scholarly journals Magnetic poly(ε-caprolactone)/iron-doped hydroxyapatite nanocomposite substrates for advanced bone tissue engineering

2013 ◽  
Vol 10 (80) ◽  
pp. 20120833 ◽  
Author(s):  
A. Gloria ◽  
T. Russo ◽  
U. D'Amora ◽  
S. Zeppetelli ◽  
T. D'Alessandro ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Laser Scanning ◽  
Magnetic Measurements ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Hyperthermia Treatment ◽  
Wide Range ◽  
Iron Doped

In biomedicine, magnetic nanoparticles provide some attractive possibilities because they possess peculiar physical properties that permit their use in a wide range of applications. The concept of magnetic guidance basically spans from drug delivery and hyperthermia treatment of tumours, to tissue engineering, such as magneto-mechanical stimulation/activation of cell constructs and mechanosensitive ion channels, magnetic cell-seeding procedures, and controlled cell proliferation and differentiation. Accordingly, the aim of this study was to develop fully biodegradable and magnetic nanocomposite substrates for bone tissue engineering by embedding iron-doped hydroxyapatite (FeHA) nanoparticles in a poly(ε-caprolactone) (PCL) matrix. X-ray diffraction analyses enabled the demonstration that the phase composition and crystallinity of the magnetic FeHA were not affected by the process used to develop the nanocomposite substrates. The mechanical characterization performed through small punch tests has evidenced that inclusion of 10 per cent by weight of FeHA would represent an effective reinforcement. The inclusion of nanoparticles also improves the hydrophilicity of the substrates as evidenced by the lower values of water contact angle in comparison with those of neat PCL. The results from magnetic measurements confirmed the superparamagnetic character of the nanocomposite substrates, indicated by a very low coercive field, a saturation magnetization strictly proportional to the FeHA content and a strong history dependence in temperature sweeps. Regarding the biological performances, confocal laser scanning microscopy and AlamarBlue assay have provided qualitative and quantitative information on human mesenchymal stem cell adhesion and viability/proliferation, respectively, whereas the obtained ALP/DNA values have shown the ability of the nanocomposite substrates to support osteogenic differentiation.

scholarly journals Evaluation of the Osteoblast Behavior to PGA Textile Functionalized with RGD as a Scaffold for Bone Regeneration

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Mariné Ortiz ◽  
Diana María Escobar-Garcia ◽  
Marco Antonio Álvarez-Pérez ◽  
Amaury Pozos-Guillén ◽  
Christian Grandfils ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Calcium Phosphate ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Laser Scanning ◽  
Tissue Injury ◽  
Polyglycolic Acid ◽  
Confocal Laser Scanning Microscope ◽  
Confocal Laser ◽  
Fiber Scaffolds

The new era of biomaterials for repairing bone tissue injury continues to be a challenge in bone tissue engineering. The fiber scaffolds allow for cellular interconnection and a microenvironment close to the bone extracellular matrix. The aim of this study was to evaluate the osteoblast behavior on a 3D textile of PGA (polyglycolic acid) fibers functionalized with the RGD (R: arginine; G: glycine; D: aspartic acid) peptide. The cell morphology, proliferation, and calcium phosphate deposition ability were evaluated on textiles at different time intervals under a confocal laser scanning microscope. The osteoblast viability ranged from 92% to 98%, and cell proliferation was higher in PGA-RGD than control PGA (uncoated). In addition, the osteoblast calcium phosphate deposition was significantly greater on PGA-RGD in osteogenic inductor medium (OIM) in contrast to controls without inducing factors. The PGA-RGD fibers supported proliferation and viability of osteoblast and stimulated bone osteogenesis and mineralization. These results support the adoption of this 3D polymeric textile as a scaffold for bone tissue engineering.

scholarly journals Combination Design of Time-Dependent Magnetic Field and Magnetic Nanocomposites to Guide Cell Behavior

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 577 ◽  
Author(s):  
Teresa Russo ◽  
Valentina Peluso ◽  
Antonio Gloria ◽  
Olimpia Oliviero ◽  
Laura Rinaldi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Tissue Engineering ◽  
Fe3o4 Nanoparticles ◽  
Laser Scanning ◽  
Peak Load ◽  
Laser Scanning Microscopy ◽  
Time Dependent ◽  
Confocal Laser ◽  
Magnetic Nanocomposites ◽  
Wide Range

