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Collagen Cross-linking

Sylvie Ricard-Blum, Georges Baffet, Nathalie Théret
The collagen network is altered in fibrotic diseases associated with extracellular matrix (ECM) biosynthesis and remodeling. This mini-review focuses on the quantitative and qualitative modifications of collagens occurring at the molecular and tissue levels in fibrosis. They result from changes in collagen expression, biosynthesis, enzymatic cross-linking and degradation by several protease families. These molecular modifications, which are mostly regulated by TGF-β, are associated with altered collagen organization at the tissue level, leading to a fibrotic signature that can be analyzed by Second Harmonic Generation (SHG) microscopy...
February 16, 2018: Matrix Biology: Journal of the International Society for Matrix Biology
Elif Erdem, Ibrahim Inan Harbiyeli, Hazal Boral, Macit Ilkit, Meltem Yagmur, Reha Ersoz
PURPOSE: To evaluate the efficiency of corneal collagen cross-linking (CXL) in addition to topical voriconazole in cases with mycotic keratitis. DESIGN: Retrospective case series in a tertiary university hospital. PARTICIPANTS: CXL was performed on 13 patients with mycotic keratitis who presented poor or no response to topical voriconazole treatment. METHODS: The clinical features, symptoms, treatment results and complications were recorded retrospectively...
February 16, 2018: Mycopathologia
Emily Forbat, Firas Al-Niaimi
Striae distensae (SD), otherwise known as "stretchmarks," are a common presenting complaint, particularly in young healthy women. SD are hypothesized to form in a patient when the cross-linked collagen is "overstretched" and rupture of this collagen matrix causes the striae. Thus, many treatments work by increasing collagen synthesis. This review critically appraises the evidence to date for the treatment of SD, including both energy-based devices and topical treatments.
February 16, 2018: Journal of Cosmetic and Laser Therapy: Official Publication of the European Society for Laser Dermatology
Jeffrey Chee Yean Chan, Krishna Burugapalli, Yi-Shiang Huang, Jack L Kelly, Abhay Pandit
Abdominal wall repair frequently utilizes either non-degradable or bio-degradable meshes, which are found to stimulate undesirable biological tissue responses or which possess suboptimal degradation rate. In this study, a biologic mesh prototype made from carbodiimide-cross-linked cholecyst-derived extracellular matrix (EDCxCEM) was compared with small intestinal submucosa (Surgisis®), cross-linked bovine pericardium (Peri-Guard®), and polypropylene (Prolene®) meshes in an in vivo rabbit model. The macroscopic appearance and stereological parameters of the meshes were evaluated...
February 16, 2018: Tissue Engineering. Part A
Rene B Svensson, Stuart T Smith, Patrick J Moyer, S Peter Magnusson
Connective tissues are ubiquitous throughout the body and consequently affect the function of many organs. In load bearing connective tissues like tendon, the mechanical functionality is provided almost exclusively by collagen fibrils that in turn are stabilized by covalent cross-links. Functionally distinct tendons display different cross-link patterns, which also change with maturation, but these differences have not been studied in detail at the fibril level. In the present study, a custom built nanomechanical test platform was designed and fabricated to measure tensile mechanics of individual fibrils from rat tendons...
February 12, 2018: Acta Biomaterialia
Héctor Capella-Monsonís, João Q Coentro, Valeria Graceffa, Zhuning Wu, Dimitrios I Zeugolis
Collagen type I is the most abundant extracellular matrix protein, and collagen type I supramolecular assemblies (e.g., tissue grafts, biomaterials and cell-assembled systems) are used extensively in tissue engineering and regenerative medicine. Many studies, for convenience or economic reasons, do not accurately determine collagen type I purity, concentration, solubility and extent of cross-linking in biological specimens, frequently resulting in erroneous conclusions. In this protocol, we describe solubility; normal, reduced and delayed (interrupted) SDS-PAGE; hydroxyproline; Sircol collagen and Pierce BCA protein; denaturation temperature; ninhydrin/trinitrobenzene sulfonic acid; and collagenase assays and assess them in a diverse range of biological samples (e...
March 2018: Nature Protocols
E Calciolari, F Ravanetti, A Strange, N Mardas, L Bozec, A Cacchioli, N Kostomitsopoulos, N Donos
BACKGROUND AND OBJECTIVE: Although collagen membranes have been clinically applied for guided tissue/bone regeneration for more than 30 years, their in vivo degradation pattern has never been fully clarified. A better understanding of the different stages of in vivo degradation of collagen membranes is extremely important, considering that the biology of bone regeneration requires the presence of a stable and cell/tissue-occlusive barrier during the healing stages in order to ensure a predictable result...
