scholarly journals Oriented Type I Collagen - A Review on Artificial Alignment Strategies

2021 ◽  
Vol 9 (2) ◽  
pp. 96-123
Author(s):  
Karina Ambrock ◽  
Bernd Grohe ◽  
Silvia Mittler
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Human Body ◽  
Type I Collagen ◽  
Da Vinci ◽  
Mechanical Stability ◽  
Leonardo Da Vinci ◽  
16Th Century ◽  
Type I ◽  
Abundant Protein

Collagen is the most abundant protein in the human body and serves many functions, from mechanical stability and elasticity in tendons and bone, to optical properties, such as transparency and a fine tuned refractive index in the cornea of the eye. Collagen has interested humankind for centuries: Leonardo Da Vinci studied and drew the tendons in the human body precisely in the 15th and 16th century. A look at the literature reveals easily > 200,000 papers. This article reviews oriented type I collagen artificial alignment strategies.

scholarly journals Optical Properties and van der Waals-London Dispersion Interactions in Inorganic and Biomolecular Assemblies

2014 ◽  
Vol 1619 ◽  
Author(s):  
Daniel M. Dryden ◽  
Yingfang Ma ◽  
Jacob Schimelman ◽  
Diana Acosta ◽  
Lijia Liu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Spectroscopic Ellipsometry ◽  
Density Functional ◽  
Type I Collagen ◽  
Strong Dependence ◽  
Van Der Waals ◽  
Fundamental Absorption Edge ◽  
Type I ◽  
Dispersion Interactions ◽  
London Dispersion

ABSTRACTThe optical properties and electronic structure of AlPO4, SiO2, Type I collagen, and DNA were examined to gain insight into the van der Waals-London dispersion behavior of these materials. Interband optical properties of AlPO4 and SiO2 were derived from vacuum ultraviolet spectroscopy and spectroscopic ellipsometry, and showed a strong dependence on the crystals’ constituent tetrahedral units, with strong implications for the role of phosphate groups in biological materials. The UV-Vis decadic molar absorption of four DNA oligonucleotides was measured, and showed a strong dependence on composition and stacking sequence. A film of Type I collagen was studied using spectroscopic ellipsometry, and showed a characteristic shoulder in the fundamental absorption edge at 6.05 eV. Ab initio calculations based on density functional theory corroborated the experimental results and provided further insights into the electronic structures, interband transitions and vdW-Ld interaction potentials for these materials.

Silver Core - Silver Oxide Shell Nanoparticles Embedded on Mesostructured Silica Films

2008 ◽  
Vol 3 ◽  
pp. 103-114 ◽  
Author(s):  
Guadalupe Valverde-Aguilar ◽  
Jorge A. García-Macedo ◽  
Víctor Rentería-Tapia
Keyword(s):  
Silver Nanoparticles ◽  
Refractive Index ◽  
Optical Properties ◽  
Absorption Spectrum ◽  
Silver Oxide ◽  
High Refractive Index ◽  
Oxide Shell ◽  
Metallic Silver ◽  
Type I ◽  
Silver Core

Metallic silver particles in the nanometer size range were obtained in SiO2 matrix by the reduction of AgNO3 with the non-ionic diblock copolymer (Brij 58). Hexagonal mesostructured sol-gel films were synthesized by dip-coating method using the surfactant Brij58 to produce channels into the film, which house the silver nanoparticles. Optical properties of the metallic nanoparticles were studied by UV-Vis spectroscopy, TEM and HRTEM images. The experimental absorption spectrum of the metallic silver nanoparticles exhibits an absorption band located at 438 nm and a shoulder at longer wavelength. The TEM images show randomly distributed silver nanoparticles (Type I) along with some oriented as long line (Type II). Both distributions exhibit a silver oxide shell around of them. The second shell covering the silver core - silver oxide shell system is related to the surfactant. The optical absorption spectrum was modelled using the Gans theory. The fit shows two main contributions related to metallic silver nanoparticles with different axial ratios, and surrounding of a dielectric medium with high refractive index. Presence of the high refractive index silver oxide shell was confirmed by X-ray diffraction technique. The contributions of silver core and silver oxide shell play important roles in the optical properties of the films.

