Biomimetic Mineralization of an Aligned, Self-Assembled Collagenous Matrix.

1991 ◽  
Vol 255 ◽  
Author(s):  
David Christiansen ◽  
Frederick H. Silver
Keyword(s):  
Mechanical Test ◽  
Double Diffusion ◽  
Diffusion Chamber ◽  
Microscopic Investigation ◽  
Collagen Fibers ◽  
Test Results ◽  
Biomimetic Mineralization ◽  
Collagenous Matrix ◽  
Self Assembled

AbstractAn in-vitro method of mineralizing an aligned, self-assembled collagenous matrix is presented. Reconstituted collagen fibers were mineralized by exposure to saturated solutions of calcium and phosphate of varying pH in a double diffusion chamber for seven days at room temperature. Microscopic investigation of the mineral precipitate within the fibers indicate the formation of hydroxyapatite crystals with features comparable to mineral observed in bone and avian tendon. Mechanical test results indicate that tensile strength and tangent modulus increase after mineralization in comparison to unmineralized control fibers. These results suggest that mineralization of collagen fiber in-vitro may parallel some of the events seen in mineralization of bone and turkey tendon. In addition, mineralized collagen fibers may be useful in the design of composites for the replacement or augmentation of hard tissue

A Novel Self-Assembled Collagenous Matrix which Serves as a Template for Oriented Growth of Hydroxyapatite Crystal

1995 ◽  
Vol 414 ◽  
Author(s):  
D. L. Christiansen ◽  
G. D. Pins ◽  
E. K. Huang ◽  
F. H. Silver
Keyword(s):  
Type I Collagen ◽  
Double Diffusion ◽  
Diffusion Chamber ◽  
Uniaxial Tensile ◽  
Type I ◽  
Oriented Growth ◽  
Selected Area Electron Diffraction ◽  
Hydroxyapatite Crystal ◽  
Self Assembled ◽  
Calcified Tissues

AbstractCollagen fibers self-assembled from solutions of molecular type I collagen were mineralized at pH 9.5, by exposure to super-saturated solutions of calcium and phosphate for a one week period in a double diffusion chamber. Uniaxial tensile mechanical properties increased with mineralization and electron microscopy of the mineral formed within the fiber was morphologically similar to the mineral phase of calcified tissues. Selected area electron diffraction confirms the presence of hydroxyapatite crystal. Further, the aligned fibrillar substructure serves as a template for the orientation of the c-axis diffraction maxima of the hydroxyapatite. These results indicate that an aligned system composed exclusively of selfassembled type I collagen fibrils serves as a scaffold for oriented growth of mineral analogous to calcification in vertebrate bone.

Biological and biomedical applications of collagenous biomaterials

1990 ◽  
Vol 48 (3) ◽  
pp. 856-857
Author(s):  
Yasushi P. Kato ◽  
Michael G. Dunn ◽  
Frederick H. Silver ◽  
Arthur J. Wasserman
Keyword(s):  
Biomedical Applications ◽  
Soft Tissues ◽  
Collagen Fibers ◽  
Bone Collagen ◽  
Cover Slip ◽  
Fibroblast Migration ◽  
Cellular Expression ◽  
Defect Repair

Collagenous biomaterials have been used for growing cells in vitro as well as for augmentation and replacement of hard and soft tissues. The substratum used for culturing cells is implicated in the modulation of phenotypic cellular expression, cellular orientation and adhesion. Collagen may have a strong influence on these cellular parameters when used as a substrate in vitro. Clinically, collagen has many applications to wound healing including, skin and bone substitution, tendon, ligament, and nerve replacement. In this report we demonstrate two uses of collagen. First as a fiber to support fibroblast growth in vitro, and second as a demineralized bone/collagen sponge for radial bone defect repair in vivo.For the in vitro study, collagen fibers were prepared as described previously. Primary rat tendon fibroblasts (1° RTF) were isolated and cultured for 5 days on 1 X 15 mm sterile cover slips. Six to seven collagen fibers, were glued parallel to each other onto a circular cover slip (D=18mm) and the 1 X 15mm cover slip populated with 1° RTF was placed at the center perpendicular to the collagen fibers. Fibroblast migration from the 1 x 15mm cover slip onto and along the collagen fibers was measured daily using a phase contrast microscope (Olympus CK-2) with a calibrated eyepiece. Migratory rates for fibroblasts were determined from 36 fibers over 4 days.

scholarly journals In Vitro Cellular Uptake Studies of Self-Assembled Fluorinated Nanoparticles Labelled with Antibodies

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1906
Author(s):  
Mona Atabakhshi-Kashi ◽  
Mónica Carril ◽  
Hossein Mahdavi ◽  
Wolfgang J. Parak ◽  
Carolina Carrillo-Carrion ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cellular Uptake ◽  
Hydrophobic Interactions ◽  
Intrinsic Properties ◽  
Wide Range ◽  
Self Assembled ◽  
Uptake Studies ◽  
Targeting Ability ◽  
Fluorinated Nanoparticles

Nanoparticles (NPs) functionalized with antibodies (Abs) on their surface are used in a wide range of bioapplications. Whereas the attachment of antibodies to single NPs to trigger the internalization in cells via receptor-mediated endocytosis has been widely studied, the conjugation of antibodies to larger NP assemblies has been much less explored. Taking into account that NP assemblies may be advantageous for some specific applications, the possibility of incorporating targeting ligands is quite important. Herein, we performed the effective conjugation of antibodies onto a fluorescent NP assembly, which consisted of fluorinated Quantum Dots (QD) self-assembled through fluorine–fluorine hydrophobic interactions. Cellular uptake studies by confocal microscopy and flow cytometry revealed that the NP assembly underwent the same uptake procedure as individual NPs; that is, the antibodies retained their targeting ability once attached to the nanoassembly, and the NP assembly preserved its intrinsic properties (i.e., fluorescence in the case of QD nanoassembly).