The concept of magnetic guidance is still challenging and has opened a wide range of perspectives in the field of tissue engineering. In this context, magnetic nanocomposites consisting of a poly(ε-caprolactone) (PCL) matrix and iron oxide (Fe3O4) nanoparticles were designed and manufactured for bone tissue engineering. The mechanical properties of PCL/Fe3O4 (80/20 w/w) nanocomposites were first assessed through small punch tests. The inclusion of Fe3O4 nanoparticles improved the punching properties as the values of peak load were higher than those obtained for the neat PCL without significantly affecting the work to failure. The effect of a time-dependent magnetic field on the adhesion, proliferation, and differentiation of human mesenchymal stem cells (hMSCs) was analyzed. The Alamar Blue assay, confocal laser scanning microscopy, and image analysis (i.e., shape factor) provided information on cell adhesion and viability over time, whereas the normalized alkaline phosphatase activity (ALP/DNA) demonstrated that the combination of a time-dependent field with magnetic nanocomposites (PCL/Fe3O4 Mag) influenced cell differentiation. Furthermore, in terms of extracellular signal-regulated kinase (ERK)1/2 phosphorylation, an insight into the role of the magnetic stimulation was reported, also demonstrating a strong effect due the combination of the magnetic field with PCL/Fe3O4 nanocomposites (PCL/Fe3O4 Mag).

scholarly journals One-step preparation of antimicrobial silicone materials based on PDMS and salicylic acid: insights from spatially and temporally resolved techniques

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Luca Barbieri ◽  
Ioritz Sorzabal Bellido ◽  
Alison J. Beckett ◽  
Ian A. Prior ◽  
Jo Fothergill ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Laser Scanning ◽  
Pathogenic Bacteria ◽  
Pharmaceutical Products ◽  
Laser Scanning Microscopy ◽  
Wound Dressings ◽  
Confocal Laser ◽  
Vis Spectroscopy ◽  
Wide Range ◽  
One Step

AbstractIn this work, we introduce a one-step strategy that is suitable for continuous flow manufacturing of antimicrobial PDMS materials. The process is based on the intrinsic capacity of PDMS to react to certain organic solvents, which enables the incorporation of antimicrobial actives such as salicylic acid (SA), which has been approved for use in humans within pharmaceutical products. By combining different spectroscopic and imaging techniques, we show that the surface properties of PDMS remain unaffected while high doses of the SA are loaded inside the PDMS matrix. The SA can be subsequently released under physiological conditions, delivering a strong antibacterial activity. Furthermore, encapsulation of SA inside the PDMS matrix ensured a diffusion-controlled release that was tracked by spatially resolved Raman spectroscopy, Attenuated Total Reflectance IR (ATR-IR), and UV-Vis spectroscopy. The biological activity of the new material was evaluated directly at the surface and in the planktonic state against model pathogenic bacteria, combining confocal laser scanning microscopy, electron microscopy, and cell viability assays. The results showed complete planktonic inhibition for clinically relevant strains of Staphylococcus aureus and Escherichia coli, and a reduction of up to 4 orders of magnitude for viable sessile cells, demonstrating the efficacy of these surfaces in preventing the initial stages of biofilm formation. Our approach adds a new option to existing strategies for the antimicrobial functionalisation of a wide range of products such as catheters, wound dressings and in-dwelling medical devices based on PDMS.

scholarly journals Astrogliosis in an Experimental Model of Hypovitaminosis B12: A Cellular Basis of Neurological Disorders due to Cobalamin Deficiency

Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2261
Author(s):  
Zuzanna Rzepka ◽  
Jakub Rok ◽  
Justyna Kowalska ◽  
Klaudia Banach ◽  
Justyna Magdalena Hermanowicz ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Cobalamin Deficiency ◽  
Confocal Laser ◽  
In Vivo Model ◽  
Cellular Expression ◽  
Wide Range ◽  
Vitro Model

Cobalamin deficiency affects human physiology with sequelae ranging from mild fatigue to severe neuropsychiatric abnormalities. The cellular and molecular aspects of the nervous system disorders associated with hypovitaminosis B12 remain largely unknown. Growing evidence indicates that astrogliosis is an underlying component of a wide range of neuropathologies. Previously, we developed an in vitro model of cobalamin deficiency in normal human astrocytes (NHA) by culturing the cells with c-lactam of hydroxycobalamin (c-lactam OH-Cbl). We revealed a non-apoptotic activation of caspases (3/7, 8, 9) in cobalamin-deficient NHA, which may suggest astrogliosis. The aim of the current study was to experimentally verify this hypothesis. We indicated an increase in the cellular expression of two astrogliosis markers: glial fibrillary acidic protein and vimentin in cobalamin-deficient NHA using Western blot analysis and immunocytochemistry with confocal laser scanning microscopy. In the next step of the study, we revealed c-lactam OH-Cbl as a potential non-toxic vitamin B12 antagonist in an in vivo model using zebrafish embryos. We believe that the presented results will contribute to a better understanding of the cellular mechanism underlying neurologic pathology due to cobalamin deficiency and will serve as a foundation for further studies.

