scholarly journals Rapid Photoinduced Single Cell Detachment from Gold Nanoparticle-Embedded Collagen Gels with Low Denaturation Temperature

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 213
Author(s):  
Chie Kojima ◽  
Misaki Nishio ◽  
Yusuke Nakajima ◽  
Takeshi Kawano ◽  
Kenji Takatsuka ◽  
...  
Keyword(s):  
Single Cell ◽  
Gold Nanoparticle ◽  
Thermal Denaturation ◽  
Collagen Gel ◽  
Collagen Fibers ◽  
Photothermal Effect ◽  
Cell Detachment ◽  
Type I ◽  
Collagen Gels ◽  
Denaturation Temperature

Cell Separation is important in various biomedical fields. We have prepared gold nanoparticle (AuNP)-embedded collagen gels as a visible-light-responsive cell scaffold in which photoinduced single cell detachment occurs through local thermal denaturation of the collagen gel via the photothermal effect of AuNP. Physicochemical properties of collagen materials depend on the origin of the collagen and the presence of telopeptides. In this study, we prepared various AuNP-embedded collagen gels by using different collagen materials with and without the telopeptides to compare their thermal denaturation properties and photoinduced single cell detachment behaviors. Cellmatrix type I-C without telopeptides exhibited a lower denaturation temperature than Cellmatrix type I-A and Atelocell IAC, as examined by Fourier transform infrared (FTIR) spectroscopy, rheological analysis, and sol–gel transition observation. Three-dimensional (3D) laser microscopic imaging revealed that collagen fibers shrank in Cellmatrix type I-A upon heating, but collagen fibers disappeared in Cellmatrix type I-C upon heating. Cells cultured on the Cellmatrix type I-C-based AuNP-embedded collagen gel detached with shorter photoirradiation than on the Cellmatrix type I-A-based AuNP-embedded collagen gel, suggesting that collagen gels without telopeptides are suitable for a photoinduced single cell detachment system.

Cytoskeleton and thyroglobulin expression change during transformation of thyroid epithelium to mesenchyme-like cells

Development ◽  
1988 ◽  
Vol 102 (3) ◽  
pp. 605-622 ◽  
Author(s):  
G. Greenburg ◽  
E.D. Hay
Keyword(s):  
Type I Collagen ◽  
Collagen Gel ◽  
Type I ◽  
Basal Cells ◽  
Collagen Gels ◽  
Expression Change ◽  
Cell Functions ◽  
The Matrix ◽  
3D Matrix ◽  
Mesenchymal Transformation

In considering the mechanism of transformation of epithelium to mesenchyme in the embryo, it is generally assumed that the ability to give rise to fibroblast-like cells is lost as epithelia mature. We reported previously that a definitive embryonic epithelium, that of the anterior lens, gives rise to freely migrating mesenchyme-like cells when suspended in type I collagen matrices. Here, we show that a highly differentiated epithelium that expresses cytokeratin changes to a vimentin cytoskeleton and loses thyroglobulin during epithelial-mesenchymal transformation induced by suspension in collagen gel. Using dispase and collagenase, we isolated adult thyroid follicles devoid of basal lamina and mesenchyme, and we suspended the follicles in 3D collagen gels. Cells bordering the follicle lumen retain epithelial polarity and thyroid phenotype, but basal cell surface organization is soon modified as a result of tissue multilayering and elongation of basal cells into the collagenous matrix. Cytodifferentiation, determined by thyroglobulin immunoreactivity, is lost as the basal epithelial cells move into the matrix after 3–4 days in collagen. By TEM, it can be seen that the elongating cells acquire pseudopodia, filopodia and mesenchyme-like nuclei and RER. Immunofluorescence examination of intermediate filaments showed that freshly isolated follicles and follicles cultured on planar substrata react only with anticytokeratin. However, all of the mesenchyme-like cells express vimentin and they gradually lose cytokeratin. These results suggest that vimentin may be necessary for cell functions associated with migration within a 3D matrix. The mesenchymal cells do not revert to epithelium when grown on planar substrata and the transformation of epithelium to mesenchyme-like cells does not occur within basement membrane gels. The results are relevant to our understanding of the initiation of epithelial-mesenchymal transformation in the embryo and the genetic mechanisms controlling cell shape, polarity and cytoskeletal phenotype.

scholarly journals Inhibition of hydroxyapatite formation in collagen gels by chondroitin sulphate

