Does tranexamic acid stabilised fibrin support the osteogenic differentiation of human periosteum derived cells?

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J Demol

2011-03-01

Full Text Available Fibrin sealants have long been used as carrier for osteogenic cells in bone regeneration. However, it has not been demonstrated whether fibrin’s role is limited to delivering cells to the bone defect or whether fibrin enhances osteogenesis. This study investigated fibrin’s influence on the behaviour of human periosteum-derived cells (hPDCs when cultured in vitro under osteogenic conditions in two-dimensional (fibrin substrate and three-dimensional (fibrin carrier environments. Tranexamic acid (TEA was used to reduce fibrin degradation after investigating its effect on hPDCs in monolayer culture on plastic.TEA did not affect proliferation nor calcium deposition of hPDCs under these conditions. Expression profiles of specific osteogenic markers were also maintained within the presence of TEA, apart from reduced alkaline phosphatase (ALP expression (day 14. Compared to plastic, proliferation was upregulated on 2D fibrin substrates with a 220% higher DNA content by day 21. Gene expression was also altered, with significantly (p<0.05 decreased Runx2 (day 7 and ALP (day 14 expression and increased collagen I expression (day 14 and 21. In contrast to plastic, mineralisation was absent on fibrin substrates. Inside fibrin carriers, hPDCs were uniformly distributed. Moderate cell growth and reduced osteogenic marker expression was observed inside fibrin carriers. After 2 weeks, increased cell death was present in the carrier’s centre. In conclusion, fibrin negatively influences osteogenic differentiation, compared to culture plastic, but enhanced proliferation (at least in 2D cultures for hPDCs cultured in osteogenic conditions. TEA maintained the integrity of fibrin-based constructs, with minor effects on the osteogenic differentiation of hPDCs.

Composition of fibrin glues significantly influences axial vascularization and degradation in isolation chamber model.

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Arkudas, Andreas; Pryymachuk, Galyna; Hoereth, Tobias; Beier, Justus P; Polykandriotis, Elias; Bleiziffer, Oliver; Gulle, Heinz; Horch, Raymund E; Kneser, Ulrich

2012-07-01

In this study, different fibrin sealants with varying concentrations of the fibrin components were evaluated in terms of matrix degradation and vascularization in the arteriovenous loop (AVL) model of the rat. An AVL was placed in a Teflon isolation chamber filled with 500 μl fibrin gel. The matrix was composed of commercially available fibrin gels, namely Beriplast (Behring GmbH, Marburg, Germany) (group A), Evicel (Omrix Biopharmaceuticals S.A., Somerville, New Jersey, USA) (group B), Tisseel VH S/D (Baxter, Vienna, Austria) with a thrombin concentration of 4 IU/ml and a fibrinogen concentration of 80 mg/ml [Tisseel S F80 (Baxter), group C] and with an fibrinogen concentration of 20 mg/ml [Tisseel S F20 (Baxter), group D]. After 2 and 4 weeks, five constructs per group and time point were investigated using micro-computed tomography, and histological and morphometrical analysis techniques. The aprotinin, factor XIII and thrombin concentration did not affect the degree of clot degradation. An inverse relationship was found between fibrin matrix degradation and sprouting of blood vessels. By reducing the fibrinogen concentration in group D, a significantly decreased construct weight and an increased generation of vascularized connective tissue were detected. There was an inverse relationship between matrix degradation and vascularization detectable. Fibrinogen as the major matrix component showed a significant impact on the matrix properties. Alteration of fibrin gel properties might optimize formation of blood vessels.

Characterization of Leukocyte-platelet Rich Fibrin, A Novel Biomaterial

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Madurantakam, Parthasarathy; Yoganarasimha, Suyog; Hasan, Fadi K.

2015-01-01

Autologous platelet concentrates represent promising innovative tools in the field of regenerative medicine and have been extensively used in oral surgery. Unlike platelet rich plasma (PRP) that is a gel or a suspension, Leukocyte-Platelet Rich Fibrin (L-PRF) is a solid 3D fibrin membrane generated chair-side from whole blood containing no anti-coagulant. The membrane has a dense three dimensional fibrin matrix with enriched platelets and abundant growth factors. L-PRF is a popular adjunct in...

HIF-2α Expression Regulates Sprout Formation into 3D Fibrin Matrices in Prolonged Hypoxia in Human Microvascular Endothelial Cells.

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Nauta, Tessa D; Duyndam, Monique C A; Weijers, Ester M; van Hinsbergh, Victor M W; Koolwijk, Pieter

2016-01-01

During short-term hypoxia, Hypoxia Inducible Factors (particular their subunits HIF-1α and HIF-2α) regulate the expression of many genes including the potent angiogenesis stimulator VEGF. However, in some pathological conditions chronic hypoxia occurs and is accompanied by reduced angiogenesis. We investigated the effect of prolonged hypoxia on the proliferation and sprouting ability of human microvascular endothelial cells and the involvement of the HIFs and Dll4/Notch signaling. Human microvascular endothelial cells (hMVECs), cultured at 20% oxygen for 14 days and seeded on top of 3D fibrin matrices, formed sprouts when stimulated with VEGF-A/TNFα. In contrast, hMVECs precultured at 1% oxygen for 14 days were viable and proliferative, but did not form sprouts into fibrin upon VEGF-A/TNFα stimulation at 1% oxygen. Silencing of HIF-2α with si-RNA partially restored the inhibition of endothelial sprouting, whereas HIF-1α or HIF-3α by si-RNA had no effect. No involvement of Dll4/Notch pathway in the inhibitory effect on endothelial sprouting by prolonged hypoxia was found. In addition, hypoxia decreased the production of urokinase-type plasminogen activator (uPA), needed for migration and invasion, without a significant effect on its inhibitor PAI-1. This was independent of HIF-2α, as si-HIF-2α did not counteract uPA reduction. Prolonged culturing of hMVECs at 1% oxygen inhibited endothelial sprouting into fibrin. Two independent mechanisms contribute. Silencing of HIF-2α with si-RNA partially restored the inhibition of endothelial sprouting pointing to a HIF-2α-dependent mechanism. In addition, reduction of uPA contributed to reduced endothelial tube formation in a fibrin matrix during prolonged hypoxia.

Fibrin glue mixed with platelet-rich fibrin as a scaffold seeded with dental bud cells for tooth regeneration.

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Yang, Kai-Chiang; Wang, Chun-Hao; Chang, Hao-Hueng; Chan, Wing P; Chi, Chau-Hwa; Kuo, Tzong-Fu

2012-11-01

Odontogenesis is a complex process with a series of epithelial-mesenchymal interactions and odontogenic molecular cascades. In tissue engineering of teeth from stem cells, platelet-rich fibrin (PRF), which is rich in growth factors and cytokines, may improve regeneration. Accordingly, PRF was added into fibrin glue to enrich the microenvironment with growth factors. Unerupted second molar tooth buds were harvested from miniature swine and cultured in vitro for 3 weeks to obtain dental bud cells (DBCs). Whole blood was collected for the preparation of PRF and fibrin glue before surgery. DBCs were suspended in fibrin glue and then enclosed with PRF, and the DBC-fibrin glue-PRF composite was autografted back into the original alveolar sockets. Radiographic and histological examinations were used to identify the regenerated tooth structure 36 weeks after implantation. Immunohistochemical staining was used to detect proteins specific to tooth regeneration. One pig developed a complete tooth with crown, root, pulp, enamel, dentin, odontoblast, cementum, blood vessels, and periodontal ligaments in indiscriminate shape. Another animal had an unerupted tooth that expressed cytokeratin 14, dentin matrix protein-1, vascular endothelial growth factor, and osteopontin. This study demonstrated, using autogenic cell transplantation in a porcine model, that DBCs seeded into fibrin glue-PRF could regenerate a complete tooth. Copyright © 2011 John Wiley & Sons, Ltd.

21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fibrinogen/fibrin degradation products assay. 864.7320 Section 864.7320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN....7320 Fibrinogen/fibrin degradation products assay. (a) Identification. A fibrinogen/fibrin degradation...

Characterization of Leukocyte-platelet Rich Fibrin, A Novel Biomaterial.

Science.gov (United States)

Madurantakam, Parthasarathy; Yoganarasimha, Suyog; Hasan, Fadi K

2015-09-29

Autologous platelet concentrates represent promising innovative tools in the field of regenerative medicine and have been extensively used in oral surgery. Unlike platelet rich plasma (PRP) that is a gel or a suspension, Leukocyte-Platelet Rich Fibrin (L-PRF) is a solid 3D fibrin membrane generated chair-side from whole blood containing no anti-coagulant. The membrane has a dense three dimensional fibrin matrix with enriched platelets and abundant growth factors. L-PRF is a popular adjunct in surgeries because of its superior handling characteristics as well as its suturability to the wound bed. The goal of the study is to demonstrate generation as well as provide detailed characterization of relevant properties of L-PRF that underlie its clinical success.

Effects of the incorporation of ε-aminocaproic acid/chitosan particles to fibrin on cementoblast differentiation and cementum regeneration.

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Park, Chan Ho; Oh, Joung-Hwan; Jung, Hong-Moon; Choi, Yoonnyoung; Rahman, Saeed Ur; Kim, Sungtae; Kim, Tae-Il; Shin, Hong-In; Lee, Yun-Sil; Yu, Frank H; Baek, Jeong-Hwa; Ryoo, Hyun-Mo; Woo, Kyung Mi

2017-10-01

Cementum formation on the exposed tooth-root surface is a critical process in periodontal regeneration. Although various therapeutic approaches have been developed, regeneration of integrated and functional periodontal complexes is still wanting. Here, we found that the OCCM30 cementoblasts cultured on fibrin matrix express substantial levels of matrix proteinases, leading to the degradation of fibrin and the apoptosis of OCCM30 cells, which was reversed upon treatment with a proteinase inhibitor, ε-aminocaproic acid (ACA). Based on these findings, ACA-releasing chitosan particles (ACP) were fabricated and ACP-incorporated fibrin (fibrin-ACP) promoted the differentiation of cementoblasts in vitro, as confirmed by bio-mineralization and expressions of molecules associated with mineralization. In a periodontal defect model of beagle dogs, fibrin-ACP resulted in substantial cementum formation on the exposed root dentin in vivo, compared to fibrin-only and enamel matrix derivative (EMD) which is used clinically for periodontal regeneration. Remarkably, the fibrin-ACP developed structural integrations of the cementum-periodontal ligament-bone complex by the Sharpey's fiber insertion. In addition, fibrin-ACP promoted alveolar bone regeneration through increased bone volume of tooth roof-of-furcation defects and root coverage. Therefore, fibrin-ACP can promote cementogenesis and osteogenesis by controlling biodegradability of fibrin, implicating the feasibility of its therapeutic use to improve periodontal regeneration. Cementum, the mineralized layer on root dentin surfaces, functions to anchor fibrous connective tissues on tooth-root surfaces with the collagenous Sharpey's fibers integration, of which are essential for periodontal functioning restoration in the complex. Through the cementum-responsible fiber insertions on tooth-root surfaces, PDLs transmit various mechanical responses to periodontal complexes against masticatory/occlusal stimulations to support teeth

Quality Assessment of Platelet-Rich Fibrin-Like Matrix Prepared from Whole Blood Samples after Extended Storage

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Hideo Kawabata

2017-09-01

Full Text Available The platelet-rich fibrin–like matrix (PRFM is usually prepared onsite and immediately used for regenerative therapy. Nonetheless, to meet the clinical necessity of preserving the PRFM without quality deterioration, we developed a method for preparation of PRFMs from short-term-stored whole blood (WB samples. In this study, to evaluate the practical expiration date of storage, we extended the storage time of WB samples from 2 to 7 days and assessed the quality of the resulting PRFMs. WB samples collected with acid-citrate-dextrose were stored with gentle agitation at ambient temperature. To prepare PRFMs, the stored WB samples were mixed with CaCl2 in glass tubes and centrifuged. Fibrin fiber networks, CD41 and CD62P expression, and Platelet Derived Growth Factor-BB (PDGF-BB levels were examined by scanning electron microscopy (SEM, flow cytometry, and an Enzyme-Linked ImmunoSorbent Assay (ELISA, respectively. Long-term storage had no significant effect on either blood cell counts or platelet functions tested. The resulting PRFMs were visually identical to freshly prepared ones. PDGF-BB levels did not markedly decrease in a time-dependent manner. However, fibrin fibers gradually became thinner after storage. Although the coagulation activity may diminish, we propose that PRFMs can be prepared—without evident loss of quality—from WB samples stored for up to 7 days by our previously developed method.

21 CFR 864.7300 - Fibrin monomer paracoagulation test.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fibrin monomer paracoagulation test. 864.7300 Section 864.7300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7300 Fibrin...

Fibrin gel as a scaffold for skin substitute – production and clinical experience.

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Kljenak, Antun; Tominac Trcin, Mirna; Bujić, Marina; Dolenec, Tamara; Jevak, Martina; Mršić, Gordan; Zmiš, Gordana; Barčot, Zoran; Muljačić, Ante; Popović, Maja

2016-06-01

The purpose of this study was to create a fibrin-based human skin substitute in vitro with epidermal and dermal component and to assess its healing potential in deep partial and full thickness burns. Fibrin scaffolds were prepared from commercial fibrin glue kits. Human fibroblasts were cultured in fibrin gel. Human keratinocytes were seeded on the top of the gel. Viability of cells was determined fluorimetrically. Scanning electron microscope and immunocytochemistry analysis of cultured cells were performed. After hydrosurgical preparation of deep burn necrotic tissue, wound bed was prepared for skin substitutes. Progress of healing was documented using visual estimation and photos. Scanning electron microscope images showed good cell attachment and colony spreading of keratinocytes and fibroblasts on fibrin scaff old. Immunofluorescent staining of cell cultures on fibrin scaffold showed expression of vimentin, a marker of fibroblast cells, cytokeratin 19, a marker of epithelial stem cells, as well as involucrin, a marker of differentiated keratinocytes. Clinical results clearly showed that appearance of the skin did not differ significantly from the areas of transplanted skin using split-thickness skin graft techniques. In conclusion, using these fibrin-cultured autografts on massive full-thickness burn resulted in good healing.

Efficacy of platelet-rich fibrin vs. enamel matrix derivative in the treatment of periodontal intrabony defects: a clinical and cone beam computed tomography study.

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Gupta, Swyeta Jain; Jhingran, Rajesh; Gupta, Vivek; Bains, Vivek Kumar; Madan, Rohit; Rizvi, Iram

2014-07-01

To evaluate and compare the efficacy of platelet-rich fibrin (PRF) with enamel matrix derivative (EMD; Emdogain) in the treatment of periodontal intrabony defects in patients with chronic periodontitis, six months after surgery. Forty-four (44) intrabony defects in 30 patients (15 males) were randomly allocated into two treatment groups: EMD (n = 22) and PRF (n = 22). Measurement of the defects was done using clinical and cone beam computed tomography at baseline and 6 months. Clinical and radiographic parameters such as probing depth, clinical attachment level, intrabony defect depth and defect angle, were recorded at baseline and 6 months post-operatively. Within group change was evaluated using the Wilcoxon signed rank test. Intergroup comparisons were made using the Mann-Whitney U test. Postsurgical measurements revealed that there was an equal reduction in probing depth and a greater but statistically non-significant attachment gain for the Emdogain group when compared to the platelet-rich fibrin group. The Emdogain group presented with significantly greater percentage defect resolution (43.07% ± 12.21) than did the platelet-rich fibrin group (32.41% ± 14.61). Post-operatively the changes in defect width and defect angle were significant in both groups, but upon intergroup comparison they were found to be statistically non-significantly different. Both Emdogain and platelet-rich fibrin were effective in the regeneration of intrabony defects. Emdogain was significantly superior in terms of percentage defect resolution.

Combination of Mineral Trioxide Aggregate and Platelet-rich Fibrin Promotes the Odontoblastic Differentiation and Mineralization of Human Dental Pulp Cells via BMP/Smad Signaling Pathway.

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Woo, Su-Mi; Kim, Won-Jae; Lim, Hae-Soon; Choi, Nam-Ki; Kim, Sun-Hun; Kim, Seon-Mi; Jung, Ji-Yeon

2016-01-01

Recent reports have shown that the combined use of platelet-rich fibrin (PRF), an autologous fibrin matrix, and mineral trioxide aggregate (MTA) as root filling material is beneficial for the endodontic management of an open apex. However, the potential of the combination of MTA and PRF as an odontogenic inducer in human dental pulp cells (HDPCs) in vitro has not yet been studied. The purpose of this study was to evaluate the effect of the combination of MTA and PRF on odontoblastic maturation in HDPCs. HDPCs extracted from third molars were directly cultured with MTA and PRF extract (PRFe). Odontoblastic differentiation of HDPCs was evaluated by measuring the alkaline phosphatase (ALP) activity, and the expression of odontogenesis-related genes was detected using reverse-transcription polymerase chain reaction or Western blot. Mineralization formation was assessed by alizarin red staining. HDPCs treated with MTA and PRFe significantly up-regulated the expression of dentin sialoprotein and dentin matrix protein-1 and enhanced ALP activity and mineralization compared with those with MTA or PRFe treatment alone. In addition, the combination of MTA and PRFe induced the activation of bone morphogenic proteins (BMP)/Smad, whereas LDN193189, the bone morphogenic protein inhibitor, attenuated dentin sialophosphoprotein and dentin matrix protein-1 expression, ALP activity, and mineralization enhanced by MTA and PRFe treatment. This study shows that the combination of MTA and PRF has a synergistic effect on the stimulation of odontoblastic differentiation of HDPCs via the modulation of the BMP/Smad signaling pathway. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Three-dimensional structure and cytokine distribution of platelet-rich fibrin.

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Bai, Meng-Yi; Wang, Ching-Wei; Wang, Jyun-Yi; Lin, Ming-Fang; Chan, Wing P

2017-02-01

Previous reports have revealed that several cytokines (including platelet-derived growth factor-BB, transforming growth factors-β1 and insulin-like growth factor-1) can enhance the rate of bone formation and synthesis of extracellular matrix in orthopaedics or periodontology. This study aimed to determine the concentration of cytokines within platelet-rich fibrin microstructures and investigate whether there are differences in the different portions of platelet-rich fibrin, which has implications for proper clinical use of platelet-rich fibrin gel. Whole blood was obtained from six New Zealand rabbits (male, 7 to 39 weeks old, weight 2.7-4 kg); it was then centrifuged for preparation of platelet-rich fibrin gels and harvest of plasma. The resultant platelet-rich fibrin gels were used for cytokine determination, histological analyses and scanning electron microscopy. All plasmas obtained were subject to the same cytokine determination assays for the purpose of comparison. Cytokines platelet-derived growth factor-BB and transforming growth factor-β1 formed concentration gradients from high at the red blood cell end of the platelet-rich fibrin gel (p=1.88×10-5) to low at the plasma end (p=0.19). Insulin-like growth factor-1 concentrations were similar at the red blood cell and plasma ends. The porosities of the platelet-rich fibrin samples taken in sequence from the red blood cell end to the plasma end were 6.5% ± 4.9%, 24.8% ± 7.5%, 30.3% ± 8.5%, 41.4% ± 12.3%, and 40.3% ± 11.7%, respectively, showing a gradual decrease in the compactness of the platelet-rich fibrin network. Cytokine concentrations are positively associated with platelet-rich fibrin microstructure and portion in a rabbit model. As platelet-rich fibrin is the main entity currently used in regenerative medicine, assessing cytokine concentration and the most valuable portion of PRF gels is essential and recommended to all physicians.

Three-dimensional structure and cytokine distribution of platelet-rich fibrin

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Meng-Yi Bai

Full Text Available OBJECTIVES: Previous reports have revealed that several cytokines (including platelet-derived growth factor-BB, transforming growth factors-β1 and insulin-like growth factor-1 can enhance the rate of bone formation and synthesis of extracellular matrix in orthopaedics or periodontology. This study aimed to determine the concentration of cytokines within platelet-rich fibrin microstructures and investigate whether there are differences in the different portions of platelet-rich fibrin, which has implications for proper clinical use of platelet-rich fibrin gel. METHODS: Whole blood was obtained from six New Zealand rabbits (male, 7 to 39 weeks old, weight 2.7-4 kg; it was then centrifuged for preparation of platelet-rich fibrin gels and harvest of plasma. The resultant platelet-rich fibrin gels were used for cytokine determination, histological analyses and scanning electron microscopy. All plasmas obtained were subject to the same cytokine determination assays for the purpose of comparison. RESULTS: Cytokines platelet-derived growth factor-BB and transforming growth factor-β1 formed concentration gradients from high at the red blood cell end of the platelet-rich fibrin gel (p=1.88×10-5 to low at the plasma end (p=0.19. Insulin-like growth factor-1 concentrations were similar at the red blood cell and plasma ends. The porosities of the platelet-rich fibrin samples taken in sequence from the red blood cell end to the plasma end were 6.5% ± 4.9%, 24.8% ± 7.5%, 30.3% ± 8.5%, 41.4% ± 12.3%, and 40.3% ± 11.7%, respectively, showing a gradual decrease in the compactness of the platelet-rich fibrin network. CONCLUSION: Cytokine concentrations are positively associated with platelet-rich fibrin microstructure and portion in a rabbit model. As platelet-rich fibrin is the main entity currently used in regenerative medicine, assessing cytokine concentration and the most valuable portion of PRF gels is essential and recommended to all physicians.

Experimental closure of gunshot wounds by fibrin glue with antibiotics in pigs

OpenAIRE

Đenić Nebojša; Višnjić Milan; Dragović Saša; Bojanić Vladmila; Bojanić Zoran; Đurđević Dragan; Đinđić Boris; Kostov Miloš

2015-01-01

Background/Aim. Gunshot wounds caused by the automatic rifle M70AB2 (AK-47) 7.62 mm, after the primary surgical management, were closed with delayed primary suture during the next four to seven days. This period coincides with the fibroblastic phase of wound healing. Fibrin glue is used as a local hemostatic and as a matrix for the local dosed release of antibiotics. Antibiotics addition to fibrin glue resulted in continuous diffusion into the surrounding n...

Effect of dextran on platelet activation by polymerizing fibrin.

OpenAIRE

Ts'ao, C. H.; Krajewski, D. V.

1982-01-01

Dextran has been shown to alter the mechanical properties and lysability of fibrin. The present study was undertaken to determine whether it would also influence the ability of polymerizing fibrin to activate platelets. Human fibrinogen, with or without the presence of dextran, was incubated with either human thrombin or reptilase at 37 C. Macroscopically evident fibrils first appeared at 7 1/2 to 8 minutes in fibrinogen solution not containing dextran and at 2 1/2 to 3 minutes in solution co...

The initiation of embryonic-like collagen fibrillogenesis by adult human tendon fibroblasts when cultured under tension

DEFF Research Database (Denmark)

Bayer, Monika L; Yeung, Chin-Yan C; Kadler, Karl E

2010-01-01

to initiate collagen fibrillogenesis when cultured in fixed-length fibrin gels. Fibroblasts were dissected from semitendinosus and gracilis tendons from healthy humans and cultured in 3D linear fibrin gels. The fibroblasts synthesized an extracellular matrix of parallel collagen fibrils that were aligned...

Effect of fibrin glue on the biomechanical properties of human Descemet's membrane.

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Shyam S Chaurasia

Full Text Available BACKGROUND: Corneal transplantation has rapidly evolved from full-thickness penetrating keratoplasty (PK to selective tissue corneal transplantation, where only the diseased portions of the patient's corneal tissue are replaced with healthy donor tissue. Descemet's membrane endothelial keratoplasty (DMEK performed in patients with corneal endothelial dysfunction is one such example where only a single layer of endothelial cells with its basement membrane (10-15 µm in thickness, Descemet's membrane (DM is replaced. It is challenging to replace this membrane due to its intrinsic property to roll in an aqueous environment. The main objective of this study was to determine the effects of fibrin glue (FG on the biomechanical properties of DM using atomic force microscopy (AFM and relates these properties to membrane folding propensity. METHODOLOGY/PRINCIPAL FINDINGS: Fibrin glue was sprayed using the EasySpray applicator system, and the biomechanical properties of human DM were determined by AFM. We studied the changes in the "rolling up" tendency of DM by examining the changes in the elasticity and flexural rigidity after the application of FG. Surface topography was assessed using scanning electron microscopy (SEM and AFM imaging. Treatment with FG not only stabilized and stiffened DM but also led to a significant increase in hysteresis of the glue-treated membrane. In addition, flexural or bending rigidity values also increased in FG-treated membranes. CONCLUSIONS/SIGNIFICANCE: Our results suggest that fibrin glue provides rigidity to the DM/endothelial cell complex that may aid in subsequent manipulation by maintaining tissue integrity.

