scholarly journals Manufacturing micropatterned collagen scaffolds with chemical-crosslinking for development of biomimetic tissue-engineered oral mucosa

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ayako Suzuki ◽  
Yoshihiro Kodama ◽  
Keito Miwa ◽  
Kazuma Kishimoto ◽  
Emi Hoshikawa ◽  
...  
Keyword(s):  
Oral Mucosa ◽  
Type I Collagen ◽  
Three Dimensional ◽  
Collagen Scaffold ◽  
Type I ◽  
Chemical Crosslinking ◽  
Graft Material ◽  
Fish Scale ◽  
Collagen Scaffolds ◽  
Aspect Ratios

AbstractThe junction between the epithelium and the underlying connective tissue undulates, constituting of rete ridges, which lack currently available soft tissue constructs. In this study, using a micro electro mechanical systems process and soft lithography, fifteen negative molds, with different dimensions and aspect ratios in grid- and pillar-type configurations, were designed and fabricated to create three-dimensional micropatterns and replicated onto fish-scale type I collagen scaffolds treated with chemical crosslinking. Image analyses showed the micropatterns were well-transferred onto the scaffold surfaces, showing the versatility of our manufacturing system. With the help of rheological test, the collagen scaffold manufactured in this study was confirmed to be an ideal gel and have visco-elastic features. As compared with our previous study, its mechanical and handling properties were improved by chemical cross-linking, which is beneficial for grafting and suturing into the complex structures of oral cavity. Histologic evaluation of a tissue-engineered oral mucosa showed the topographical microstructures of grid-type were well-preserved, rather than pillar-type, a well-stratified epithelial layer was regenerated on all scaffolds and the epithelial rete ridge-like structure was developed. As this three-dimensional microstructure is valuable for maintaining epithelial integrity, our micropatterned collagen scaffolds can be used not only intraorally but extraorally as a graft material for human use.

Enhancement of the Mechanical Property of Apatite-Fiber Scaffold Using Type I-Collagen

2007 ◽  
Vol 361-363 ◽  
pp. 943-946
Author(s):  
S. Motojima ◽  
N. Igeta ◽  
Michiyo Honda ◽  
Nobuyuki Kanzawa ◽  
Mamoru Aizawa
Keyword(s):  
Mechanical Properties ◽  
Type I Collagen ◽  
Three Dimensional ◽  
Collagen Gel ◽  
Cross Linking ◽  
Type I ◽  
Collagen Scaffolds ◽  
Chemically Modified ◽  
Strength Tests ◽  
Fiber Scaffolds

We have successfully fabricated apatite-fiber scaffolds (AFSs) that enable three-dimensional cell culture. The AFSs possessing large pores of 100~250 μm and micro pores of about 5 μm were fabricated by firing the green compacts consisting of the single-crystal apatite fibers and the carbon beads with a size of 150 μm. In order to enhance the mechanical properties of the AFSs, we have improved the process of AFS fabrication: Collagen gel (type I) solutions were introduced into the pores in the scaffolds; in addition, the resulting apatite/collagen scaffolds were chemically modified by thermally dehydrated cross-linking. Actually, the results of compressive strength tests show that the value of the AFS with chemically cross-linked I-collagen was about twice as high as that of the conventional AFS without I-collagen. We conclude that combination of I-collagen and thermal dehydrated cross-linking is effective for enhancement of the mechanical properties of AFSs.

A new model for packing of type-I collagen molecules in the native fibril

1981 ◽  
Vol 1 (10) ◽  
pp. 801-810 ◽  
Author(s):  
Karl A. Piez ◽  
Benes L. Trus
Keyword(s):  
Type I Collagen ◽  
Hexagonal Lattice ◽  
Three Dimensional ◽  
Equatorial Region ◽  
Type I ◽  
X Ray Diffraction ◽  
X Ray ◽  
Left Handed ◽  
Crystal Model ◽  
Collagen Molecules

A specific fibril model is presented consisting of bundles of five-stranded microfibrils, which are usually disordered (except axially) but under lateral compression become ordered. The features are as follows (where D = 234 residues or 67 nm): (1) D-staggered collagen molecules 4.5 D long in the helical microfibril have a left-handed supercoil with a pitch of 400–700 residues, but microfibrils need not have helical symmetry. (2) Straight-tilted 0.5-D overlap regions on a near-hexagonal lattice contribute the discrete x-ray diffraction reflections arising from lateral order, while the gap regions remain disordered. (3) The overlap regions are equivalent, but are crystallographically distinguished by systematic displacements from the near-hexagonal lattice. (4) The unit cell is the same as in a recently proposed three-dimensional crystal model, and calculated intensities in the equatorial region of the x-ray diffraction pattern agree with observed values.

scholarly journals Protease-dependent versus -independent cancer cell invasion programs: three-dimensional amoeboid movement revisited

2009 ◽  
Vol 185 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Farideh Sabeh ◽  
Ryoko Shimizu-Hirota ◽  
Stephen J. Weiss
Keyword(s):  
Cancer Cells ◽  
Type I Collagen ◽  
Three Dimensional ◽  
Amoeboid Movement ◽  
Type I ◽  
Collagen Network ◽  
Normal Tissues ◽  
Tissue Invasion ◽  
Absolute Requirement ◽  
Cross Links