1985 ◽  
Vol 228 (2) ◽  
pp. 463-469 ◽  
Author(s):  
G K Hunter ◽  
B L Allen ◽  
M D Grynpas ◽  
P T Cheng
Keyword(s):  
Type I Collagen ◽  
Chondroitin Sulphate ◽  
Collagen Gel ◽  
Calcium Pyrophosphate ◽  
Molar Ratio ◽  
Crystal Formation ◽  
Type I ◽  
Collagen Gels ◽  
High Concentrations ◽  
Hydroxyapatite Formation

Crystal growth in native collagen gels has been used to determine the role of extracellular matrix macromolecules in biological calcification phenomena. In this system, type I collagen gels containing sodium phosphate and buffered at pH 7.4 are overlayed with a solution containing CaCl2. Crystals form in the collagen gel adjacent to the gel-solution interface. Conditions were determined which permit the growth of crystals of hydroxyapatite [Ca10(PO4)6(OH)2]. At a Ca/P molar ratio of 2:1, the minimum concentrations of calcium and phosphate necessary for precipitation of hydroxyapatite are 10 mM and 5 mM, respectively. Under these conditions, precipitation is initiated at 18-24h, and is maximal between 24h and 6 days. Addition of high concentrations of chondroitin 4-sulphate inhibits the formation of hydroxyapatite in collagen gels; initiation of precipitation is delayed, and the final (equilibrium) amount of precipitation is decreased. Inhibition of hydroxyapatite formation requires concentrations of chondroitin sulphate higher than those required to inhibit calcium pyrophosphate crystal formation.

Bacterial Endotoxin Inhibits Migration, Attachment, and Orientation of Human Gingival Fibroblasts in vitro and Delays Collagen Gel Contraction

1987 ◽  
Vol 66 (9) ◽  
pp. 1449-1455 ◽  
Author(s):  
S. Pitaru ◽  
M. Soldinger ◽  
D. Madgar ◽  
Z. Metzger
Keyword(s):  
Collagen Type ◽  
Cell Attachment ◽  
Collagen Gel ◽  
Collagen Type I ◽  
Human Gingival Fibroblasts ◽  
Bacterial Endotoxin ◽  
Type I ◽  
Gingival Fibroblasts ◽  
Collagen Gels

The purpose of this study was to assess the effect of endotoxin adsorbed to dental surfaces and to collagen type I on the migration, attachment, and orientation of human gingival fibroblasts (HGF). Transversely cut porcine tooth root slices (RS), 200 μm thick, were prepared. Half of the RS obtained were partially demineralized in EDTA. Half of the demineralized and non-demineralized RS were incubated with 400 μg/mL of endotoxin for 24 hr, whereas the other half were maintained in PBS and served as controls. Experimental and control RS were placed on confluent layers of HFG and cultured for six days. Cell migration toward and cell attachment to the periphery of the RS and the formation of oriented cell sheets were assessed by means of photographic techniques. Additionally, six-day-old cultures were fixed and processed for SEM observation. In separate experiments, the effect of endotoxin on cell attachment to collagen type I and on contraction of three-dimensional collagen gels was assessed. It was found that: (i) bacterial endotoxin inhibited migration and attachment of HGF to both demineralized and non-demineralized cementum and interfered with the development of oriented cellular structure ; (ii) the inhibitory effect was significantly more pronounced for non-demineralized than for demineralized cementum; (iii) the morphology of HGF attached to endotoxin-treated dental surfaces was altered compared with that of their controls; and (iv) bacterial endotoxin inhibited cell attachment to collagen type I and delayed the contraction of collagen gel.

Modeling of Fibroblast-Controlled Strengthening and Remodeling of Uniaxially Constrained Collagen Gels

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
Martin Kroon
Keyword(s):  
Theoretical Model ◽  
Collagen Gel ◽  
Collagen Fibers ◽  
Collagen Fibrils ◽  
Collagen Gels ◽  
Material Stiffness ◽  
Proposed Model

A theoretical model for the remodeling of collagen gels is proposed. The collagen fabric is modeled as a network of collagen fibers, which in turn are composed of collagen fibrils. In the model, the strengthening of collagen fabric is accomplished by fibroblasts, which continuously recruit and attach more collagen fibrils to existing collagen fibers. The fibroblasts also accomplish a reorientation of collagen fibers. Fibroblasts are assumed to reorient collagen fibers toward the direction of maximum material stiffness. The proposed model is applied to experiments in which fibroblasts were inserted into a collagen gel. The model is able to predict the force-strain curves for the experimental collagen gels, and the final distribution of collagen fibers also agrees qualitatively with the experiments.