Effect of Fibrin Glue on the Biomechanical Properties of Human Descemet's Membrane

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Chaurasia, Shyam S.; Champakalakshmi, Ravi; Li, Ang; Poh, Rebekah; Tan, Xiao Wei; Lakshminarayanan, Rajamani; Lim, Chwee T.; Tan, Donald T.; Mehta, Jodhbir S.

2012-01-01

Background Corneal transplantation has rapidly evolved from full-thickness penetrating keratoplasty (PK) to selective tissue corneal transplantation, where only the diseased portions of the patient's corneal tissue are replaced with healthy donor tissue. Descemet's membrane endothelial keratoplasty (DMEK) performed in patients with corneal endothelial dysfunction is one such example where only a single layer of endothelial cells with its basement membrane (10–15 µm in thickness), Descemet's membrane (DM) is replaced. It is challenging to replace this membrane due to its intrinsic property to roll in an aqueous environment. The main objective of this study was to determine the effects of fibrin glue (FG) on the biomechanical properties of DM using atomic force microscopy (AFM) and relates these properties to membrane folding propensity. Methodology/Principal Findings Fibrin glue was sprayed using the EasySpray applicator system, and the biomechanical properties of human DM were determined by AFM. We studied the changes in the “rolling up” tendency of DM by examining the changes in the elasticity and flexural rigidity after the application of FG. Surface topography was assessed using scanning electron microscopy (SEM) and AFM imaging. Treatment with FG not only stabilized and stiffened DM but also led to a significant increase in hysteresis of the glue-treated membrane. In addition, flexural or bending rigidity values also increased in FG-treated membranes. Conclusions/Significance Our results suggest that fibrin glue provides rigidity to the DM/endothelial cell complex that may aid in subsequent manipulation by maintaining tissue integrity. PMID:22662156

Efficacy of platelet-rich fibrin matrix on viability of diced cartilage grafts in a rabbit model.

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Güler, İsmail; Billur, Deniz; Aydin, Sevim; Kocatürk, Sinan

2015-03-01

The objective of this study was to compare the viability of cartilage grafts embedded in platelet-rich fibrin matrix (PRFM) wrapped with no material (bare diced cartilage grafts), oxidized methylcellulose (Surgicel), or acellular dermal tissue (AlloDerm). Experimental study. In this study, six New Zealand rabbits were used. Cartilage grafts including perichondrium were excised from each ear and diced into 2-mm-by 2-mm pieces. There were four comparison groups: 1) group A, diced cartilage (not wrapped with any material); 2) group B, diced cartilage wrapped with AlloDerm; 3) group C, diced cartilage grafts wrapped with Surgicel; and 4) group D, diced cartilage wrapped with PRFM. Four cartilage grafts were implanted under the skin at the back of each rabbit. All rabbits were sacrificed at the end of 10 weeks. The cartilages were stained with hematoxylin-eosin, Masson's Trichrome, and Orcein. After that, they were evaluated for the viability of chondrocytes, collagen content, fibrillar structure of matrix, and changes in peripheral tissues. When the viability of chondrocytes, the content of fiber in matrix, and changes in peripheral tissues were compared, the cartilage embedded in the PRFM group was statistically significantly higher than in the other groups (P < 0.05). We concluded that PRFM has significant advantages in ensuring the chondrocyte viability of diced cartilage grafts. It is also biocompatible, with relatively lesser inflammation and fibrosis. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

FIBRIN GLUE DAN APLIKASINYA

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Agi Harliani S

2015-08-01

Full Text Available Fibrin Tissue Adhesive (FTA, Fibrin Sealant (FS or Fibrin Glue (FG are names given to a group of product that lead to the formation of fibrin clot at the site of application. Fibrin Glue represents a new revolution for local haemostatic, which produced by based on the understanding about blood coagulation process. The mechanism of FG mimics the last stage of blood coagulation process. Haemophilia, is a congenital inherited bleeding disorder, characterized by repeated bleeding episodes. The basic pathology is deficiency of factor VIII (hemophilia A or factor IX (hemophilia B. At bleeding episodes, hemophilia patients need replacement therapy. Hemophilia patients need transfusion of cryoprecipitate, Fresh Frozen Plasma (FFP or factor concentrate as replacement therapy. Oral surgery, dental extraction, circumcision, and orthopedic operations are the most important indications for fibrin glue in hemophilia care. As haemostatic local, FG minimizes bleeding, reducing the need of transfusion or factor concentrate, reducing the complication of transfusion, hospitalization and cost.

Glucose metabolism in cultured trophoblasts from human placenta

International Nuclear Information System (INIS)

Moe, A.J.; Farmer, D.R.; Nelson, D.M.; Smith, C.H.

1990-01-01

The development of appropriate placental trophoblast isolation and culture techniques enables the study of pathways of glucose utilization by this important cell layer in vitro. Trophoblasts from normal term placentas were isolated and cultured 24 hours and 72 hours in uncoated polystyrene culture tubes or tubes previously coated with a fibrin matrix. Trophoblasts cultured on fibrin are morphologically distinct from those cultured on plastic or other matrices and generally resemble in vivo syncytium. Cells were incubated up to 3 hours with 14 C-labeled glucose and reactions were stopped by addition of perchloric acid. 14 CO 2 production by trophoblasts increased linearly with time however the largest accumulation of label was in organic acids. Trophoblasts cultured in absence of fibrin utilized more glucose and accumulated more 14 C in metabolic products compared to cells cultured on fibrin. Glucose oxidation to CO 2 by the phosphogluconate (PG) pathway was estimated from specific yields of 14 CO 2 from [1- 14 C]-D-glucose and [6- 14 C]-D-glucose. Approximately 6% of glucose oxidation was by the PG pathway when cells were cultured on fibrin compared to approximately 1% by cells cultured in the absence of fibrin. The presence of a fibrin growth matrix appears to modulate the metabolism of glucose by trophoblast from human placenta in vitro

Fibrin and poly(lactic-co-glycolic acid) hybrid scaffold promotes early chondrogenesis of articular chondrocytes: an in vitro study.

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Sha'ban, Munirah; Kim, Soon Hee; Idrus, Ruszymah Bh; Khang, Gilson

2008-04-25

Synthetic- and naturally derived- biodegradable polymers have been widely used to construct scaffolds for cartilage tissue engineering. Poly(lactic-co-glycolic acid) (PLGA) are bioresorbable and biocompatible, rendering them as a promising tool for clinical application. To minimize cells lost during the seeding procedure, we used the natural polymer fibrin to immobilize cells and to provide homogenous cells distribution in PLGA scaffolds. We evaluated in vitro chondrogenesis of rabbit articular chondrocytes in PLGA scaffolds using fibrin as cell transplantation matrix. PLGA scaffolds were soaked in chondrocytes-fibrin suspension (1 x 10(6) cells/scaffold) and polymerized by dropping thrombin-calcium chloride (CaCl2) solution. PLGA-seeded chondrocytes was used as control. All constructs were cultured for a maximum of 21 days. Cell proliferation activity was measured at 1, 3, 7, 14 and 21 days in vitro using 3-(4,5-dimethylthiazole-2-yl)-2-, 5-diphenyltetrazolium-bromide (MTT) assay. Morphological observation, histology, immunohistochemistry (IHC), gene expression and sulphated-glycosaminoglycan (sGAG) analyses were performed at each time point of 1, 2 and 3 weeks to elucidate in vitro cartilage development and deposition of cartilage-specific extracellular matrix (ECM). Cell proliferation activity was gradually increased from day-1 until day-14 and declined by day-21. A significant cartilaginous tissue formation was detected as early as 2-week in fibrin/PLGA hybrid construct as confirmed by the presence of cartilage-isolated cells and lacunae embedded within basophilic ECM. Cartilage formation was remarkably evidenced after 3 weeks. Presence of cartilage-specific proteoglycan and glycosaminoglycan (GAG) in fibrin/PLGA hybrid constructs were confirmed by positive Safranin O and Alcian Blue staining. Collagen type II exhibited intense immunopositivity at the pericellular matrix. Chondrogenic properties were further demonstrated by the expression of genes encoded for

Combination of heterologous fibrin sealant and bioengineered human embryonic stem cells to improve regeneration following autogenous sciatic nerve grafting repair.

Science.gov (United States)

Mozafari, Roghayeh; Kyrylenko, Sergiy; Castro, Mateus Vidigal; Ferreira, Rui Seabra; Barraviera, Benedito; Oliveira, Alexandre Leite Rodrigues

2018-01-01

Peripheral nerve injury is a worldwide clinical problem, and the preferred surgical method for treating it is the end-to-end neurorrhaphy. When it is not possible due to a large nerve gap, autologous nerve grafting is used. However, these surgical techniques result in nerve regeneration at highly variable degrees. It is thus very important to seek complementary techniques to improve motor and sensory recovery. One promising approach could be cell therapy. Transplantation therapy with human embryonic stem cells (hESCs) is appealing because these cells are pluripotent and can differentiate into specialized cell types and have self-renewal ability. Therefore, the main objective of this study was to find conditions under which functional recovery is improved after sciatic nerve neurorrhaphy. We assumed that hESC, either alone or in combination with heterologous fibrin sealant scaffold, could be used to support regeneration in a mouse model of sciatic nerve injury and repair via autografting with end-to-end neurorrhaphy. Five millimeters of the sciatic nerve of C57BL/6 J mice were transected off and rotated 180 degrees to simulate an injury, and then stumps were sutured. Next, we applied heterologous fibrin sealant and/or human embryonic stem cells genetically altered to overexpress fibroblast growth factor 2 (FGF2) at the site of the injury. The study was designed to include six experimental groups comprising neurorrhaphy (N), neurorrhaphy + heterologous fibrin sealant (N + F), neurorrhaphy + heterologous fibrin sealant + doxycycline (N + F + D), neurorrhaphy + heterologous fibrin sealant + wild-type hESC (N + F + W), neurorrhaphy + heterologous fibrin sealant + hESC off (N + F + T), and neurorrhaphy + heterologous fibrin sealant + hESC on via doxycycline (N + F + D + T). We evaluated the recovery rate using Catwalk and von Frey functional recovery tests, as well as immunohistochemistry analysis. The experiments indicated that

A novel platelet concentrate: titanium-prepared platelet-rich fibrin.

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Tunalı, Mustafa; Özdemir, Hakan; Küçükodacı, Zafer; Akman, Serhan; Yaprak, Emre; Toker, Hülya; Fıratlı, Erhan

2014-01-01

We developed a new product called titanium-prepared platelet-rich fibrin (T-PRF). The T-PRF method is based on the hypothesis that titanium may be more effective in activating platelets than the silica activators used with glass tubes in Chouckroun's leukocyte- and platelet-rich fibrin (L-PRF) method. In this study, we aimed to define the structural characteristics of T-PRF and compare it with L-PRF. Blood samples were collected from 10 healthy male volunteers. The blood samples were drawn using a syringe. Nine milliliters was transferred to a dry glass tube, and 9 mL was transferred to a titanium tube. Half of each clot (i.e., the blood that was clotted using T-PRF or L-PRF) was processed with a scanning electron microscope (SEM). The other half of each clot was processed for fluorescence microscopy analysis and light microscopy analysis. The T-PRF samples seemed to have a highly organized network with continuous integrity compared to the other L-PRF samples. Histomorphometric analysis showed that T-PRF fibrin network covers larger area than L-PRF fibrin network; also fibrin seemed thicker in the T-PRF samples. This is the first human study to define T-PRF as an autogenous leukocyte- and platelet-rich fibrin product. The platelet activation by titanium seems to offer some high characteristics to T-PRF.

A Novel Platelet Concentrate: Titanium-Prepared Platelet-Rich Fibrin

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Mustafa Tunalı

2014-01-01

Full Text Available We developed a new product called titanium-prepared platelet-rich fibrin (T-PRF. The T-PRF method is based on the hypothesis that titanium may be more effective in activating platelets than the silica activators used with glass tubes in Chouckroun’s leukocyte- and platelet-rich fibrin (L-PRF method. In this study, we aimed to define the structural characteristics of T-PRF and compare it with L-PRF. Blood samples were collected from 10 healthy male volunteers. The blood samples were drawn using a syringe. Nine milliliters was transferred to a dry glass tube, and 9 mL was transferred to a titanium tube. Half of each clot (i.e., the blood that was clotted using T-PRF or L-PRF was processed with a scanning electron microscope (SEM. The other half of each clot was processed for fluorescence microscopy analysis and light microscopy analysis. The T-PRF samples seemed to have a highly organized network with continuous integrity compared to the other L-PRF samples. Histomorphometric analysis showed that T-PRF fibrin network covers larger area than L-PRF fibrin network; also fibrin seemed thicker in the T-PRF samples. This is the first human study to define T-PRF as an autogenous leukocyte- and platelet-rich fibrin product. The platelet activation by titanium seems to offer some high characteristics to T-PRF.

Fibrin accumulation secondary to loss of plasmin-mediated fibrinolysis drives inflammatory osteoporosis in mice.

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Cole, Heather A; Ohba, Tetsuro; Nyman, Jeffry S; Hirotaka, Haro; Cates, Justin M M; Flick, Matthew J; Degen, Jay L; Schoenecker, Jonathan G

2014-08-01

Osteoporosis is a skeletal disorder characterized by low bone mass and increased bone fragility associated with aging, menopause, smoking, obesity, or diabetes. Persistent inflammation has been identified as an instigating factor in progressive bone loss. In addition to the role of fibrin in coagulation, inordinate fibrin deposition within a tissue matrix results in increased local inflammation. Given that fibrin accumulation is a hallmark of osteoporosis-related comorbidities, we undertook this study to test the hypothesis that persistent fibrin deposition causes inflammatory osteoporosis. Multiple imaging modalities, bone integrity metrics, and histologic analyses were employed to evaluate skeletal derangements in relation to fibrin deposition, circulating fibrinogen levels, and systemic markers of inflammation in mice that were plasminogen deficient and in plasminogen-deficient mice that were concomitantly either fibrinogen deficient or carrying a mutant form of fibrinogen lacking the αM β2 binding motif. Mice generated with a genetic deficit in the key fibrinolytic protease, plasmin, uniformly developed severe osteoporosis. Furthermore, the development of osteoporosis was fibrin(ogen) dependent, and the derangements in the bone remodeling unit were mechanistically tied to fibrin(ogen)-mediated activation of osteoclasts via activation of the leukocyte integrin receptor αM β2 on monocytes and secondary stimulation of osteoblasts by RANKL. Notably, the genetic elimination of fibrin(ogen) or the expression of a mutant form of fibrinogen retaining clotting function but lacking the αM β2 binding motif prevented the degenerative skeletal phenotypes, resulting in normal local and systemic cytokine levels. Taken together, these data reveal for the first time that fibrin promotes inflammation-driven systemic osteoporosis, which suggests a novel association between hemostasis, inflammation, and bone biology. Copyright © 2014 by the American College of Rheumatology.

Culture on fibrin matrices maintains the colony-forming capacity and osteoblastic differentiation of mesenchymal stem cells

International Nuclear Information System (INIS)

Colley, Helen; McArthur, Sally L; Stolzing, Alexandra; Scutt, Andy

2012-01-01

Mesenchymal stem cells (MSC) are multipotent cells capable of differentiating into a number of mesenchymal tissues including bone, cartilage, and tendon. Low numbers in vivo means exponential growth is needed in culture to enable therapeutic applications. MSC can expand rapidly in culture but usually lose their extensive capacity for differentiation that makes them therapeutically attractive. To try and maintain their capacity for differentiation and expansion in vitro, we cultured MSC on fibrin gels of different concentrations to create more physiological growth conditions for the cells. The cells were then re-plated onto tissue culture plastic and analysed. The cells that had been pre-cultured for seven days on fibrin, proliferated and maintained their differential potential to the osteogenic lineage better than tissue culture plastic expanded MSC. A concentration relationship between colony number and fibrin concentration was seen with decreasing numbers as fibrin concentration increased. These data support the concept that substrate signals significantly influence MSC growth and differentiation and that growth on a fibrin matrix could be used to maintain a stem cell phenotype during MSC expansion. (paper)

The Effect of Chondroitin Sulphate and Hyaluronic Acid on Chondrocytes Cultured within a Fibrin-Alginate Hydrogel

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Christopher J. Little

2014-09-01

Full Text Available Osteoarthritis is a painful degenerative joint disease that could be better managed if tissue engineers can develop methods to create long-term engineered articular cartilage tissue substitutes. Many of the tissue engineered cartilage constructs currently available lack the chemical stimuli and cell-friendly environment that promote the matrix accumulation and cell proliferation needed for use in joint cartilage repair. The goal of this research was to test the efficacy of using a fibrin-alginate hydrogel containing hyaluronic acid (HA and/or chondroitin sulphate (CS supplements for chondrocyte culture. Neonatal porcine chondrocytes cultured in fibrin-alginate hydrogels retained their phenotype better than chondrocytes cultured in monolayer, as evidenced by analysis of their relative expression of type II versus type I collagen mRNA transcripts. HA or CS supplementation of the hydrogels increased matrix glycosaminoglycan (GAG production during the first week of culture. However, the effects of these supplements on matrix accumulation were not additive and were no longer observed after two weeks of culture. Supplementation of the hydrogels with CS or a combination of both CS and HA increased the chondrocyte cell population after two weeks of culture. Statistical analysis indicated that the HA and CS treatment effects on chondrocyte numbers may be additive. This research suggests that supplementation with CS and/or HA has positive effects on cartilage matrix production and chondrocyte proliferation in three-dimensional (3D fibrin-alginate hydrogels.

Fibrinogen and fibrin.

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Weisel, John W

2005-01-01

Fibrinogen is a large, complex, fibrous glycoprotein with three pairs of polypeptide chains linked together by 29 disulfide bonds. It is 45 nm in length, with globular domains at each end and in the middle connected by alpha-helical coiled-coil rods. Both strongly and weakly bound calcium ions are important for maintenance of fibrinogen's structure and functions. The fibrinopeptides, which are in the central region, are cleaved by thrombin to convert soluble fibrinogen to insoluble fibrin polymer, via intermolecular interactions of the "knobs" exposed by fibrinopeptide removal with "holes" always exposed at the ends of the molecules. Fibrin monomers polymerize via these specific and tightly controlled binding interactions to make half-staggered oligomers that lengthen into protofibrils. The protofibrils aggregate laterally to make fibers, which then branch to yield a three-dimensional network-the fibrin clot-essential for hemostasis. X-ray crystallographic structures of portions of fibrinogen have provided some details on how these interactions occur. Finally, the transglutaminase, Factor XIIIa, covalently binds specific glutamine residues in one fibrin molecule to lysine residues in another via isopeptide bonds, stabilizing the clot against mechanical, chemical, and proteolytic insults. The gene regulation of fibrinogen synthesis and its assembly into multichain complexes proceed via a series of well-defined steps. Alternate splicing of two of the chains yields common variant molecular isoforms. The mechanical properties of clots, which can be quite variable, are essential to fibrin's functions in hemostasis and wound healing. The fibrinolytic system, with the zymogen plasminogen binding to fibrin together with tissue-type plasminogen activator to promote activation to the active enzyme plasmin, results in digestion of fibrin at specific lysine residues. Fibrin(ogen) also specifically binds a variety of other proteins, including fibronectin, albumin

Fibrin and poly(lactic-co-glycolic acid hybrid scaffold promotes early chondrogenesis of articular chondrocytes: an in vitro study

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Idrus Ruszymah BH

2008-04-01

Full Text Available Abstract Background Synthetic- and naturally derived- biodegradable polymers have been widely used to construct scaffolds for cartilage tissue engineering. Poly(lactic-co-glycolic acid (PLGA are bioresorbable and biocompatible, rendering them as a promising tool for clinical application. To minimize cells lost during the seeding procedure, we used the natural polymer fibrin to immobilize cells and to provide homogenous cells distribution in PLGA scaffolds. We evaluated in vitro chondrogenesis of rabbit articular chondrocytes in PLGA scaffolds using fibrin as cell transplantation matrix. Methods PLGA scaffolds were soaked in chondrocytes-fibrin suspension (1 × 106cells/scaffold and polymerized by dropping thrombin-calcium chloride (CaCl2 solution. PLGA-seeded chondrocytes was used as control. All constructs were cultured for a maximum of 21 days. Cell proliferation activity was measured at 1, 3, 7, 14 and 21 days in vitro using 3-(4,5-dimethylthiazole-2-yl-2-, 5-diphenyltetrazolium-bromide (MTT assay. Morphological observation, histology, immunohistochemistry (IHC, gene expression and sulphated-glycosaminoglycan (sGAG analyses were performed at each time point of 1, 2 and 3 weeks to elucidate in vitro cartilage development and deposition of cartilage-specific extracellular matrix (ECM. Results Cell proliferation activity was gradually increased from day-1 until day-14 and declined by day-21. A significant cartilaginous tissue formation was detected as early as 2-week in fibrin/PLGA hybrid construct as confirmed by the presence of cartilage-isolated cells and lacunae embedded within basophilic ECM. Cartilage formation was remarkably evidenced after 3 weeks. Presence of cartilage-specific proteoglycan and glycosaminoglycan (GAG in fibrin/PLGA hybrid constructs were confirmed by positive Safranin O and Alcian Blue staining. Collagen type II exhibited intense immunopositivity at the pericellular matrix. Chondrogenic properties were further

Concentration independent modulation of local micromechanics in a fibrin gel.

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Maxwell A Kotlarchyk

Full Text Available Methods for tuning extracellular matrix (ECM mechanics in 3D cell culture that rely on increasing the concentration of either protein or cross-linking molecules fail to control important parameters such as pore size, ligand density, and molecular diffusivity. Alternatively, ECM stiffness can be modulated independently from protein concentration by mechanically loading the ECM. We have developed a novel device for generating stiffness gradients in naturally derived ECMs, where stiffness is tuned by inducing strain, while local mechanical properties are directly determined by laser tweezers based active microrheology (AMR. Hydrogel substrates polymerized within 35 mm diameter Petri dishes are strained non-uniformly by the precise rotation of an embedded cylindrical post, and exhibit a position-dependent stiffness with little to no modulation of local mesh geometry. Here we present the device in the context of fibrin hydrogels. First AMR is used to directly measure local micromechanics in unstrained hydrogels of increasing fibrin concentration. Changes in stiffness are then mapped within our device, where fibrin concentration is held constant. Fluorescence confocal imaging and orbital particle tracking are used to quantify structural changes in fibrin on the micro and nano levels respectively. The micromechanical strain stiffening measured by microrheology is not accompanied by ECM microstructural changes under our applied loads, as measured by confocal microscopy. However, super-resolution orbital tracking reveals nanostructural straightening, lengthening, and reduced movement of fibrin fibers. Furthermore, we show that aortic smooth muscle cells cultured within our device are morphologically sensitive to the induced mechanical gradient. Our results demonstrate a powerful cell culture tool that can be used in the study of mechanical effects on cellular physiology in naturally derived 3D ECM tissues.

Effectiveness of Fibrin Glue in Adherence of Skin Graft.

