In situ implantable three-dimensional extracellular matrix bioactive composite scaffold for postoperative skin cancer therapy

2020 ◽  
Vol 400 ◽  
pp. 125949
Author(s):  
Yutian Su ◽  
Xichen Zhang ◽  
Guohong Ren ◽  
Zhicheng Zhang ◽  
Ying Liang ◽  
...  
Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 497 ◽  
Author(s):  
Moumita Ghosh ◽  
Michal Halperin-Sternfeld ◽  
Itzhak Grinberg ◽  
Lihi Adler-Abramovich

The high demand for tissue engineering scaffolds capable of inducing bone regeneration using minimally invasive techniques prompts the need for the development of new biomaterials. Herein, we investigate the ability of Alginate incorporated with the fluorenylmethoxycarbonyl-diphenylalanine (FmocFF) peptide composite hydrogel to serve as a potential biomaterial for bone regeneration. We demonstrate that the incorporation of the self-assembling peptide, FmocFF, in sodium alginate leads to the production of a rigid, yet injectable, hydrogel without the addition of cross-linking agents. Scanning electron microscopy reveals a nanofibrous structure which mimics the natural bone extracellular matrix. The formed composite hydrogel exhibits thixotropic behavior and a high storage modulus of approximately 10 kPA, as observed in rheological measurements. The in vitro biocompatibility tests carried out with MC3T3-E1 preosteoblast cells demonstrate good cell viability and adhesion to the hydrogel fibers. This composite scaffold can induce osteogenic differentiation and facilitate calcium mineralization, as shown by Alizarin red staining, alkaline phosphatase activity and RT-PCR analysis. The high biocompatibility, excellent mechanical properties and similarity to the native extracellular matrix suggest the utilization of this hydrogel as a temporary three-dimensional cellular microenvironment promoting bone regeneration.


2007 ◽  
Vol 342-343 ◽  
pp. 133-136
Author(s):  
Jae Bong Choi

The objective of this study was to quantify the zonal difference of the in situ chondron’s Poisson effect under different magnitudes of compression. Fluorescence immunolabeling for type VI collagen was used to identify the pericellular matrix (PCM) and chondron, and a series of fluorescent confocal images were recorded and reconstructed to form quantitative three-dimensional models. The zonal variations in the mechanical response of the chondron do not appear to be due to zonal differences in PCM properties, but rather seem to result from significant inhomogeneities in relative stiffnesses of the extracellular matrix (ECM) and PCM with depth.


Author(s):  
J. P. Revel

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.


Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.


Author(s):  
S. Naka ◽  
R. Penelle ◽  
R. Valle

The in situ experimentation technique in HVEM seems to be particularly suitable to clarify the processes involved in recrystallization. The material under investigation was unidirectionally cold-rolled titanium of commercial purity. The problem was approached in two different ways. The three-dimensional analysis of textures was used to describe the texture evolution during the primary recrystallization. Observations of bulk-annealed specimens or thin foils annealed in the microscope were also made in order to provide information concerning the mechanisms involved in the formation of new grains. In contrast to the already published work on titanium, this investigation takes into consideration different values of the cold-work ratio, the temperature and the annealing time.Two different models are commonly used to explain the recrystallization textures i.e. the selective grain growth model (Beck) or the oriented nucleation model (Burgers). The three-dimensional analysis of both the rolling and recrystallization textures was performed to identify the mechanismsl involved in the recrystallization of titanium.


Author(s):  
W.F. Marshall ◽  
A.F. Dernburg ◽  
B. Harmon ◽  
J.W. Sedat

Interactions between chromatin and nuclear envelope (NE) have been implicated in chromatin condensation, gene regulation, nuclear reassembly, and organization of chromosomes within the nucleus. To further investigate the physiological role played by such interactions, it will be necessary to determine which loci specifically interact with the nuclear envelope. This will not only facilitate identification of the molecular determinants of this interaction, but will also allow manipulation of the pattern of chromatin-NE interactions to probe possible functions. We have developed a microscopic approach to detect and map chromatin-NE interactions inside intact cells.Fluorescence in situ hybridization (FISH) is used to localize specific chromosomal regions within the nucleus of Drosophila embryos and anti-lamin immunofluorescence is used to detect the nuclear envelope. Widefield deconvolution microscopy is then used to obtain a three-dimensional image of the sample (Fig. 1). The nuclear surface is represented by a surface-harmonic expansion (Fig 2). A statistical test for association of the FISH spot with the surface is then performed.


Author(s):  
Greg V. Martin ◽  
Ann L. Hubbard

The microtubule (MT) cytoskeleton is necessary for many of the polarized functions of hepatocytes. Among the functions dependent on the MT-based cytoskeleton are polarized secretion of proteins, delivery of endocytosed material to lysosomes, and transcytosis of integral plasma membrane (PM) proteins. Although microtubules have been shown to be crucial to the establishment and maintenance of functional and structural polarization in the hepatocyte, little is known about the architecture of the hepatocyte MT cytoskeleton in vivo, particularly with regard to its relationship to PM domains and membranous organelles. Using an in situ extraction technique that preserves both microtubules and cellular membranes, we have developed a protocol for immunofluorescent co-localization of cytoskeletal elements and integral membrane proteins within 20 µm cryosections of fixed rat liver. Computer-aided 3D reconstruction of multi-spectral confocal microscope images was used to visualize the spatial relationships among the MT cytoskeleton, PM domains and intracellular organelles.


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