NONLINEAR SPECTRAL IMAGING OF ELASTIC CARTILAGE IN RABBIT EARS

Elastic cartilage in the rabbit external ear is an important animal model with attractive potential value for researching the physiological and pathological states of cartilages especially during wound healing. In this work, nonlinear optical microscopy based on two-photon excited fluorescence and second harmonic generation were employed for imaging and quantifying the intact elastic cartilage. The morphology and distribution of main components in elastic cartilage including cartilage cells, collagen and elastic fibers were clearly observed from the high-resolution two-dimensional nonlinear optical images. The areas of cell nuclei, a parameter related to the pathological changes of normal or abnormal elastic cartilage, can be easily quantified. Moreover, the three-dimensional structure of chondrocytes and matrix were displayed by constructing three-dimensional image of cartilage tissue. At last, the emission spectra from cartilage were obtained and analyzed. We found that the different ratio of collagen over elastic fibers can be used to locate the observed position in the elastic cartilage. The redox ratio based on the ratio of nicotinamide adenine dinucleotide (NADH) over flavin adenine dinucleotide (FAD) fluorescence can also be calculated to analyze the metabolic state of chondrocytes in different regions. Our results demonstrated that this technique has the potential to provide more accurate and comprehensive information for the physiological states of elastic cartilage.

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A new phase-matchable nonlinear optical silicate: Rb2ZnSi3O8

Journal of Materials Chemistry C ◽

10.1039/c7tc03000b ◽

2017 ◽

Vol 5 (42) ◽

pp. 11025-11029 ◽

Cited By ~ 9

Author(s):

Bingqing Zhao ◽

Yi Yang ◽

Sangen Zhao ◽

Yaoguo Shen ◽

Xianfeng Li ◽

...

Keyword(s):

Second Harmonic Generation ◽

Harmonic Generation ◽

Nonlinear Optical ◽

Second Harmonic ◽

Three Dimensional ◽

Dimensional Structure ◽

Three Dimensional Structure ◽

New Phase

A new asymmetric silicate Rb2ZnSi3O8with a three-dimensional structure shows phase-matchability and enhanced second-harmonic generation as compared with α-SiO2.

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Na4Yb(CO3)3F: A New UV Nonlinear Optical Material with a Large Second Harmonic Generation Response

Crystals ◽

10.3390/cryst8100381 ◽

2018 ◽

Vol 8 (10) ◽

pp. 381

Author(s):

Qiaoling Chen ◽

Min Luo ◽

Chensheng Lin

Keyword(s):

Second Harmonic Generation ◽

Harmonic Generation ◽

Nonlinear Optical ◽

Diffuse Reflectance ◽

Second Harmonic ◽

Three Dimensional ◽

One Dimensional ◽

Nonlinear Optical Crystals ◽

3D Network ◽

3D Framework

A new nonlinear optical crystals fluoride carbonate, Na4Yb(CO3)3F, has been synthesized by mild hydrothermal method. The Na4Yb(CO3)3F crystallizes in the noncentrosymmetric space group Cc (no. 9) with the lattice parameters a = 8.018(3), b = 15.929(5), c = 13.950(5) Å and β = 101.425(6)°. The compound Na4Yb(CO3)3F has a high density of [CO3] groups. The structure can be described as one-dimensional [Na5Yb(CO3)2F2] chains connected by [CO3] groups, forming an intricate three-dimensional (3D) framework. Other Na+ and Yb3+ cations are located in the cavities of 3D network. The powder second harmonic generation (SHG) measurement shows that Na4Yb(CO3)3F features a large SHG response, about 4.3 times that of KH2PO4 (KDP), and is a phase-matchable material. In addition, its UV-Vis-NIR diffuse reflectance spectral data indicate that Na4Yb(CO3)3F has a large optical gap about 4.72 eV, which corresponds to the UV cut-off edge of 263 nm.

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CHARACTERIZING THREE-DIMENSIONAL MICROSTRUCTURE OF COLLAGEN/CHITOSAN SCAFFOLDS USING MULTIPHOTON MICROSCOPE

Biomedical Engineering Applications Basis and Communications ◽

10.4015/s1016237213500385 ◽

2013 ◽

Vol 25 (03) ◽

pp. 1350038

Author(s):

Hsin-Yuan Tan ◽

Wen Lo ◽

Chiu-Mei Hsueh ◽

Chia-Yi Wang ◽

Sung-Jan Lin ◽

...