Science.gov (United States)

Reddy, Konda Sireesha; Chittoria, Ravi Kumar; Babu, Preethitha; Marimuthu, Senthil Kumaran; Kumar, Sudhanva Hemanth; Subbarayan, Elan Kumar; Chavan, Vinayak; Mohapatra, Devi Prasad; Sivakumar, Dinesh Kumar; Friji, M T

2017-01-01

Graft fixation is important for graft take. Fibrin glue has been proposed as an ideal material, because of its human origin and it provides firm adhesion in seconds or minutes. To evaluate the efficiency of fibrin glue, in increasing the take of skin graft. Assessment includes surgical time taken for graft fixation, haematoma/seroma formation, engraftment and wound closure by day 14. The study is an observational prospective study conducted in the Department of Plastic Surgery, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, from January 2016 to June 2016. Sixteen patients who underwent split skin grafting were assessed during the study period. Fibrin glue was used on the recipient bed before grafting. Better haemostasis and graft adhesion, with a significant reduction of surgical time, were noted. The safety profile of fibrin glue was excellent as indicated by the lack of any related serious adverse experiences. These findings demonstrate that it is safe and effective for attachment of skin grafts, with outcomes at least as good as conventional methods.

Platelet Counts in Insoluble Platelet-Rich Fibrin Clots: A Direct Method for Accurate Determination

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Yutaka Kitamura

2018-02-01

Full Text Available Platelet-rich fibrin (PRF clots have been used in regenerative dentistry most often, with the assumption that growth factor levels are concentrated in proportion to the platelet concentration. Platelet counts in PRF are generally determined indirectly by platelet counting in other liquid fractions. This study shows a method for direct estimation of platelet counts in PRF. To validate this method by determination of the recovery rate, whole-blood samples were obtained with an anticoagulant from healthy donors, and platelet-rich plasma (PRP fractions were clotted with CaCl2 by centrifugation and digested with tissue-plasminogen activator. Platelet counts were estimated before clotting and after digestion using an automatic hemocytometer. The method was then tested on PRF clots. The quality of platelets was examined by scanning electron microscopy and flow cytometry. In PRP-derived fibrin matrices, the recovery rate of platelets and white blood cells was 91.6 and 74.6%, respectively, after 24 h of digestion. In PRF clots associated with small and large red thrombi, platelet counts were 92.6 and 67.2% of the respective total platelet counts. These findings suggest that our direct method is sufficient for estimating the number of platelets trapped in an insoluble fibrin matrix and for determining that platelets are distributed in PRF clots and red thrombi roughly in proportion to their individual volumes. Therefore, we propose this direct digestion method for more accurate estimation of platelet counts in most types of platelet-enriched fibrin matrix.

First step in developing a 3D biodegradable fibrin scaffold for an artificial ovary.

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Luyckx, Valérie; Dolmans, Marie-Madeleine; Vanacker, Julie; Scalercio, Sarah R; Donnez, Jacques; Amorim, Christiani A

2013-11-25

Although transplantation of cryopreserved ovarian tissue is a promising approach to restore fertility in cancer patients, it is not advisable for women at risk of ovarian involvement due to the threat of reintroducing malignant cells. The aim of this study was therefore to find an alternative for these patients by development of an artificial ovary. For construction of the artificial ovary matrix, we used a central composite design to investigate nine combinations of fibrinogen (mg/ml) and thrombin (IU/mL) (F/T): F1/T4, F12.5/T1, F12.5/T20, F25/T0.1, F25/T4, F25/T500, F50/T1, F50/T20 and F100/T4. From the first qualitative analyses (handling and matrix size), five combinations (F12.5/T1, F25/T4, F50/T20, F50/T1 and F100/T4) yielded positive results. They were further evaluated in order to assess fibrin matrix degradation and homogeneous cell encapsulation (density), survival and proliferation (Ki67), and atresia (TUNEL) before and after 7 days of in vitro culture. To determine the best compromise between maximizing the dynamic density (Y1) and minimizing the apoptosis rate (Y2), we used the desirability function approach. Two combinations (F12.5/T1 and F25/T4) showed greater distribution of cells before in vitro culture, reproducible degradation of the fibrin network and adequate support for isolated human ovarian stromal cells, with a high proportion of Ki67-positive cells. SEM analysis revealed a network of fibers with regular pores and healthy stromal cells after in vitro culture with both F/T combinations. This study reports two optimal F/T combinations that allow survival and proliferation of isolated human ovarian cells. Further studies are required to determine if such a scaffold will also be a suitable environment for isolated ovarian follicles.

A novel fibrin gel derived from hyaluronic acid-grafted fibrinogen

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Yang, Chiung L; Chen, Hui W; Wang, Tzu C; Wang, Yng J, E-mail: wang@ym.edu.tw [Institute of Biomedical Engineering, National Yang Ming University, No. 155, Sec. 2, Li-Nung St., Shih-Pai, Taipei, Taiwan 112 (China)

2011-04-15

Fibrinogen is a major plasma protein that forms a three-dimensional fibrin gel upon being activated by thrombin. In this study, we report the synthesis and potential applications of hybrid molecules composed of fibrinogen coupled to the reducing ends of short-chain hyaluronic acids (sHAs) by reductive amination. The grafting of sHAs to fibrinogen was verified by analyzing particle size, zeta potential and gel-electrophoretic mobility of the hybrid molecules. The sHA-fibrinogen hybrid molecules with graft ratios (sHA/fibrinogen) of up to 6.5 retained the ability to form gels in response to thrombin activation. The sHA-fibrin gels were transparent in appearance and exhibited high water content, which were characteristics distinct from those of gels formed by mixtures of sHAs and fibrinogen. The potential applications of the sHA-fibrin gels were evaluated. The sHA-fibrinogen gel with a graft ratio of 3.6 (S3.6F) was examined for its ability to encapsulate and support the differentiation of ATDC5 chondrocyte-like cells. Compared with the fibrinogen-formed gel, cells cultured in the S3.6F gel exhibited increased lacunae formation; moreover, the abundance of cartilaginous extracellular matrix molecules and the expression of chondrocyte marker genes, such as aggrecan, collagen II and Sox9, were also significantly increased. Our data suggest that the three-dimensional gel formed by the sHA-fibrinogen hybrid is a better support than the fibrin gel for chondrogenesis induction.

A novel fibrin gel derived from hyaluronic acid-grafted fibrinogen

International Nuclear Information System (INIS)

Yang, Chiung L; Chen, Hui W; Wang, Tzu C; Wang, Yng J

2011-01-01

Fibrinogen is a major plasma protein that forms a three-dimensional fibrin gel upon being activated by thrombin. In this study, we report the synthesis and potential applications of hybrid molecules composed of fibrinogen coupled to the reducing ends of short-chain hyaluronic acids (sHAs) by reductive amination. The grafting of sHAs to fibrinogen was verified by analyzing particle size, zeta potential and gel-electrophoretic mobility of the hybrid molecules. The sHA-fibrinogen hybrid molecules with graft ratios (sHA/fibrinogen) of up to 6.5 retained the ability to form gels in response to thrombin activation. The sHA-fibrin gels were transparent in appearance and exhibited high water content, which were characteristics distinct from those of gels formed by mixtures of sHAs and fibrinogen. The potential applications of the sHA-fibrin gels were evaluated. The sHA-fibrinogen gel with a graft ratio of 3.6 (S3.6F) was examined for its ability to encapsulate and support the differentiation of ATDC5 chondrocyte-like cells. Compared with the fibrinogen-formed gel, cells cultured in the S3.6F gel exhibited increased lacunae formation; moreover, the abundance of cartilaginous extracellular matrix molecules and the expression of chondrocyte marker genes, such as aggrecan, collagen II and Sox9, were also significantly increased. Our data suggest that the three-dimensional gel formed by the sHA-fibrinogen hybrid is a better support than the fibrin gel for chondrogenesis induction.

Platelet-rich fibrin versus albumin in surgical wound repair: a randomized trial with paired design

DEFF Research Database (Denmark)

Danielsen, Patricia L; Ågren, Sven Per Magnus; Jørgensen, Lars Nannestad

2010-01-01

To study the effects of autologous platelet-rich fibrin (PRF) versus human albumin on incisional wound breaking strength and subcutaneous collagen deposition in patients undergoing laparoscopic cholecystectomy in a randomized trial.......To study the effects of autologous platelet-rich fibrin (PRF) versus human albumin on incisional wound breaking strength and subcutaneous collagen deposition in patients undergoing laparoscopic cholecystectomy in a randomized trial....

Tumour imaging by the detection of fibrin clots in tumour stroma using an anti-fibrin Fab fragment

Science.gov (United States)

Obonai, Toshifumi; Fuchigami, Hirobumi; Furuya, Fumiaki; Kozuka, Naoyuki; Yasunaga, Masahiro; Matsumura, Yasuhiro

2016-01-01

The diagnosis of early and aggressive types of cancer is important for providing effective cancer therapy. Cancer-induced fibrin clots exist only within lesions. Previously, we developed a monoclonal antibody (clone 102-10) that recognizes insoluble fibrin but not fibrinogen or soluble fibrin and confirmed that fibrin clots form continuously in various cancers. Here, we describe the development of a Fab fragment probe of clone 102-10 for tumour imaging. The distribution of 102-10 Fab was investigated in genetically engineered mice bearing pancreatic ductal adenocarcinoma (PDAC), and its effect on blood coagulation was examined. Immunohistochemical and ex vivo imaging revealed that 102-10 Fab was distributed selectively in fibrin clots in PDAC tumours 3 h after injection and that it disappeared from the body after 24 h. 102-10 Fab had no influence on blood coagulation or fibrinolysis. Tumour imaging using anti-fibrin Fab may provide a safe and effective method for the diagnosis of invasive cancers by detecting fibrin clots in tumour stroma. PMID:27009516

Experimental Evaluation of the Effectiveness of Demineralized Bone Matrix and Collagenated Heterologous Bone Grafts Used Alone or in Combination with Platelet-Rich Fibrin on Bone Healing in Sinus Floor Augmentation.

Science.gov (United States)

Peker, Elif; Karaca, Inci Rana; Yildirim, Benay

2016-01-01

The aim of this study was an experimental evaluation of the effectiveness of demineralized bone matrix (DBM) and collagenated heterologous bone graft (CHBG) used alone or in combination with platelet-rich fibrin on bone healing in sinus floor augmentation procedures. In this study, 36 New Zealand rabbits were used. The bilateral sinus elevation was performed, and 72 defects were obtained. The rabbit maxillary sinuses were divided into four groups according to the augmentation biomaterials obtained: demineralized bone matrix (Grafton DBM Putty, Osteotech; DBM group), DBM combined with platelet-rich fibrin (PRF; DBM + PRF group), collagenated heterologous bone graft (CHBG; Apatos Mix, OsteoBiol, Tecnoss; CHBG group), CHBG combined with PRF (CHBG + PRF group). All groups were sacrificed at 2, 4, and 8 weeks after surgery for histologic, histomorphometric, and immunohistochemical analyses. The inflammatory reaction was moderate to intense at the second week in all groups and declined from 2 to 8 weeks. New bone formation was started at the second week and increased from 2 to 8 weeks in all groups. There was no significant difference in bone formation between the experimental groups that used PRF mixed graft material and control groups that used only graft material. The percentage of new bone formation showed a significant difference in DBM groups and DBM + PRF groups compared with other groups. There were osteoclasts around all the bone graft materials used, but the percentage of residual graft particles was significantly higher in CHBG groups and CHBG + PRF groups at the eighth week. There is no beneficial effect of the application of PRF in combination with demineralized bone matrix or collagenated heterologous bone graft on bone formation in sinus floor augmentation. The results of this study showed that both collagenated heterologous bone graft and demineralized bone matrix have osteoconductive properties, but demineralized bone matrix showed more bone formation

Determination of fibrin glue with antibiotics on collagen production in colon anastomosis

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Stanojković Zoran

2008-01-01

Full Text Available Background/Aim. Fibrin glue is used as a matrix for local application of antibiotics. The aim of this study was to determine whether application of fibrin glue in combination with antibiotics can strengthen collagen production, prevent dehiscence of colon anastomoses due to infection, and reduce frequency of mortality and morbidity comparing to the control group and the group with fibrin glue application. Methods. The adult male Wistar rats divided into three groups were used in the experiment. The group 1 was the control one (after partial colon resection, colonic anastomoses performed were not treated, while to the group 2 and the group 3 were applied fibrin glue and fibrin glue with antibiotics (clindamycin and ceftriaxon on the site of anastomoses, respectively. Quality of colonic anastomoses were estimated by means of determination of collagen (L-hydroxyproline amount in the collon wall with anastomoses and histological analysis of this colon segment using light and electronic microscope on the days 5, 7 and 13 postoperatively. Results. The highest morbidity rate was registered in the group 1 (30%, then in the group 2 (13.3% and the lowest one in the group 3 (3.33%; p < 0,05 vs group 1. Mortality rate was significantly higher in the group 1 than in the group 3 (20% and 0%, respectively; p < 0,05. In the postoperative course, the highest concentrations of collagen in the colon wall on the site of anastomoses, which was confirmed by both light and electronic microscopy, were found in the group 3. Conclusion. The application of fibrin glue with antibiotics on colon anastomoses reduces the number of dehiscence, provides good mechanical protection and shorten the time of anastomoses healing.

Biomimetic chimeric peptide-tethered hydrogels for human mesenchymal stem cell delivery.

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Shim, Gayong; Kim, Gunwoo; Choi, Junhyeok; Yi, TacGhee; Cho, Yun Kyoung; Song, Sun Uk; Byun, Youngro; Oh, Yu-Kyoung

2015-12-01

Here, we report a chimeric peptide-tethered fibrin hydrogel scaffold for delivery of human mesenchymal stem cells (hMSC). Osteopontin-derived peptide (OP) was used as an hMSC-tethering moiety. OP showed hMSC adhesion properties and enhanced hMSC proliferation. A natural fibrin-binding protein-derived peptide (FBP) was tested for its ability to tether hMSC to the fibrin gel matrix. FBP loading on fibrin gels was 8.2-fold higher than that of a scrambled peptide (scFBP). FBP-loaded fibrin gels were retained at injection sites longer than scFBP-loaded fibrin gels, showing a 15.9-fold higher photon intensity of fluorescent FBP-grafted fibrin gels than fluorescent scFBP-loaded fibrin gels 48 h after injection. On the basis of the fibrin gel-binding properties of FBP and the hMSC-binding and proliferation-supporting properties of OP, we constructed chimeric peptides containing FBP and OP linked with a spacer (FBPsOP). Four days after transplantation, the survival of hMSC in FBPsOP-grafted fibrin gels was 3.9-fold higher than hMSC in fibrin gels alone. Our results suggest the potential of FBPsOP-grafted fibrin gels as a bioactive delivery system for enhanced survival of stem cells. Copyright © 2015 Elsevier B.V. All rights reserved.

Fibrin related antigens: assay development, clinical and kinetic studies

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Kruskal, J B

1987-08-01

This thesis describes an assay which is able to measure and to determine the proportions of fibrin- and fibrinogen-related antigens (FRA) present in clinical samples. No assay exists at present which is capable of distinguishing between fibrin and fibrinogen degradation products concurrently and in a clinical setting. The assay may be used as a tool with which to gain further insight to pathophysiology of disorders characterized by activation of the coagulation and fibrinolytic pathways. This study provides and analysis of the FRA profiles in patients with disorders characterised by possible enhanced fibrinolytic activity. Studies have been undertaken on patients with acute and chronic liver diseases, on patients with the various syndromes of coronary artery disease and on patients with insulin-dependent diabetes mellitus with and without evidence of microvascular disease. Certain observations made it evident that further studies were required in order to explain previously undocumented fibrinolytic abnormalities in certain patient groups. Data obtained from patients with liver disease provided information compatible with the activation of their fibrinolytic pathways. The initial scope of this study was then extended to further investigate the deranged haemostatic mechanisms in patients with severe liver diseases. Kinetic studies were performed which required the development of specific technology to be able to measure certain previously undertermined parameters. Mathematical models describing the rates of fibrin formation and lysis were developed for human studies. Fibrin-derived D-dimer was radiolabelled and its validity as and intravenous tracer and maker of fibrin degradation established.

Fibrin network pattern changes of platelet-rich fibrin in young versus old age group of individuals: A cell block cytology study

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Shravanthi Raghav Yajamanya

2016-01-01

Full Text Available Background: To evaluate variations in fibrin network patterns of the platelet-rich fibrin (PRF in different age groups. Materials and Methods: Ninety-five patients were divided into three age groups: Group 1: (20–39 years; Group 2: (40–59 years; and Group 3: (60 years and above. PRF was prepared from blood samples of all patients and were subjected to cell block cytology method of histological analysis and slides were prepared to histologically assess the age-related changes in (i fibrin network patterns in terms of density and (ii entrapment of platelets and white blood cells (WBCs within fibrin meshwork. Results: Two types of fibrin network pattern arrangements noticed: Dense and loose types in three age groups. However, there was a noticeable decrease in the dense type of fibrin network with progressing age and increase in the loose type of fibrin arrangement. Furthermore, variation in a number of platelets and WBCs entrapped within fibrin network in relation to age was noticed. Conclusion: From the current study it can be concluded that age can be considered as one of the influencing factors on quality of PRF in terms of fibrin network patterns and hence, platelet and WBCs entrapment within these fibrin networks.

Fibrin Sheath Angioplasty: A Technique to Prevent Superior Vena Cava Stenosis Secondary to Dialysis Catheters

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Hacker, Robert I.; Garcia, Lorena De Marco; Chawla, Ankur; Panetta, Thomas F.

2012-01-01

Fibrin sheaths are a heterogeneous matrix of cells and debris that form around catheters and are a known cause of central venous stenosis and catheter failure. A total of 50 cases of central venous catheter fibrin sheath angioplasty (FSA) after catheter removal or exchange are presented. A retrospective review of an outpatient office database identified 70 eligible patients over a 19-month period. After informed consent was obtained, the dialysis catheter exiting the skin was clamped, amputated, and a wire was inserted. The catheter was then removed and a 9-French sheath was inserted into the superior vena cava, a venogram was performed. If a fibrin sheath was present, angioplasty was performed using an 8 × 4 or 10 × 4 balloon along the entire length of the fibrin sheath. A completion venogram was performed to document obliteration of the sheath. During the study, 50 patients were diagnosed with a fibrin sheath, and 43 had no pre-existing central venous stenosis. After FSA, 39 of the 43 patient's (91%) central systems remained patent without the need for subsequent interventions; 3 patients (7%) developed subclavian stenoses requiring repeat angioplasty and stenting; 1 patent (2.3%) developed an occlusion requiring a reintervention. Seven patients with prior central stenosis required multiple angioplasties; five required stenting of their central lesions. Every patient had follow-up fistulograms to document long-term patency. We propose that FSA is a prudent and safe procedure that may help reduce the risk of central venous stenosis from fibrin sheaths due to central venous catheters. PMID:23997555

Hyaline Articular Matrix Formed by Dynamic Self-Regenerating Cartilage and Hydrogels.

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Meppelink, Amanda M; Zhao, Xing; Griffin, Darvin J; Erali, Richard; Gill, Thomas J; Bonassar, Lawrence J; Redmond, Robert W; Randolph, Mark A

2016-07-01

Injuries to the articular cartilage surface are challenging to repair because cartilage possesses a limited capacity for self-repair. The outcomes of current clinical procedures aimed to address these injuries are inconsistent and unsatisfactory. We have developed a novel method for generating hyaline articular cartilage to improve the outcome of joint surface repair. A suspension of 10(7) swine chondrocytes was cultured under reciprocating motion for 14 days. The resulting dynamic self-regenerating cartilage (dSRC) was placed in a cartilage ring and capped with fibrin and collagen gel. A control group consisted of chondrocytes encapsulated in fibrin gel. Constructs were implanted subcutaneously in nude mice and harvested after 6 weeks. Gross, histological, immunohistochemical, biochemical, and biomechanical analyses were performed. In swine patellar groove, dSRC was implanted into osteochondral defects capped with collagen gel and compared to defects filled with osteochondral plugs, collagen gel, or left empty after 6 weeks. In mice, the fibrin- and collagen-capped dSRC constructs showed enhanced contiguous cartilage matrix formation over the control of cells encapsulated in fibrin gel. Biochemically, the fibrin and collagen gel dSRC groups were statistically improved in glycosaminoglycan and hydroxyproline content compared to the control. There was no statistical difference in the biomechanical data between the dSRC groups and the control. The swine model also showed contiguous cartilage matrix in the dSRC group but not in the collagen gel and empty defects. These data demonstrate the survivability and successful matrix formation of dSRC under the mechanical forces experienced by normal hyaline cartilage in the knee joint. The results from this study demonstrate that dSRC capped with hydrogels successfully engineers contiguous articular cartilage matrix in both nonload-bearing and load-bearing environments.

Differentiation within autologous fibrin scaffolds of porcine dermal cells with the mesenchymal stem cell phenotype

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Puente, Pilar de la; Ludeña, Dolores; López, Marta; Ramos, Jennifer; Iglesias, Javier

2013-01-01

Porcine mesenchymal stem cells (pMSCs) are an attractive source of cells for tissue engineering because their properties are similar to those of human stem cells. pMSCs can be found in different tissues but their dermal origin has not been studied in depth. Additionally, MSCs differentiation in monolayer cultures requires subcultured cells, and these cells are at risk of dedifferentiation when implanting them into living tissue. Following this, we attempted to characterize the MSCs phenotype of porcine dermal cells and to evaluate their cellular proliferation and differentiation in autologous fibrin scaffolds (AFSs). Dermal biopsies and blood samples were obtained from 12 pigs. Dermal cells were characterized by flow cytometry. Frozen autologous plasma was used to prepare AFSs. pMSC differentiation was studied in standard structures (monolayers and pellets) and in AFSs. The pMSCs expressed the CD90 and CD29 markers of the mesenchymal lineage. AFSs afforded adipogenic, osteogenic and chondrogenic differentiation. The porcine dermis can be proposed to be a good source of MSCs with adequate proliferative capacity and a suitable expression of markers. The pMSCs also showed optimal proliferation and differentiation in AFSs, such that these might serve as a promising autologous and implantable material for use in tissue engineering. -- Highlights: ► Low fibrinogen concentration provides a suitable matrix for cell migration and differentiation. ► Autologous fibrin scaffolds is a promising technique in tissue engineering. ► Dermal cells are an easily accessible mesenchymal stem cell source. ► Fibrin scaffolds afforded adipogenic, osteogenic and chondrogenic differentiation.

A safe and efficient method to retrieve mesenchymal stem cells from three-dimensional fibrin gels.

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Carrion, Bita; Janson, Isaac A; Kong, Yen P; Putnam, Andrew J

2014-03-01

Mesenchymal stem cells (MSCs) display multipotent characteristics that make them ideal for potential therapeutic applications. MSCs are typically cultured as monolayers on tissue culture plastic, but there is increasing evidence suggesting that they may lose their multipotency over time in vitro and eventually cease to retain any resemblance to in vivo resident MSCs. Three-dimensional (3D) culture systems that more closely recapitulate the physiological environment of MSCs and other cell types are increasingly explored for their capacity to support and maintain the cell phenotypes. In much of our own work, we have utilized fibrin, a natural protein-based material that serves as the provisional extracellular matrix during wound healing. Fibrin has proven to be useful in numerous tissue engineering applications and has been used clinically as a hemostatic material. Its rapid self-assembly driven by thrombin-mediated alteration of fibrinogen makes fibrin an attractive 3D substrate, in which cells can adhere, spread, proliferate, and undergo complex morphogenetic programs. However, there is a significant need for simple cost-effective methods to safely retrieve cells encapsulated within fibrin hydrogels to perform additional analyses or use the cells for therapy. Here, we present a safe and efficient protocol for the isolation of MSCs from 3D fibrin gels. The key ingredient of our successful extraction method is nattokinase, a serine protease of the subtilisin family that has a strong fibrinolytic activity. Our data show that MSCs recovered from 3D fibrin gels using nattokinase are not only viable but also retain their proliferative and multilineage potentials. Demonstrated for MSCs, this method can be readily adapted to retrieve any other cell type from 3D fibrin gel constructs for various applications, including expansion, bioassays, and in vivo implantation.

Adipose-Derived-Stem-Cell-Seeded Fibrin Matrices for Periodontal Ligament Engineering: The Need for Dynamic Strain

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de Jong, Thijs; Oostendorp, Corien; Bakker, Astrid D.; van Kuppevelt, Toin H.; Smit, Theo H.

