Exogenous Temporal Assessment of Lysyl Oxidase on Engineered Articular Cartilage as a Method for Promoting Collagen Crosslinking

2012 ◽  
Author(s):  
Eleftherios A. Makris ◽  
Donald J. Responte ◽  
Jerry Hu ◽  
Kyriacos A. Athanasiou
Keyword(s):  
Articular Cartilage ◽  
Self Assembly ◽  
Lysyl Oxidase ◽  
Compressive Properties ◽  
Collagen Crosslinking ◽  
3 Dimensional ◽  
Assembly Method ◽  
The Poor ◽  
Challenging Environment ◽  
Made In

The poor ability of articular cartilage (AC) to repair following disease and/or injury makes the tissue a key target for cell-based regenerative strategies. Progress made in the development of tissue engineered AC, using a 3-dimensional, scaffoldless, self-assembly method, has yielded neotissues with compressive properties on par with native tissue [1]. However, the tensile properties of these engineered tissues remain to be improved. This is particularly important because, while the tissue functions mainly in compression, the tensile strains within the joint nonetheless present a mechanically challenging environment.

Enhancing the Mechanical Properties of Articular Cartilage Through Enzyme-Mediated Collagen Crosslinking as Regulated by Low Oxygen Tension

2012 ◽  
Author(s):  
Eleftherios A. Makris ◽  
Jerry Hu ◽  
Kyriacos A. Athanasiou
Keyword(s):  
Articular Cartilage ◽  
Oxygen Tension ◽  
Low Oxygen ◽  
Healthy Human ◽  
Collagen Crosslinking ◽  
Human Knee ◽  
Hypoxic Conditions ◽  
The Poor ◽  
Human Knee Joint ◽  
Low Oxygen Tension

The poor ability of articular cartilage to repair following disease and injury makes the tissue a key target for reparative and regenerative medicine strategies. It has been shown that human knee joint resides under hypoxic conditions. Oxygen tension in healthy human synovium is between 7 and 11% and in articular cartilage may therefore be as low as 1–2.5% [1].

Self-assembly of sodium 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoate into ultralong microbelts

CrystEngComm ◽  
2014 ◽  
Vol 16 (32) ◽  
pp. 7507-7514 ◽  
Author(s):  
Hongyan Zhao ◽  
Hongbiao Chen ◽  
Yong Gao ◽  
Huaming Li
Keyword(s):  
Electrical Properties ◽  
Self Assembly ◽  
Optical And Electrical Properties ◽  
Assembly Method ◽  
The Poor ◽  
Poor Solvent

Ultralong SDB microbelts with interesting optical and electrical properties were successfully fabricated by the poor solvent mediated self-assembly method.

Overlapping Allografts Provide Superior and More Reliable Surface Topography Matching Than Oblong Allografts: A Computer-Simulated Model Study

2021 ◽  
pp. 036354652110030
Author(s):  
Hailey P. Huddleston ◽  
Atsushi Urita ◽  
William M. Cregar ◽  
Theodore M. Wolfson ◽  
Brian J. Cole ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Surface Topography ◽  
Osteochondral Allograft ◽  
Cartilage Defects ◽  
Radius Of Curvature ◽  
Cartilage Surface ◽  
3 Dimensional ◽  
Cloud Models ◽  
And Cartilage ◽  
Osteochondral Allografts