Tissue invasion during metastasis requires cancer cells to negotiate a stromal environment dominated by cross-linked networks of type I collagen. Although cancer cells are known to use proteinases to sever collagen networks and thus ease their passage through these barriers, migration across extracellular matrices has also been reported to occur by protease-independent mechanisms, whereby cells squeeze through collagen-lined pores by adopting an ameboid phenotype. We investigate these alternate models of motility here and demonstrate that cancer cells have an absolute requirement for the membrane-anchored metalloproteinase MT1-MMP for invasion, and that protease-independent mechanisms of cell migration are only plausible when the collagen network is devoid of the covalent cross-links that characterize normal tissues.

Maturation process and characterization of a novel thermostable and halotolerant subtilisin-like protease with high collagenolytic but low gelatinolytic activity

2021 ◽  
Author(s):  
Kui Zhang ◽  
Qianqian Huang ◽  
Yu Li ◽  
Lanhua Liu ◽  
Xiao-Feng Tang ◽  
...  
Keyword(s):  
High Temperatures ◽  
Type I Collagen ◽  
Elevated Temperatures ◽  
Catalytic Domain ◽  
Ion Pairs ◽  
Gelatinolytic Activity ◽  
Type I ◽  
Fish Scale ◽  
Collagenolytic Proteases ◽  
Collagenolytic Protease

Enzymatic degradation of collagen is of great industrial and environmental significance; however, little is known about thermophile-derived collagenolytic proteases. Here, we report a novel collagenolytic protease (TSS) from thermophilic Brevibacillus sp. WF146. The TSS precursor comprises a signal peptide, an N-terminal propeptide, a subtilisin-like catalytic domain, a β-jelly roll (βJR) domain, and a prepeptidase C-terminal (PPC) domain. The maturation of TSS involves a stepwise autoprocessing of the N-terminal propeptide and the PPC domain, and the βJR rather than the PPC domain is necessary for correct folding of the enzyme. Purified mature TSS displayed optimal activity at 70°C and pH 9.0, a half-life of 1.5 h at 75°C, and an increased thermostability with rising salinity up to 4 M. TSS possesses an increased number of surface acidic residues and ion pairs, as well as four Ca 2+ -binding sites, which contribute to its high thermostability and halotolerance. At high temperatures, TSS exhibited high activity toward insoluble type I collagen and azocoll, but showed a low gelatinolytic activity, with a strong preference for Arg and Gly at the P1 and P1’ positions, respectively. Both the βJR and PPC domains could bind but not swell collagen, and thus facilitate TSS-mediated collagenolysis via improving the accessibility of the enzyme to the substrate. Additionally, TSS has the ability to efficiently degrade fish scale collagen at high temperatures. IMPORTANCE Proteolytic degradation of collagen at high temperatures has the advantages of increasing degradation efficiency and minimizing the risk of microbial contamination. Reports on thermostable collagenolytic proteases are limited, and their maturation and catalytic mechanisms remain to be elucidated. Our results demonstrate that the thermophile-derived TSS matures in an autocatalytic manner, and represents one of the most thermostable collagenolytic proteases reported so far. At elevated temperatures, TSS prefers hydrolyzing insoluble heat-denatured collagen rather than gelatin, providing new insight into the mechanism of collagen degradation by thermostable collagenolytic proteases. Moreover, TSS has the potential to be used in recycling collagen-rich wastes such as fish scales.

APPLICATION OF DENDRIMER/PLASMID hBMP-2 COMPLEXES LOADED INTO β-TCP/COLLAGEN SCAFFOLD IN THE TREATMENT OF FEMORAL DEFECTS IN RATS

2014 ◽  
Vol 26 (01) ◽  
pp. 1450005 ◽  
Author(s):  
Tingwei Bao ◽  
Huiming Wang ◽  
Wentao Zhang ◽  
Xuefeng Xia ◽  
Jiabei Zhou ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Type I Collagen ◽  
Cell Attachment ◽  
Collagen Scaffold ◽  
Bone Defects ◽  
Bone Morphogenetic Protein 2 ◽  
Porous Scaffolds ◽  
Type I

Purpose: Plasmid loading into scaffolds to enhance sustained release of growth factors is an important focus of regenerative medicine. The aim of this study was to build gene-activated matrices (GAMs) and examine the bone augmentation properties. Methods: Generation 5 polyamidoamine dendrimers (G5 dPAMAM)/plasmid recombinant human bone morphogenetic protein-2 (rhBMP-2) complexes were immobilized into beta-tricalcium phosphate (β-TCP)/type I collagen porous scaffolds. After cultured with rat mesenchymal stem cells (rMSCs), transfection efficiencies were examined. The secretion of rhBMP-2 and alkaline phosphatase (ALP) were detected to evaluate the osteogenic properties. Scanning electron microscopy (SEM) was used to observe attachment and proliferation. Moreover, we applied these GAMs directly into freshly created segmental bone defects in rat femurs, and their osteogenic efficiencies were evaluated. Results: Released plasmid complexes were transfected into stem cells and were expressed, which caused osteogenic differentiations of rat mesenchymal stem cells (rMSCs). SEM analysis showed excellent cell attachment. Bioactivity of plasmid rhBMP-2 was maintained in vivo, and the X-ray observation, histological analysis and immunohistochemistry (IHC) of bone tissue demonstrated that the bone healing in segmental femoral defects was enhanced by implantation of GAMs. Conclusions: Such biomaterials offer therapeutic opportunities in critical-sized bone defects.