The Mechanization of Design in the 16th Century: The Structural Formulae of Rodrigo Gil de Hontañón

1982 ◽  
Vol 41 (4) ◽  
pp. 281-293 ◽  
Author(s):  
Sergio Luis Sanabria
Keyword(s):  
Theoretical Analysis ◽  
Design Process ◽  
Structural Design ◽  
Da Vinci ◽  
Leonardo Da Vinci ◽  
16Th Century ◽  
Fundamental Identity ◽  
Geometric Thinking ◽  
Structural Formulae

The existing fragments of an architectural booklet by the 16th-century Spanish architect Rodrigo Gil de Hontañón reveal an ingenious attempt to systematize the design process by creating a sequence of formulaic procedures to be followed in ecclesiastical projects. The formulae are addressed to two more or less separate issues. The first is to synthesize Gothic and Classic proportioning methods, and demonstrate their fundamental identity. The second is to establish an independent "science" of structural design. Aside from the more theoretical writings of Leonardo da Vinci, the work of Rodrigo Gil is the principal evidence extant for the development of structural thinking among 16th-century master masons. Seven formulae discussed here are concerned with the correct depth of a buttress to support an arch or a rib vault. The formulae do not seem to have been derived through theoretical analysis, using the medieval Scientia de Ponderibus. Rather they are the result of new experimentation and traditional Gothic geometric thinking applied to classical arches, and of new arithmetic procedures applied to Gothic rib vaults.

Effect of Liquid/Powder Ratio on the Setting, Handling and Mechanical Properties of Collagen–Apatitic Cements

2011 ◽  
Vol 493-494 ◽  
pp. 415-421 ◽  
Author(s):  
N.J. Dunne ◽  
R. O’Hara ◽  
F. Buchanan ◽  
J. Orr
Keyword(s):  
Calcium Phosphate ◽  
Type I Collagen ◽  
Mechanical Stability ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Hardened Cement ◽  
Type I ◽  
Fibre Reinforcement ◽  
Compressive Properties ◽  
Collagen Fibres

Due to their insufficient mechanical stability and brittle nature, calcium phosphate cements (CPCs) have not been used for the treatment of vertebral fractures. Mechanical stability of human bone is provided by a complex interaction of type I collagen fibres and hydroxyapatite crystals. In the present study, fibre reinforcement of an apatitic calcium phosphate prepared at different liquid/powder ratio (LPR) was investigated. Different lengths of type I collagen fibres sourced from bovine Achilles tendon were used. Compressive strength and fracture behaviour were examined. Fibre addition of up to 5 wt.% had a significant influence on the compressive properties of the CPC. The mechanism of fibre reinforcement appeared to be crack bridging. Setting time and injectability of the CPC with fibre reinforcement was also investigated and decreased with fibre volume fraction. Increasing the LPR, improved the injectability and delayed the setting reaction. However, the compressive properties of the hardened cement were reduced as a consequence.

scholarly journals Enhancing Bioactivity of Hydroxyapatite Scaffolds Using Fibrous Type I Collagen

2021 ◽  
Vol 9 ◽  
Author(s):  
Paola Nitti ◽  
Sanosh Kunjalukkal Padmanabhan ◽  
Serena Cortazzi ◽  
Eleonora Stanca ◽  
Luisa Siculella ◽  
...  
Keyword(s):  
Weight Loss ◽  
Bone Tissue ◽  
Tissue Regeneration ◽  
Composite Structures ◽  
Type I Collagen ◽  
Mechanical Stability ◽  
Cold Water ◽  
Essential Feature ◽  
Bone Tissue Regeneration ◽  
Type I

In the field of bone tissue regeneration, the development of osteoconductive and osteoinductive scaffolds is an open challenge. The purpose of this work was the design and characterization of composite structures made of hydroxyapatite scaffold impregnated with a collagen slurry in order to mimic the bone tissue structure. The effect of magnesium and silicon ions enhancing both mechanical and biological properties of partially substituted hydroxyapatite were evaluated and compared with that of pure hydroxyapatite. The use of an innovative freeze-drying approach was developed, in which composite scaffolds were immersed in cold water, frozen and then lyophilized, thereby creating an open-pore structure, an essential feature for tissue regeneration. The mechanical stability of bone scaffolds is very important in the first weeks of slow bone regeneration process. Therefore, the biodegradation behavior of 3D scaffolds was evaluated by incubating them for different periods of time in Tris-HCl buffer. The microstructure observation, the weight loss measurements and mechanical stability up to 28 days of incubation (particularly for HA-Mg_Coll scaffolds), revealed moderate weight loss and mechanical performances reduction due to collagen dissolution. At the same time, the presence of collagen helps to protect the ceramic structure until it degrades. These results, combined with MTT tests, confirm that HA-Mg_Coll scaffolds may be the suitable candidate for bone remodeling.

scholarly journals Mapping the Ligand-binding Sites and Disease-associated Mutations on the Most Abundant Protein in the Human, Type I Collagen

2001 ◽  
Vol 277 (6) ◽  
pp. 4223-4231 ◽  
Author(s):  
Gloria A. Di Lullo ◽  
Shawn M. Sweeney ◽  
Jarmo Körkkö ◽  
Leena Ala-Kokko ◽  
James D. San Antonio
Keyword(s):  
Ligand Binding ◽  
Binding Sites ◽  
Type I Collagen ◽  
Type I ◽  
Abundant Protein ◽  
Human Type ◽  
Ligand Binding Sites
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