The Nature of Covalent Complexes of Phosphoproteins with Collagen in the Bovine Dentin Matrix

1979 ◽  
Vol 58 (6) ◽  
pp. 1625-1633 ◽  
Author(s):  
Jean Curley-Joseph ◽  
Arthur Veis

The bovine dentin matrix still contains some non-collagenous proteins after thorough extraction and decalcification. These have been obtained following digestion of the matrix by cyanogen bromide. Peptides containing non-collagenous portions were isolated by chromatography on diethylaminoethyl cellulose columns and fractionated on hydroxyapatite columns. Several fractions were obtained. The principal component was a complex between a highly-phosphorylated serine-aspartic acid-rich protein and a collagen peptide. These collagenous and non-collagenous moieties could not be separated from each other even under highly dissociative solvent conditions. After digestion with collagenase, the resulting phosphoprotein fraction still contained a few residues of hydroxyproline and hydroxylysine, and an enhanced content of pro-line, compared to the equivalent directly extractable phosphophoryn of the matrix. These data were interpreted as indicating that the phosphophoryn which is not extractable in 0.5M ethylenediaminetetraacetic acid is in fact covalently bound to some specific section of the matrix collagen. The covalent modification of the collagen matrix with highly acidic phosphoproteins may have an important role in the mineralization process.

2021 ◽  
Vol 9 ◽  
pp. 2050313X2110136
Author(s):  
Afsaneh Alavi ◽  
Jeannine Archer ◽  
Patricia Coutts

The objective of this case series was to assess the wound healing effectiveness of a collagen matrix wound dressing containing partially denatured collagen, carboxymethyl cellulose, alginate and ethylenediaminetetraacetic acid in chronic lower extremity ulcers. A total of nine patients with refractory lower extremity ulcers were treated with the collagen contact layer in addition to standard of care. Wound healing progress was measured at 2, 4 and 8 weeks. An average decrease in wound size of 73% was achieved across patients at week 8, with complete healing in two patients. The intervention was easy to use and well tolerated by patients. The results of this study, although preliminary, suggest that the advanced collagen matrix dressing represents an effective and safe treatment strategy for healing refractory chronic lower extremity ulcers of varying etiologies. Further investigation is needed to evaluate efficacy in a larger randomized clinical trial with focus on cost-effectiveness and impact on patient’s quality-of-life.


2018 ◽  
Vol 7 (3) ◽  
pp. 16 ◽  
Author(s):  
Alberto Castañeda-Yañez ◽  
Sandra T. Martín-del-Campo ◽  
Alejandra San-Martin ◽  
Anaberta Cardador-Martínez

In this work, it was evaluated the effect of microencapsulation using spray drying over natural colorants present in two varieties (red and purple) of prickly pear juice (Opuntia spp.), using three kinds of carrier agents (matrixes). The dried samples after microencapsulation retained a high total amount of the betalains and their antioxidant characteristics. However, some individual betalains were lost after microencapsulation. According to ANOVA results, matrix 3204 showed a more protective effect than matrix 4801 in both microencapsulated juices over color, individual betalains, and antioxidant capacity. Globally, the protective effect was better for purple juices than red juices no matter the matrix used. Principal Component Analysis (PCA) confirmed these results. Matrix 3204 resulted in the best carrier agent since it gave a less disperse PCA group for both color juices. The parameters that separated both PCA matrixes groups were L*, a*, b* and DPPH. 


Author(s):  
Monica HARMANESCU

Principal Components and Classification Analysis (PC&CA) represents one of the most utilised multivariate chemometric techniques, having the advantage to use many measurements for a single sample in the same time, being recommended for understanding better the complexity of one phenomenon. The aim of this paper was to use PC&CA to study the effects of different types of fertilizers on polyphenols content of forages harvested in autumn from permanent grassland. Gravimetrically was established the matrix of floristic composition. The experimental field was fertilized first time in 2003, organic and/or NPK mineral. The determination of polyphenols contents was made using UV-VIS SPECORD 205 spectrophotometer, in conformity to chemical Folin and Ciocalteu colorimetric method. The highest polyphenols content was identified in forages from unfertilized variant (108 µM gallic acid/g). PC&CA can be a useful tool in describing the modification of polyphenols contents of forages under the effects of organic and/or mineral fertilisation of permanent grassland.