Keyword(s):

Nonlinear Optical ◽

Second Harmonic ◽

Imaging Modality ◽

Three Dimensional ◽

Minimal Invasive ◽

Multiphoton Imaging ◽

Optical Signals ◽

Polymeric Scaffolds ◽

Chitosan Scaffolds ◽

Chitosan Blends

In this work, we used multiphoton microscopic system for characterizing three-dimensional microstructure of collagen/chitosan polymeric scaffolds in a noninvasive fashion. Nonlinear optical signals including multiphoton autofluorescence (MAF) and second harmonic generation (SHG) derived from collagen/chitosan scaffolds were collected and analyzed. The three-dimensional porous microstructures of collagen/chitosan scaffolds were visualized by co-localized and evenly distributed MAF and SHG signals. The distribution of collagen and chitosan compositions within miscible collagen/chitosan blends cannot be either localized or differentiated simply using these nonlinear optical signals. However, the intensity of MAF signals in scaffolds was found to be markedly decreased in correlation to the supplementation of chitosan within blends, regardless of collagen/chitosan weight ratios. It therefore implied that the MAF-generating molecules within collagen being altered in miscible collagen/chitosan blends. And the SHG signals also decreased significantly in collagen/chitosan scaffolds with the supplementation of chitosan, regardless of different weight ratios. This finding supported the hypothesis regarding the miscibility of collagen/chitosan blends that triple helix structure of collagen, a proven SHG-generating microstructure, was altered in miscible collagen/chitosan blends. In conclusion, our work demonstrated that multiphoton imaging modality can be versatile for investigating three-dimensional microstructure of miscible polymeric scaffolds in a minimal invasive fashion, and may potentially be applicable in the field of tissue engineering.

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New Perspectives in the Microscopic Structure of Human Dura Mater in the Dorsolumbar Region

Regional Anesthesia The Journal of Neural Blockade in Obstetrics Surgery & Pain Control ◽

10.1136/rapm-00115550-199722020-00010 ◽

1997 ◽

Vol 22 (2) ◽

pp. 161-166 ◽

Cited By ~ 1

Author(s):

Miguel Angel Reina ◽

Martin Dittmann ◽

Andrés López Garcia ◽

André van Zundert

Keyword(s):

Dura Mater ◽

External Surface ◽

Three Dimensional ◽

Longitudinal Direction ◽

Collagen Fibers ◽

Dimensional Structure ◽

Elastic Fibers ◽

Microscopic Structure ◽

Laminated Structure ◽

Parallel Fashion

Background and ObjectivesThe object of this study was to describe the three-dimensional structure of the dura mater by use of scanning electron microscopy.MethodsMicroscopic dissection of the dura mater from four fresh cadavers (aged 70, 75, 76, and 80 years) 8-12 hours after death were investigated in three different planes (longitudinal, tangential, and transverse).ResultsThe external surface of the dura mater, facing the epidural space, consisted of a network of randomly oriented fine collagen fibers. The thicker elastic fibers (2 μm in diameter) were observed on the surface of the dura. In the inner part of the dura mater, there were very fine lamellae of collagen fibers, which were bundled into thicker (4-5 μm) layers. The dura mater consisted of 78-82 layers, each layer including 8-12 very fine lamellae.ConclusionsThe fibers of the dura mater do not run in a longitudinal direction and are not arranged in a parallel fashion. Cytoarchitecturally the dura mater is a laminated structure built up from well-defined layers oriented concentrically around the medulla spinalis.

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Microstructure and mechanics of human resistance arteries

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00002.2016 ◽

2016 ◽

Vol 311 (6) ◽

pp. H1560-H1568 ◽

Cited By ~ 4

Author(s):

J. S. Bell ◽

A. O. Adio ◽

A. Pitt ◽

L. Hayman ◽

C. E. Thorn ◽

...