Sodium nitroprusside augments human lung fibroblast collagen gel contraction independently of NO-cGMP pathway

2000 ◽  
Vol 278 (5) ◽  
pp. L1032-L1038 ◽  
Author(s):  
X. D. Liu ◽  
C. M. Skold ◽  
T. Umino ◽  
J. R. Spurzem ◽  
D. J. Romberger ◽  
...  
Keyword(s):  
Type I Collagen ◽  
Human Lung ◽  
Three Dimensional ◽  
Collagen Gel ◽  
Lung Fibroblast ◽  
Type I ◽  
Collagen Gels ◽  
Human Lung Fibroblast ◽  
Collagen Gel Contraction ◽  
Cgmp Pathway

Nitric oxide (NO) relaxes vascular smooth muscle in part through an accumulation of cGMP in the target cells. We hypothesized that a similar effect may also exist on collagen gel contraction mediated by human fetal lung (HFL1) fibroblasts, a model of wound contraction. To evaluate this, HFL1 cells were cultured in three-dimensional type I collagen gels and floated in serum-free DMEM with and without various NO donors. Gel size was measured with an image analyzer. Sodium nitroprusside (SNP, 100 μM) significantly augmented collagen gel contraction by HFL1 cells (78.5 ± 0.8 vs. 58.3 ± 2.1, P < 0.01), whereas S-nitroso- N-acetylpenicillamine, 5-amino-3-(4-morpholinyl)-1,2,3-oxadiazolium chloride, NONOate, and N G-monomethyl-l-arginine did not affect the contraction. Sodium ferricyanide, sodium nitrate, or sodium nitrite was not active. The augmentory effect of SNP could not be blocked by 1 H-[1,2,4]-oxadiazolo-[4,3- a]-quinoxalin-1-one, whereas it was partially reversed by 8-(4-chlorophenylthio) (CPT)-cGMP. To further explore the mechanisms by which SNP acted, fibronectin and PGE2 production were measured by immunoassay after 2 days of gel contraction. SNP inhibited PGE2 production and increased fibronectin production by HFL1 cells in a concentration-dependent manner. CPT-cGMP had opposite effects on fibronectin and PGE2 production. Addition of exogenous PGE2 blocked SNP-augmented contraction and fibronectin production by HFL1 cells. Therefore, SNP was able to augment human lung fibroblast-mediated collagen gel contraction, an effect that appears to be independent of NO production and not mediated through cGMP. Decreased PGE2 production and augmented fibronectin production may have a role in this effect. These data suggest that human lung fibroblasts in three-dimensional type I collagen gels respond distinctly to SNP by mechanisms unrelated to the NO-cGMP pathway.

Visible Laser-Induced In Situ Cell Detachment from Gold Nanoparticle-Embedded Collagen Gel

2016 ◽  
Vol 17 (5) ◽  
pp. 1600341 ◽  
Author(s):  
Chie Kojima ◽  
Yusuke Nakajima ◽  
Naoya Oeda ◽  
Takeshi Kawano ◽  
Yusuke Taki
Keyword(s):  
Gold Nanoparticle ◽  
Collagen Gel ◽  
Cell Detachment ◽  
Visible Laser

scholarly journals Multiscale Model Predicts Tissue-Level Failure From Collagen Fiber-Level Damage

2012 ◽  
Vol 134 (9) ◽  
Author(s):  
Mohammad F. Hadi ◽  
Edward A. Sander ◽  
Victor H. Barocas
Keyword(s):  
Type I Collagen ◽  
Soft Tissues ◽  
Mechanical Response ◽  
Collagen Gel ◽  
Multiscale Model ◽  
Tissue Level ◽  
Type I ◽  
Collagen Gels ◽  
Damage And Failure ◽  
Failure Data

Excessive tissue-level forces communicated to the microstructure and extracellular matrix of soft tissues can lead to damage and failure through poorly understood physical processes that are multiscale in nature. In this work, we propose a multiscale mechanical model for the failure of collagenous soft tissues that incorporates spatial heterogeneity in the microstructure and links the failure of discrete collagen fibers to the material response of the tissue. The model, which is based on experimental failure data derived from different collagen gel geometries, was able to predict the mechanical response and failure of type I collagen gels, and it demonstrated that a fiber-based rule (at the micrometer scale) for discrete failure can strongly shape the macroscale failure response of the gel (at the millimeter scale). The model may be a useful tool in predicting the macroscale failure conditions for soft tissues and engineered tissue analogs. In addition, the multiscale model provides a framework for the study of failure in complex fiber-based mechanical systems in general.