Confocal Laser Scanning Microscopy Examination of Cell Cultures in threedimensional Scaffolds for Tissue Engineering

2003 ◽  
Vol 9 (S03) ◽  
pp. 452-453 ◽  
Author(s):  
Thomas Hanke ◽  
Marcus Wollenweber ◽  
Beatrice Burmeister ◽  
Monika Kruse de Pacheco ◽  
Michael Gelinsky ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Confocal Laser Scanning Microscopy ◽  
Cell Cultures ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser ◽  
Microscopy Examination

scholarly journals Carbon Nanostructures in Bone Tissue Engineering

2016 ◽  
Vol 10 (1) ◽  
pp. 877-899 ◽  
Author(s):  
Brian Lee Perkins ◽  
Naghmeh Naderi
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Tissue Regeneration ◽  
Carbon Nanostructures ◽  
Bone Tissue Regeneration ◽  
Biophysical Properties ◽  
Carbon Nanostructure ◽  
Natural Bone ◽  
Wide Range

Background:Recent advances in developing biocompatible materials for treating bone loss or defects have dramatically changed clinicians’ reconstructive armory. Current clinically available reconstructive options have certain advantages, but also several drawbacks that prevent them from gaining universal acceptance. A wide range of synthetic and natural biomaterials is being used to develop tissue-engineered bone. Many of these materials are currently in the clinical trial stage.Methods:A selective literature review was performed for carbon nanostructure composites in bone tissue engineering.Results:Incorporation of carbon nanostructures significantly improves the mechanical properties of various biomaterials to mimic that of natural bone. Recently, carbon-modified biomaterials for bone tissue engineering have been extensively investigated to potentially revolutionize biomaterials for bone regeneration.Conclusion:This review summarizes the chemical and biophysical properties of carbon nanostructures and discusses their functionality in bone tissue regeneration.

scholarly journals Cell-to-Cell Signaling in Xylella fastidiosa Suppresses Movement and Xylem Vessel Colonization in Grape

2008 ◽  
Vol 21 (10) ◽  
pp. 1309-1315 ◽  
Author(s):  
Subhadeep Chatterjee ◽  
Karyn L. Newman ◽  
Steven E. Lindow
Keyword(s):  
Cell Signaling ◽  
Type Strain ◽  
Laser Scanning ◽  
Wild Type Strain ◽  
Xylella Fastidiosa ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Deficient Mutant ◽  
Wild Type ◽  
Wide Range

Cell-to-cell signaling mediated by a fatty acid diffusible signaling factor (DSF) is central to the regulation of the virulence of Xylella fastidiosa. DSF production by X. fastidiosa is dependent on rpfF and, although required for insect colonization, appears to reduce its virulence to grape. To understand what aspects of colonization of grape are controlled by DSF in X. fastidiosa and, thus, those factors that contribute to virulence, we assessed the colonization of grape by a green fluorescent protein–marked rpfF-deficient mutant. The rpfF-deficient mutant was detected at a greater distance from the point of inoculation than the wild-type strain at a given sampling time, and also attained a population size that was up to 100-fold larger than that of the wild-type strain at a given distance from the point of inoculation. Confocal laser-scanning microscopy revealed that approximately 10-fold more vessels in petioles of symptomatic leaves harbored at least some cells of either the wild type or rpfF mutant when compared with asymptomatic leaves and, thus, that disease symptoms were associated with the extent of vessel colonization. Importantly, the rpfF mutant colonized approximately threefold more vessels than the wild-type strain. Although a wide range of colony sizes were observed in vessels colonized by both the wild type and rpfF mutant, the proportion of colonized vessels harboring large numbers of cells was significantly higher in plants inoculated with the rpfF mutant than with the wild-type strain. These studies indicated that the hypervirulence phenotype of the rpfF mutant is due to both a more extensive spread of the pathogen to xylem vessels and unrestrained multiplication within vessels leading to blockage. These results suggest that movement and multiplication of X. fastidiosa in plants are linked, perhaps because cell wall degradation products are a major source of nutrients. Thus, DSF-mediated cell-to-cell signaling, which restricts movement and colonization of X. fastidiosa, may be an adaptation to endophytic growth of the pathogen that prevents the excessive growth of cells in vessels.