Background: Osteochondral allograft transplantation is 1 treatment option for focal articular cartilage defects of the knee. Large irregular defects, which can be treated using an oblong allograft or multiple overlapping allografts, increase the procedure’s technical complexity and may provide suboptimal cartilage and subchondral surface matching between donor grafts and recipient sites. Purpose: To quantify and compare cartilage and subchondral surface topography mismatch and cartilage step-off for oblong and overlapping allografts using a 3-dimensional simulation model. Study Design: Controlled laboratory study. Methods: Human cadaveric medial femoral hemicondyles (n = 12) underwent computed tomography and were segmented into cartilage and bone components using 3-dimensional reconstruction and modeling software. Segments were then exported into point-cloud models. Modeled defect sizes of 17 × 30 mm were created on each recipient hemicondyle. There were 2 types of donor allografts from each condyle utilized: overlapping and oblong. Grafts were virtually harvested and implanted to optimally align with the defect to provide minimal cartilage surface topography mismatch. Least mean squares distances were used to measure cartilage and subchondral surface topography mismatch and cartilage step-off. Results: Cartilage and subchondral topography mismatch for the overlapping allograft group was 0.27 ± 0.02 mm and 0.80 ± 0.19 mm, respectively. In comparison, the oblong allograft group had significantly increased cartilage (0.62 ± 0.43 mm; P < .001) and subchondral (1.49 ± 1.10 mm; P < .001) mismatch. Cartilage step-off was also found to be significantly increased in the oblong group compared with the overlapping group ( P < .001). In addition, overlapping allografts more reliably provided a significantly higher percentage of clinically acceptable (0.5- and 1-mm thresholds) cartilage surface topography matching (overlapping: 100% for both 0.5 and 1 mm; oblong: 90% for 1 mm and 56% for 0.5 mm; P < .001) and cartilage step-off (overlapping: 100% for both 0.5 and 1 mm; oblong: 86% for 1 mm and 12% for 0.5 mm; P < .001). Conclusion: This computer simulation study demonstrated improved topography matching and decreased cartilage step-off with overlapping osteochondral allografts compared with oblong osteochondral allografts when using grafts from donors that were not matched to the recipient condyle by size or radius of curvature. These findings suggest that overlapping allografts may be superior in treating large, irregular osteochondral defects involving the femoral condyles with regard to technique. Clinical Relevance: This study suggests that overlapping allografts may provide superior articular cartilage surface topography matching compared with oblong allografts and do so in a more reliable fashion. Surgeons may consider overlapping allografts over oblong allografts because of the increased ease of topography matching during placement.

scholarly journals Taming nitroformate through encapsulation with nitrogen-rich hydrogen-bonded organic frameworks

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jichuan Zhang ◽  
Yongan Feng ◽  
Richard J. Staples ◽  
Jiaheng Zhang ◽  
Jean’ne M. Shreeve
Keyword(s):  
Thermal Stability ◽  
Hydrogen Bonds ◽  
Self Assembly ◽  
Energetic Materials ◽  
Decomposition Temperature ◽  
High Oxygen Content ◽  
The Poor ◽  
Simple Preparation ◽  
First Time ◽  
Hydrogen Bonded

AbstractOwing to its simple preparation and high oxygen content, nitroformate [−C(NO2)3, NF] is an extremely attractive oxidant component for propellants and explosives. However, the poor thermostability of NF-based derivatives has been an unconquerable barrier for more than 150 years, thus hindering its application. In this study, the first example of a nitrogen-rich hydrogen-bonded organic framework (HOF-NF) is designed and constructed through self-assembly in energetic materials, in which NF anions are trapped in pores of the resulting framework via the dual force of ionic and hydrogen bonds from the strengthened framework. These factors lead to the decomposition temperature of the resulting HOF-NF moiety being 200 °C, which exceeds the challenge of thermal stability over 180 °C for the first time among NF-based compounds. A large number of NF-based compounds with high stabilities and excellent properties can be designed and synthesized on the basis of this work.

Different Adsorption States between Thiophene and α-Bithiophene Thin Films Prepared by Self-Assembly Method

2003 ◽  
Vol 42 (Part 2, No. 7B) ◽  
pp. L852-L855 ◽  
Author(s):  
Eisuke Ito ◽  
Jaegeun Noh ◽  
Masahiko Hara
Keyword(s):  
Thin Films ◽  
Self Assembly ◽  
Assembly Method

The synthesis of calcium carbonate microparticles with multiple morphologies through self-assembly method

2015 ◽  
Vol 284 ◽  
pp. 253-256 ◽  
Author(s):  
Guang Yuan ◽  
Xiaofeng Chen ◽  
Xian Li ◽  
Qiming Liang ◽  
Guohou Miao ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Self Assembly ◽  
Assembly Method

The Big Push Déjà Vu: A Review of Jeffrey Sachs's The End of Poverty: Economic Possibilities for Our Time

