scholarly journals Characterizing and optimizing poly- l -lactide-co-ε-caprolactone membranes for urothelial tissue engineering

2012 ◽  
Vol 9 (77) ◽  
pp. 3444-3454 ◽  
Author(s):  
Reetta Sartoneva ◽  
Anne-Marie Haaparanta ◽  
Tuija Lahdes-Vasama ◽  
Bettina Mannerström ◽  
Minna Kellomäki ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Cell Culture ◽  
Material Characterization ◽  
Mechanical Characteristics ◽  
Mechanical Characterization ◽  
Growth Surface ◽  
Urothelial Cells ◽  
Assessment Period ◽  
Better Than

Different synthetic biomaterials such as polylactide (PLA), polycaprolactone and poly- l -lactide-co-ε-caprolactone (PLCL) have been studied for urothelial tissue engineering, with favourable results. The aim of this research was to further optimize the growth surface for human urothelial cells (hUCs) by comparing different PLCL-based membranes: smooth (s) and textured (t) PLCL and knitted PLA mesh with compression-moulded PLCL (cPLCL). The effects of topographical texturing on urothelial cell response and mechanical properties under hydrolysis were studied. The main finding was that both sPLCL and tPLCL supported hUC growth significantly better than cPLCL. Interestingly, tPLCL gave no significant advantage to hUC attachment or proliferation compared with sPLCL. However, during the 14 day assessment period, the majority of cells were viable and maintained phenotype on all the membranes studied. The material characterization exhibited potential mechanical characteristics of sPLCL and tPLCL for urothelial applications. Furthermore, the highest elongation of tPLCL supports the use of this kind of texturing. In conclusion, in light of our cell culture results and mechanical characterization, both sPLCL and tPLCL should be further studied for urothelial tissue engineering.

Durability of BFRP and Hybrid FRP Sheets under Freeze-Thaw Cycling

2010 ◽  
Vol 163-167 ◽  
pp. 3297-3300 ◽  
Author(s):  
Jia Wei Shi ◽  
Hong Zhu ◽  
Zhi Shen Wu ◽  
Gang Wu
Keyword(s):  
Mechanical Properties ◽  
Test Data ◽  
Mechanical Characteristics ◽  
Test Results ◽  
Freeze Thaw ◽  
Frp Composites ◽  
Test Parameters ◽  
The Stability ◽  
Better Than

Coupon tests were conducted to investigate the mechanical characteristics of basalt FRP (BFRP) sheet, basalt-carbon hybrid FRP sheets and the corresponding epoxy rein under the effect of freeze-thaw cycling. FRP sheets and epoxy rein coupons were subjected to up to 200 and 250 freeze-thaw cycles respectively. Test parameters included the number of freeze-thaw cycles and the types of FRP composites. Test results show that (1) BFRP sheet perform better than CFRP or GFRP sheets under high freeze-thaw cycles; (2) exposed hybrid FRP sheets not only show very little loss in mechanical properties, but also contribute to the stability of test data; (3) mechanical properties of rein epoxy decrease significantly with increasing freeze-thaw cycles.

Characterization of Medium Density Particleborads Using Agricultural Residues

2015 ◽  
Vol 1088 ◽  
pp. 656-659
Author(s):  
Ivaldo D. Valarelli ◽  
Rosane A.G. Battistelle ◽  
Barbara Stolte Bezerra ◽  
Luiz A. Melgaço N. Branco ◽  
Eduardo Chahud ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Castor Oil ◽  
Mechanical Characteristics ◽  
Mechanical Characterization ◽  
Raw Materials ◽  
Construction Materials ◽  
Agricultural Residues ◽  
Medium Density ◽  
Polyurethane Resin

In recent years the production of products derived from wood and bamboo are increasing, due to the search for a more rational exploitation of these raw materials. Amongst these products, the particleboards production combine sustainability and rationality in the use of these materials. In this context, this work has the objective to study the application of alternative raw materials in the manufacture of Medium Density Particleboards (MDP), using residues from industrial processimg of coffee and bamboo. MDP had been produced with particles of giganteus bamboo of the Dendrocalamus species and particle of coffee rind in the intermediate layer of the particleboard, bonded with polyurethane resin based on castor oil. The physical and mechanical characterization was carried out accordingly to NBR 14810-3 (2006). The physical properties evaluated were: of water absorption for 2h and 24h; thickness swallowing for 2h and 24h; density, humidity content. The mechanical properties evaluated were: Tensile strength, static bending (MOR and MOE). The results were compared with NBR 14810-2 (2006) and also with the ANSI A208-1 (1993). The physical performance of these particleboards was below the values recommend by the Brazilian norm. Also the mechanical characteristics are not improve, demonstrating that the inclusion of coffee rind did not benefit the physical characteristics and nor the mechanical ones. However it can be used as construction materials for partitions and ceiling panels.