2017-01-01

Introduction: The periodontal ligament (PDL) connects the tooth to the alveolar bone. For PDL regeneration after tissue damage, we propose human adipose-derived stem cells (hASCs) embedded in fibrin. We showed previously that hASCs in fibrin extensively produce collagen, but in a non-functional,

Role of Fibrin Sealants in Liver Surgery

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de Boer, Marieke T.; Boonstra, Elizabeth A.; Lisman, Ton; Porte, Robert J.

2012-01-01

Background: Fibrin sealants are widely used in liver surgery. The aim of this article is to review the literature on evidence of hemostatic and biliostatic capacities of different fibrin sealants in liver surgery. Methods: In PubMed, a literature search was done with the search terms 'fibrin

Comparing different preparation methods to study human fibrin fibers and platelets using TEM.

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Buys, Antoinette V; Pretorius, Etheresia

2012-06-01

For the study of cellular ultrastructure, the sample needs to be stabilized by fixation, with the ultimate aim to preserve the native tissue organization and to protect the tissue against later stages of preparation. Chemical and freezing fixation are most used, and chemical fixation employs agents that permeate tissues and cells by diffusion and covalently bind with their major biochemical constituents to fix them. Most widely used chemical fixatives are aldehydes, e.g., formaldehyde and glutaraldehyde, which are noncoagulating, crosslinking agents. Cryofixation methods for ultrastructural studies are also popular, and high-pressure freezing immobilizes all cell constituents and arrests biological activity by removing the thermal energy from the system. In the current research, we used platelet-rich plasma (PRP) to study expansive fibrin fibers and platelet ultrastructure to compare the two fixation techniques. We also used thrombin and calcium chloride as a clotting agent to determine the technique most suitable for the formation of extensive fibrin networks. Chemically fixated fibrin fibers were more compact and condensed and also showed a banding pattern on longitudinal sections. High-pressure frozen samples were more dispersed while platelets fixated showed better preserved cellular membranes and organelle structure. PRP coagulated by addition of CaCl(2) showed blood platelets that are noticeably more activated compared with PRP; however, with thrombin, a sharp ultrastructure was seen. We conclude that PRP mixed with thrombin, and freeze substituted, is the most suitable method for the study of extensive fibrin fibers as well as platelets. Copyright © 2011 Wiley Periodicals, Inc.

Role of plasma-rich fibrin in oral surgery

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K Retna Kumar

2016-01-01

Full Text Available Platelet-rich fibrin (PRF is a fibrin meshwork, in which platelet cytokines, growth factors, and cells are entrapped and discharged after a period and can serve as a resorbable film. PRF is the next generation of platelet concentrates equipped to improve arrangement without biochemical blood handling; PRF is an evolution of the fibrin adhesive, which is widely used in the oral surgery. The guidelines of this innovation depend on concentrating platelets and growth factors in a plasma medium, and initiating them in a fibrin gel, keeping in mind the end goal to enhance the healing of wounds. Maxillary bone loss requires numerous regenerative techniques: as a supplement to the procedures of tissue regeneration, a platelet concentrate called PRF was tested for the 1st time in France by Dr. Choukroun. This article enriches the benefits and role of plasma-rich fibrin in oral surgery. Platelet-concentrate fibrin is an evolution of the fibrin glue, which is widely used in the oral surgery.

Three-dimensional architecture and cell composition of a Choukroun's platelet-rich fibrin clot and membrane.

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Dohan Ehrenfest, David M; Del Corso, Marco; Diss, Antoine; Mouhyi, Jaafar; Charrier, Jean-Baptiste

2010-04-01

Platelet-rich fibrin (PRF; Choukroun's technique) is a second-generation platelet concentrate for surgical use. This easy protocol allows the production of leukocyte and platelet-rich fibrin clots and membranes starting from 10-ml blood samples. The purposes of this study were to determine the cell composition and three-dimensional organization of this autologous biomaterial and to evaluate the influence of different collection tubes (dry glass or glass-coated plastic tubes) and compression procedures (forcible or soft) on the final PRF-membrane architecture. After centrifugation, blood analyses were performed on the residual waste plasmatic layers after collecting PRF clots. The PRF clots and membranes were processed for examination by light microscopy and scanning electron microscopy. Approximately 97% of the platelets and >50% of the leukocytes were concentrated in the PRF clot and showed a specific three-dimensional distribution, depending on the centrifugation forces. Platelets and fibrin formed large clusters of coagulation in the first millimeters of the membrane beyond the red blood cell base. The fibrin network was very mature and dense. Moreover, there was no significant difference in the PRF architecture between groups using the different tested collection tubes and compression techniques, even if these two parameters could have influenced the growth factor content and biologic matrix properties. The PRF protocol concentrated most platelets and leukocytes from a blood harvest into a single autologous fibrin biomaterial. This protocol offers reproducible results as long as the main production principles are respected.

Growth factor and proteinase profile of Vivostat® platelet-rich fibrin linked to tissue repair.

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Agren, M S; Rasmussen, K; Pakkenberg, B; Jørgensen, B

2014-07-01

Autologous platelet-rich fibrin (PRF(®)) is prepared by the automatic Vivostat(®) system. Conflicting results with Vivostat PRF in acute wound healing prompted us to examine its cellular and biomolecular composition. Specifically, platelets, selected growth factors and matrix metalloproteinase (MMP)-9 were quantified using novel analytical methods. Ten healthy non-thrombocytopenic volunteers donated blood for generation of intermediate fibrin-I and final PRF. Anticoagulated whole blood and serum procured in parallel served as baseline controls. Leucocyte, erythrocyte and platelet counts in whole blood and fibrin-I were determined by automated haematology analyser. Platelet concentration in PRF was quantified manually by stereologic analysis of Giemsa-stained tissue sections, and the total content of five growth factors and MMP-9 by enzyme-linked immunosorbent assays. The number of leucocytes and erythrocytes was reduced (P platelets increased (P fibrin-I versus whole blood. PRF contained 982 ± 206 × 10(9) platelets/l representing 3·9-fold (P platelet-derived growth factor (PDGF)-AB [2·5-fold, P PDGF-BB [1·6-fold, P vascular endothelial growth factor > basic fibroblast growth factor [75-fold, P platelet enrichment and biomolecular constituents may guide clinicians in their optimal use of Vivostat PRF for tissue regenerative applications. © 2013 International Society of Blood Transfusion.

A review of bioceramics and fibrin sealant.

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Le Guéhennec, L; Layrolle, P; Daculsi, G

2004-09-13

This review focuses on bone substitute composites made by mixing ceramic biomaterials with fibrin sealants. Different biomaterials such as coral, bone-derived materials, bioactive glass ceramics, and synthetic calcium phosphate have been mixed with fibrin sealant, resulting in a combination of the biological properties of the two components. This type of association has not produced identical results in all studies. In the past for some, the addition of fibrin sealant to the biomaterial failed to produce any significant, positive effect on osteointegration, whereas others found a positive impact on bone colonization. Despite the negative biological effects reported previously, bioceramic-fibrin composites have been widely used in various types of bone surgery because they are easy to manipulate. In particular, the intra-operative preparation of these composites makes it possible to add bone growth factors or autologous osteoprogenitor cells prior to bone reconstruction. The bone growth factors and autologous osteoprogenitor cells associated with the bioceramic-fibrin composites should provide surgeons with tissue engineered grafts with enhanced osteointegrative properties. This review discusses both the advantages and disadvantages, as well as the future perspectives, of using bioceramic-fibrin composites in various clinical indications.

A Review of Bioceramics and Fibrin Sealant

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Le Guéhennec L.

2004-09-01

Full Text Available This review focuses on bone substitute composites made by mixing ceramic biomaterials with fibrin sealants. Different biomaterials such as coral, bone-derived materials, bioactive glass ceramics, and synthetic calcium phosphate have been mixed with fibrin sealant, resulting in a combination of the biological properties of the two components. This type of association has not produced identical results in all studies. In the past for some, the addition of fibrin sealant to the biomaterial failed to produce any significant, positive effect on osteointegration, whereas others found a positive impact on bone colonization. Despite the negative biological effects reported previously, bioceramic-fibrin composites have been widely used in various types of bone surgery because they are easy to manipulate. In particular, the intra-operative preparation of these composites makes it possible to add bone growth factors or autologous osteoprogenitor cells prior to bone reconstruction. The bone growth factors and autologous osteoprogenitor cells associated with the bioceramic-fibrin composites should provide surgeons with tissue engineered grafts with enhanced osteointegrative properties. This review discusses both the advantages and disadvantages, as well as the future perspectives, of using bioceramic-fibrin composites in various clinical indications.

Fibrin(ogen) is internalized and degraded by activated human monocytoid cells via Mac-1 (CD11b/CD18): a nonplasmin fibrinolytic pathway.

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Simon, D I; Ezratty, A M; Francis, S A; Rennke, H; Loscalzo, J

1993-10-15

Fibrin(ogen) (FGN) is important for hemostasis and wound healing and is cleared from sites of injury primarily by the plasminogen activator system. However, there is emerging evidence in plasminogen activator-deficient transgenic mice that nonplasmin pathways may be important in fibrin(ogen)olysis, as well. Given the proximity of FGN and monocytes within the occlusive thrombus at sites of vascular injury, we considered the possibility that monocytes may play an ancillary role in the degradation and clearance of fibrin. We found that monocytes possess an alternative fibrinolytic pathway that uses the integrin Mac-1, which directly binds and internalizes FGN, resulting in its lysosomal degradation. At 4 degrees C, FGN binds to U937 monocytoid cells in a specific and saturable manner with a kd of 1.8 mumol/L. Binding requires adenosine diphosphate stimulation and is calcium-dependent. At 37 degrees C, FGN and fibrin monomer (FM) are internalized and degraded at rates of 0.37 +/- 0.13 and 0.55 +/- 0.03 microgram/10(6) cells/h by U937 cells, 1.38 +/- 0.02 and 1.20 +/- 0.30 microgram/10(6) cells/h by THP-1 cells, and 2.10 +/- 0.20 and 2.52 +/- 0.18 micrograms/10(6) cells/h by human peripheral blood mononuclear cells, respectively. The serine protease inhibitors, PPACK and aprotinin, and the specific elastase inhibitor, AAPVCK, do not significantly inhibit degradation. However, degradation is inhibited by chloroquine, suggesting that a lysosomal pathway is involved. Factor X, a competitive ligand with FGN for the Mac-1 receptor, also blocks degradation, as does a monoclonal antibody to the alpha-subunit of Mac-1. Autoradiography of radioiodinated, internalized FGN shows that FGN proteolysis by the pathway produces a unique degradation pattern distinct from that observed with plasmin. In a fibrin clot lysis assay, Mac-1-mediated fibrinolysis contributed significantly to total fibrinolysis. In summary, FGN is internalized and degraded by activated human monocytoid cells via

Antimicrobial drugs encapsulated in fibrin nanoparticles for treating microbial infested wounds.

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Alphonsa, B Maria; Sudheesh Kumar, P T; Praveen, G; Biswas, Raja; Chennazhi, K P; Jayakumar, R

2014-05-01

In vitro evaluation of antibacterial and antifungal drugs encapsulated fibrin nanoparticles to prove their potential prospect of using these nanocomponent for effective treatment of microbial infested wounds. Surfactant-free oil-in-water emulsification-diffusion method was adopted to encapsulate 1 mg/ml each of antimicrobial drugs (Ciprofloxacin and Fluconazole) in 4 ml of aqueous fibrinogen suspension and subsequent thrombin mediated cross linking to synthesize drug loaded fibrin nanoparticles. Ciprofloxacin loaded fibrin nanoparticles (CFNPs) showed size range of 253 ± 6 nm whereas that of Fluconazole loaded fibrin nanoparticles (FFNPs) was 260 ± 10 nm. Physico chemical characterizations revealed the firm integration of antimicrobial drugs within fibrin nanoparticles. Drug release studies performed at physiological pH 7.4 showed a release of 16% ciprofloxacin and 8% of fluconazole while as the release of ciprofloxacin at alkaline pH 8.5, was 48% and that of fluconazole was 37%. The antimicrobial activity evaluations of both drug loaded systems independently showed good antibacterial activity against Escherichia coli (E.coli), Staphylococcus aureus (S. aureus) and antifungal activity against Candida albicans (C. albicans). The in vitro toxicity of the prepared drug loaded nanoparticles were further analyzed using Human dermal fibroblast cells (HDF) and showed adequate cell viability. The efficacies of both CFNPs and FFNPs for sustained delivery of encapsulated anti microbial drugs were evaluated in vitro suggesting its potential use for treating microbial infested wounds (diabetic foot ulcer).

Availability of the B beta(15-21) epitope on cross-linked human fibrin and its plasmic degradation products

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Chen, F.; Haber, E.; Matsueda, G. R.

1992-01-01

The binding of radiolabeled monoclonal antifibrin antibody 59D8 (specific for fibrin but not fibrinogen) to a series of degraded fibrin clots showed that the availability of the B beta(15-21) epitope (against which 59D8 had been raised) was inversely proportional to the extent of clot lysis. Examination of digest supernatants revealed that the B beta(15-21) epitope was released from clots as a high molecular weight degradation product in the presence of calcium ions but that the generation of low molecular weight peptides occurred in the absence of calcium ions. To address the question of epitope accessibility, we compared levels of fibrin clot binding among four radioactively labeled antibodies: antifibrin monoclonal antibody 59D8, two antifibrinogen monoclonal antibodies that cross-reacted with fibrin, and an affinity-purified polyclonal antifibrinogen antibody. We expected that the antifibrinogen antibodies would show enhanced binding to clots in comparison with the antifibrin antibody. However, the epitope accessibility experiments showed that all four antibody preparations bound fibrin clots at comparable levels. Taken together, these studies demonstrated that one fibrin-specific epitope, B beta(15-21), remains available on clots as they undergo degradation by plasmin and, importantly, that the epitope is not solubilized at a rate faster than the rate at which the clot is itself solubilized. The availability of the B beta(15-21) epitope during the course of plasminolysis assures the potential utility of antifibrin antibodies such as 59D8 for detecting thrombi and targeting plasminogen activators.

Experimental closure of gunshot wounds by fibrin glue with antibiotics in pigs

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Đenić Nebojša

2015-01-01

Full Text Available Background/Aim. Gunshot wounds caused by the automatic rifle M70AB2 (AK-47 7.62 mm, after the primary surgical management, were closed with delayed primary suture during the next four to seven days. This period coincides with the fibroblastic phase of wound healing. Fibrin glue is used as a local hemostatic and as a matrix for the local dosed release of antibiotics. Antibiotics addition to fibrin glue resulted in continuous diffusion into the surrounding next 4 to 7 days. The aim of this study was to create the preconditions for gunshot wounds closing without complications by the application of fibrin glue with antibiotics 24 h after primary surgical treatment. Methods. A total of 14 pigs were wounded in the gluteofemoral region by the bullet M67, initial velocity of 720 m/s. All wounded animals were surgically treated according to the principles of the warsurgery doctrine. Seven wounds were closed with primary delayed suture four days after the primary surgical treatment (traditional approach. Fibrin glue with antibiotics was introduced in seven wounds during the primary surgical treatment and primary delayed suture was done after 24 h. The macroscopic appearance and the clinical assessment of the wound were done during the primary surgical treatment and during its revision after 24 h, as well as histopathological findings at the days 4 and 7 after wounding. Results. Gunshot wounds caused by the automatic rifle M70AB2 (AK-47 7.62 mm, and treated with fibrin glue with antibiotics after primary surgical management, were closed with primary delayed suture after 24 h. In further wound evolution there were no complications. Conclusion. Uncomplicated soft-tissue wounds caused by an automatic M70AB2 rifle may be closed primarily with delayed suture without the risk of developing complications if on revision, 24 h after primary surgery, there were no present necrotic tissues, hematoma, and any signs of infection when fibrin glue with antibiotics

SPECT imaging of fibrin using fibrin-binding peptides

NARCIS (Netherlands)

Starmans, L.W.E.; Duijnhoven, van S.M.J.; Rossin, R.; Aime, S.; Daemen, M.J.A.P.; Nicolay, K.; Grüll, H.

2013-01-01

Noninvasive detection of fibrin in vivo using diagnostic imaging modalities may improve clinical decision-making on possible therapeutic options in atherosclerosis, cancer and thrombus-related pathologies such as pulmonary embolism and deep venous thrombosis. The aim of this study was to assess the

Platelet-rich fibrin: the benefits.

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Kumar, Yuvika Raj; Mohanty, Sujata; Verma, Mahesh; Kaur, Raunaq Reet; Bhatia, Priyanka; Kumar, Varun Raj; Chaudhary, Zainab

2016-01-01

Current published data presents confusing results about the effects of platelet-rich fibrin on bone, and there is a need for studies that throw light on its effect. Our main objective therefore was to evaluate (by fractal analysis) osseous regeneration in extraction sockets with and without platelet-rich fibrin in a study with a substantial sample and a reliable technique to calibrate its effects on bone cells. We also assessed the soft tissue response. Thirty-four patients had their bilaterally impacted third molars (68 surgical sites) extracted in this split-mouth study, following which platelet-rich fibrin was placed in one of the sockets. Patients were followed up clinically and radiographically, and a pain score and fractal analysis were used to evaluate healing of soft tissue and bone, respectively. We conclude that platelet-rich fibrin improves healing of both soft and hard tissues. Although osseous healing did not differ significantly between the groups, healing of soft tissue as judged by the pain score was significantly better in the experimental group. Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Improved adhesion and differentiation of endothelial cells on surface-attached fibrin structures containing extracellular matrix proteins

Czech Academy of Sciences Publication Activity Database

Filová, Elena; Brynda, Eduard; Riedel, Tomáš; Chlupáč, Jaroslav; Vandrovcová, Marta; Švindrych, Zdeněk; Lisá, Věra; Houska, Milan; Pirk, J.; Bačáková, Lucie

2014-01-01

Roč. 102, č. 3 (2014), s. 698-712 ISSN 1549-3296 R&D Projects: GA MZd(CZ) NT11270 Institutional support: RVO:67985823 ; RVO:61389013 Keywords : two-dimensional assembly * fibrin * endothelial cells Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery; CD - Macromolecular Chemistry (UMCH-V) Impact factor: 3.369, year: 2014

Silk-fibrin/hyaluronic acid composite gels for nucleus pulposus tissue regeneration.

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Park, Sang-Hyug; Cho, Hongsik; Gil, Eun Seok; Mandal, Biman B; Min, Byoung-Hyun; Kaplan, David L

2011-12-01

Scaffold designs are critical for in vitro culture of tissue-engineered cartilage in three-dimensional environments to enhance cellular differentiation for tissue engineering and regenerative medicine. In the present study we demonstrated silk and fibrin/hyaluronic acid (HA) composite gels as scaffolds for nucleus pulposus (NP) cartilage formation, providing both biochemical support for NP outcomes as well as fostering the retention of size of the scaffold during culture due to the combined features of the two proteins. Passage two (P2) human chondrocytes cultured in 10% serum were encapsulated within silk-fibrin/HA gels. Five study groups with fibrin/HA gel culture (F/H) along with varying silk concentrations (2% silk gel only, fibrin/HA gel culture with 1% silk [F/H+1S], 1.5% silk [F/H+1.5S], and 2% silk [F/H+2S]) were cultured in serum-free chondrogenic defined media (CDM) for 4 weeks. Histological examination with alcian blue showed a defined chondrogenic area at 1 week in all groups that widened homogenously until 4 weeks. In particular, chondrogenic differentiation observed in the F/H+1.5S had no reduction in size throughout the culture period. The results of biochemical and molecular biological evaluations supported observations made during histological examination. Mechanical strength measurements showed that the silk mixed gels provided stronger mechanical properties for NP tissue than fibrin/HA composite gels in CDM. This effect could potentially be useful in the study of in vitro NP tissue engineering as well as for clinical implications for NP tissue regeneration.

Scintigraphic evaluation of osteoblastic activity in extraction sockets treated with platelet-rich fibrin.

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Gürbüzer, Bahadir; Pikdöken, Levent; Tunali, Mustafa; Urhan, Muammer; Küçükodaci, Zafer; Ercan, Feriha

2010-05-01

To evaluate the effect of platelet-rich fibrin (PRF) on the early bone healing process with bone scintigraphy based on technetium-99m methylene diphosphonate uptake in third molar extraction sockets. Fourteen patients with bilaterally soft tissue impacted third mandibular molars were included in the study. The right and left impacted third molars were surgically extracted in the same session. PRF was randomly administered into one of the extraction sockets, whereas the contralateral sockets were left without treatment. Four weeks after surgery, scintigrams were obtained to evaluate scintigraphic differences between PRF-treated and non-PRF-treated sockets. After completion of the clinical study, PRF samples were evaluated by light and scanning electron microscopy. The average increase in technetium-99m methylene diphosphonate uptake as an indication of enhanced bone healing did not differ significantly between PRF-treated and non-PRF-treated sockets 4 weeks postoperatively (P > .05). Abundant fibrin and inflammatory cells were observed by light microscopic examination of PRF samples. Scanning electron microscopic analysis of PRF revealed the existence of platelet aggregates in a fibrin network and crystalline particles on the outer surface of PRF. PRF might not lead to enhanced bone healing in soft tissue impacted mandibular third molar extraction sockets 4 weeks after surgery. PRF exhibits the potential characteristics of an autologous fibrin matrix. However, whether the presence of crystal-like particles on the outer surface of PRF alters bone healing should be investigated further. Copyright 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Stretching single fibrin fibers hampers their lysis.

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Li, Wei; Lucioni, Tomas; Li, Rongzhong; Bonin, Keith; Cho, Samuel S; Guthold, Martin

2017-09-15

Blood clots, whose main structural component is a mesh of microscopic fibrin fibers, experience mechanical strain from blood flow, clot retraction and interactions with platelets and other cells. We developed a transparent, striated and highly stretchable substrate made from fugitive glue (a styrenic block copolymer) to investigate how mechanical strain affects lysis of single, suspended fibrin fibers. In this suspended fiber assay, lysis manifested itself by fiber elongation, thickening (disassembly), fraying and collapse. Stretching single fibrin fibers significantly hampered their lysis. This effect was seen in uncrosslinked and crosslinked fibers. Crosslinking (without stretching) also hampered single fiber lysis. Our data suggest that strain is a novel mechanosensitive factor that regulates blood clot dissolution (fibrinolysis) at the single fiber level. At the molecular level of single fibrin molecules, strain may distort, or hinder access to, plasmin cleavage sites and thereby hamper lysis. Fibrin fibers are the major structural component of a blood clot. We developed a highly stretchable substrate made from fugitive glue and a suspended fibrin fiber lysis assay to investigate the effect of stretching on single fibrin fibers lysis. The key findings from our experiments are: 1) Fibers thicken and elongate upon lysis; 2) stretching strongly reduces lysis; 3) this effect is more pronounced for uncrosslinked fibers; and 4) stretching fibers has a similar effect on reducing lysis as crosslinking fibers. At the molecular level, strain may distort plasmin cleavage sites, or restrict access to those sites. Our results suggest that strain may be a novel mechanobiological factor that regulates fibrinolysis. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

A new step toward the artificial ovary: survival and proliferation of isolated murine follicles after autologous transplantation in a fibrin scaffold.