Surface Characterization Using Wavelet Theory and Confocal Laser Scanning Microscopy

2005 ◽  
Vol 127 (2) ◽  
pp. 394-404 ◽  
Author(s):  
Chengqing Yuan ◽  
Zhongxiao Peng ◽  
Xinping Yan
Keyword(s):  
Surface Roughness ◽  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Surface Characterization ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser ◽  
Wavelet Theory ◽  
Wide Range

Surface characterization, particularly roughness analysis, is very important for a wide range of applications including wear assessment. This paper proposes a set of methods and techniques to acquire appropriate images using confocal laser scanning microscopy, to separate roughness, waviness, and form using wavelet theory, and to characterize surface roughness for engineering surfaces and surfaces of small particles. Two application examples on engineering surfaces and wear particles have been presented in the paper to demonstrate that the method developed in this study can be used to measure surface roughness reliably and precisely. A guide on how to determine the iris size, step size, and objective lens has been scientifically provided according to theoretical analysis and experimental results.

scholarly journals Morphology of powerful suction organs from blepharicerid larvae living in raging torrents

BMC Zoology ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Victor Kang ◽  
Richard Johnston ◽  
Thomas van de Kamp ◽  
Tomáš Faragó ◽  
Walter Federle
Keyword(s):  
Laser Scanning ◽  
Close Contact ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Wide Range ◽  
Flow Speeds ◽  
Micro Tomography ◽  
Structural Adaptations ◽  
Attachment Devices

Abstract Background Suction organs provide powerful yet dynamic attachments for many aquatic animals, including octopus, squid, remora, and clingfish. While the functional morphology of suction organs from some cephalopods and fishes has been investigated in detail, there are only few studies on such attachment devices in insects. Here we characterise the morphology and ultrastructure of the suction attachment organs of net-winged midge larvae (genus Liponeura; Diptera: Blephariceridae) – aquatic insects that live on rocks in rapid alpine waterways where flow speeds can reach 3 m s− 1 – using scanning electron microscopy, confocal laser scanning microscopy, and X-ray computed micro-tomography (micro-CT). Furthermore, we study the function of these organs in vivo using interference reflection microscopy. Results We identified structural adaptations important for the function of the suction attachment organs in L. cinerascens and L. cordata. First, a dense array of spine-like microtrichia covering each suction disc comes into contact with the substrate upon attachment, analogous to hairy structures on suction organs from octopus, clingfish, and remora fish. These spine-like microtrichia may contribute to the seal and provide increased shear force resistance in high-drag environments. Second, specialised rim microtrichia at the suction disc periphery were found to form a continuous ring in close contact and may serve as a seal on a variety of surfaces. Third, a V-shaped cut on the suction disc (“V-notch“) is actively opened via two cuticular apodemes inserting on its flanks. The apodemes are attached to dedicated V-notch opening muscles, thereby providing a unique detachment mechanism. The complex cuticular design of the suction organs, along with specialised muscles that attach to them, allows blepharicerid larvae to generate powerful attachments which can withstand strong hydrodynamic forces and quickly detach for locomotion. Conclusion The suction organs from Liponeura are underwater attachment devices specialised for resisting extremely fast flows. Structural adaptations from these suction organs could translate into future bioinspired attachment systems that perform well on a wide range of surfaces.

scholarly journals The effect of geometry on three-dimensional tissue growth

2008 ◽  
Vol 5 (27) ◽  
pp. 1173-1180 ◽  
Author(s):  
Monika Rumpler ◽  
Alexander Woesz ◽  
John W.C Dunlop ◽  
Joost T van Dongen ◽  
Peter Fratzl
Keyword(s):  
Tissue Engineering ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Tissue Growth ◽  
Growth Patterns ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Physical Parameters ◽  
Curvature Driven ◽  
Biochemical Signals

Tissue formation is determined by uncountable biochemical signals between cells; in addition, physical parameters have been shown to exhibit significant effects on the level of the single cell. Beyond the cell, however, there is still no quantitative understanding of how geometry affects tissue growth, which is of much significance for bone healing and tissue engineering. In this paper, it is shown that the local growth rate of tissue formed by osteoblasts is strongly influenced by the geometrical features of channels in an artificial three-dimensional matrix. Curvature-driven effects and mechanical forces within the tissue may explain the growth patterns as demonstrated by numerical simulation and confocal laser scanning microscopy. This implies that cells within the tissue surface are able to sense and react to radii of curvature much larger than the size of the cells themselves. This has important implications towards the understanding of bone remodelling and defect healing as well as towards scaffold design in bone tissue engineering.

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