Mechanical, Electrical and Thermal Characterization of Commercially Available LTCC Dielectric Tapes

2013 ◽  
Vol 543 ◽  
pp. 212-215
Author(s):  
Goran Radosavljević ◽  
Nelu Blaž ◽  
Andrea Marić ◽  
W. Smetana ◽  
Ljiljana Živanov
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Electrical Properties ◽  
Material Characterization ◽  
Mechanical Characterization ◽  
Thermal Characterization ◽  
Material Parameters ◽  
Mechanical And Electrical Properties

Presented paper deals with mechanical and electrical properties of several commercially available LTCC (Low Temperature Co-fired Technology) tapes, as well as their thermal characterization. Three commercially available dielectric tape materials provided by Heraeus (CT700, CT707 and CT800) are investigated. The samples for determination of significant material parameters are prepared using the standard LTCC fabrication process. Results of the material characterization (chemical analysis, surface roughness electrical and mechanical properties) are presented. In addition thermo-electrical and-mechanical characterization of investigated tapes analysis is performed.

Mechanically Enhanced Precipitation of Phase-Inversion Sprayed Polyurethane Scaffold May Be Used to Match Tissue Specific Anisotropy

2009 ◽  
Author(s):  
James P. Kennedy ◽  
Robert W. Hitchcock
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Cell Culture ◽  
Pore Size ◽  
Phase Inversion ◽  
Anisotropy Ratio ◽  
Material Anisotropy ◽  
Polyurethane Scaffold ◽  
Stiffness Anisotropy

Methods of creating a scaffold for tissue engineering that allow for modification of properties such as pore size, porosity, and anisotropy are essential for tissue engineering applications. For example the pore size and material anisotropy have been shown to affect cardiomyocyte elongation and alignment [1]. Phase-inversion spray polymerization (PISP) is a method for rapidly precipitating polymers onto a surface by depositing the polymer solution simultaneously with a nonsolvent, and may be used to create biocompatible scaffolds of engineered morphological and mechanical properties by varying the solubility of the polymer in the nonsolvent [2]. We report here on the fabrication of scaffolds using different nonsolvents and methods of in-process elongation that allow for control of stiffness, anisotropy ratio, porosity, and in vitro cell culture.

scholarly journals Heat-Inactivation of Fetal and Newborn Sera Did Not Impair the Expansion and Scaffold Engineering Potentials of Fibroblasts

2021 ◽  
Vol 8 (11) ◽  
pp. 184
Author(s):  
Félix-Antoine Pellerin ◽  
Christophe Caneparo ◽  
Ève Pellerin ◽  
Stéphane Chabaud ◽  
Martin Pelletier ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Cell Culture ◽  
Growth Factors ◽  
Production Process ◽  
Significant Benefit ◽  
Heat Inactivation ◽  
Histological Appearance

Heat inactivation of bovine sera is routinely performed in cell culture laboratories. Nevertheless, it remains debatable whether it is still necessary due to the improvement of the production process of bovine sera. Do the benefits balance the loss of many proteins, such as hormones and growth factors, that are very useful for cell culture? This is even truer in the case of tissue engineering, the processes of which is often very demanding. This balance is examined here, from nine populations of fibroblasts originating from three different organs, by comparing the capacity of adhesion and proliferation of cells, their metabolism, and the capacity to produce the stroma; their histological appearance, thickness, and mechanical properties were also evaluated. Overall, serum inactivation does not appear to provide a significant benefit.

The effects of common footwear on stance-phase mechanical properties of the prosthetic foot-shoe system

2017 ◽  
Vol 42 (2) ◽  
pp. 198-207 ◽  
Author(s):  
Matthew J Major ◽  
Joel Scham ◽  
Michael Orendurff
Keyword(s):  
Mechanical Properties ◽  
Repeated Measures ◽  
Clinical Relevance ◽  
Stance Phase ◽  
Mechanical Characteristics ◽  
Mechanical Characterization ◽  
Test Machine ◽  
Mechanical Function ◽  
Prosthetic Foot ◽  
Prosthetic Feet

Background:Prosthetic feet are prescribed based on their mechanical function and user functional level. Subtle changes to the stiffness and hysteresis of heel, midfoot, and forefoot regions can influence the dynamics and economy of gait in prosthesis users. However, the user’s choice of shoes may alter the prosthetic foot-shoe system mechanical characteristics, compromising carefully prescribed and rigorously engineered performance of feet.Objectives:Observe the effects of footwear on the mechanical properties of the prosthetic foot-shoe system including commonly prescribed prosthetic feet.Study design:Repeated-measures, Mechanical characterization.Methods:The stiffness and energy return was measured using a hydraulic-driven materials test machine across combinations of five prosthetic feet and four common shoes as well as a barefoot condition.Results:Heel energy return decreased by an average 4%–9% across feet in all shoes compared to barefoot, with a cushioned trainer displaying the greatest effect. Foot designs that may improve perceived stability by providing low heel stiffness and rapid foot-flat were compromised by the addition of shoes.Conclusion:Shoes altered prosthesis mechanical characteristics in the sagittal and frontal planes, suggesting that shoe type should be controlled or reported in research comparing prostheses. Understanding of how different shoes could alter certain gait-related characteristics of prostheses may aid decisions on footwear made by clinicians and prosthesis users.Clinical relevanceShoes can alter function of the prosthetic foot-shoe system in unexpected and sometimes undesirable ways, often causing similar behavior across setups despite differences in foot design, and prescribing clinicians should carefully consider these effects on prosthesis performance.