Keyword(s):

Structural Changes ◽

Subcutaneous Fat ◽

Three Dimensional ◽

Vascular Diseases ◽

Local Strain ◽

Honeycomb Structure ◽

Transmural Pressure ◽

Elastic Fibers ◽

Resistance Arteries ◽

Cell Nuclei

Vascular diseases such as diabetes and hypertension cause changes to the vasculature that can lead to vessel stiffening and the loss of vasoactivity. The microstructural bases of these changes are not presently fully understood. We present a new methodology for stain-free visualization, at a microscopic scale, of the morphology of the main passive components of the walls of unfixed resistance arteries and their response to changes in transmural pressure. Human resistance arteries were dissected from subcutaneous fat biopsies, mounted on a perfusion myograph, and imaged at varying transmural pressures using a multimodal nonlinear microscope. High-resolution three-dimensional images of elastic fibers, collagen, and cell nuclei were constructed. The honeycomb structure of the elastic fibers comprising the internal elastic layer became visible at a transmural pressure of 30 mmHg. The adventitia, comprising wavy collagen fibers punctuated by straight elastic fibers, thinned under pressure as the collagen network straightened and pulled taut. Quantitative measurements of fiber orientation were made as a function of pressure. A multilayer analytical model was used to calculate the stiffness and stress in each layer. The adventitia was calculated to be up to 10 times as stiff as the media and experienced up to 8 times the stress, depending on lumen diameter. This work reveals that pressure-induced reorganization of fibrous proteins gives rise to very high local strain fields and highlights the unique mechanical roles of both fibrous networks. It thereby provides a basis for understanding the micromechanical significance of structural changes that occur with age and disease.

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Hemolytic, Biocompatible, and Functional Effect of Cellularized Polycaprolactone-Hydrolyzed Collagen Electrospun Membranes for Possible Application as Vascular Implants

Journal of Biomedical Nanotechnology ◽

10.1166/jbn.2021.3087 ◽

2021 ◽

Vol 17 (6) ◽

pp. 1184-1198

Author(s):

Camilo Atehortua ◽

Yuliet Montoya ◽

Alejandra García ◽

John Bustamante

Keyword(s):

Cell Viability ◽

Incubation Period ◽

Morphological Changes ◽

Three Dimensional ◽

Small Diameter ◽

Dimensional Structure ◽

Fibrillar Structure ◽

Cell Nuclei ◽

Functional Effect ◽

Hydrolyzed Collagen

In search of bioactive vascular prostheses that exhibit greater biocompatibility through the combination of natural and synthetic polymers, tissue engineering from a biomimetic perspective has proposed the development of three-dimensional structures as therapeutic strategies in the field of cardiovascular medicine. Techniques such as electrospinning allow obtaining of scaffolds that emulate the microarchitecture of the extracellular matrix of native vessels; thus, this study aimed to evaluate the biological influence of microarchitecture on polycaprolactone (PCL) and hydrolyzed collagen (H-Col) electrospun scaffolds, which have a homogeneous (microscale) or heterogeneous (micro-nanoscale) fibrillar structure. The hemolytic, biocompatible, and functional effect of the scaffolds in interaction with an in vitro fibroblast model was determined, in view of its potential use for vascular implants. Scaffolds were characterized by scanning electron microscopy and atomic force microscopy, Fourier transform infrared spectroscopy, wettability, static permeability, tensile test, and degradation. In addition, direct and indirect 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays were used to identify the cell viability of fibroblasts, fluorescence assays were performed to establish morphological changes of the cell nuclei, and the hemolytic effect of the scaffolds was calculated. Results showed that ethanol-treated biocompositescaffolds exhibited mass losses lower than 6.65% and slow wettability and absorption, resulting from an increase in secondary structures that contribute to the crystalline phase of H-Col. The scaffolds demonstrated stable degradation in saline during the incubation period because of the availability of soluble structures in aqueous media, and the inclusion of H-Col increased the elastic properties of the scaffold. As regards hemocompatibility, the scaffolds had hemolysis levels lower than 1%; moreover, in terms of biocompatible characteristics, scaffolds exhibited good adhesion, proliferation, and cell viability and insignificant changes in the circularity of the cell nuclei. However, scaffolds with homogeneous fibers showed cell agglomerates after 48 h of interaction. By contrast, permeability decreased as the incubation period progressed, because of the cellularization of the three-dimensional structure. In conclusion, multiscale scaffolds could exhibit a suitable behavior as a bioactive small-diameter vascular implant.