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Luyckx, Valérie; Dolmans, Marie-Madeleine; Vanacker, Julie; Legat, Camille; Fortuño Moya, Cristina; Donnez, Jacques; Amorim, Christiani Andrade

2014-04-01

To create an artificial ovary to provide an alternative way of restoring fertility in patients who cannot benefit from transplantation of cryopreserved ovarian tissue due to the threat of reintroducing malignant cells. In vivo experimental study. Gynecology research unit in a university hospital. Six-week-old female NMRI mice. Autografting of isolated preantral follicles and ovarian cells (OCs) encapsulated in two fibrin matrices containing low concentrations of fibrinogen (F; mg/mL) and thrombin (T; IU/mL): F12.5/T1 and F25/T4. Follicular density and development, OC survival and proliferation, inflammatory response, and vascularization. After 1 week, the follicle recovery rate ranged from 30.8% (F25/T4) to 31.8% (F12.5/T1). With both fibrin formulations, all follicles were found to be alive or minimally damaged, as demonstrated by terminal deoxynucleotide transferase-mediated dUTP nick-end labeling assay, and at the growing stage (primary, secondary, and antral follicles), confirmed by Ki67 immunostaining. Isolated OCs also survived and proliferated after grafting, as evidenced by <1% apoptotic cells and a high proportion of Ki67-positive cells. Vessels were found in both fibrin formulations, and the global vascular surface area varied from 1.35% (F25/T4) to 1.88% (F12.5/T1). Numerous CD45-positive cells were also observed in both F25/T4 and F12.5/T1 combinations. The present study is the first to show survival and growth of isolated murine ovarian follicles 1 week after autotransplantation of isolated OCs in a fibrin scaffold. The results indicate that fibrin is a promising candidate as a matrix for the construction of an artificial ovary. Xenotransplantation of isolated human follicles and OCs is the necessary next step to validate these findings. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Autologous fibrin glue as an encapsulating scaffold for delivery of retinal progenitor cells

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Tamer Anwar Esmail Ahmed

2015-02-01

Full Text Available The retina is a highly sophisticated piece of the neural machinery that begins the translation of incoming light signals into meaningful visual information. Several degenerative diseases of the retina are characterized by photoreceptor loss and eventually lead to irreversible blindness. Regenerative medicine, using tissue engineering-based constructs to deliver progenitor cells or photoreceptors along with supporting carrier matrix is a promising approach for restoration of structure and function. Fresh fibrin glue (FG produced by the CryoSeal®FS system in combination with mouse retinal progenitor cells (RPCs were evaluated in this study. In vitro expanded RPCs isolated from postnatal mouse retina were encapsulated into FG and cultured in the presence of the protease inhibitor, tranexamic acid. Encapsulation of RPCs into FG did not show adverse effects on cell proliferation or cell survival. RPCs exhibited fibroblast-like morphology concomitantly with attachment to the encapsulating FG surface. They expressed α7 and β3 integrin subunits that could mediate attachment to fibrin matrix via an RGD independent mechanism. The three dimensional environment and the attachment surface provided by FG was associated with a rapid downregulation of the progenitor marker SOX2 and enhanced the expression of the differentiation markers CRX and recoverin. However, the in vitro culture conditions did not promote full differentiation into mature photoreceptors. Nevertheless, we have shown that autologous fibrin, when fabricated into a scaffold for RPCs for delivery to the retina, provides the cells with external cues that could potentially improve the differentiation events. Hence, transient encapsulation of RPCs into FG could be a valid and potential treatment strategy to promote retinal regeneration following degenerative diseases. However, further optimization is necessary to maximize the outcomes in terms of mature photoreceptors.

Use of fibrin sealants in cardiovascular surgery: a systematic review.

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Rousou, John A

2013-05-01

Fibrin sealants are used for hemostasis and tissue adherence. This systematic review summarizes published clinical data for fibrin sealant use in cardiovascular surgery. A literature search for the following terms was conducted using PubMed and EMBASE: (TISSEEL or Tissucol or Beriplast P or Evicel or Quixil or Crosseal or Reliseal or Fibringluraas or Bolheal or Tachosil or Vivostat or Vitagel or Artiss or "fibrin glue" or "fibrin sealant" or "fibrin tissue adhesive") and (cardiac or cardiovascular or vascular or heart or coronary or surgery). Case reports and series were excluded; although reports of controlled trials were preferred, uncontrolled trial data were also considered. Clinical trials and chart review analyses of fibrin sealants were identified and summarized. Although clinical trial data were available for other agents, the majority of published studies examined TISSEEL. Overall, TISSEEL and other fibrin sealants showed improvements over standard of care or control groups for a variety of predefined endpoints. Safety findings are also summarized. Data from these studies showed that fibrin sealants were well tolerated and provided effective hemostasis in a range of cardiac and aortic surgeries. © 2013 Wiley Periodicals, Inc.

Fibrin-Enhanced Canonical Wnt Signaling Directs Plasminogen Expression in Cementoblasts

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Saeed Ur Rahman

2017-11-01

Full Text Available Cementum is a mineralized layer on the tooth’s root surface and facilitates the biomechanical anchoring of fibrous connective tissues as a part of tooth-supportive complexes. Previously, we observed that OCCM30 cementoblasts cultured on fibrin matrices underwent apoptosis due to fibrin degradation through the expression of proteases. Here, we demonstrated that OCCM30 on fibrin matrices (OCCM30-fibrin enhanced canonical Wnt signaling, which directed to plasminogen expression. The OCCM30-fibrin showed higher levels of Wnt3a expression, nuclear translocation of β-catenin, and T-cell factor (TCF optimal motif (TOP reporter activity than the cells on tissue culture dishes (OCCM30-TCD, indicating that the OCCM30-fibrin enhanced canonical Wnt/β-catenin signaling. Also, OCCM30-fibrin expressed biomineralization-associated markers at higher levels than OCCM30-TCD, of which levels were further increased with LiCl, a Wnt signaling activator. The OCCM30 cementoblasts simultaneously showed that high levels of plasminogen, a critical component of fibrinolysis, were expressed in the OCCM30-fibrin. Activation of canonical Wnt signaling with LiCl treatment or with forced lymphoid enhancer factor 1 (LEF1-expression increased the expression of plasminogen. On the contrary, the inhibition of canonical Wnt signaling with siRNAs against Wnt3a or β-catenin abrogated fibrin-enhanced plasminogen expression. Furthermore, there are three conserved putative response elements for the LEF1/β-catenin complex in the plasminogen proximal promoter regions (−900 to +54. Site-directed mutations and chromatin immunoprecipitation indicated that canonical Wnt signaling directed plasminogen expression. Taken together, this study suggests that fibrin-based materials can modulate functional periodontal formations in controlling cementoblast differentiation and fibrin degradation.

[Research of repairing rabbit knee joint cartilage defect by compound material of fibrin glue and decalcified bone matrix (DBM) and chondrocytes].

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He, Jie; Yang, Xiang; Yue, Peng-ju; Wang, Guan-yu; Guo, Ting; Zhao, Jian-ning

2009-07-01

To investigate the feasibility and effectivity of using compound material of fibrin glue and DBM as scaffolds for cartilage tissue engineering. Chondrocytes isolated from articular cartilage were seeded into prepared scaffolds, after incubation for 4 weeks in vitro. Chondrocytes and fibrin glue and DBM constructs were implanted in the joint cave of rabbit. The specimens were excised at the 4th, 8th, 12th week, examined grossly analyzed by haematoxylin cosine, toluidine blues staining and type II collagen immunohistochemistry reaction. Wakitani score was counted to evaluate the repairing effect. Grossly analysis showed some ivory tissue filled the caves after 4 weeks and the caves were full filled with smooth surface after 12 weeks. The microscope showed a good deal of chondrocytes appeared after 8 weeks and more type II collagen than 4 weeks. Twelve weeks later, cartilage lacuna could be observed. The cells arrangement and the amount of type II collagen both showed the same as the natural one. Complicated material of fibrin glue and DBM as scaffolds can be used as scaffolds for cartilage tissue engineering.

Safety and feasibility of platelet rich fibrin matrix injections for treatment of common urologic conditions

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Ethan L Matz

2018-01-01

Full Text Available Purpose: Autologous platelet rich plasma (PRP is used increasingly in a variety of settings. PRP injections have been used for decades to improve angiogenesis and wound healing. They have also been offered commercially in urology with little to no data on safety or efficacy. PRP could theoretically improve multiple urologic conditions, such as erectile dysfunction (ED, Peyronie's disease (PD, and stress urinary incontinence (SUI. A concern with PRP, however, is early washout, a situation potentially avoided by conversion to platelet rich fibrin matrix (PRFM. Before clinical trials can be performed, safety analysis is desirable. We reviewed an initial series of patients receiving PRFM for urologic pathology to assess safety and feasibility. Materials and Methods: Data were reviewed for patients treated with PRFM at our center from November 2012 to July 2017. Patients were observed immediately post-injection and at follow-up for complications and tolerability. Where applicable, International Index of Erectile Function (IIEF-5 scores were reviewed before and after injections for ED and/or PD. Pad use data was collected pre/post injection for SUI. Results: Seventeen patients were identified, with a mean receipt of 2.1 injections per patient. Post-procedural minor adverse events were seen in 3 men, consisting of mild pain at injection site and mild penile bruising. No patients experienced complications at follow-up. No decline was observed in men completing pre/post IIEF-5 evaluations. Conclusions: PRFM appears to be a safe and feasible treatment modality in patients with urologic disease. Further placebo-controlled trials are warranted.

Circulating Microparticles Alter Formation, Structure, and Properties of Fibrin Clots.

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Zubairova, Laily D; Nabiullina, Roza M; Nagaswami, Chandrasekaran; Zuev, Yuriy F; Mustafin, Ilshat G; Litvinov, Rustem I; Weisel, John W

2015-12-04

Despite the importance of circulating microparticles in haemostasis and thrombosis, there is limited evidence for potential causative effects of naturally produced cell-derived microparticles on fibrin clot formation and its properties. We studied the significance of blood microparticles for fibrin formation, structure, and susceptibility to fibrinolysis by removing them from platelet-free plasma using filtration. Clots made in platelet-free and microparticle-depleted plasma samples from the same healthy donors were analyzed in parallel. Microparticles accelerate fibrin polymerisation and support formation of more compact clots that resist internal and external fibrinolysis. These variations correlate with faster thrombin generation, suggesting thrombin-mediated kinetic effects of microparticles on fibrin formation, structure, and properties. In addition, clots formed in the presence of microparticles, unlike clots from the microparticle-depleted plasma, contain 0.1-0.5-μm size granular and CD61-positive material on fibres, suggesting that platelet-derived microparticles attach to fibrin. Therefore, the blood of healthy individuals contains functional microparticles at the levels that have a procoagulant potential. They affect the structure and stability of fibrin clots indirectly through acceleration of thrombin generation and through direct physical incorporation into the fibrin network. Both mechanisms underlie a potential role of microparticles in haemostasis and thrombosis as modulators of fibrin formation, structure, and resistance to fibrinolysis.

Fibrin Sealants in Dura Sealing: A Systematic Literature Review.

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Felice Esposito

Full Text Available Fibrin sealants are widely used in neurosurgery to seal the suture line, provide watertight closure, and prevent cerebrospinal fluid leaks. The aim of this systematic review is to summarize the current efficacy and safety literature of fibrin sealants in dura sealing and the prevention/treatment of cerebrospinal fluid leaks.A comprehensive electronic literature search was run in the following databases: Cochrane Database of Systematic Reviews, Cochrane Central Resister of Controlled Trials, clinicaltrials.gov, MEDLINE/PubMed, and EMBASE. Titles and abstracts of potential articles of interest were reviewed independently by 3 of the authors.A total of 1006 database records and additional records were identified. After screening for duplicates and relevance, a total of 78 articles were assessed by the investigators for eligibility. Thirty-eight were excluded and the full-text of 40 articles were included in the qualitative synthesis. Seven of these included only safety data and were included in the safety assessment. The remaining 33 articles included findings from 32 studies that enrolled a total of 2935 patients who were exposed to fibrin sealant. Among these 33 studies there were only 3 randomized controlled trials, with the remaining being prospective cohort analysis, case controlled studies, prospective or retrospective case series. One randomized controlled trial, with 89 patients exposed to fibrin sealant, found a greater rate of intraoperative watertight dura closure in the fibrin sealant group than the control group (92.1% versus 38.0%, p0.05. Other clinical trials evaluated the effect of fibrin sealant in the postoperative prevention of cerebrospinal fluid leaks. These were generally lower level evidence studies (ie, not prospective, randomized, controlled trials that were not designed or powered to demonstrate a significant advantage to fibrin sealant use. Two small case series studies evaluated the effect of fibrin sealants in

Introduction of a potent single-donor fibrin glue for vascular anastomosis: An animal study

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Mehdi Rasti Ardakani

2012-01-01

Full Text Available Background: Vascular anastomosis is considered as a difficult surgical procedure. Although different alternative methods have been tried to tackle these difficulties, none were found to be successful. Commercial fibrin glue has recently been used for vascular anastomosis. However, it did not gain popularity due to some limitations such as low tensile strength, rapid removal by the immune system, and risk of transmission of blood-borne viral infections. In this article, we presented a novel method for producing single-donor human fibrin glue and determined its success rate for vascular anastomosis in an animal model. Materials ans Methods : In this study, 3 mL of single-donor fibrin sealant was prepared from 150 mL of whole blood containing 50-70 mg/mL of fibrinogen. The study was performed on 10 dogs and 5 cats. After transection of the carotid artery, both ends were anastomosed by means of 3-4 sutures (Prolene 8-0. The suture line was then sealed with one layer of the new fibrin sealant. After 3-8 weeks, the site of anastomosis was evaluated angiographically and morphologically for healing and possible complications such as thrombosis or aneurysm. Results: In evaluations 3 weeks after the surgery, all arterial anastomoses were patent in dogs, but some degree of subintimal hyperplasia was noted. After 8 weeks, all anastomoses were patent and the degree of subintimal hyperplasia was decreased. In cats on the other hand, after 4 weeks, all anastomoses were patent and subintimal hyperplasia was absent. Conclusions: Single-donor fibrin glue was a quite reliable and practical alternative to minimize suturing and therefore operative time in our animal model. This sealant can easily be obtained from the patient′s whole blood. Its application in humans would require further studies.

Fibrin Gels Exhibit Improved Biological, Structural, and Mechanical Properties Compared with Collagen Gels in Cell-Based Tendon Tissue-Engineered Constructs

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Dyment, Nathaniel A.; Lu, Yinhui; Rao, Marepalli; Shearn, Jason T.; Rowe, David W.; Kadler, Karl E.; Butler, David L.

2015-01-01

The prevalence of tendon and ligament injuries and inadequacies of current treatments is driving the need for alternative strategies such as tissue engineering. Fibrin and collagen biopolymers have been popular materials for creating tissue-engineered constructs (TECs), as they exhibit advantages of biocompatibility and flexibility in construct design. Unfortunately, a few studies have directly compared these materials for tendon and ligament applications. Therefore, this study aims at determining how collagen versus fibrin hydrogels affect the biological, structural, and mechanical properties of TECs during formation in vitro. Our findings show that tendon and ligament progenitor cells seeded in fibrin constructs exhibit improved tenogenic gene expression patterns compared with their collagen-based counterparts for approximately 14 days in culture. Fibrin-based constructs also exhibit improved cell-derived collagen alignment, increased linear modulus (2.2-fold greater) compared with collagen-based constructs. Cyclic tensile loading, which promotes the maturation of tendon constructs in a previous work, exhibits a material-dependent effect in this study. Fibrin constructs show trending reductions in mechanical, biological, and structural properties, whereas collagen constructs only show improved tenogenic expression in the presence of mechanical stimulation. These findings highlight that components of the mechanical stimulus (e.g., strain amplitude or time of initiation) need to be tailored to the material and cell type. Given the improvements in tenogenic expression, extracellular matrix organization, and material properties during static culture, in vitro findings presented here suggest that fibrin-based constructs may be a more suitable alternative to collagen-based constructs for tissue-engineered tendon/ligament repair. PMID:25266738

Scaffold architecture and fibrin gels promote meniscal cell proliferation

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Pawelec, K. M., E-mail: pawelec.km@gmail.com, E-mail: jw626@cam.ac.uk; Best, S. M.; Cameron, R. E. [Cambridge Centre for Medical Materials, Materials Science and Metallurgy Department, University of Cambridge, Cambridge CB3 0FS (United Kingdom); Wardale, R. J., E-mail: pawelec.km@gmail.com, E-mail: jw626@cam.ac.uk [Division of Trauma and Orthopaedic Surgery, Department of Surgery, University of Cambridge, Cambridge CB2 2QQ (United Kingdom)

2015-01-01

Stability of the knee relies on the meniscus, a complex connective tissue with poor healing ability. Current meniscal tissue engineering is inadequate, as the signals for increasing meniscal cell proliferation have not been established. In this study, collagen scaffold structure, isotropic or aligned, and fibrin gel addition were tested. Metabolic activity was promoted by fibrin addition. Cellular proliferation, however, was significantly increased by both aligned architectures and fibrin addition. None of the constructs impaired collagen type I production or triggered adverse inflammatory responses. It was demonstrated that both fibrin gel addition and optimized scaffold architecture effectively promote meniscal cell proliferation.

USAGE OF MONOCLONAL ANTIBODIES FOR DETERMINATION OF LOCALIZATION OF ANTIGENIC DETERMINANTS AND FIBRIN POLYMERIZATION SITES WITHIN FIBRINOGEN AND FIBRIN MOLECULES AND THEIR APPLICATION IN TEST--SYSTEMS FOR DIAGNOSTICS AND THE THREAT OF THROMBUS FORMATION

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E. V. Lugovskoi

2013-08-01

Full Text Available It was shown by monoclonal antibodies that B?N-region of fibrin desA molecule (B?1-53 comprises the polymerization site including the peptide bond B?14-15. This site participates in the second stage of fibrin polymerization — lateral association of protofibrils. In the B?15-53 fragment was also found the site called «C», which together with the site «A» participate in the first stage of polymerization — the protofibrils formation. The model of the primary intermolecular interaction of fibrin was designed. It was found by monoclonal antibodies II-4d the site («c» in the N-terminal half of ? chain of the fibrin D-region. This site participates in the protofibrils formation and is complement to site «C» as we assume. We have discovered two neoantigenic determinants. One of these determinants exposes within the coiledcoil fragment B?126-135 of fibrin as a result of fibrinopeptide A splitting off from fibrinogen by thrombin. The structural rearrangements discovered in this site of the fibrin molecule are necessary for the following protofibrils lateral association. The second neoantigenic determinant is localized in the fragment B?134-190 of D-dimer formed after plasmin degradation of fibrin stabilized by FXIIIa. We have obtained the fibrin-specific monoclonal antibodie FnI-3C to the first determinant and D-dimer-specific mAb III-3b to the second one. Three monoclonal antibodies were obtained against the ?C-region of fibrin(ogen molecule. It has been experimentally shown by of one of them that ?C-domains is connected with the fibrinopeptides B in fibrinogen and fibrin desA molecules, but removes from the core of the molecules after fibrinopeptides B splitting off by thrombin. Two other monoclonal antibodies specifically inhibit the fibrin polymerization by blocking two unknown polymerization sites within the ?C-region. The test-systems for the soluble fibrin and D-dimer quantification in human blood plasma were designed on the basis of

Role of plasma-rich fibrin in oral surgery

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Kumar, K. Retna; Genmorgan, K.; Abdul Rahman, S. M.; Rajan, M. Alaguvel; Kumar, T. Arul; Prasad, V. Srinivas

2016-01-01

Platelet-rich fibrin (PRF) is a fibrin meshwork, in which platelet cytokines, growth factors, and cells are entrapped and discharged after a period and can serve as a resorbable film. PRF is the next generation of platelet concentrates equipped to improve arrangement without biochemical blood handling; PRF is an evolution of the fibrin adhesive, which is widely used in the oral surgery. The guidelines of this innovation depend on concentrating platelets and growth factors in a plasma medium, ...

Alginate nanobeads interspersed fibrin network as in situ forming hydrogel for soft tissue engineering.

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Deepthi, S; Jayakumar, R

2018-06-01

Hydrogels are a class of materials that has the property of injectability and in situ gel formation. This property of hydrogels is manipulated in this study to develop a biomimetic bioresorbable injectable system of alginate nanobeads interspersed in fibrin network. Alginate nanobeads developed by calcium cross-linking yielded a size of 200-500 nm. The alginate nanobeads fibrin hydrogel was formed using dual syringe apparatus. Characterization of the in situ injectable hydrogel was done by SEM, FTIR and Rheometer. The developed hydrogel showed mechanical strength of 19 kPa which provides the suitable compliance for soft tissue engineering. Cytocompatibility studies using human umbilical cord blood derived mesenchymal stem cells showed good attachment, proliferation and infiltration within the hydrogel similar to fibrin gel. The developed in situ forming hydrogel could be a suitable delivery carrier of stem cells for soft tissue regeneration.

A CCR2 macrophage endocytic pathway mediates extravascular fibrin clearance in vivo

DEFF Research Database (Denmark)

Motley, Michael P; Madsen, Daniel H; Jürgensen, Henrik J

2016-01-01

cellular endocytosis and lysosomal targeting, revealing a novel intracellular pathway for extravascular fibrin degradation. A C-C chemokine receptor type 2 (CCR2)-positive macrophage subpopulation constituted the majority of fibrin-uptaking cells. Consequently, cellular fibrin uptake was diminished...... by elimination of CCR2-expressing cells. The CCR2-positive macrophage subtype was different from collagen-internalizing M2-like macrophages. Cellular fibrin uptake was strictly dependent on plasminogen and plasminogen activator. Surprisingly, however, fibrin endocytosis was unimpeded by the absence of the fibrin...... subsets of macrophages employing distinct molecular pathways....

Bone induction by composites of bioresorbable carriers and demineralized bone in rats: a comparative study of fibrin-collagen paste, fibrin sealant, and polyorthoester with gentamicin

DEFF Research Database (Denmark)

Pinholt, E M; Solheim, E; Bang, G

1992-01-01

fibrin-collagen paste and fibrin sealant inhibited bone induction and produced a chronic inflammation; part of the fibrin-collagen paste was still present at 4 weeks. Polyorthoester with gentamicin was almost completely absorbed, induced minimal tissue reaction, and did not inhibit osteoinduction....

Fibrin-Targeted Magnetic Resonance Imaging Allows In Vivo Quantification of Thrombus Fibrin Content and Identifies Thrombi Amenable for Thrombolysis

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Jenkins, Julia; Modarai, Bijan; Wiethoff, Andrea J.; Phinikaridou, Alkystis; Grover, Steven P.; Patel, Ashish S.; Schaeffter, Tobias; Smith, Alberto; Botnar, Rene M.

2014-01-01

Objective Deep venous thrombosis is a major health problem. Thrombolytic therapies are effective in recanalizing the veins and preventing post-thrombotic complications, but there is no consensus on selection criteria. The aim of this study was to investigate a fibrin-specific MRI contrast agent (EP-2104R) for the accurate quantification of thrombus’ fibrin content in vivo and for the identification of thrombus suitable for thrombolysis. Approach and Results Venous thrombosis was induced in the inferior vena cava of 8- to 10-week-old male BALB/C mice and MRI performed 2, 4, 7, 10, 14, and 21 days later. Eighteen mice were scanned at each time point pre and 2 hours post injection of EP-2104R (8.0 μmol/kg) with 12 mice at each time point used to correlate fibrin contrast uptake with thrombus’ histological stage and fibrin content. Six mice at each time point were immediately subjected to intravascular thrombolytic therapy (10 mg/kg of tissue-type plasminogen activator). Mice were imaged to assess response to lytic therapy 24 hours after thrombolytic treatment. Two mice at each time point were scanned post injection of 0.2 mmol/kg of Gd-DTPA (gadolinium with diethylenetriaminepentacetate, Magnevist, Schering AG, Berlin, Germany) for control purpose. Contrast uptake was correlated positively with the fibrin content of the thrombus measured by Western blotting (R2=0.889; PThrombus relaxation rate (R1) post contrast and the change in visualized thrombus size on late gadolinium enhancement inversion recovery MRI pre–EP-2104R and post–EP-2104R injection were the best predictors for successful thrombolysis (area under the curve, 0.989 [95% confidence interval, 0.97–1.00] and 0.994 [95% confidence interval, 0.98–1.00] respectively). Conclusions MRI with a fibrin-specific contrast agent accurately estimates thrombus fibrin content in vivo and identifies thrombi that are amenable for thrombolysis. PMID:24723557

Fibrin network pattern changes of platelet-rich fibrin in young versus old age group of individuals: A cell block cytology study

OpenAIRE

Shravanthi Raghav Yajamanya; Anirban Chatterjee; Chaitanya Nischay Babu; Deepika Karunanithi

2016-01-01

Background: To evaluate variations in fibrin network patterns of the platelet-rich fibrin (PRF) in different age groups. Materials and Methods: Ninety-five patients were divided into three age groups: Group 1: (20?39 years); Group 2: (40?59 years); and Group 3: (60 years and above). PRF was prepared from blood samples of all patients and were subjected to cell block cytology method of histological analysis and slides were prepared to histologically assess the age-related changes in (i) fibrin...