scholarly journals Synthesis and Characterizations of a Collagen-Rich Biomembrane with Potential for Tissue-Guided Regeneration

2019 ◽  
Vol 13 (03) ◽  
pp. 295-302 ◽  
Author(s):  
Marcos J. Silva ◽  
Carolina P. Gonçalves ◽  
Kleber M. Galvão ◽  
Paulo H. P. D’Alpino ◽  
Fábio D. Nascimento
Keyword(s):  
Mechanical Properties ◽  
Mechanical Characteristics ◽  
Guided Bone Regeneration ◽  
Commercial Products ◽  
Physical Chemical ◽  
Strength And Deformation ◽  
Mechanical Tensile ◽  
Intestinal Submucosa ◽  
Deformation Tests ◽  
Better Than

Abstract Objectives In this study, a collagen-rich biomembrane obtained from porcine ­intestinal submucosa for application in guided bone regeneration was developed and characterized. Then, its biological and mechanical properties were compared with that of commercial products (GenDerm [Baumer], Lumina-Coat [Critéria], Surgitime PTFE [Bionnovation], and Surgidry Dental F [Technodry]). Materials and Methods The biomembrane was extracted from porcine intestinal submucosa. Scanning electron microscopy, spectroscopic dispersive energy, glycosaminoglycan quantification, and confocal microscopy by intrinsic fluorescence were used to evaluate the collagen structural patterns of the biomembrane. Mechanical tensile and deformation tests were also performed. Statistical Analysis  The results of the methods used for experimental membrane characterizations were compared with that obtained by the commercial membranes and statistically analyzed (significance of 5%). Results The collagen-rich biomembrane developed also exhibited a more organized, less porous collagen fibril network, with the presence of glycosaminoglycans. The experimental biomembrane exhibited mechanical properties, tensile strength, and deformation behavior with improved average stress/strain when compared with other commercial membranes tested. Benefits also include a structured, flexible, and ­bioresorbable characteristics scaffold. Conclusions The experimental collagen-rich membrane developed presents physical–chemical, molecular, and mechanical characteristics similar to or better than that of the commercial products tested, possibly allowing it to actively participating in the process of bone neoformation.

Poly(glycerol sebacate) – a revolutionary biopolymer

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Israd H. Jaafar ◽  
Sabrina S. Jedlicka ◽  
John P. Coulter
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Cell Culture ◽  
Surface Modification ◽  
Mammalian Cell Culture ◽  
Chemical Properties ◽  
Tunable Mechanical Properties ◽  
And Chemical Properties

Abstract Novel materials possessing physical, mechanical, and chemical properties similar to those found in vivo provide a potential platform for building artificial microenvironments for tissue engineering applications. Poly(glycerol sebacate) is one such material. It has tunable mechanical properties within the range of common tissue, and favorable cell response without surface modification with adhesive ligands, and biodegradability. In this chapter, an overview of the material is presented, focusing on synthesis, characterization, microfabrication, use as a substrate in in vitro mammalian cell culture, and degradation characteristics.

MECHANICAL CHARACTERISTICS OF CAST AC7AV ALLOY AFTER ALTERNATIVE MULTI-PASS FRICTION STIR PROCESSING

2010 ◽  
Vol 17 (01) ◽  
pp. 69-72 ◽  
Author(s):  
JAE-CHEUL PARK ◽  
SEONG-JONG KIM
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Processing ◽  
Mechanical Characteristics ◽  
Mg Alloy ◽  
Al Alloy ◽  
Friction Stir ◽  
Friction Heat ◽  
Alternative Method ◽  
Better Than

Friction stir processing (FSP) was used to improve the mechanical characteristics and microstructure of AC7AV cast Al–Mg alloy. The mechanical characteristics of AC7AV deteriorated due to significant defects caused by excessive friction heat after being subjected to multi-pass FSP. An alternative method of multi-pass FSP with two traveling directions was used to solve the defect problems in multi-pass FSP for cast AC7AV Al alloy. The results of various multi-pass FSP experiments showed that the mechanical properties of the cast AC7AV Al alloy specimens subjected to this alternative multi-pass FSP were better than those produced by the conventional multi-pass FSP method.

Electron Microscopic Observation of the Longitudinal Organization of Poly (p-Phenylene Terephthalamide) Fibers

1982 ◽  
Vol 40 ◽  
pp. 680-681
Author(s):  
Li Li-Sheng ◽  
L.F. Allard ◽  
W.C. Bigelow
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Microscopic Observation ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Aromatic Polyamides ◽  
Radial Arrangement ◽  
Scanning Electron ◽  
Better Than

The aromatic polyamides form a class of fibers having mechanical properties which are much better than those of aliphatic polyamides. Currently, the accepted morphology of these fibers as proposed by M.G. Dobb, et al. is a radial arrangement of pleated sheets, with the plane of the pleats parallel to the axis of the fiber. We have recently obtained evidence which supports a different morphology of this type of fiber, using ultramicrotomy and ion-thinning techniques to prepare specimens for transmission and scanning electron microscopy.

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