scholarly journals Hierarchical Characterization and Nanomechanical Assessment of Biomimetic Scaffolds Mimicking Lamellar Bone via Atomic Force Microscopy Cantilever-Based Nanoindentation

Materials ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1257 ◽  
Author(s):  
Brian Wingender ◽  
Yongliang Ni ◽  
Yifan Zhang ◽  
Curtis Taylor ◽  
Laurie Gower

The hierarchical structure of bone and intrinsic material properties of its two primary constituents, carbonated apatite and fibrillar collagen, when being synergistically organized into an interpenetrating hard-soft composite, contribute to its excellent mechanical properties. Lamellar bone is the predominant structural motif in mammalian hard tissues; therefore, we believe the fabrication of a collagen/apatite composite with a hierarchical structure that emulates bone, consisting of a dense lamellar microstructure and a mineralized collagen fibril nanostructure, is an important first step toward the goal of regenerative bone tissue engineering. In this work, we exploit the liquid crystalline properties of collagen to fabricate dense matrices that assemble with cholesteric organization. The matrices were crosslinked via carbodiimide chemistry to improve mechanical properties, and are subsequently mineralized via the polymer-induced liquid-precursor (PILP) process to promote intrafibrillar mineralization. Neither the crosslinking procedure nor the mineralization affected the cholesteric collagen microstructures; notably, there was a positive trend toward higher stiffness with increasing crosslink density when measured by cantilever-based atomic force microscopy (AFM) nanoindentation. In the dry state, the average moduli of moderately (X51; 4.8 ± 4.3 GPa) and highly (X76; 7.8 ± 6.7 GPa) crosslinked PILP-mineralized liquid crystalline collagen (LCC) scaffolds were higher than the average modulus of bovine bone (5.5 ± 5.6 GPa).

2000 ◽  
Vol 39 (Part 1, No. 6B) ◽  
pp. 3711-3716 ◽  
Author(s):  
Hatsuki Shiga ◽  
Yukako Yamane ◽  
Etsuro Ito ◽  
Kazuhiro Abe ◽  
Kazushige Kawabata ◽  
...  

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 652
Author(s):  
Divine Sebastian ◽  
Chun-Wei Yao ◽  
Lutfun Nipa ◽  
Ian Lian ◽  
Gary Twu

In this work, a mechanically durable anticorrosion superhydrophobic coating is developed using a nanocomposite coating solution composed of silica nanoparticles and epoxy resin. The nanocomposite coating developed was tested for its superhydrophobic behavior using goniometry; surface morphology using scanning electron microscopy and atomic force microscopy; elemental composition using energy dispersive X-ray spectroscopy; corrosion resistance using atomic force microscopy; and potentiodynamic polarization measurements. The nanocomposite coating possesses hierarchical micro/nanostructures, according to the scanning electron microscopy images, and the presence of such structures was further confirmed by the atomic force microscopy images. The developed nanocomposite coating was found to be highly superhydrophobic as well as corrosion resistant, according to the results from static contact angle measurement and potentiodynamic polarization measurement, respectively. The abrasion resistance and mechanical durability of the nanocomposite coating were studied by abrasion tests, and the mechanical properties such as reduced modulus and Berkovich hardness were evaluated with the aid of nanoindentation tests.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1661
Author(s):  
Katarzyna Adamiak ◽  
Katarzyna Lewandowska ◽  
Alina Sionkowska

Collagen films are widely used as adhesives in medicine and cosmetology. However, its properties require modification. In this work, the influence of salicin on the properties of collagen solution and films was studied. Collagen was extracted from silver carp skin. The rheological properties of collagen solutions with and without salicin were characterized by steady shear tests. Thin collagen films were prepared by solvent evaporation. The structure of films was researched using infrared spectroscopy. The surface properties of films were investigated using Atomic Force Microscopy (AFM). Mechanical properties were measured as well. It was found that the addition of salicin modified the roughness of collagen films and their mechanical and rheological properties. The above-mentioned parameters are very important in potential applications of collagen films containing salicin.


2018 ◽  
Vol 114 (3) ◽  
pp. 513a
Author(s):  
Yuri M. Efremov ◽  
Mirian Velay-Lizancos ◽  
Daniel M. Suter ◽  
Pablo D. Zavattieri ◽  
Arvind Raman

PLoS ONE ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. e30204 ◽  
Author(s):  
David Martinez-Martin ◽  
Carolina Carrasco ◽  
Mercedes Hernando-Perez ◽  
Pedro J. de Pablo ◽  
Julio Gomez-Herrero ◽  
...  

Author(s):  
Hosam Gharib Abdelhady

Objectives: This research aims at investigating the effect of nano-encapsulating the MagnevistTM, a magnetic resonance imaging agent, within generation four, 1, 4- diaminobutane core polyamidoamine dendrimers on their molecular morphology and their nano-mechanical properties in liquid.Methods: Atomic force microscopy was applied in its imaging and force measuring modes to investigate, on the molecular scale, the morphological and nano-mechanical changes in generation four, 1, 4-diaminobutane core polyamidoamine dendrimers due to the nano-encapsulation of Magnevist in liquid.Results: The weight gain of dendrimers indicates the loading of ~ 30 Magnevist molecules. This has increased the rigidity of the dendrimer molecules, compared to unloaded dendrimers. Atomic force microscopy showed individual well-defined nano-spherical particles with nanoscopic dimensions of (40±13 nm in diameter and 4.38±0.54 nm in height). In contrast, imaging of non encapsulated dendrimers revealed loose aggregates of 15±3.5 nm in diameter and 0.9±0.2 nm in height.Conclusions: The atomic force microscopy, in liquid, was successfully applied to differentiate between Magnevist nano-encapsulated and non-encapsulated dendrimers, in their morphology and in their nano-mechanical properties. The results confirm the nano-encapsulation of Magnevist within generation four, 1,4-diaminobutane core polyamidoamine dendrimers. This loading increased the rigidity of the nanoencapsulated dendrimer, packed ~ 9 Magnevist-G 4 molecules together and may probably enhance the magnetic resonance images and increase their duration of time in the bloodstream when compared with Magnevist alone. Thus elongating the imaging sessions without the need for additional contrast agent doses.


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