February 15, 2018: Journal of Periodontal Research
Frans Eberth Costa Andrade, Joyce Luciana Covre, Lisandra Ramos, Rossen Mihaylov Hazarbassanov, Myrna Serapião Dos Santos, Mauro Campos, José Álvaro Pereira Gomes, Cristiane Damas Gil
AIMS: To evaluate the expression of β-galactoside-binding proteins galectin (Gal)-1 and Gal-3 in patients with keratoconus (KC) and postcorneal collagen cross-linking (CXL) treatment in vitro. METHODS: Tear fluid, cornea samples and conjunctival impression cytology specimens from control and KC patients were used to evaluate Gal-1 and Gal-3 expressions. Primary keratocytes were isolated by collagenase digestion from surgically removed corneas of five normal or KC human corneal buttons and cultured in Dulbecco's modified eagle medium/Ham's F12 medium supplemented with 2% fetal bovine serum...
February 8, 2018: British Journal of Ophthalmology
B Gao, X J Li, M Lin, Y Y Li, Y Dong
Objective: To evaluate the application effect of nanofiber chitosan-collagen membrane (NCM) on guided bone regeneration (GBR). Methods: The mixture of collagen, chitosan, polyethylene oxide was used to make up the NCM by electrospinning, then the NCM was crosslinked by glutaraldehyde vapor. The physical property of the NCM was measured by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). MC3T3-E1 osteoblasts were cultured on NCM to characterize the biocompatibility. The effectiveness of four groups [contrast group, Bio-gide membrane (BGM), compressed chitosan-collagen menbrane (CCM), NCM/CCM] on bone regeneration were evaluated in critical-sized defects (diameter=5 mm) in SD rats...
February 9, 2018: Zhonghua Kou Qiang Yi Xue za Zhi, Zhonghua Kouqiang Yixue Zazhi, Chinese Journal of Stomatology
Iva Karesova, Julius Simko, Sona Fekete, Eva Zimcikova, Jana Malakova, Helena Zivna, Ladislava Pavlikova, Vladimir Palicka
Some data suggest that exposure to levetiracetam (LEV) might be associated with a risk for bone health in the model of orchidectomized rats. The aim of this study was to investigate if there is any significant risk of LEV for bone health in the model of gonadally intact animals. Wistar rats were divided into a control group and a test group, 8 rats in each group. The control rats received standard laboratory diet (SLD) while rats in the test group were fed SLD enriched with LEV for 12 weeks. Dual energy X-ray absorptiometry was used to measure BMD of the whole body, femur and lumbar vertebrae...
February 8, 2018: European Journal of Pharmacology
Min Zhang, Junhui Yang, Qili Yang, Liulian Huang, Hui Wu, Lihui Chen, Cuicui Ding
The poly(γ-glutamic acid)-NHS (γ-PGA-NHS) esters were used to endow collagen with both of excellent water-solubility and thermal stability via cross-linking reaction between γ-PGA-NHS and collagen. In the present work, the effect of γ-PGA-NHS on the aggregation of collagen molecules was studied by fluorescence techniques. The fluorescence emission spectra of pyrene in collagen solutions and the intrinsic fluorescence emission spectra of collagen suggested different effects of γ-PGA-NHS on collagen molecules: inhibiting aggregation below critical aggregation concentration (CAC) and promoting aggregation above CAC...
February 6, 2018: International Journal of Biological Macromolecules
Janet Brown, Emma Rathbone, Samantha Hinsley, Walter Gregory, Fatma Gossiel, Helen Marshall, Roger Burkinshaw, Helen Shulver, Hasina Thandar, Gianfilippo Bertelli, Keane Maccon, Angela Bowman, Andrew Hanby, Richard Bell, David Cameron, Robert Coleman
Background: Adjuvant therapies can prevent/delay bone metastasis development in breast cancer. We investigated whether serum bone turnover markers in early disease have clinical utility in identifying patients with a high risk of developing bone metastasis. Methods: Markers of bone formation (N-terminal propeptide of type-1 collagen [P1NP]) and bone resorption (C-telopeptide of type-1 collagen [CTX], pyridinoline cross-linked carboxy-terminal telopeptide of type-1 collagen [1-CTP]) were measured in baseline (pretreatment blood samples from 872 patients from a large randomized trial of adjuvant zoledronic acid (AZURE-ISRCTN79831382) in early breast cancer...
February 7, 2018: Journal of the National Cancer Institute
Mingshen Sun, Fengju Zhang, Bowen Ouyang, Mengmeng Wang, Yu Li, Xuan Jiao, Li Zhang, Ningli Wang
To evaluate ocular fundus biological changes after scleral collagen cross-linking (CXL) with riboflavin/ ultraviolet A (UVA) on rhesus monkeys in vivo by analyzing retina and choroid biological parameters. Six 3-year-old male rhesus monkeys (12 eyes) were observed in this study, with scleral CXL procedures applied on superior temporal equatorial sclera on random eyes of all rhesus. Optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) examination were performed before and 1 week, 1 month, 3 months and 6 months after CXL...
2018: PloS One
Laura Duffy, Steven O'Reilly
BACKGROUND/AIMS: The Trabecular meshwork (TM) is the tissue responsible for outflow resistance and therefore intraocular pressure. TM cells contain a contractile apparatus that is composed of actin stress fibres which run parallel to the axis of the cell and are responsible for facilitating contraction. Cross-Linked Actin Networks (CLANs) are polygonal arrangements of actin that form a geodesic network found predominantly in TM cells both in situ and in vitro. The aim of this work is to determine the functional significance of CLANs in TM cells and to assess the effect of mechanical stretch stimulation on the induction (or not) of CLANs...
