scholarly journals Development and AFM study of porous scaffolds for wound healing applications

2004 ◽  
Vol 18 (4) ◽  
pp. 587-596 ◽  
Author(s):  
T. A. Doneva ◽  
H. B. Yin ◽  
P. Stephens ◽  
W. R. Bowen ◽  
D. W. Thomas
Keyword(s):  
Atomic Force Microscopy ◽  
Wound Healing ◽  
Human Fibroblasts ◽  
Three Dimensional ◽  
Positive Influence ◽  
Porous Scaffolds ◽  
Force Microscopy ◽  
Cellular Assays ◽  
Atomic Force

An engineering approach to the development of biomaterials for promotion of wound healing emphasises the importance of a well‒controlled architecture and concentrates on optimisation of morphology and surface chemistry to stimulate guidance of the cells within the wound environment. A series of three‒dimensional porous scaffolds with 80–90% bulk porosity and fully interconnected macropores were prepared from two biodegradable materials – cellulose acetate (CA) and poly (lactic‒co‒glycolic acid) (PLGA) through the phase inversion mechanism of formation. Surface morphology of obtained scaffolds was determined using atomic force microscopy (AFM) in conjunction with optical microscopy. Scanning Electron Microscopy (SEM) was applied to characterise scaffolds bulk morphology. Biocompatibility and biofunctionality of the prepared materials were assessed through a systematic study of cell/material interactions using atomic force microscopy (AFM) methodologies together within vitrocellular assays. Preliminary data with human fibroblasts demonstrated a positive influence of both scaffolds on cellular attachment and growth. The adhesion of cells on both biomaterials were quantified by AFM force measurements in conjunction with a cell probe technique since, for the first time, a fibroblast probe has been successfully developed and optimal conditions of immobilisation of the cells on the AFM cantilever have been experimentally determined.

scholarly journals Imaging and force-distance analysis of human fibroblasts in vitro by atomic force microscopy

Cytometry ◽  
1999 ◽  
Vol 36 (3) ◽  
pp. 254-264 ◽  
Author(s):  
Gillian R. Bushell ◽  
Colm Cahill ◽  
Frank M. Clarke ◽  
Christopher T. Gibson ◽  
Sverre Myhra ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Human Fibroblasts ◽  
Force Microscopy ◽  
Distance Analysis ◽  
Atomic Force

scholarly journals Acoustic subsurface-atomic force microscopy: Three-dimensional imaging at the nanoscale

2021 ◽  
Vol 129 (3) ◽  
pp. 030901
Author(s):  
Hossein J. Sharahi ◽  
Mohsen Janmaleki ◽  
Laurene Tetard ◽  
Seonghwan Kim ◽  
Hamed Sadeghian ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Three Dimensional ◽  
Three Dimensional Imaging ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Osteoblast-Like Cell Behavior on Porous Scaffolds Based on Poly(styrene) Fibers

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Andrada Serafim ◽  
Romain Mallet ◽  
Florence Pascaretti-Grizon ◽  
Izabela-Cristina Stancu ◽  
Daniel Chappard
Keyword(s):  
Interference Microscopy ◽  
Porous Scaffolds ◽  
Allogenic Bone ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dry Spinning ◽  
Bone Trabeculae ◽  
Large Bone

Scaffolds of nonresorbable biomaterials can represent an interesting alternative for replacing large bone defects in some particular clinical cases with massive bone loss. Poly(styrene) microfibers were prepared by a dry spinning method. They were partially melted to provide 3D porous scaffolds. The quality of the material was assessed by Raman spectroscopy. Surface roughness was determined by atomic force microscopy and vertical interference microscopy. Saos-2 osteoblast-like cells were seeded on the surface of the fibers and left to proliferate. Cell morphology, evaluated by scanning electron microscopy, revealed that they can spread and elongate on the rough microfiber surface. Porous 3D scaffolds made of nonresorbable poly(styrene) fibers are cytocompatible biomaterials mimicking allogenic bone trabeculae and allowing the growth and development of osteoblast-like cellsin vitro.

scholarly journals Visualization by atomic force microscopy of tobacco mosaic virus movement protein–RNA complexes formed in vitro

2001 ◽  
Vol 82 (6) ◽  
pp. 1503-1508 ◽  
Author(s):  
O. I. Kiselyova ◽  
I. V. Yaminsky ◽  
E. M. Karger ◽  
O. Yu. Frolova ◽  
Y. L. Dorokhov ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Movement Protein ◽  
Structural Conversion ◽  
Force Microscopy ◽  
Rna Transcripts ◽  
Atomic Force ◽  
Rna Complexes

The structure of complexes formed in vitro by tobacco mosaic virus (TMV)-coded movement protein (MP) with TMV RNA and short (890 nt) synthetic RNA transcripts was visualized by atomic force microscopy on a mica surface. MP molecules were found to be distributed along the chain of RNA and the structure of MP–RNA complexes depended on the molar MP:RNA ratios at which the complexes were formed. A rise in the molar MP:TMV RNA ratio from 20:1 to 60–100:1 resulted in an increase in the density of the MP packaging on TMV RNA and structural conversion of complexes from RNase-sensitive ‘beads-on-a-string’ into a ‘thick string’ form that was partly resistant to RNase. The ‘thick string’-type RNase-resistant complexes were also produced by short synthetic RNA transcripts at different MP:RNA ratios. The ‘thick string’ complexes are suggested to represent clusters of MP molecules cooperatively bound to discrete regions of TMV RNA and separated by protein-free RNA segments.

scholarly journals The extruded non-template strand determines the architecture of R-loops

2019 ◽  
Vol 47 (13) ◽  
pp. 6783-6795 ◽  
Author(s):  
Yeraldinne Carrasco-Salas ◽  
Amélie Malapert ◽  
Shaheen Sulthana ◽  
Bastien Molcrette ◽  
Léa Chazot-Franguiadakis ◽  
...  
Keyword(s):  
Single Molecule ◽  
Genome Stability ◽  
Three Dimensional ◽  
Dna Breaks ◽  
Yeast Gene ◽  
Physical Constraints ◽  
Force Microscopy ◽  
Template Strand ◽  
Atomic Force

Abstract Three-stranded R-loop structures have been associated with genomic instability phenotypes. What underlies their wide-ranging effects on genome stability remains poorly understood. Here we combined biochemical and atomic force microscopy approaches with single molecule R-loop footprinting to demonstrate that R-loops formed at the model Airn locus in vitro adopt a defined set of three-dimensional conformations characterized by distinct shapes and volumes, which we call R-loop objects. Interestingly, we show that these R-loop objects impose specific physical constraints on the DNA, as revealed by the presence of stereotypical angles in the surrounding DNA. Biochemical probing and mutagenesis experiments revealed that the formation of R-loop objects at Airn is dictated by the extruded non-template strand, suggesting that R-loops possess intrinsic sequence-driven properties. Consistent with this, we show that R-loops formed at the fission yeast gene sum3 do not form detectable R-loop objects. Our results reveal that R-loops differ by their architectures and that the organization of the non-template strand is a fundamental characteristic of R-loops, which could explain that only a subset of R-loops is associated with replication-dependent DNA breaks.

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