Proliferation and differentiation of stem cells in contact with eluate from fibrin-rich plasma membrane

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Fernanda Gimenez de Souza

Full Text Available ABSTRACT Objective: To evaluate the ability of the eluate from fibrin-rich plasma (FRP membrane to induce proliferation and differentiation of isolated human adipose-derived stem cells (ASCs into chondrocytes. Method: FRP membranes were obtained by centrifugation of peripheral blood from two healthy donors, cut, and maintained in culture plate wells for 48 h to prepare the fibrin eluate. The SCATh were isolated from adipose tissue by collagenase digestion solution, and expanded in vitro. Cells were expanded and treated with DMEM-F12 culture, a commercial media for chondrogenic differentiation, and eluate from FRP membrane for three days, and labeled with BrdU for quantitative assessment of cell proliferation using the High-Content Operetta® imaging system. For the chondrogenic differentiation assay, the SCATh were grown in micromass for 21 days and stained with toluidine blue and aggrecan for qualitative evaluation by light microscopy. The statistical analysis was performed using ANOVA and Tukey's test. Results: There was a greater proliferation of cells treated with the eluate from FRP membrane compared to the other two treatments, where the ANOVA test showed significance (p < 0.001. The differentiation into chondrocytes was visualized by the presence of mucopolysaccharide in the matrix of the cells marked in blue toluidine and aggrecan. Conclusions: Treatment with eluate from FRP membrane stimulated cell proliferation and induced differentiation of the stem cells into chondrocytes, suggesting a potential application of FRP membranes in hyaline cartilage regeneration therapies.

Alginate nanobeads interspersed fibrin network as in situ forming hydrogel for soft tissue engineering

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S. Deepthi

2018-06-01

Full Text Available Hydrogels are a class of materials that has the property of injectability and in situ gel formation. This property of hydrogels is manipulated in this study to develop a biomimetic bioresorbable injectable system of alginate nanobeads interspersed in fibrin network. Alginate nanobeads developed by calcium cross-linking yielded a size of 200–500 nm. The alginate nanobeads fibrin hydrogel was formed using dual syringe apparatus. Characterization of the in situ injectable hydrogel was done by SEM, FTIR and Rheometer. The developed hydrogel showed mechanical strength of 19 kPa which provides the suitable compliance for soft tissue engineering. Cytocompatibility studies using human umbilical cord blood derived mesenchymal stem cells showed good attachment, proliferation and infiltration within the hydrogel similar to fibrin gel. The developed in situ forming hydrogel could be a suitable delivery carrier of stem cells for soft tissue regeneration.

Engineering fibrin hydrogels to promote the wound healing potential of mesenchymal stem cell spheroids.

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Murphy, Kaitlin C; Whitehead, Jacklyn; Zhou, Dejie; Ho, Steve S; Leach, J Kent

2017-12-01

Mesenchymal stem cells (MSCs) secrete endogenous factors such as vascular endothelial growth factor (VEGF) and prostaglandin E2 (PGE 2 ) that promote angiogenesis, modulate the inflammatory microenvironment, and stimulate wound repair, and MSC spheroids secrete more trophic factors than dissociated, individual MSCs. Compared to injection of cells alone, transplantation of MSCs in a biomaterial can enhance their wound healing potential by localizing cells at the defect site and upregulating trophic factor secretion. To capitalize on the therapeutic potential of spheroids, we engineered a fibrin gel delivery vehicle to simultaneously enhance the proangiogenic and anti-inflammatory potential of entrapped human MSC spheroids. We used multifactorial statistical analysis to determine the interaction between four input variables derived from fibrin gel synthesis on four output variables (gel stiffness, gel contraction, and secretion of VEGF and PGE 2 ). Manipulation of the four input variables tuned fibrin gel biophysical properties to promote the simultaneous secretion of VEGF and PGE 2 by entrapped MSC spheroids while maintaining overall gel integrity. MSC spheroids in stiffer gels secreted the most VEGF, while PGE 2 secretion was highest in more compliant gels. Simultaneous VEGF and PGE 2 secretion was greatest using hydrogels with intermediate mechanical properties, as small increases in stiffness increased VEGF secretion while maintaining PGE 2 secretion by entrapped spheroids. The fibrin gel formulation predicted to simultaneously increase VEGF and PGE 2 secretion stimulated endothelial cell proliferation, enhanced macrophage polarization, and promoted angiogenesis when used to treat a wounded three-dimensional human skin equivalent. These data demonstrate that a statistical approach is an effective strategy to formulate fibrin gel formulations that enhance the wound healing potential of human MSCs. Mesenchymal stem cells (MSCs) are under investigation for wound

Sequential changes in histologic pattern and extracellular matrix deposition during the healing of chronic venous ulcers.

OpenAIRE

Herrick, S. E.; Sloan, P.; McGurk, M.; Freak, L.; McCollum, C. N.; Ferguson, M. W.

1992-01-01

As part of a major clinical trial, sequential biopsies were taken from the margins of venous leg ulcers during their healing. The changing patterns of tissue architecture and extracellular matrix synthesis during healing were documented histologically and immunocytochemically. Initial biopsies were similar in appearance: prominent fibrin cuffs, variable inflammation, hemosiderin, and red blood cell extravasation. So called "fibrin cuffs" were highly organized structures composed of laminin, f...

Predictive factors for anterior chamber fibrin formation after vitreoretinal surgery

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Leonardo Provetti Cunha

2014-04-01

Full Text Available Purpose: The aim of this study was to investigate possible predictive factors related to anterior chamber fibrin formation after vitreoretinal surgery in a large series of patients. Methods: The data of 185 eyes of 185 patients submitted to vitreoretinal surgery was reviewed. The following variables were evaluated: the postoperatively presence of fibrin, age, diabetes mellitus, the vitrectomy system gauge (20, 23 or 25 gauge, the type of vitreous substitute, the influence of prior surgical procedures and the combination with cataract extraction. To evaluate predictive factors for anterior chamber fibrin formation, univariate analysis was performed. A multivariate stepwise logistic regression model was adjusted to investigate factors associated with fibrin formation (p<0.05. Results: Fibrinoid anterior chamber reaction was found in 12 (6.4% patients. For multivariate logistic regression analysis, balanced salt solution (BSS, the chance of fibrin occurrence was 5 times greater (odds ratio 4.83, CI 95% 1.302 - 17.892; p=0.019, while combination with phacoemulsification increased the chance of fibrin formation by 20 times (odds ratio 20, CI 95% 2.480 - 161.347; p=0.005. No significant difference was found regarding other variables. Conclusion: Anterior chamber fibrin formation is an unwanted complication after vitreoretinal surgery. Factors such as combined performance of phacoemulsification and the use of balanced salt solution as a vitreous substitute may predispose the occurrence of this complication.

Contaminating fibrin in CPD-blood: solubility in plasma and distribution in blood components following separation

International Nuclear Information System (INIS)

Skjonsberg, O.H.; Kierulf, P.; Gravem, K.; Fagerhol, M.K.; Godal, H.C.

1986-01-01

In order to estimate the solubility of contaminating fibrin in CPD-blood, thrombin induced fibrin polymerzation in CPD-plasma was examined by light scattering and fibrinopeptide A (FPA) determinations. In addition, I-125 fibrin monomer enriched CPD-blood was used to investigate fibrin monomer retention in blood bags and transfusion filters (170 microns) and fibrin distribution in blood components derived from CPD-blood. Initial fibrin polymerization in CPD-blood occurred after conversion of 15 per cent of the fibrinogen to fibrin, implying that substantial amounts of fibrin may be kept solubilized in CPD-blood bags. Only minor amounts of I-125 fibrin monomers were retained in blood bags (2.4 per cent) and in transfusion filters (2.9 per cent) after sham transfusions. After separating I-125-fibrin monomer enriched CPD-blood into its constituent components, the major part of fibrin (75.0 per cent) could be traced in the cryoprecipitate

Submillisecond elastic recoil reveals molecular origins of fibrin fiber mechanics.

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Hudson, Nathan E; Ding, Feng; Bucay, Igal; O'Brien, E Timothy; Gorkun, Oleg V; Superfine, Richard; Lord, Susan T; Dokholyan, Nikolay V; Falvo, Michael R

2013-06-18

Fibrin fibers form the structural scaffold of blood clots. Thus, their mechanical properties are of central importance to understanding hemostasis and thrombotic disease. Recent studies have revealed that fibrin fibers are elastomeric despite their high degree of molecular ordering. These results have inspired a variety of molecular models for fibrin's elasticity, ranging from reversible protein unfolding to rubber-like elasticity. An important property that has not been explored is the timescale of elastic recoil, a parameter that is critical for fibrin's mechanical function and places a temporal constraint on molecular models of fiber elasticity. Using high-frame-rate imaging and atomic force microscopy-based nanomanipulation, we measured the recoil dynamics of individual fibrin fibers and found that the recoil was orders of magnitude faster than anticipated from models involving protein refolding. We also performed steered discrete molecular-dynamics simulations to investigate the molecular origins of the observed recoil. Our results point to the unstructured αC regions of the otherwise structured fibrin molecule as being responsible for the elastic recoil of the fibers. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Platelet glycoprotein VI binds to polymerized fibrin and promotes thrombin generation.

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Mammadova-Bach, Elmina; Ollivier, Véronique; Loyau, Stéphane; Schaff, Mathieu; Dumont, Bénédicte; Favier, Rémi; Freyburger, Geneviève; Latger-Cannard, Véronique; Nieswandt, Bernhard; Gachet, Christian; Mangin, Pierre H; Jandrot-Perrus, Martine

2015-07-30

Fibrin, the coagulation end product, consolidates the platelet plug at sites of vascular injury and supports the recruitment of circulating platelets. In addition to integrin αIIbβ3, another as-yet-unidentified receptor is thought to mediate platelet interaction with fibrin. Platelet glycoprotein VI (GPVI) interacts with collagen and several other adhesive macromolecules. We evaluated the hypothesis that GPVI could be a functional platelet receptor for fibrin. Calibrated thrombin assays using platelet-rich plasma (PRP) showed that tissue factor-triggered thrombin generation was impaired in GPVI-deficient patients and reduced by the anti-GPVI Fab 9O12. Assays on reconstituted PRP and PRP from fibrinogen-deficient patients revealed a fibrinogen-dependent enhancement of thrombin generation, which relied on functional GPVI. The effect of GPVI was found to depend on fibrin polymerization. A binding assay showed a specific interaction between GPVI-Fc and fibrin, inhibited by the Fab 9O12. This Fab also reduced platelet adhesion to fibrin at low (300 s(-1)) and high (1500 s(-1)) wall shear rates. Platelets adherent to fibrin displayed shape change, exposure of procoagulant phospholipids, and the formation of small clots. When hirudinated blood was perfused at 1500 s(-1) over preformed fibrin-rich clots, the Fab 9O12 decreased the recruitment of platelets by up to 85%. This study identifies GPVI as a platelet receptor for polymerized fibrin with 2 major functions: (1) amplification of thrombin generation and (2) recruitment of circulating platelets to clots. These so-far-unrecognized properties of GPVI confer on it a key role in thrombus growth and stabilization. © 2015 by The American Society of Hematology.

Platelet-Rich Fibrin Lysate Can Ameliorate Dysfunction of Chronically UVA-Irradiated Human Dermal Fibroblasts.

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Wirohadidjojo, Yohanes Widodo; Budiyanto, Arief; Soebono, Hardyanto

2016-09-01

To determine whether platelet-rich fibrin lysate (PRF-L) could restore the function of chronically ultraviolet-A (UVA)-irradiated human dermal fibroblasts (HDFs), we isolated and sub-cultured HDFs from six different human foreskins. HDFs were divided into two groups: those that received chronic UVA irradiation (total dosages of 10 J cm⁻²) and those that were not irradiated. We compared the proliferation rates, collagen deposition, and migration rates between the groups and between chronically UVA-irradiated HDFs in control and PRF-L-treated media. Our experiment showed that chronic UVA irradiation significantly decreased (p<0.05) the proliferation rates, migration rates, and collagen deposition of HDFs, compared to controls. Compared to control media, chronically UVA-irradiated HDFs in 50% PRF-L had significantly increased proliferation rates, migration rates, and collagen deposition (p<0.05), and the migration rates and collagen deposition of chronically UVA-irradiated HDFs in 50% PRF-L were equal to those of normal fibroblasts. Based on this experiment, we concluded that PRF-L is a good candidate material for treating UVA-induced photoaging of skin, although the best method for its clinical application remains to be determined.

Microfluidic production of bioactive fibrin micro-beads embedded in crosslinked collagen used as an injectable bulking agent for urinary incontinence treatment.

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Vardar, E; Larsson, H M; Allazetta, S; Engelhardt, E M; Pinnagoda, K; Vythilingam, G; Hubbell, J A; Lutolf, M P; Frey, P

2018-02-01

Endoscopic injection of bulking agents has been widely used to treat urinary incontinence, often due to urethral sphincter complex insufficiency. The aim of the study was to develop a novel injectable bioactive collagen-fibrin bulking agent restoring long-term continence by functional muscle tissue regeneration. Fibrin micro-beads were engineered using a droplet microfluidic system. They had an average diameter of 140 μm and recombinant fibrin-binding insulin-like growth factor-1 (α 2 PI 1-8 -MMP-IGF-1) was covalently conjugated to the beads. A plasmin fibrin degradation assay showed that 72.5% of the initial amount of α 2 PI 1-8 -MMP-IGF-1 loaded into the micro-beads was retained within the fibrin micro-beads. In vitro, the growth factor modified fibrin micro-beads enhanced cell attachment and the migration of human urinary tract smooth muscle cells, however, no change of the cellular metabolic activity was seen. These bioactive micro-beads were mixed with genipin-crosslinked homogenized collagen, acting as a carrier. The collagen concentration, the degree of crosslinking, and the mechanical behavior of this bioactive collagen-fibrin injectable were comparable to reference samples. This novel injectable showed no burst release of the growth factor, had a positive effect on cell behavior and may therefore induce smooth muscle regeneration in vivo, necessary for the functional treatment of stress and other urinary incontinences. Urinary incontinence is involuntary urine leakage, resulting from a deficient function of the sphincter muscle complex. Yet there is no functional cure for this devastating condition using current treatment options. Applied physical and surgical therapies have limited success. In this study, a novel bioactive injectable bulking agent, triggering new muscle regeneration at the injection site, has been evaluated. This injectable consists of cross-linked collagen and fibrin micro-beads, functionalized with bound insulin-like growth factor

Protective fibrin-sealed plication of the small bowel in recurrent laparotomy.

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Holland-Cunz, S; Boelter, A V; Waag, K L

2003-09-01

Adhesions after recurrent abdominal operations remain extremely common and are sources of severe morbidity. Fibrin-glued plication of the small gut in a meander-like formation is supposed to guarantee a decreased risk of intestinal obstruction postoperatively. This retrospective study analyses the clinical outcome after recurrent laparotomy in children treated with bowel plication by fibrin sealant. The surgical technique of performing the fibrin-glued plication is rather simple and quick: after taking off all adhesions two to four loops of the small gut are positioned so that they lie side by side. Beginning proximal fibrin [Tissucol fibrin sealant (Baxter)] is applied between the loops; approximately 20-30 s are needed to keep the loops in position until the fibrin dries. This manoeuvre is continued until all of the small gut is fixed in one block. The gut is brought back into the abdominal cavity without loosening the loops. This fixed formation by sero-serosal adhesions or mesenterial plications is supposed to guarantee postoperative free passage. The charts of 60 children who had undergone a fibrin plication of the small bowel between 1991 and 1999 were evaluated. Additionally, questionnaires were sent to all patients, and they were invited for an examination. Sixty patients (38 boys and 22 girls) received a fibrin sealant plication because of recurrent laparotomies with heavily serosal defects or recurrent ileus because of adhesions. The youngest baby was 10 days. Since 23 patients were premature the oldest patient was 11 years old. There were no intraoperative complications attributed to the method. In the postoperative period 7/60 (12%) patients had a recurrent ileus or subileus, leading in three (5%) patients to an early relaparotomy. The fibrin-glued plication of the small bowel decreases the risk of recurrent ileus or subileus considering the high figures in the literature concerning this issue. The time-saving method is very simple and easily feasible

The disulfide isomerase ERp57 is required for fibrin deposition in vivo.

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Zhou, J; Wu, Y; Wang, L; Rauova, L; Hayes, V M; Poncz, M; Essex, D W

2014-11-01

ERp57 is required for platelet function; however, whether ERp57 contributes to fibrin generation is unknown. Using an inhibitory anti-ERp57 antibody (mAb1), Pf4-Cre/ERp57(fl/fl) mice, Tie2-Cre/ERp57(fl/fl) mice, and mutants of ERp57, we analyzed the function of ERp57 in laser-induced thrombosis. Fibrin deposition was decreased in Pf4-Cre/ERp57(fl/fl) mice, consistent with a role for platelet ERp57 in fibrin generation. Fibrin deposition was further decreased with infusion of mAb1 and in Tie2-Cre/ERp57(fl/fl) mice, consistent with endothelial cells also contributing to fibrin deposition. Infusion of eptibifatide inhibited platelet and fibrin deposition, confirming a role for platelets in fibrin deposition. Infusion of recombinant ERp57 corrected the defect in fibrin deposition but not platelet accumulation, suggesting a direct effect of ERp57 on coagulation. mAb1 inhibited thrombin generation in vitro, consistent with a requirement for ERp57 in coagulation. Platelet accumulation was decreased to similar extents in Pf4-Cre/ERp57(fl/fl) mice, Tie2-Cre/ERp57(fl/fl) mice and normal mice infused with mAb1. Infusion of completely inactivated ERp57 or ERp57 with a non-functional second active site inhibited fibrin deposition and platelet accumulation, indicating that the isomerase activity of the second active site is required for these processes. ERp57 regulates thrombosis via multiple targets. © 2014 International Society on Thrombosis and Haemostasis.

Reticuloendothelial hyperphagocytosis occurs in streptozotocin-diabetic rats. Studies with colloidal carbon, albumin microaggregates, and soluble fibrin monomers

International Nuclear Information System (INIS)

Cornell, R.P.

1982-01-01

In contrast to previous studies of diabetic humans and animals, which reported unchanged or depressed function, reticuloendothelial system (RES) hyperphagocytosis of colloidal carbon, 125 I-albumin microaggregates, and 125 I-fibrin monomers were observed in rats as early as 14 days after the induction of diabetes with streptozotocin (STZ). The fact that enhanced phagocytosis by RE macrophages was prevented by chronic insulin replacement therapy indicates that the diabetic internal environment of hyperglycemia and hypoinsulinemia was perhaps responsible for the observed changes. Experiments involving organ localization of intravenously administered particles, perfusion of isolated livers, and microscopic examination of the liver all suggested that increased Kupffer cell activity was the primary event in RES hyperphagocytosis by STZ-diabetic rats. Both hypertrophy and hyperplasia of Kupffer cells were apparent in livers of STZ-diabetic animals as evidenced by photomicrographs and hepatic cell quantification. Plasma fibronectin, which binds fibrin monomers to RE macrophages before phagocytosis, was significantly decreased in the circulation of STZ-diabetic rats, but the level of cell-associated fibronectin was not measured. Renal localization of urea-soluble 125 I-fibrin monomers exceeded splenic and pulmonary uptake in normal control rats and was enhanced in animals with STZ-diabetes. Changes in fibronectin levels, fibrin monomer localization, and Kupffer cell size and numbers in experimental diabetes in rats may have implications for the pathogenesis of vascular disease involving phagocytic mesangial and foam cells in diabetic humans

Reticuloendothelial hyperphagocytosis occurs in streptozotocin-diabetic rats. Studies with colloidal carbon, albumin microaggregates, and soluble fibrin monomers.

Science.gov (United States)

Cornell, R P

1982-02-01

In contrast to previous studies of diabetic humans and animals, which reported unchanged or depressed function, reticuloendothelial system (RES) hyperphagocytosis of colloidal carbon, 125I-albumin microaggregates, and 125I-fibrin monomers were observed in rats as early as 14 days after the induction of diabetes with streptozotocin (STZ). The fact that enhanced phagocytosis by RE macrophages was prevented by chronic insulin replacement therapy indicates that the diabetic internal environment of hyperglycemia and hypoinsulinemia was perhaps responsible for the observed changes. Experiments involving organ localization of intravenously administered particles, perfusion of isolated livers, and microscopic examination of the liver all suggested that increased Kupffer cell activity was the primary event in RES hyperphagocytosis by STZ-diabetic rats. Both hypertrophy and hyperplasia of Kupffer cells were apparent in livers of STZ-diabetic animals as evidenced by photomicrographs and hepatic cell quantification. Plasma fibronectin, which binds fibrin monomers to RE macrophages before phagocytosis, was significantly decreased in the circulation of STZ-diabetic rats, but the level of cell-associated fibronectin was not measured. Renal localization of urea-soluble 125I-fibrin monomers exceeded splenic and pulmonary uptake in normal control rats and was enhanced in animals with STZ-diabetes. Changes in fibronectin levels, fibrin monomer localization, and Kupffer cell size and numbers in experimental diabetes in rats may have implications for the pathogenesis of vascular disease involving phagocytic mesangial and foam cells in diabetic humans.

Platelet-rich fibrin prepared from stored whole-blood samples.

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Isobe, Kazushige; Suzuki, Masashi; Watanabe, Taisuke; Kitamura, Yutaka; Suzuki, Taiji; Kawabata, Hideo; Nakamura, Masayuki; Okudera, Toshimitsu; Okudera, Hajime; Uematsu, Kohya; Nakata, Koh; Tanaka, Takaaki; Kawase, Tomoyuki

2017-12-01

In regenerative therapy, self-clotted platelet concentrates, such as platelet-rich fibrin (PRF), are generally prepared on-site and are immediately used for treatment. If blood samples or prepared clots can be preserved for several days, their clinical applicability will expand. Here, we prepared PRF from stored whole-blood samples and examined their characteristics. Blood samples were collected from non-smoking, healthy male donors (aged 27-67 years, N = 6), and PRF clots were prepared immediately or after storage for 1-2 days. Fibrin fiber was examined by scanning electron microscopy. Bioactivity was evaluated by means of a bioassay system involving human periosteal cells, whereas PDGF-BB concentrations were determined by an enzyme-linked immunosorbent assay. Addition of optimal amounts of a 10% CaCl 2 solution restored the coagulative ability of whole-blood samples that contained an anticoagulant (acid citrate dextrose) and were stored for up to 2 days at ambient temperature. In PRF clots prepared from the stored whole-blood samples, the thickness and cross-links of fibrin fibers were almost identical to those of freshly prepared PRF clots. PDGF-BB concentrations in the PRF extract were significantly lower in stored whole-blood samples than in fresh samples; however, both extracts had similar stimulatory effects on periosteal-cell proliferation. Quality of PRF clots prepared from stored whole-blood samples is not reduced significantly and can be ensured for use in regenerative therapy. Therefore, the proposed method enables a more flexible treatment schedule and choice of a more suitable platelet concentrate immediately before treatment, not after blood collection.

