most cost-effective technologies available to provide wet strength to paper. Throughout the past three decades, regulatory directives and sustainability initiatives from various organizations have driven the development of cleaner and safer PAE resins and paper products. Early efforts in this area focused on improving worker safety and reducing the impact of PAE resins on the environment. These efforts led to the development of resins containing significantly reduced levels of 1,3-dichloro-2-propanol (1,3-DCP) and 3-monochloropropane-1,2-diol (3-MCPD), potentially carcinogenic byproducts formed during the manufacturing process of PAE resins. As the levels of these byproducts decreased, the environmental, health, and safety (EH&S) profile of PAE resins and paper products improved. Recent initiatives from major retailers are focusing on product ingredient transparency and quality, thus encouraging the development of safer product formulations while maintaining performance. PAE resin research over the past 20 years has been directed toward regulatory requirements to improve consumer safety and minimize exposure to potentially carcinogenic materials found in various paper products. One of the best known regulatory requirements is the recommendations of the German Federal Institute for Risk Assessment (BfR), which defines the levels of 1,3-DCP and 3-MCPD that can be extracted by water from various food contact grades of paper. These criteria led to the development of third generation (G3) products that contain very low levels of 1,3-DCP (typically <10 parts per million in the as-received/delivered resin). This paper outlines the PAE resin chemical contributors to adsorbable organic halogens and 3-MCPD in paper and provides recommendations for the use of each PAE resin product generation (G1, G1.5, G2, G2.5, and G3).

scholarly journals 3D-Bioprinting Strategies Based on In Situ Bone-Healing Mechanism for Vascularized Bone Tissue Engineering

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 287
Author(s):  
Ye Lin Park ◽  
Kiwon Park ◽  
Jae Min Cha
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Bone Healing ◽  
Critical Size ◽  
Current Knowledge ◽  
3D Bioprinting ◽  
The Past ◽  
Regeneration Processes

Over the past decades, a number of bone tissue engineering (BTE) approaches have been developed to address substantial challenges in the management of critical size bone defects. Although the majority of BTE strategies developed in the laboratory have been limited due to lack of clinical relevance in translation, primary prerequisites for the construction of vascularized functional bone grafts have gained confidence owing to the accumulated knowledge of the osteogenic, osteoinductive, and osteoconductive properties of mesenchymal stem cells and bone-relevant biomaterials that reflect bone-healing mechanisms. In this review, we summarize the current knowledge of bone-healing mechanisms focusing on the details that should be embodied in the development of vascularized BTE, and discuss promising strategies based on 3D-bioprinting technologies that efficiently coalesce the abovementioned main features in bone-healing systems, which comprehensively interact during the bone regeneration processes.

A recent overview on the porphyrin-based π-extended small molecules as donors and acceptors for high-performance organic solar cells

2021 ◽  
Author(s):  
Venkatesh Piradi ◽  
Feng Yan ◽  
Xunjin Zhu ◽  
Wai-Yeung Raymond Wong
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Small Molecules ◽  
Organic Solar Cells ◽  
High Performance ◽  
Cost Effective ◽  
Effective Alternative ◽  
The Past ◽  
Cost Effective Alternative ◽  
Silicon Based

Organic solar cells (OSCs) have been considered as a promising cost-effective alternative to silicon-based solar cell counterparts due to their lightweight, mechanical flexibility, and easy fabrication features. Over the past...

scholarly journals Introduction to the Special Issue on New Longitudinal Data for Retirement Analysis and Policy

2021 ◽  
pp. 1-5
Author(s):  
Marco Angrisani ◽  
Anya Samek ◽  
Arie Kapteyn
Keyword(s):  
Big Data ◽  
Academic Research ◽  
Cost Effective ◽  
Research Data ◽  
Data Sources ◽  
Special Issue ◽  
Administrative Records ◽  
The Past ◽  
Survey Questionnaires ◽  
Internet Panels