scholarly journals Performance Study of Grass-Derived Nano-Cellulose and Polycaprolactone Composites for 3D Printing

2021 ◽  
Vol 11 (3) ◽  
pp. 1273
Author(s):  
Chen Feng ◽  
Jiping Zhou ◽  
Xiaodong Xu ◽  
Yani Jiang ◽  
Hongcan Shi ◽  
...  
Keyword(s):  
3D Printing ◽  
Mechanical Test ◽  
Chemical Properties ◽  
Test Results ◽  
Performance Study ◽  
Compression Process ◽  
Ansys Fluent ◽  
Nano Cellulose ◽  
Physical And Chemical ◽  
And Chemical Properties

In recent years, 3D printing has received increasing attention from researchers. This technology overcomes the limitations of traditional technologies by printing precise and personalized scaffold with arbitrary shapes, pore structures, and porosities for the applications in various tissues. The cellulose nanocrystal (CNC) is extracted from Humulus Japonicus (HJS) and mixed with poly(ε-caprolactone) (PCL) to prepare a series of CNC/PCL composites for printing. Based on the analysis of the physical and chemical properties of the series of the CNC/PCL composites, an optimal mass ratio of CNC to PCL was obtained. The Solidworks was used to simulate the stretching and compression process of the scaffolds with three different patterns under an external force. The flow of nutrient solution in the scaffolds with different patterns was simulated by ANSYS FLUENT, and then a new optimization scaffold pattern with a concave hexagon shape was advised based on the simulation results. Collectively, the mechanical test results of the material and scaffold confirmed that the optimal filling amount of the CNC was 5%, and the scaffold pattern with concave hexagon shape exhibited better mechanical properties and suitable for the transport of cells and nutrients, which is expected to be more widely used in 3D printing.

Transient liquid phase bonding of Cu and Al using metallic particles interlayers

2021 ◽  
pp. 095440542098823
Author(s):  
Alireza Zaheri ◽  
Mohammadreza Farahani ◽  
Alireza Sadeghi ◽  
Naser Souri
Keyword(s):  
Liquid Phase ◽  
Mechanical Test ◽  
Transient Liquid Phase ◽  
Transient Liquid Phase Bonding ◽  
Joint Interface ◽  
Test Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metallic Particles ◽  
Powder Interlayer

The bonding strength, and microstructures of Cu and Al couples using metallic powders as interlayer during transient liquid phase bonding (TLP bonding) were investigated. The interfacial morphologies and microstructures were studied by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, and X-ray diffraction. First, to explore the optimum bonding time and temperature, nine samples were bonded without interlayers in a vacuum condition. Mechanical test results indicated that bonding at 560°C in 20 min returns the highest bond strength (84% of Al). This bonding condition was used to join ten samples with powder interlayers. Powders were prepared by mixing different combinations of Cu, Al (+Fe nanoparticles) and Zn. In the bonding zone, different Cu9Al4, CuAl, and CuAl2 intermetallic co-precipitate. The strongest bonding is formed in the sample with the 70Al (+Fe)-30Cu powder interlayer. Powder interlayers present thinner and more uniform intermetallic layers at the joint interface.

scholarly journals A Proposed Fabrication Method of Novel PCL-GEL-HAp Nanocomposite Scaffolds for Bone Tissue Engineering Applications

2010 ◽  
Vol 19 (4) ◽  
pp. 096369351001900 ◽  
Author(s):  
A. Hamlekhan ◽  
M. Mozafari ◽  
N. Nezafati ◽  
M. Azami ◽  
H. Hadipour
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Mechanical Test ◽  
Fibroblast Cell ◽  
Mouse Fibroblast ◽  
Fabrication Method ◽  
Engineering Applications ◽  
Poly Caprolactone

In this study, poly(∊-caprolactone) (PCL), gelatin (GEL) and nanocrystalline hydroxyapatite (HAp) was applied to fabricate novel PCL-GEL-HAp nanaocomposite scaffolds through a new fabrication method. With the aim of finding the best fabrication method, after testing different methods and solvents, the best method and solvents were found, and the nanocomposites were prepared through layer solvent casting combined with freeze-drying. Acetone and distillated water were used as the PCL and GEL solvents, respectively. The mechanical test showed that the increasing of the PCL weight through the scaffolds caused the improvement of the final nanocomposite mechanical behavior due to the increasing of the ultimate stress, stiffness and elastic modulus (8 MPa for 0% wt PCL to 23.5 MPa for 50% wt PCL). The biomineralization investigation of the scaffolds revealed the formation of bone-like apatite layers after immersion in simulated body fluid (SBF). In addition, the in vitro cytotoxity of the scaffolds using L929 mouse fibroblast cell line (ATCC) indicated no sign of toxicity. These results indicated that the fabricated scaffold possesses the prerequisites for bone tissue engineering applications.

Multifunctional self-assembled cationic peptide nanostructures efficiently carry plasmid DNA in vitro and exhibit antimicrobial activity with minimal toxicity

2014 ◽  
Vol 2 (30) ◽  
pp. 4848-4861 ◽  
Author(s):  
Santosh Yadav ◽  
Manohar Mahato ◽  
Rajiv Pathak ◽  
Diksha Jha ◽  
Bipul Kumar ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Plasmid Dna ◽  
Cationic Peptide ◽  
Minimal Toxicity ◽  
Amphiphilic Peptide ◽  
Self Assembled ◽  
Multifunctional Properties

An amphiphilic peptide–aminoglycoside (Pep–Neo) conjugate has been synthesized, self-assembled into nanostructures and evaluated for its multifunctional properties.

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