Evaluation of gold nanotracers to track adipose-derived stem cells in a PEGylated fibrin gel for dermal tissue engineering applications

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Chung E

2013-01-01

Full Text Available Eunna Chung,1 Seung Yun Nam,1,2 Laura M Ricles,1 Stanislav Y Emelianov,1,2 Laura J Suggs11Department of Biomedical Engineering, 2Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX, USAAbstract: Evaluating the regenerative capacity of a tissue-engineered device in a noninvasive and synchronous manner is critical to determining the mechanisms for success in clinical applications. In particular, directly tracking implanted cells in a three-dimensional (3D scaffold is desirable in that it enables the monitoring of cellular activity in a specific and localized manner. The authors' group has previously demonstrated that the PEGylation of fibrin results in a 3D scaffold that supports morphologic and phenotypic changes in mesenchymal stem cells that may be advantageous in wound healing applications. Recently, the authors have evaluated adipose-derived stem cells (ASCs as a mesenchymal cell source to regenerate skin and blood vessels due to their potential for proliferation, differentiation, and production of growth factors. However, tracking and monitoring ASCs in a 3D scaffold, such as a PEGylated fibrin gel, have not yet been fully investigated. In the current paper, nanoscale gold spheres (20 nm as cell tracers for ASCs cultured in a PEGylated fibrin gel were evaluated. An advanced dual-imaging modality combining ultrasound and photoacoustic imaging was utilized to monitor rat ASCs over time. The ASCs took up gold nanotracers and could be detected up to day 16 with high sensitivity using photoacoustic imaging. There were no detrimental effects on ASC morphology, network formation, proliferation, and protein expression/secretion (ie, smooth muscle α-actin, vascular endothelial growth factor, matrix metalloproteinase-2, and matrix metalloproteinase-9 associated with gold nanotracers. Therefore, utilization of gold nanotracers can be an effective strategy to monitor the regenerative process of a stem cell

Scaffold-assisted cartilage tissue engineering using infant chondrocytes from human hip cartilage.

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Kreuz, P C; Gentili, C; Samans, B; Martinelli, D; Krüger, J P; Mittelmeier, W; Endres, M; Cancedda, R; Kaps, C

2013-12-01

Studies about cartilage repair in the hip and infant chondrocytes are rare. The aim of our study was to evaluate the use of infant articular hip chondrocytes for tissue engineering of scaffold-assisted cartilage grafts. Hip cartilage was obtained from five human donors (age 1-10 years). Expanded chondrocytes were cultured in polyglycolic acid (PGA)-fibrin scaffolds. De- and re-differentiation of chondrocytes were assessed by histological staining and gene expression analysis of typical chondrocytic marker genes. In vivo, cartilage matrix formation was assessed by histology after subcutaneous transplantation of chondrocyte-seeded PGA-fibrin scaffolds in immunocompromised mice. The donor tissue was heterogenous showing differentiated articular cartilage and non-differentiated tissue and considerable expression of type I and II collagens. Gene expression analysis showed repression of typical chondrocyte and/or mesenchymal marker genes during cell expansion, while markers were re-induced when expanded cells were cultured in PGA-fibrin scaffolds. Cartilage formation after subcutaneous transplantation of chondrocyte loaded PGA-fibrin scaffolds in nude mice was variable, with grafts showing resorption and host cell infiltration or formation of hyaline cartilage rich in type II collagen. Addition of human platelet rich plasma (PRP) to cartilage grafts resulted robustly in formation of hyaline-like cartilage that showed type II collagen and regions with type X collagen. These results suggest that culture of expanded and/or de-differentiated infant hip cartilage cells in PGA-fibrin scaffolds initiates chondrocyte re-differentiation. The heterogenous donor tissue containing immature chondrocytes bears the risk of cartilage repair failure in vivo, which may be possibly overcome by the addition of PRP. Copyright © 2013 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Injectable alginate-O-carboxymethyl chitosan/nano fibrin composite hydrogels for adipose tissue engineering.

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Jaikumar, Dhanya; Sajesh, K M; Soumya, S; Nimal, T R; Chennazhi, K P; Nair, Shantikumar V; Jayakumar, R

2015-03-01

Injectable, biodegradable scaffolds are required for soft tissue reconstruction owing to its minimally invasive approach. Such a scaffold can mimic the native extracellular matrix (ECM), provide uniform distribution of cells and overcome limitations like donor site morbidity, volume loss, etc. So, here we report two classes of biocompatible and biodegradable hydrogel blend systems namely, Alginate/O-carboxymethyl chitosan (O-CMC) and Alginate/poly (vinyl alcohol) (PVA) with the inclusion of fibrin nanoparticles in each. The hydrogels were prepared by ionic cross-linking method. The developed hydrogels were compared in terms of its swelling ratio, degradation profile, compressive strength and elastic moduli. From these preliminary findings, it was concluded that Alginate/O-CMC formed a better blend for tissue engineering applications. The potential of the formed hydrogel as an injectable scaffold was revealed by the survival of adipose derived stem cells (ADSCs) on the scaffold by its adhesion, proliferation and differentiation into adipocytes. Cell differentiation studies of fibrin incorporated hydrogel scaffolds showed better differentiation was confirmed by Oil Red O staining technique. These injectable gels have potential in soft tissue regeneration. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of Fibrin-Based Interpenetrating Polymer Networks as Potential Biomaterials for Tissue Engineering

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Olfat Gsib

2017-12-01

Full Text Available Interpenetrating polymer networks (IPNs have gained great attention for a number of biomedical applications due to their improved properties compared to individual components alone. In this study, we investigated the capacity of newly-developed naturally-derived IPNs as potential biomaterials for tissue engineering. These IPNs combine the biologic properties of a fibrous fibrin network polymerized at the nanoscale and the mechanical stability of polyethylene oxide (PEO. First, we assessed their cytotoxicity in vitro on L929 fibroblasts. We further evaluated their biocompatibility ex vivo with a chick embryo organotypic culture model. Subcutaneous implantations of the matrices were subsequently conducted on nude mice to investigate their biocompatibility in vivo. Our preliminary data highlighted that our biomaterials were non-cytotoxic (viability above 90%. The organotypic culture showed that the IPN matrices induced higher cell adhesion (across all the explanted organ tissues and migration (skin, intestine than the control groups, suggesting the advantages of using a biomimetic, yet mechanically-reinforced IPN-based matrix. We observed no major inflammatory response up to 12 weeks post implantation. All together, these data suggest that these fibrin-based IPNs are promising biomaterials for tissue engineering.

Fibrin glue in ophthalmology

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Panda Anita

2009-01-01

Full Text Available Suturing is a time consuming task in ophthalmology and suture induced irritation and redness are frequent problems. Postoperative wound infection and corneal graft rejection are examples of possible suture related complications. To prevent these complications, ophthalmic surgeons are switching to sutureless surgery. A number of recent developments have established tissue adhesives like cyanoacrylate glue and fibrin glue as attractive alternatives to sutures. A possible and promising new application for tissue adhesives is to provide a platform for tissue engineering. Currently, tissue glue is being used for conjunctival closure following pterygium and strabismus surgery, forniceal reconstruction surgery, amniotic membrane transplantation, lamellar corneal grafting, closure of corneal perforations and descematoceles, management of conjunctival wound leaks after trabeculectomy, lid surgery, adnexal surgery and as a hemostat to minimise bleeding. The purpose of this review is to discuss the currently available information on fibrin glue.

Wound healing and degradation of the fibrin sealant Beriplast P following partial liver resection in rabbits.

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Kroez, Monika; Lang, Wiegand; Dickneite, Gerhard

2005-01-01

The objective of this study was to investigate the degradation kinetics of the fibrin sealant (FS) Beriplast P in an experimental liver surgery model in rabbits. A partial liver resection was performed in 21 rabbits, and the wound area covered with Beriplast P to ensure hemostasis. Wound healing of the resection sites was evaluated morphologically over 11 weeks. Degradation of the FS was evaluated by measuring the thickness of the remaining fibrin layer. Plasma samples were analyzed for antibodies against fibrinogen, albumin, thrombin, fibrin, and factor XIII. No postoperative hemorrhage was observed, indicating successful hemostasis throughout. The FS was degraded with a half-life of about 25 days postapplication and was completely replaced by granulation tissue within 9 weeks. The FS degradation and tissue development followed the general stages of wound healing: inflammation and resorption, proliferation, organization and production of collagen, maturation, and scarring. An immune reaction was elicited against the main four human proteins of the FS. The antibody titers peaked on day 14, with a gradual decrease thereafter. We conclude that the FS accomplished hemostasis, facilitated healing in accordance with natural processes, and was completely degraded over time. In humans, the reduced immunogenicity of the FS would potentially increase its degradation half-life.

Growth of hydroxyapatite on physiologically clotted fibrin capped gold nanoparticles

International Nuclear Information System (INIS)

Sastry, T P; Sundaraseelan, J; Swarnalatha, K; Sobhana, S S Liji; Makheswari, M Uma; Sekar, S; Mandal, A B

2008-01-01

The growth of hydroxyapatite (HAp) on physiologically clotted fibrin (PCF)-gold nanoparticles is presented for the first time by employing a wet precipitation method. Fourier transform infrared (FTIR) spectroscopy confirmed the characteristic functionalities of PCF and HAp in the PCF-Au-HAp nanocomposite. Scanning electron microscopy (SEM) images have shown cuboidal nanostructures having a size in the range of 70-300 nm of HAp, whereas 2-50 nm sized particles were visualized in high-resolution transmission electron microscopy (TEM). Energy-dispersive x-ray (EDX) and x-ray diffraction (XRD) studies have confirmed the presence of HAp. These results show that gold nanoparticles with PCF acted as a matrix for the growth of HAp, and that PCF-Au-HAp nanocomposite is expected to have better osteoinductive properties

Fibrin structural and diffusional analysis suggests that fibers are permeable to solute transport.

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Leonidakis, Kimon Alexandros; Bhattacharya, Pinaki; Patterson, Jennifer; Vos, Bart E; Koenderink, Gijsje H; Vermant, Jan; Lambrechts, Dennis; Roeffaers, Maarten; Van Oosterwyck, Hans

2017-01-01

Fibrin hydrogels are promising carrier materials in tissue engineering. They are biocompatible and easy to prepare, they can bind growth factors and they can be prepared from a patient's own blood. While fibrin structure and mechanics have been extensively studied, not much is known about the relation between structure and diffusivity of solutes within the network. This is particularly relevant for solutes with a size similar to that of growth factors. A novel methodological approach has been used in this study to retrieve quantitative structural characteristics of fibrin hydrogels, by combining two complementary techniques, namely confocal fluorescence microscopy with a fiber extraction algorithm and turbidity measurements. Bulk rheological measurements were conducted to determine the impact of fibrin hydrogel structure on mechanical properties. From these measurements it can be concluded that variations in the fibrin hydrogel structure have a large impact on the rheological response of the hydrogels (up to two orders of magnitude difference in storage modulus) but only a moderate influence on the diffusivity of dextran solutes (up to 25% difference). By analyzing the diffusivity measurements by means of the Ogston diffusion model we further provide evidence that individual fibrin fibers can be semi-permeable to solute transport, depending on the average distance between individual protofibrils. This can be important for reducing mass transport limitations, for modulating fibrinolysis and for growth factor binding, which are all relevant for tissue engineering. Fibrin is a natural biopolymer that has drawn much interest as a biomimetic carrier in tissue engineering applications. We hereby use a novel combined approach for the structural characterization of fibrin networks based on optical microscopy and light scattering methods that can also be applied to other fibrillar hydrogels, like collagen. Furthermore, our findings on the relation between solute transport

The provisional matrix: setting the stage for tissue repair outcomes.

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Barker, Thomas H; Engler, Adam J

2017-07-01

Since its conceptualization in the 1980s, the provisional matrix has often been characterized as a simple fibrin-containing scaffold for wound healing that supports the nascent blood clot and is functionally distinct from the basement membrane. However subsequent advances have shown that this matrix is far from passive, with distinct compositional differences as the wound matures, and providing an active role for wound remodeling. Here we review the stages of this matrix, provide an update on the state of our understanding of provisional matrix, and present some of the outstanding issues related to the provisional matrix, its components, and their assembly and use in vivo. Copyright © 2017. Published by Elsevier B.V.

Novel use of platelet-rich fibrin matrix and MTA as an apical barrier in the management of a failed revascularization case.

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Yadav, Pankaj; Pruthi, Preeti Jain; Naval, Ruchika Roongta; Talwar, Sangeeta; Verma, Mahesh

2015-08-01

We report management of a failed revascularization/revitalization case, which could be due to inadequate removal of biofilm and bacteria in dentinal tubules. The use of an apical matrix barrier in form of a platelet-rich fibrin (PRF) membrane for stabilization of MTA in root end apexification procedure is described. The canal was cleansed of old MTA present in the cervical third using H files, irrigated using saline and finally irrigated with 2.5% NaOCl and saline. To obtain canal disinfection, calcium hydroxide paste was temporized in the canal. In subsequent appointments, PRF was placed at the root tip followed by 5-mm apical plug with mineral trioxide aggregate. One week later, the root canal was obturated with thermoplasticized gutta-percha. A 6-month and a 2-year follow ups showed reduction of periapical radiolucency and adequately functional tooth. One-visit apexification techniques provide an alternative treatment for failed revascularization cases. Follow up confirmed complete healing periradicularly. Apexification in one step using an apical barrier of PRF and a plug of MTA can be considered a predictable treatment and may be an alternative to long-term revascularization failures. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Anti-fibrin antibody binding in valvular vegetations and kidney lesions during experimental endocarditis.

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Yokota, M; Basi, D L; Herzberg, M C; Meyer, M W

2001-01-01

In Streptococcus sanguinis (sanguis) induced experimental endocarditis, we sought evidence that the development of aortic valvular vegetation depends on the availability of fibrin. Endocarditis was induced in New Zealand white rabbits by catheter placement into the left ventricle and inoculation of the bacteria. Fibrin was localized in the developing vegetation with 99mTechnetium (Tc)-labeled anti-fibrin antibody one or three days later. When rabbit anti-fibrin antibody was given intravenously on day 1, the mass of aortic valvular vegetation was significantly reduced at day 3; infusion of non-specific rabbit IgG showed no effect. The 99mTc-labeled anti-fibrin antibody also labeled kidneys that showed macroscopic subcapsular hemorrhage. To learn if the deposition of fibrin in the kidneys was a consequence of endocarditis required a comparison of farm-bred and specific pathogen-free rabbits before and after the induction of endocarditis. Before induction, the kidneys of farm-bred rabbits were labeled, but specific pathogen-free rabbits were free of labeling and signs of macroscopic hemorrhage. After 3 days of endocarditis, kidneys of 10 of 14 specific pathogen-free rabbits labeled with 99mTc-labeled anti-fibrin antibody and showed hemorrhage. Kidney lesions were suggested to be a frequent sequellae of S. sanguinis infective endocarditis. For the first time, fibrin was shown to be required for the continued development of aortic valvular vegetations.

Retina tissue engineering by conjunctiva mesenchymal stem cells encapsulated in fibrin gel: Hypotheses on novel approach to retinal diseases treatment.

Science.gov (United States)

Soleimannejad, Mostafa; Ebrahimi-Barough, Somayeh; Nadri, Samad; Riazi-Esfahani, Mohammad; Soleimani, Masoud; Tavangar, Seyed Mohammad; Ai, Jafar

2017-04-01

Retinitis pigmentosa (RP) and age related macular degeneration (AMD) are two retinal diseases that progress by photoreceptor cells death. In retinal transplantation studies, stem and progenitor cells inject into the sub retinal space or vitreous and then these cells can be migrate to the site of retinal degeneration and locate in the host retina and restitute vision. Our hypothesis suggests that using human conjunctiva stem cells (as the source for increasing the number of human stem cells progenitor cells in retina dysfunction diseases) with fibrin gel and also assessing its relating in vitro (cellular and molecular processes) and in vivo (vision tests and pathology) could be a promising strategy for treatment of AMD and RP disorders. In this idea, we describe a novel approach for retina tissue engineering with differentiation of conjunctiva mesenchymal stem cells (CJMSCs) into photoreceptor-like cells in fibrin gel with induction medium contain taurine. For assessment of differentiation, immunocytochemistry and real time PCR are used for the expression of Rhodopsin, RPE65, Nestin as differentiated photoreceptor cell markers in 2D and 3D culture. The results show that fibrin gel will offer a proper 3D scaffold for CJMSCs derived photoreceptor cell-like cells. Application of immune-privileged, readily available sources of adult stem cells like human conjunctiva stem cells with fibrin gel would be a promising strategy to increase the number of photoreceptor progenitor cells and promote involuntary angiogenesis needed in retina layer repair and regeneration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Identification of quantitative trait loci for fibrin clot phenotypes: the EuroCLOT study

DEFF Research Database (Denmark)

Williams, Frances M K; Carter, Angela M; Kato, Bernet

2009-01-01

OBJECTIVE: Fibrin makes up the structural basis of an occlusive arterial thrombus, and variability in fibrin phenotype relates to cardiovascular risk. The aims of the current study from the EU consortium EuroCLOT were to (1) determine the heritability of fibrin phenotypes and (2) identify QTLs as...

The combination use of platelet-rich fibrin and treated dentin matrix for tooth root regeneration by cell homing.

Science.gov (United States)

Ji, Baohui; Sheng, Lei; Chen, Gang; Guo, Shujuan; Xie, Li; Yang, Bo; Guo, Weihua; Tian, Weidong

2015-01-01

Endogenous regeneration through cell homing provides an alternative approach for tissue regeneration, except cell transplantation, especially considering clinical translation. However, tooth root regeneration through cell homing remains a provocative approach in need of intensive study. Both platelet-rich fibrin (PRF) and treated dentin matrix (TDM) are warehouses of various growth factors, which can promote cell homing. We hypothesized that endogenous stem cells are able to sense biological cues from PRF membrane and TDM, and contribute to the regeneration of tooth root, including soft and hard periodontal tissues. Therefore, the biological effects of canine PRF and TDM on periodontal ligament stem cells (PDLSCs) and bone marrow mesenchymal stem cells (BMSCs) were evaluated respectively in vitro. Beagle dogs were used as orthotopic transplantation model. It was found that PRF significantly recruited and stimulated the proliferation of PDLSCs and BMSCs in vitro. Together, PRF and TDM induced cell differentiation by upregulating the mineralization-related gene expression of bone sialoprotein (BSP) and osteopotin (OPN) after 7 days coculture. In vivo, transplantation of autologous PRF and allogeneic TDM into fresh tooth extraction socket achieved successful root regeneration 3 months postsurgery, characterized by the regeneration of cementum and periodontal ligament (PDL)-like tissues with orientated fibers, indicative of functional restoration. The results suggest that tooth root connected to the alveolar bone by cementum-PDL complex can be regenerated through the implantation of PRF and TDM in a tooth socket microenvironment, probably by homing of BMSCs and PDLSCs. Furthermore, bioactive cues and inductive microenvironment are key factors for endogenous regeneration. This approach provides a tangible pathway toward clinical translation.

Comparison of bioengineered human bone construct from four sources of osteogenic cells.

Science.gov (United States)

Ng, Angela Min-Hwei; Saim, Aminuddin Bin; Tan, Kok-Keong; Tan, G H; Mokhtar, Sabarul Afian; Rose, Isa Mohamed; Othman, Fauziah; Idrus, Ruszymah Binti Haji

2005-01-01

Osteoprogenitor cells have been reported to be present in periosteum, cancellous and cortical bone, and bone marrow; but no attempt to identify the best cell source for bone tissue engineering has yet been reported. In this study, we aimed to investigate the growth and differentiation pattern of cells derived from these four sources in terms of cell doubling time and expression of osteoblast-specific markers in both monolayer cells and three-dimensional cell constructs in vitro. In parallel, human plasma derived-fibrin was evaluated for use as biomaterial when forming three-dimensional bone constructs. Our findings showed osteoprogenitor cells derived from periosteum to be most proliferative followed by cortical bone, cancellous bone, and then bone marrow aspirate. Bone-forming activity was observed in constructs formed with cells derived from periosteum, whereas calcium deposition was seen throughout the constructs formed with cells derived from cancellous and cortical bones. Although no mineralization activity was seen in constructs formed with osteoprogenitor cells derived from bone marrow, well-organized lacunae as would appear in the early phase of bone reconstruction were noted. Scanning electron microscopy evaluation showed cell proliferation throughout the fibrin matrix, suggesting the possible application of human fibrin as the bioengineered tissue scaffold at non-load-bearing sites.

Fibrin glue as agent for sealing corneal and conjunctival wound leaks.

Science.gov (United States)

Scalcione, C; Ortiz-Vaquerizas, D; Said, D G; Dua, H S

2018-02-01

PurposeTo describe a novel use of fibrin glue in managing leaking blebs and leaking wounds following trauma or surgery.MethodsInterventional case series.ResultsWe report eight patients, including three where intra-operative or immediate post-penetrating keratoplasty recalcitrant leaks from the graft-host junction and/or openings created by the needle pass, were noted. All three had thin recipient beds in the sector of leak. This was managed by intra-cameral injection of fibrin glue in the affected quadrant. This stopped the leak and allowed the defect to heal. One patient of Descemets-stripping-endothelial-keratoplasty had leak from the surgical wound, which was also sealed with fibrin glue. Two patients with leaking glaucoma-surgery-related blebs were treated with intra-bleb injection of fibrin glue to stop the leak. One patient with a penetrating corneal injury with a metal wire had a brisk leak upon removal of the wire. This was sealed with fibrin glue. Another patient of chemical burn with spontaneous leaks was managed by glue injection in the perforations. Transient rise of intraocular pressure in one patient with a leaking bleb was the only adverse event recorded.ConclusionThis novel adaptation of the application of fibrin glue can help to deal with persistent intra-operative, post-operative and traumatic aqueous and air leaks.

Tensile strength of biological fibrin sealants: a comparative study.

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Lacaze, Laurence; Le Dem, Nicolas; Bubenheim, Michael; Tsilividis, Basile; Mezghani, Julien; Schwartz, Lilian; Francois, Arnaud; Ertaud, Jean Yves; Bagot d'Arc, Maurice; Scotté, Michel

2012-08-01

Fibrin sealants are commonly used in liver surgery, although their effectiveness in routine clinical practice remains controversial. Individual sealant characteristics are based on hemostatic effects and adhesion properties that can be experimentally measured using the 'rat skin test' or the 'pig skin test'. This study used a more relevant and realistic experimental canine model to compare the differences in the adhesive properties of four fibrin sealants in hepatectomy: Tisseel/Tissucol, Tachosil, Quixil, and Beriplast. A partial hepatectomy was performed in beagle dogs under general anesthesia to obtain liver cross-sections. Fibrin sealants were allocated to dog livers using a Youden square design. The tensile strength measurement was performed using a traction system to measure the rupture stress point of a small wooden cylinder bonded to the liver cross-section. Significantly greater adhesion properties were observed with Tisseel/Tissucol compared with Quixil or Beriplast (P = 0.002 and 0.001, respectively). Similarly, Tachosil demonstrated significantly greater adhesive properties compared with Beriplast (P = 0.009) or Quixil (P = 0.014). No significant differences were observed between Tisseel/Tissucol and Tachosil or between Beriplast and Quixil. The results of this comparative study demonstrate that different fibrin sealants exhibit different adhesive properties. Tisseel/Tissucol and Tachosil provided greatest adhesion to liver cross-section in our canine model of hepatectomy. These results may enable the optimal choice of fibrin sealants for this procedure in clinical practice. Copyright © 2012 Elsevier Inc. All rights reserved.

Fibrin(ogen)olytic activity of bumblebee venom serine protease

International Nuclear Information System (INIS)

Qiu Yuling; Choo, Young Moo; Yoon, Hyung Joo; Jia Jingming; Cui Zheng; Wang Dong; Kim, Doh Hoon; Sohn, Hung Dae; Jin, Byung Rae

2011-01-01

Bee venom is a rich source of pharmacologically active components; it has been used as an immunotherapy to treat bee venom hypersensitivity, and venom therapy has been applied as an alternative medicine. Here, we present evidence that the serine protease found in bumblebee venom exhibits fibrin(ogen)olytic activity. Compared to honeybee venom, bumblebee venom contains a higher content of serine protease, which is one of its major components. Venom serine proteases from bumblebees did not cross-react with antibodies against the honeybee venom serine protease. We provide functional evidence indicating that bumblebee (Bombus terrestris) venom serine protease (Bt-VSP) acts as a fibrin(ogen)olytic enzyme. Bt-VSP activates prothrombin and directly degrades fibrinogen into fibrin degradation products. However, Bt-VSP is not a plasminogen activator, and its fibrinolytic activity is less than that of plasmin. Taken together, our results define roles for Bt-VSP as a prothrombin activator, a thrombin-like protease, and a plasmin-like protease. These findings offer significant insight into the allergic reaction sequence that is initiated by bee venom serine protease and its potential usefulness as a clinical agent in the field of hemostasis and thrombosis. - Graphical abstract: Display Omitted Highlights: → Bumblebee venom serine protease (Bt-VSP) is a fibrin(ogen)olytic enzyme. → Bt-VSP activates prothrombin. → Bt-VSP directly degrades fibrinogen into fibrin degradation products. → Bt-VSP is a hemostatically active protein that is a potent clinical agent.