scholarly journals Collagenolytic Potential of Rat Liver Myofibroblasts

2013 ◽  
pp. 15-25 ◽  
Author(s):  
A. JIROUTOVÁ ◽  
E. PETEROVÁ ◽  
L. BITTNEROVÁ ◽  
R. SLAVKOVSKÝ ◽  
P. ČEVELOVÁ ◽  
...  
Keyword(s):  
Rat Liver ◽  
Type I Collagen ◽  
Collagen Gel ◽  
Plastic Substrate ◽  
Type I ◽  
Collagen Gels ◽  
Rt Pcr ◽  
Fibrotic Liver ◽  
Fibrin Gels ◽  
Liver Myofibroblasts

Rat liver myofibroblasts (MFB) were isolated by repeated passaging of nonparenchymal liver cell fraction. They were cultured on polystyrene Petri dishes, on fibrin or on type I collagen gels for 5 days. Quantitative RT-PCR, Western blotting, zymography and immunocytochemistry were used to study differences in cell morphology and protein expression. MFB were large and spread on plastic substrate, with prominent α-smooth muscle (α-SMA) fibres. They turned much smaller and elongated on collagen which was accompanied by the rearrangement of the cytoskeleton and a decrease in α-SMA and β-actin content. Collagen gel induced the expression of a group of metalloproteinases (MMP-2, -3, -9, -13), on mRNA and protein level which resulted in the degradation of the gel. This response was accompanied by changes in the mRNA expression of cytokines of TGF-β family, CTGF and interleukin-6, as well as of osteopontin and thrombospondin-2 that are involved in metalloproteinases (MMPs) regulation. The expression of MMPs substrates, collagen types I, IV and XII did not change or decreased. The effects of fibrin gels on MFB were milder than those of collagen. MFB assumed to deposit collagen and other ECM components in fibrotic liver, besides hepatic stellate cells, also possess a great collagenolytic potential.

Comparison of Temperature Metrics of Heating-Induced Damage

2002 ◽  
Author(s):  
Neil T. Wright
Keyword(s):  
Thermal Denaturation ◽  
Transition State Theory ◽  
Type I Collagen ◽  
Arrhenius Equation ◽  
Frequency Factor ◽  
State Theory ◽  
Type I ◽  
Denaturation Temperature ◽  
First Order ◽  
First Order Phase

The temperature dependence of the rate of denaturation of Type I collagen due to heating is described well by chemical kinetics via the Arrhenius equation or transition state theory (TST) [1, 2, 3], each of which requires two material parameters. Nevertheless, many have sought to find a single convenient metric, such as one with units of temperature, to describe thermal denaturation of collagen. Comparing the results of studies that measured denaturation and cell death for a variety of biological samples shows that the parameters for either the Arrhenius equation (i.e. activation energy Ea and the frequency factor A) appear correlated over the range of temperatures for which biological materials are tested [4]. It has also been suggested that denaturation is a first-order phase change (i.e., melting) and thus should be characterized by a melting or denaturation temperature Td [5].

Fabrication and Properties of Collagen Fibers With Increased Surface Areas for Enhanced Fiber-Matrix Interactions

2007 ◽  
Author(s):  
J. J. Finkbiner ◽  
K. L. Harrigan ◽  
K. C. Dee ◽  
G. A. Livesay
Keyword(s):  
Extracellular Matrix ◽  
Fiber Strength ◽  
Collagen Gel ◽  
Fiber Surface ◽  
Soft Tissue Injuries ◽  
Collagen Fibers ◽  
Collagen Gels ◽  
Surface Areas ◽  
Matrix Interactions ◽  
Fiber Interaction

Collagen plays an important structural role in many natural tissues, such as ligaments and tendons. Due to its ubiquity in the human body and its commercial availability, biomaterials using collagen gel as a scaffold for an extracellular matrix are being developed as alternative treatments for soft tissue injuries [1]. The use of collagen fibers as a matrix in cell-seeded collagen gels has been shown to limit contraction of the gels as well as increase scaffold permeability and cell viability [2,3]. Additionally, it has been found that dehydration of collagen fibers increases fiber strength [4]. Therefore, investigating the effect of changing fiber shape to increase fiber surface and gel/fiber interaction is important.

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