2006 ◽  
Vol 44 (1) ◽  
pp. 96-105 ◽  
Author(s):  
William Easterly
Keyword(s):  
New York ◽  
Development Economics ◽  
Large Scale ◽  
The Poor ◽  
World Poverty ◽  
Incentive Problems ◽  
The 1950S ◽  
Déjà Vu ◽  
Big Push ◽  
Made In

Jeffrey Sachs's new book (The End of Poverty: Economic Possibilities for Our Time, Penguin Press: New York, 2005) advocates a “Big Push” featuring large increases in aid to finance a package of complementary investments in order to end world poverty. These recommendations are remarkably similar to those first made in the 1950s and 1960s in development economics. Today, as then, the Big Push recommendation overlooks the unsolvable information and incentive problems facing any large-scale planning exercise. A more promising approach would be to design incentives for aid agents to implement interventions piecemeal whenever they deliver large benefits for the poor relative to costs.

Preparation and Characterization of Polyaniline Nanotubes Doped with Different Acid

2013 ◽  
Vol 401-403 ◽  
pp. 663-666
Author(s):  
Xue Lian Bai ◽  
Jian Ting Mei ◽  
Zhong Guo Mu ◽  
Yun Bai
Keyword(s):  
Acetic Acid ◽  
Self Assembly ◽  
Ammonium Persulfate ◽  
Tetraacetic Acid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Property ◽  
Assembly Method ◽  
Polyaniline Nanotubes

Polyaniline (PANI) nanotubes were synthesized separately using amino acetic acid (AA), ethylenediamine tetraacetic acid (EDTA), oxalic acid (OA) as dopant and ammonium persulfate (APS) as oxidant by a self-assembly method. SEM, TEM,FTIR and X-ray diffraction (XRD) and applying the 4 probes method characterized the morphology, structure and property of the product. It was found that nanotubes morphology were synthesized when the [Aci/[A ratio is 1:2.The room template conductivity of the products were studied.

Chemically Responsive Polymer Inverse-Opal Photonic Crystal Films Created by a Self-Assembly Method

2016 ◽  
Vol 120 (22) ◽  
pp. 11938-11946 ◽  
Author(s):  
Huilin Zhao ◽  
Jianping Gao ◽  
Zeng Pan ◽  
Guanbo Huang ◽  
Xiaoyang Xu ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Self Assembly ◽  
Inverse Opal ◽  
Assembly Method ◽  
Responsive Polymer ◽  
Crystal Films

Hydrogen-Bonding Layer Protecting Polyelectrolyte Capsules and Its Mechanical Property Study with Atomic Force Microscope

2008 ◽  
Vol 8 (6) ◽  
pp. 2996-3002 ◽  
Author(s):  
Liqin Ge ◽  
Xing Wang ◽  
Long Ba ◽  
Zhongze Gu
Keyword(s):  
Hydrogen Bonding ◽  
Atomic Force Microscope ◽  
Elastic Deformation ◽  
Self Assembly ◽  
Laser Scanning ◽  
Confocal Laser ◽  
Bonding Layer ◽  
Layer By Layer ◽  
Assembly Method ◽  
Atomic Force

The hydrogen-bonding multilayered polyelectrolyte capsules with sizes around 6 μm were fabricated by layer-by-layer self-assembly method. The morphology of the obtained capsules was observed with Scanning Electron Microscope (SEM), Confocal Laser Scanning Microscope (CLSM) and Atomic Force Microscope (AFM), respectively. The elastic properties of the capsules were studied with AFM. The capsule was pressed by cantilever with different lengths, a glass bead glued at the end of the cantilever. The force curves were measured on the capsule in air. The Young's modulus of the capsule was obtained (E = 170 MPa for the loading). Results show that this model can predict the elastic deformation of the microcapsule. The accuracy of the elastic deformation of polymer capsule can be ensured using a cantilever of mediate stiffness. Our results show that the existence of the hydrogen-bonding layer makes the multilayered polyelectrolyte harder in comparison with the pure multilayered polyelectrolyte capsules.

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