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Using second harmonic generation microscopy to study the three-dimensional structure of collagen and its degradation mechanism

10.17760/d20003077 ◽

2013 ◽

Author(s):

Yair Mega

Keyword(s):

Second Harmonic Generation ◽

Harmonic Generation ◽

Second Harmonic ◽

Degradation Mechanism ◽

Three Dimensional ◽

Dimensional Structure ◽

Three Dimensional Structure ◽

Second Harmonic Generation Microscopy

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The Effects of a Short Self-Assembling Peptide on the Physical and Biological Properties of Biopolymer Hydrogels

Pharmaceutics ◽

10.3390/pharmaceutics13101602 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1602

Author(s):

Sumit Chowdhuri ◽

Moumita Ghosh ◽

Lihi Adler-Abramovich ◽

Debapratim Das

Keyword(s):

Tissue Engineering ◽

Cartilage Tissue Engineering ◽

Three Dimensional ◽

Biological Properties ◽

Cartilage Tissue ◽

Dimensional Structure ◽

Short Peptide ◽

Hydrogel Scaffolds ◽

Composite Hydrogels ◽

Thixotropic Behavior

Hydrogel scaffolds have attracted much interest in the last few years for applications in the field of bone and cartilage tissue engineering. These scaffolds serve as a convenient three-dimensional structure on which cells can grow while sensing the native environment. Natural polymer-based hydrogels are an interesting choice for such purposes, but they lack the required mechanical properties. In contrast, composite hydrogels formed by biopolymers and short peptide hydrogelators possess mechanical characteristics suitable for osteogenesis. Here, we describe how combining the short peptide hydrogelator, Pyrene-Lysine-Cysteine (PyKC), with other biopolymers, can produce materials that are suitable for tissue engineering purposes. The presence of PyKC considerably enhances the strength and water content of the composite hydrogels, and confers thixotropic behavior. The hyaluronic acid-PyKC composite hydrogels were shown to be biocompatible, with the ability to support osteogenesis, since MC3 T3-E1 osteoblast progenitor cells grown on the materials displayed matrix calcification and osteogenic differentiation. The osteogenesis results and the injectability of these composite hydrogels hold promise for their future utilization in tissue engineering.

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Development of a Method for Scaffold-Free Elastic Cartilage Creation

International Journal of Molecular Sciences ◽

10.3390/ijms21228496 ◽

2020 ◽

Vol 21 (22) ◽

pp. 8496

Author(s):

Masahiro Enomura ◽

Soichiro Murata ◽

Yuri Terado ◽

Maiko Tanaka ◽

Shinji Kobayashi ◽

...

Keyword(s):

Progenitor Cells ◽

Transplant Rejection ◽

Costal Cartilage ◽

Three Dimensional ◽

Cartilage Tissue ◽

Culture Vessel ◽

Biological Origin ◽

Cartilage Grafts ◽

Elastic Cartilage ◽

Over Time

Microtia is a congenital aplasia of the auricular cartilage. Conventionally, autologous costal cartilage grafts are collected and shaped for transplantation. However, in this method, excessive invasion occurs due to limitations in the costal cartilage collection. Due to deformation over time after transplantation of the shaped graft, problems with long-term morphological maintenance exist. Additionally, the lack of elasticity with costal cartilage grafts is worth mentioning, as costal cartilage is a type of hyaline cartilage. Medical plastic materials have been transplanted as alternatives to costal cartilage, but transplant rejection and deformation over time are inevitable. It is imperative to create tissues for transplantation using cells of biological origin. Hence, cartilage tissues were developed using a biodegradable scaffold material. However, such materials suffer from transplant rejection and biodegradation, causing the transplanted cartilage tissue to deform due to a lack of elasticity. To address this problem, we established a method for creating elastic cartilage tissue for transplantation with autologous cells without using scaffold materials. Chondrocyte progenitor cells were collected from perichondrial tissue of the ear cartilage. By using a multilayer culture and a three-dimensional rotating suspension culture vessel system, we succeeded in creating scaffold-free elastic cartilage from cartilage progenitor cells.

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