February 1, 2018: Cellular Physiology and Biochemistry
Baptiste Depalle, Andre G Duarte, Imke A K Fiedler, Laurent Pujo-Menjouet, Markus J Buehler, Jean-Philippe Berteau
Enzymatic collagen cross-linking has been shown to play an important role in the macroscopic elastic and plastic deformation of bone across ages. However, its direct contribution to collagen fibril deformation is unknown. The aim of this study is to determine how covalent intermolecular connections from enzymatic collagen cross-links contribute to collagen fibril elastic and plastic deformation of adults and children's bone matrix. We used ex vivo data previously obtained from biochemical analysis of children and adults bone samples (n = 14; n = 8, respectively) to create 22 sample-specific computational models of cross-linked collagen fibrils...
February 1, 2018: Bone
Leilei Sun, Bafang Li, Di Yao, Wenkui Song, Hu Hou
The objective of this study was to explore the effects of dehydrothermal treatment (DHT) and glutaraldehyde (GTA) cross-linking on mechanical, biological properties and biodegradation behavior of Nile tilapia skin collagen sponge fabricated by freeze-drying technology. It was found that the GTA cross-linked collagen sponge exhibited a higher degree of cross-linking in comparison with DHT. The extent of increased tensile strength as well as hygroscopicity indicated that GTA cross-linking was superior to DHT in mechanical properties and liquid absorption, which was attributed to different cross-linking mechanisms...
January 10, 2018: Journal of the Mechanical Behavior of Biomedical Materials
Hou-Fu Guo, Chi-Lin Tsai, Masahiko Terajima, Xiaochao Tan, Priyam Banerjee, Mitchell D Miller, Xin Liu, Jiang Yu, Jovita Byemerwa, Sarah Alvarado, Tamer S Kaoud, Kevin N Dalby, Neus Bota-Rabassedas, Yulong Chen, Mitsuo Yamauchi, John A Tainer, George N Phillips, Jonathan M Kurie
Collagen lysyl hydroxylases (LH1-3) are Fe2+- and 2-oxoglutarate (2-OG)-dependent oxygenases that maintain extracellular matrix homeostasis. High LH2 levels cause stable collagen cross-link accumulations that promote fibrosis and cancer progression. However, developing LH antagonists will require structural insights. Here, we report a 2 Å crystal structure and X-ray scattering on dimer assemblies for the LH domain of L230 in Acanthamoeba polyphaga mimivirus. Loop residues in the double-stranded β-helix core generate a tail-to-tail dimer...
February 6, 2018: Nature Communications
G Franchi, C Neiva-Vaz, A Picard, M-P Vazquez
BACKGROUND: Cross-linked hyaluronic acid-based fillers have gained rapid acceptance for treating facial wrinkles, deep tissue folds and sunken areas due to aging. This study evaluates, in addition to space-filling properties, their effects on softness and elasticity as a secondary effect, following injection of 3 commercially available cross-linked hyaluronic acid-based fillers (15mg/mL, 17,5mg/mL and 20mg/mL) in patients presenting with congenital or acquired facial malformations. PATIENTS ET METHODS: We started injecting gels of cross-linked hyaluronic acid-based fillers in those cases in 2013; we performed 46 sessions of injections in 32 patients, aged from 13-32...
February 2, 2018: Annales de Chirurgie Plastique et Esthétique
Ehsan Ban, J Matthew Franklin, Sungmin Nam, Lucas R Smith, Hailong Wang, Rebecca G Wells, Ovijit Chaudhuri, Jan T Liphardt, Vivek B Shenoy
Contractile cells can reorganize fibrous extracellular matrices and form dense tracts of fibers between neighboring cells. These tracts guide the development of tubular tissue structures and provide paths for the invasion of cancer cells. Here, we studied the mechanisms of the mechanical plasticity of collagen tracts formed by contractile premalignant acinar cells and fibroblasts. Using fluorescence microscopy and second harmonic generation, we quantified the collagen densification, fiber alignment, and strains that remain within the tracts after cellular forces are abolished...
January 23, 2018: Biophysical Journal
Xueshi Luo, Zhenzhao Guo, Ping He, Tian Chen, Lihua Li, Shan Ding, Hong Li
Collagen electrospun scaffolds properly reproduce the framework of the extracellular matrix (ECM) of tissues that are natural with the fibrous morphology of the protein by coupling large biomimetism of the biological material. However, traditional solvents employed for collagen electrospinning lead to poor mechanical attributes and bad hydro-stability. In this work, by N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride with N-hydroxysulfosuccinimide (EDC-NHS), glutaraldehyde (GTA) and genipin (GP) respectively, electrospun collagen fibers cross-linked, effectively stabilized the fiber morphology over 2 months and improved the mechanical properties in both dry and wet state, especially EDC-NHS with large ultimate tensile stress and εb...
January 29, 2018: International Journal of Biological Macromolecules
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