Synthesis and Incorporation of Quaternary Ammonium Silane Antimicrobial into Self‐Crosslinked Type I Collagen Scaffold: A Hybrid Formulation for 3D Printing

2021 ◽  
pp. 2100326
Author(s):  
Ranjeet Ajit Bapat ◽  
Senthil Kumar Muthusamy ◽  
Preena Sidhu ◽  
Mak Kit‐Kay ◽  
Abhishek Parolia ◽  
...  
Keyword(s):  
3D Printing ◽  
Quaternary Ammonium ◽  
Type I Collagen ◽  
Collagen Scaffold ◽  
Type I ◽  
Hybrid Formulation

Mechanical Stress-Induced Orientation and Ultrastructural Change of Smooth Muscle Cells Cultured in Three-Dimensional Collagen Lattices

1994 ◽  
Vol 3 (6) ◽  
pp. 481-492 ◽  
Author(s):  
Keiichi Kanda ◽  
Takehisa Matsuda
Keyword(s):  
Smooth Muscle ◽  
Tensile Stress ◽  
Smooth Muscle Cells ◽  
Type I Collagen ◽  
Dynamic Stress ◽  
Three Dimensional ◽  
Muscle Cells ◽  
The Other ◽  
Type I ◽  
Oriented Parallel

The effect of tensile stress on the orientation and phenotype of arterial smooth muscle cells (SMCs) cultured in three-dimensional (3D) type I collagen gels was morphologically investigated. Ring-shaped hybrid tissues were prepared by thermal gelation of a cold mixed solution of type I collagen and SMCs derived from bovine aorta. The tissues were subjected to three different modes of tensile stress. They were floated (isotonic control), stretched isometrically (static stress) and periodically stretched and recoiled by 5% above and below the resting tissue length at 60 RPM frequency (dynamic stress). After incubation for up to four wk, the tissues were investigated under a light microscope (LM) and a transmission electron microscope (TEM). Hematoxylin and eosinstained LM samples revealed that, irrespective of static or dynamic stress loading, SMCs in stress-loaded tissues exhibited elongated bipolar spindle shape and were regularly oriented parallel to the direction of the strain, whereas those in isotonic control tissues were polygonal or spherical and had no preferential orientation. In Azan-stained samples, collagen fiber bundles in isotonic control tissues were somewhat retracted around the polygonal SMCs to form a random network. On the other hand, those in statically and dynamically stressed tissues were accumulated and prominently oriented parallel to the stretch direction. Ultrastructural investigation using a TEM showed that SMCs in control and statically stressed tissues were almost totally filled with synthetic organelles such as rough endoplasmic reticulums, free ribosomes, Golgi complexes and mitochondria, indicating that the cells remained in the synthetic phenotype. On the other hand, SMCs in dynamically stressed tissues had increased fractions of contractile apparatus, such as myofilaments, dense bodies and extracellular filamentous materials equivalent to basement membranes, that progressed with incubation time. These results indicate that periodic stretch, in concert with 3-D extracellular collagen matrices, play a significant role in the phenotypic modulation of SMCs from the synthetic to the contractile state, as well as cellular and biomolecular orientation.

A Continuous-Discrete Finite Element Model of Angiogenesis That Couples Vessel Growth With Matrix Deformation

2013 ◽  
Author(s):  
Lowell T. Edgar ◽  
Steve A. Maas ◽  
James E. Guilkey ◽  
Jeffrey A. Weiss
Keyword(s):  
Type I Collagen ◽  
Three Dimensional ◽  
Collagen Gel ◽  
Element Model ◽  
Fibrillar Structure ◽  
Type I ◽  
Major Pathway ◽  
Vessel Growth ◽  
Discrete Finite Element

Recent developments in tissue engineering have created demand for the ability to create microvascular networks with specific topologies in vitro. During angiogenesis, sprouting endothelial cells apply traction forces and migrate along components of the extracellular matrix (ECM), resulting in neovessel elongation [1]. The fibrillar structure of the ECM serves as the major pathway for mechanotransduction between contact-dependent cells. Using a three-dimensional (3D) organ culture model of microvessel fragments within a type-I collagen gel, we have shown that subjecting the culture to different boundary conditions during angiogenesis can lead to drastically different vascular topologies [2]. Fragments cultured in a rectangular gel that were free to contract grew into a randomly oriented network [3, 4]. When the long-axis of the gel was constrained as to prevent contraction, microvessels and collagen fibers were found aligned along the constrained axis (Fig. 1) [4].

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