Author(s):  
Gerard A. Ateshian ◽  
Vikram Rajan ◽  
Nadeen O. Chahine ◽  
Clare Canal Guterl ◽  
Clark T. Hung

A number of theoretical frameworks embodying the disparity between tensile and compressive properties of cartilage have been proposed, accounting for the collagen fibers implicitly [1,2] or explicitly [3–5]. These models generally propose discrete fiber families to describe the collagen matrix. They are able to capture the most salient features of the cartilage mechanical response, namely, the tension-compression nonlinearity of the stress-strain curve [6].


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Yan Zhang ◽  
Marc Lamoureux ◽  
Stephanie Thorn ◽  
Vincent Chan ◽  
Joel Price ◽  
...  

Background: To investigate the mechanisms involved in the potentiation of cell therapy by delivery matrices, we evaluated the retention and engraftment of transplanted human circulating progenitor cells (CPCs) injected in a collagen matrix by using in vivo positron emission tomography (PET) imaging, ex vivo biodistribution, and immunohistochemistry. Methods: CPCs were labeled with 18 F-FDG and injected with or without a collagen type I-based matrix in the ischemic hindlimb muscle (IM) of rats (2x10 6 cells; n=15/group). Localization of cells was acquired by PET imaging (15 min) at 150 min post-injection. In addition, radionuclide biodistribution, immunofluorescence, and immunohistochemical examination of transplanted CPCs were performed at up to 14 days. Results: Cell labeling efficiency was CPC-concentration dependent (r=0.61, p <0.001), but not 18 F-FDG-dose dependent. Labeled CPCs exhibited excellent short-term stability and viability. Persistence of 18 F-FDG radioactivity in cells was markedly greater than non-specific retention in the matrix. Wholebody (WB) PET images revealed better CPC retention in the IM and less non-specific leakage to other tissues when CPCs were delivered within the matrix (IM/WB retention ratio of 43.9±8.2%), compared to cells injected alone (22.3±10.4%; p =0.040) and to 18 F-FDG injected with or without the matrix (9.7±5.5% and 11.0±5.5%, respectively; p <0.005). Radioactivity biodistribution confirmed that accumulation was increased (by 92.5%; p =0.024) in the IM and reduced (by 1.1 to 23.8%; p <0.05) in non-specific tissues when cells were injected within the matrix, compared to cells injected alone. Anti-human mitochondria staining showed increased cell retention in the IM with use of matrices (3.0±2.1%) versus cells only (1.9±0.8%; p =0.048). At 14 days the number of CD31 + transplanted human cells was greater (1.6±0.1%) when injected within the matrix than injected alone (0.7±0.1%; p =0.004). Conclusions: Collagen-based delivery matrices improve the early retention of transplanted CPCs, which in turn favors subsequent cell engraftment in the ischemic tissue. This mechanism conferred by the matrix has potential implications for the optimization of cell therapy at the early stages after cell delivery.


2016 ◽  
Vol 28 (4) ◽  
pp. 516-529 ◽  
Author(s):  
Junjie Cao ◽  
Nannan Wang ◽  
Jie Zhang ◽  
Zhijie Wen ◽  
Bo Li ◽  
...  

Purpose – The purpose of this paper is to present a novel method for fabric defect detection. Design/methodology/approach – The method based on joint low-rank and spare matrix recovery, since patterned fabric is manufactured by a set of predefined symmetry rules, and it can be seen as the superposition of sparse defective regions and low-rank defect-free regions. A robust principal component analysis model with a noise term is designed to handle fabric images with diverse patterns robustly. The authors also estimate a defect prior and use it to guide the matrix recovery process for accurate extraction of various fabric defects. Findings – Experiments on plain and twill, dot-, box- and star-patterned fabric images with various defects demonstrate that the method is more efficient and robust than previous methods. Originality/value – The authors present a RPCA-based model for fabric defects detection, and show how to incorporate defect prior to improve the detection results. The authors also show that more robust detection and less running time can be obtained by introducing a noise term into the model.


Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Yue Hu ◽  
Jin-Xing Liu ◽  
Ying-Lian Gao ◽  
Sheng-Jun Li ◽  
Juan Wang

In the big data era, sequencing technology has produced a large number of biological sequencing data. Different views of the cancer genome data provide sufficient complementary information to explore genetic activity. The identification of differentially expressed genes from multiview cancer gene data is of great importance in cancer diagnosis and treatment. In this paper, we propose a novel method for identifying differentially expressed genes based on tensor robust principal component analysis (TRPCA), which extends the matrix method to the processing of multiway data. To identify differentially expressed genes, the plan is carried out as follows. First, multiview data containing cancer gene expression data from different sources are prepared. Second, the original tensor is decomposed into a sum of a low-rank tensor and a sparse tensor using TRPCA. Third, the differentially expressed genes are considered to be sparse perturbed signals and then identified based on the sparse tensor. Fourth, the differentially expressed genes are evaluated using Gene Ontology and Gene Cards tools. The validity of the TRPCA method was tested using two sets of multiview data. The experimental results showed that our method is superior to the representative methods in efficiency and accuracy aspects.


MRS Advances ◽  
2016 ◽  
Vol 1 (18) ◽  
pp. 1295-1300 ◽  
Author(s):  
XingGuo Cheng ◽  
Nicole Edwards ◽  
Kelly Leung ◽  
David Zhang ◽  
Robert J. Christy

ABSTRACTDue to injuries and disease, there is a great need for a robust, biocompatible, biodegradable, skin-like dermal substitute to repair and regenerate damaged or lost skin. A novel electrochemical process was used to fabricate planarly aligned, densely packed collagen-based sheet which closely mimics the major structure of collagen in skin. The collagen matrix was characterized by scanning electron microscopy (SEM), oxygen permeation, moisture vapor transmission rate (MVTR), and mechanical strength. The seeding and proliferation of adipose derived stem cells (ADSCs) on the matrix was also evaluated. The results indicate that electrochemically-aligned collagen matrix has good MVTR, superior oxygen permeability, and is robust and biocompatible. Thus, it will be evaluated in vivo in the near future as a dermal substitute material.


Author(s):  
Yu-Chen Cheng ◽  
Pen-Hsiu Grace Chao

Many strategies have been proposed to enhance the healing capability of the anterior cruciate ligament (ACL). A novel treatment option, called enhanced primary repair, places a provisional matrix at the tear site to promote cell infiltration of the wound and aims to reestablish the structure-function relationship of the ACL [1]. This approach of guided tissue regeneration offers great potential benefits of retaining the complex native tissue matrix structure, innervation, and vascularization as compared with grafts. A major aspect of this procedure is enhancing ligament fibroblast infiltration into the matrix material and promoting matrix synthesis. We have previously demonstrated that applied electric fields (EFs) enhance knee ligament fibroblast migration, alignment, and collagen gene expressions on planar substrates [2]. In the current study, we developed a new system to simulate cell infiltration from the tissue to a provisional collagen matrix. An EF was applied across the construct to investigate its effects of on ACL fibroblast migration into the provisional matrix.


1987 ◽  
Vol 252 (1) ◽  
pp. H71-H79 ◽  
Author(s):  
R. J. Mullins ◽  
M. R. Powers ◽  
D. R. Bell

The acute effect of removing plasma equivalent to 1.7% body wt and replacing it with saline equivalent to 10% body wt on the extravascular distribution of water, albumin, and immunoglobulin G (IgG) in skin and skeletal muscle was studied in anesthetized rabbits. The plasma protein concentration decreased by 43%. Prenodal lymph was collected from hindpaw skin or skeletal muscle. The extracellular and plasma volumes in excised tissue samples were measured using 51Cr-labeled ethylenediaminetetraacetic acid and 125I-labeled albumin, respectively. The protein spaces were calculated from measurements of endogenous albumin and IgG concentrations using immunochemical techniques. Lymph flow from both tissues increased more than twice control, whereas the lymph total protein concentration decreased to less than one-half control. Three to six hours after the saline infusion, the skin interstitial volume was 30% greater than control, whereas the extravascular masses of albumin and IgG were 20% greater than control. For muscle, the interstitial volume was twice the control value, whereas the extravascular masses of albumin and IgG were not significantly altered. There was a large decrease in the lymph protein concentration after acute plasmapheresis. However, there was not an acute decrease in the extravascular albumin or IgG masses from skin or skeletal muscle. This may be due to the presence of the collagen matrix and edema fluid.


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