The number of data sources available for academic research on retirement economics and policy has increased rapidly in the past two decades. Data quality and comparability across studies have also improved considerably, with survey questionnaires progressively converging towards common ways of eliciting the same measurable concepts. Probability-based Internet panels have become a more accepted and recognized tool to obtain research data, allowing for fast, flexible, and cost-effective data collection compared to more traditional modes such as in-person and phone interviews. In an era of big data, academic research has also increasingly been able to access administrative records (e.g., Kostøl and Mogstad, 2014; Cesarini et al., 2016), private-sector financial records (e.g., Gelman et al., 2014), and administrative data married with surveys (Ameriks et al., 2020), to answer questions that could not be successfully tackled otherwise.

scholarly journals Oxygen Permeability of Silk Fibroin Hydrogels and Their Use as Materials for Contact Lenses: A Purposeful Analysis

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 58
Author(s):  
Traian V. Chirila
Keyword(s):  
Tissue Engineering ◽  
Bombyx Mori ◽  
Silk Fibroin ◽  
Biomedical Applications ◽  
Oxygen Permeability ◽  
Contact Lenses ◽  
The Past ◽  
Fibrous Protein ◽  
Silk Moth ◽  
Bombyx Mori Silk

Fibroin is a fibrous protein that can be conveniently isolated from the silk cocoons produced by the larvae of Bombyx mori silk moth. In its form as a hydrogel, Bombyx mori silk fibroin (BMSF) has been employed in a variety of biomedical applications. When used as substrates for biomaterial-cells constructs in tissue engineering, the oxygen transport characteristics of the BMSF membranes have proved so far to be adequate. However, over the past three decades the BMSF hydrogels have been proposed episodically as materials for the manufacture of contact lenses, an application that depends on substantially elevated oxygen permeability. This review will show that the literature published on the oxygen permeability of BMSF is both limited and controversial. Additionally, there is no evidence that contact lenses made from BMSF have ever reached commercialization. The existing literature is discussed critically, leading to the conclusion that BMSF hydrogels are unsuitable as materials for contact lenses, while also attempting to explain the scarcity of data regarding the oxygen permeability of BMSF. To the author’s knowledge, this review covers all publications related to the topic.

Smurf1-targeting miR-19b-3p-modified BMSCs combined PLLA composite scaffold to enhance osteogenic activity and treat critical-sized bone defects

2020 ◽  
Vol 8 (21) ◽  
pp. 6069-6081
Author(s):  
Ao Xiong ◽  
Yijun He ◽  
Liang Gao ◽  
Guoqing Li ◽  
Jian Weng ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Composite Scaffold ◽  
Biological Materials ◽  
Bone Defects ◽  
Engineering Technology ◽  
Osteogenic Activity ◽  
The Past ◽  
Seed Cells ◽  
Tissue Engineering Technology

Over the past few years, tissue-engineering technology provided a new direction for bone defects therapy, which involved developing applicable biological materials composite with seed cells to repair bone defects tissue.

scholarly journals Mechanical and thermal stability of retained austenite in plastically deformed bainite-based TRIP-aided medium-Mn steels

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Aleksandra Kozłowska ◽  
Adam Grajcar ◽  
Aleksandra Janik ◽  
Krzysztof Radwański ◽  
Ulrich Krupp ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Retained Austenite ◽  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Mechanical Stability ◽  
Electron Backscatter Diffraction ◽  
Cost Effective ◽  
Tensile Tests ◽  
Thermal Stability Of

AbstractAdvanced medium-Mn sheet steels show an opportunity for the development of cost-effective and light-weight automotive parts with improved safety and optimized environmental performance. These steels utilize the strain-induced martensitic transformation of metastable retained austenite to improve the strength–ductility balance. The improvement of mechanical performance is related to the tailored thermal and mechanical stabilities of retained austenite. The mechanical stability of retained austenite was estimated in static tensile tests over a wide temperature range from 20 °C to 200 °C. The thermal stability of retained austenite during heating at elevated temperatures was assessed by means of dilatometry. The phase composition and microstructure evolution were investigated by means of scanning electron microscopy, electron backscatter diffraction, X-ray diffraction and transmission electron microscopy techniques. It was shown that the retained austenite stability shows a pronounced temperature dependence and is also stimulated by the manganese addition in a 3–5% range.

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