The fast release of stem cells from alginate-fibrin microbeads in injectable scaffolds for bone tissue engineering

Science.gov (United States)

Zhou, Hongzhi; Xu, Hockin H. K.

2011-01-01

Stem cell-encapsulating hydrogel microbeads of several hundred microns in size suitable for injection, that could quickly degrade to release the cells, are currently unavailable. The objectives of this study were to: (1) develop oxidized alginate-fibrin microbeads encapsulating human umbilical cord mesenchymal stem cells (hUCMSCs); (2) investigate microbead degradation, cell release, and osteogenic differentiation of the released cells for the first time. Three types of microbeads were fabricated to encapsulate hUCMSCs: (1) Alginate microbeads; (2) oxidized alginate microbeads; (3) oxidized alginate-fibrin microbeads. Microbeads with sizes of about 100–500 µm were fabricated with 1×106 hUCMSCs/mL of alginate. For the alginate group, there was little microbead degradation, with very few cells released at 21 d. For oxidized alginate, the microbeads started to slightly degrade at 14 d. In contrast, the oxidized alginate-fibrin microbeads started to degrade at 4 d and released the cells. At 7 d, the number of released cells greatly increased and showed a healthy polygonal morphology. At 21 d, the oxidized alginate-fibrin group had a live cell density that was 4-fold that of the oxidized alginate group, and 15-fold that of the alginate group. The released cells had osteodifferentiation, exhibiting highly elevated bone marker gene expressions of ALP, OC, collagen I, and Runx2. Alizarin staining confirmed the synthesis of bone minerals by hUCMSCs, with the mineral concentration at 21 d being 10-fold that at 7 d. In conclusion, fast-degradable alginate-fibrin microbeads with hUCMSC encapsulation were developed that could start to degrade and release the cells at 4 d. The released hUCMSCs had excellent proliferation, osteodifferentiation, and bone mineral synthesis. The alginate-fibrin microbeads are promising to deliver stem cells inside injectable scaffolds to promote tissue regeneration. PMID:21757229

Microneural anastomosis with fibrin glue : an experimental study.

OpenAIRE

Suri A; Mehta V; Sarkar C

2002-01-01

An experimental study was designed to compare the histological analysis of nerve anastomosis with 10-0 microsurgical sutures and fibrin adhesive. Wistar albino rats′ sciatic nerves were transected and repaired either with fibrin adhesive-Beriplast P (M/s Centeon-Cadila Health Care) or with 10-0 monofilament microsutures. Histological assessment was performed at 10, 20, 30, 60 and 90 days after surgery. Functional recovery of the sciatic nerves started at two months and was near normal ...

Characteristics of an autologous leukocyte and platelet-rich fibrin patch intended for the treatment of recalcitrant wounds

DEFF Research Database (Denmark)

Lundquist, Rasmus; Holmstrøm, Kim; Clausen, Christian

2012-01-01

We have investigated the physical, biochemical, and cellular properties of an autologous leukocyte and platelet-rich fibrin patch. This was generated in an automated device from a sample of a patient's blood at the point of care. Using microscopy, cell counting, enzyme-linked immunosorbent assay...... of chronic wound fluid. By comparison with traditional platelet-rich plasma, differences in immune components were found. The relevance of these findings was assessed by showing a mitogenic and migratory effect on cultured human dermal fibroblasts. Further, we showed that fibrocytes, a cell type important......, antibody arrays, and cell culture assays, we show that the patch is a three-layered membrane comprising a fibrin sheet, a layer of platelets, and a layer of leukocytes. Mean recovery of platelets from the donated blood was 98% (±95%CI 0.8%). Mean levels of platelet-derived growth factor AB, human...

Effects of fibrin, thrombin, and blood on breast capsule formation in a preclinical model.

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Marques, Marisa; Brown, Spencer A; Cordeiro, Natália D S; Rodrigues-Pereira, Pedro; Cobrado, M Luís; Morales-Helguera, Aliuska; Lima, Nuno; Luís, André; Mendanha, Mário; Gonçalves-Rodrigues, Acácio; Amarante, José

2011-03-01

The root cause of capsular contracture (CC) associated with breast implants is unknown. Recent evidence points to the possible role of fibrin and bacteria in CC formation. The authors sought to determine whether fibrin, thrombin, and blood modulated the histological and microbiological outcomes of breast implant capsule formation in a rabbit model. The authors carried out a case-control study to assess the influence of fibrin, thrombin, and blood on capsule wound healing in a rabbit model. Eighteen New Zealand white rabbits received four tissue expanders. One expander acted as a control, whereas the other expander pockets received one of the following: fibrin glue, rabbit blood, or thrombin sealant. Intracapsular pressure/volume curves were compared among the groups, and histological and microbiological evaluations were performed (capsules, tissue expanders, rabbit skin, and air). The rabbits were euthanized at two or four weeks. At four weeks, the fibrin and thrombin expanders demonstrated significantly decreased intracapsular pressure compared to the control group. In the control and fibrin groups, mixed inflammation correlated with decreased intracapsular pressure, whereas mononuclear inflammation correlated with increased intracapsular pressure. The predominant isolate in the capsules, tissue expanders, and rabbit skin was coagulase-negative staphylococci. For fibrin and thrombin, both cultures that showed an organism other than staphylococci and cultures that were negative were associated with decreased intracapsular pressure, whereas cultures positive for staphylococci were associated with increased intracapsular pressure. Fibrin application during breast implantation may reduce rates of CC, but the presence of staphylococci is associated with increased capsule pressure even in the presence of fibrin, so care should be taken to avoid bacterial contamination.

Fibrin glue as a protective tool for microanastomoses in limb reconstructive surgery

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Langer, Stefan

2015-12-01

Full Text Available Aim: Fibrin glue becomes a more and more routinely used tool for stabilization of microanastomoses and nerve repair. This paper summarizes the technical properties and advantages of its use in a wide variety of microsurgical contexts, and includes an exemplary limb reconstructive case.Patients and methods: A total of 131 patients who had undergone elective and emergency microsurgery mainly of the limbs were retrospectively analyzed, as was the use of free flaps.Results: The use of fibrin glue allows for proper positioning of anastomoses and repaired nerves. No torsion of the pedicle could be seen. The flap survival rated >94%. The fibrin glue could stay in place in >99%. In the rare case of revision, the fibrin glue could easily be removed without damaging the region of the microanastomosis.Conclusion: Fibrin glue should not be used to repair insufficient, i.e., leaking anastomoses, but it does protect the site of anastomosis from tissue and fluid pressure. It prevents the pedickle from torsion and its use facilitates relocation of the microanastomoses in cases of revision surgery.

Submillisecond Elastic Recoil Reveals Molecular Origins of Fibrin Fiber Mechanics

Science.gov (United States)

Hudson, Nathan E.; Ding, Feng; Bucay, Igal; O’Brien, E. Timothy; Gorkun, Oleg V.; Superfine, Richard; Lord, Susan T.; Dokholyan, Nikolay V.; Falvo, Michael R.

2013-01-01

Fibrin fibers form the structural scaffold of blood clots. Thus, their mechanical properties are of central importance to understanding hemostasis and thrombotic disease. Recent studies have revealed that fibrin fibers are elastomeric despite their high degree of molecular ordering. These results have inspired a variety of molecular models for fibrin’s elasticity, ranging from reversible protein unfolding to rubber-like elasticity. An important property that has not been explored is the timescale of elastic recoil, a parameter that is critical for fibrin’s mechanical function and places a temporal constraint on molecular models of fiber elasticity. Using high-frame-rate imaging and atomic force microscopy-based nanomanipulation, we measured the recoil dynamics of individual fibrin fibers and found that the recoil was orders of magnitude faster than anticipated from models involving protein refolding. We also performed steered discrete molecular-dynamics simulations to investigate the molecular origins of the observed recoil. Our results point to the unstructured αC regions of the otherwise structured fibrin molecule as being responsible for the elastic recoil of the fibers. PMID:23790375

Bioactivity and stability of endogenous fibrogenic factors in platelet-rich fibrin

DEFF Research Database (Denmark)

Lundquist, R.; Dziegiel, M.H.; Agren, M.S.

2008-01-01

Platelet-rich fibrin (PRF) is an autologous fibrin sealant (FS) enriched with a platelet concentrate (> 1,000,000 platelets/microL) produced by the automated Vivostat system and used to enhance wound healing. The effects of PRF were compared with supernatant from thrombin-activated platelet conce...

The potential of 3-dimensional construct engineered from poly(lactic-co-glycolic acid)/fibrin hybrid scaffold seeded with bone marrow mesenchymal stem cells for in vitro cartilage tissue engineering.

Science.gov (United States)

Abdul Rahman, Rozlin; Mohamad Sukri, Norhamiza; Md Nazir, Noorhidayah; Ahmad Radzi, Muhammad Aa'zamuddin; Zulkifly, Ahmad Hafiz; Che Ahmad, Aminudin; Hashi, Abdurezak Abdulahi; Abdul Rahman, Suzanah; Sha'ban, Munirah

2015-08-01

Articular cartilage is well known for its simple uniqueness of avascular and aneural structure that has limited capacity to heal itself when injured. The use of three dimensional construct in tissue engineering holds great potential in regenerating cartilage defects. This study evaluated the in vitro cartilaginous tissue formation using rabbit's bone marrow mesenchymal stem cells (BMSCs)-seeded onto poly(lactic-co-glycolic acid) PLGA/fibrin and PLGA scaffolds. The in vitro cartilaginous engineered constructs were evaluated by gross inspection, histology, cell proliferation, gene expression and sulphated glycosaminoglycan (sGAG) production at week 1, 2 and 3. After 3 weeks of culture, the PLGA/fibrin construct demonstrated gross features similar to the native tissue with smooth, firm and glistening appearance, superior histoarchitectural and better cartilaginous extracellular matrix compound in concert with the positive glycosaminoglycan accumulation on Alcian blue. Significantly higher cell proliferation in PLGA/fibrin construct was noted at day-7, day-14 and day-21 (ptissue engineered cartilage. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of two fibrin glues in anastomoses and skin closure.

Science.gov (United States)

Park, W; Kim, W H; Lee, C H; Kim, D Y; Choi, J H; Huh, J W; Sung, H M; Kim, I S; Kweon, O K

2002-09-01

To control intra-operative haemorrhage, fibrin glues are preferred by many surgeons because of their biological advantages and convenience of application. Manufacturers have developed a few kinds of fibrin glues with a little difference in their composition. This study was to compare the effectiveness of two commercially available fibrin glues; Greenplast (Green Cross P. D. Company, Yongin, Korea) and Tisseel (Baxter-Immuno AG, Vienna, Austria). They were applied experimentally to several kinds of surgery in dogs - renal vessel anastomosis, partial splenectomy, intestinal anastomosis and incision skin wound - and evaluated for their haemostatic and adhesive effects. When the two glues were applied in renal vessel anastomosis, the amount of haemorrhage in artery and vein decreased significantly. They also decreased the haemorrhage in partial splenectomy. At 10 min after application of the glues to an incision skin wound, the tensile strengths developed were significantly higher than that of control. The present study indicates that two-component fibrin glues have a haemostatic effect as a mechanical barrier in renal vessel anastomosis and an adhesive effect in the early stage of incision skin wound closure, and the two glues have similar effects with no complications.

Membrane-type-3 matrix metalloproteinase (MT3-MMP functions as a matrix composition-dependent effector of melanoma cell invasion.

Directory of Open Access Journals (Sweden)

Olga Tatti

Full Text Available In primary human melanoma, the membrane-type matrix metalloproteinase, MT3-MMP, is overexpressed in the most aggressive nodular-type tumors. Unlike MT1-MMP and MT2-MMP, which promote cell invasion through basement membranes and collagen type I-rich tissues, the function of MT3-MMP in tumor progression remains unclear. Here, we demonstrate that MT3-MMP inhibits MT1-MMP-driven melanoma cell invasion in three-dimensional collagen, while yielding an altered, yet MT1-MMP-dependent, form of expansive growth behavior that phenocopies the formation of nodular cell colonies. In melanoma cell lines originating from advanced primary or metastatic lesions, endogenous MT3-MMP expression was associated with limited collagen-invasive potential. In the cell lines with highest MT3-MMP expression relative to MT1-MMP, collagen-invasive activity was increased following stable MT3-MMP gene silencing. Consistently, MT3-MMP overexpression in cells derived from less advanced superficially spreading melanoma lesions, or in the MT3-MMP knockdown cells, reduced MT1-MMP-dependent collagen invasion. Rather than altering MT1-MMP transcription, MT3-MMP interacted with MT1-MMP in membrane complexes and reduced its cell surface expression. By contrast, as a potent fibrinolytic enzyme, MT3-MMP induced efficient invasion of the cells in fibrin, a provisional matrix component frequently found at tumor-host tissue interfaces and perivascular spaces of melanoma. Since MT3-MMP was significantly upregulated in biopsies of human melanoma metastases, these results identify MT3-MMP as a matrix-dependent modifier of the invasive tumor cell functions during melanoma progression.

Characterization of Fibrin and Collagen Gels for Engineering Wound Healing Models

Directory of Open Access Journals (Sweden)

Oihana Moreno-Arotzena

2015-04-01

Full Text Available Hydrogels are used for 3D in vitro assays and tissue engineering and regeneration purposes. For a thorough interpretation of this technology, an integral biomechanical characterization of the materials is required. In this work, we characterize the mechanical and functional behavior of two specific hydrogels that play critical roles in wound healing, collagen and fibrin. A coherent and complementary characterization was performed using a generalized and standard composition of each hydrogel and a combination of techniques. Microstructural analysis was performed by scanning electron microscopy and confocal reflection imaging. Permeability was measured using a microfluidic-based experimental set-up, and mechanical responses were analyzed by rheology. We measured a pore size of 2.84 and 1.69 μm for collagen and fibrin, respectively. Correspondingly, the permeability of the gels was 1.00·10−12 and 5.73·10−13 m2. The shear modulus in the linear viscoelastic regime was 15 Pa for collagen and 300 Pa for fibrin. The gels exhibited strain-hardening behavior at ca. 10% and 50% strain for fibrin and collagen, respectively. This consistent biomechanical characterization provides a detailed and robust starting point for different 3D in vitro bioapplications, such as collagen and/or fibrin gels. These features may have major implications for 3D cellular behavior by inducing divergent microenvironmental cues.

Vivostat®: an autologous fibrin sealant as useful adjunct in endoscopic transnasal CSF-leak repair.

Science.gov (United States)

Tomazic, Peter Valentin; Edlinger, Stefan; Gellner, Verena; Koele, Wolfgang; Gerstenberger, Claus; Braun, Hannes; Mokry, Michael; Stammberger, Heinz

2015-06-01

The benefit of fibrin glue for reduction of postoperative CSF-leaks after endoscopic skull base surgery is not clearly evident in literature. However, its use is supposed to be beneficial in fixing grafting material. As of today there is no specific data available for otolaryngological procedures. A retrospective data analysis at a tertiary care referral center on 73 patients treated endoscopically transnasally for CSF-leaks at the ENT-department Graz between 2009 and 2012 was performed. Primary closure rate between conventional fibrin glue and autologous fibrin glue were analyzed. The Vivostat(®) system was used in 33 CSF-leak closures and in 40 cases conventional fibrin glue was used. Comparing the two methods the primary closure rate using the autologous Vivostat(®) system was 75.8 and 85.0 % with conventional fibrin glue. The secondary closure the rates were 90.9 % with Vivostat(®) 92.5 % with conventional fibrin glue. The Vivosat(®) system is a useful adjunct in endoscopic CSF-leak closure. Its advantages over conventional fibrin glue are its application system for fixation of grafting material particularly in underlay techniques. Despite this advantage it cannot replace grafting material or is a substitute for proper endoscopic closure which is reflected by the closure rates.

A Novel Platelet Concentrate: Titanium-Prepared Platelet-Rich Fibrin

OpenAIRE

Mustafa Tunalı; Hakan Özdemir; Zafer Küçükodacı; Serhan Akman; Emre Yaprak; Hülya Toker; Erhan Fıratlı

2014-01-01

We developed a new product called titanium-prepared platelet-rich fibrin (T-PRF). The T-PRF method is based on the hypothesis that titanium may be more effective in activating platelets than the silica activators used with glass tubes in Chouckroun's leukocyte- and platelet-rich fibrin (L-PRF) method. In this study, we aimed to define the structural characteristics of T-PRF and compare it with L-PRF. Blood samples were collected from 10 healthy male volunteers. The blood samples were drawn us...

Do fibrin sealants impact negative outcomes after robot-assisted partial nephrectomy?

Science.gov (United States)

Cohen, Jason; Jayram, Gautam; Mullins, Jeffrey K; Ball, Mark W; Allaf, Mohamad E

2013-10-01

Contemporary rates of postoperative hemorrhage after partial nephrectomy (PN) are low. Commercially available hemostatic agents are commonly used during this surgery to reduce this risk despite a paucity of data supporting the practice. We assessed the impact of fibrin sealant hemostatic agents, a costly addition to surgeries, during robot-assisted partial nephrectomy (RAPN). Between 2007 and 2011, 114 consecutive patients underwent RAPN by a single surgeon (MEA). Evicel fibrin sealant was used in the first 74 patients during renorraphy. The last 40 patients had renorraphy performed without the use of any hemostatic agents. Clinicopathologic, operative, and complication data were compared between groups. Multivariate and univariate logistic regression analysis was performed to test the association between the use of fibrin sealants and operative outcomes. Patient demographic data and clinical tumor characteristics were similar between groups. The use of fibrin sealant did not increase operative time (166.3 vs 176.1 minutes, P=0.28), warm ischemia time (WIT) (14.4 vs 16.1 minutes, P=0.18), or length of hospital stay (2.6 vs 2.4 days, P=0.35). The omission of these agents did not increase estimated blood loss (116.6 vs 176.1 mL, P=0.8) or postoperative blood transfusion (0% vs 2.5%, P=0.17). Univariate analysis demonstrated no association between use of fibrin sealants and increased complications (P>0.05). Multivariable logistic regression showed no statistically significant predictive value of omission of hemostatic agents for perioperative outcomes (P>0.05). Perioperative hemorrhage and other major complications after contemporary RAPN are rare in experienced hands. In our study, the use of fibrin sealants during RAPN does not decrease the rate of complications, blood loss, or hospital stay. Furthermore, no impact is seen on operative time, WIT, or other negative outcomes. Omitting these agents during RAPN could be a safe, effective, cost-saving measure.

Topical tissue plasminogen activator appears ineffective for the clearance of intraocular fibrin.

Science.gov (United States)

Zwaan, J; Latimer, W B

1998-06-01

To determine the efficacy of topical tissue plasminogen activator (tPA) for the resolution of postoperative or inflammatory intraocular fibrinous exudates. Each treatment consisted of drops of 1 mg/ml tPA given 9 times 5 minutes apart. Records were reviewed and the results at 24 and 48 hours were recorded. Sixty-two patients had a total of 94 treatments. Fibrin exudates following intraocular surgery in 34 patients were treated 44 times. In 6 patients there was a positive result. Fibrin associated with intraocular infection was treated in 9 patients. None showed clear improvement. Nineteen patients had a total of 34 treatments for poorly controlled intraocular pressure (IOP) after glaucoma surgery. Five patients showed adequate control of the IOP, 12 did not change, and 2 had a questionable improvement. Eleven patients had adequate IOP control after additional treatment. Seven required suture lysis, 2 ab interno bleb revision, and 2 YAG capsulotomy or iridotomy to reduce the IOP to an acceptable level. Within the limits of this retrospective study and taking into account that fibrin may resolve spontaneously, it appears that topical tPA drops are not effective for the liquefaction of intraocular fibrin after surgery or in association with intraocular inflammation. They did not improve IOP control after glaucoma surgery.

Towards a quantitative understanding of oxygen tension and cell density evolution in fibrin hydrogels.

Science.gov (United States)

Demol, Jan; Lambrechts, Dennis; Geris, Liesbet; Schrooten, Jan; Van Oosterwyck, Hans

2011-01-01

The in vitro culture of hydrogel-based constructs above a critical size is accompanied by problems of unequal cell distribution when diffusion is the primary mode of oxygen transfer. In this study, an experimentally-informed mathematical model was developed to relate cell proliferation and death inside fibrin hydrogels to the local oxygen tension in a quantitative manner. The predictive capacity of the resulting model was tested by comparing its outcomes to the density, distribution and viability of human periosteum derived cells (hPDCs) that were cultured inside fibrin hydrogels in vitro. The model was able to reproduce important experimental findings, such as the formation of a multilayered cell sheet at the hydrogel periphery and the occurrence of a cell density gradient throughout the hydrogel. In addition, the model demonstrated that cell culture in fibrin hydrogels can lead to complete anoxia in the centre of the hydrogel for realistic values of oxygen diffusion and consumption. A sensitivity analysis also identified these two parameters, together with the proliferation parameters of the encapsulated cells, as the governing parameters for the occurrence of anoxia. In conclusion, this study indicates that mathematical models can help to better understand oxygen transport limitations and its influence on cell behaviour during the in vitro culture of cell-seeded hydrogels. Copyright © 2010 Elsevier Ltd. All rights reserved.

Does Fibrin Sealant Reduce Seroma after Immediate Breast Reconstruction Utilizing a Latissimus Dorsi Myocutaneous Flap?

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Han Gyu Cha

2012-09-01

Full Text Available Background The most common complication of latissimus dorsi myocutaneous flap in breastreconstruction is seroma formation in the back. Many clinical studies have shown that fibrinsealant reduces seroma formation. We investigated any statistically significant differences inpostoperative drainage and seroma formation when utilizing the fibrin sealant on the site ofthe latissimus dorsi myocutaneous flap harvested for immediate breast reconstruction afterskin-sparing partial mastectomy.Methods A total of 46 patients underwent immediate breast reconstruction utilizing alatissimus dorsi myocutaneous island flap. Of those, 23 patients underwent the procedurewithout fibrin sealant and the other 23 were administered the fibrin sealant. All flaps wereelevated with manual dissection by the same surgeon and were analyzed to evaluate thepotential benefits of the fibrin sealant. The correlation analysis and Mann-Whitney U testwere used for analyzing the drainage volume according to age, weight of the breast specimen,and body mass index.Results Although not statistically significant, the cumulative drainage fluid volume was higherin the control group until postoperative day 2 (530.1 mL compared to 502.3 mL, but thefibrin sealant group showed more drainage beginning on postoperative day 3. The donor sitecomparisons showed the fibrin sealant group had more drainage beginning on postoperativeday 3 and the drain was removed 1 day earlier in the control group.Conclusions The use of fibrin sealant resulted in no reduction of seroma formation. Becausethe benefits of the fibrin sealant are not clear, the use of fibrin sealant must be fully discussedwith patients before its use as a part of informed consent.

Evaluation of osteoblastic activity in extraction sockets treated with platelet-rich fibrin.

Science.gov (United States)

Baslarli, Ozgur; Tumer, Celal; Ugur, Omer; Vatankulu, Betul

2015-01-01

The aim of this study was to determine whether the use of platelet rich fibrin (PRF) improved the healing of extraction sockets. A total of 20 patients with bilateral soft tissue impacted mandibular third molars were included in this study. The left and right third molars were extracted during the same session. Subsequently, the PRF membrane was randomly administered to one of the extraction sockets, whereas the contralateral sockets were left without treatment. On postoperative 30. and 90. days, panoramic images and bone scintigrams were taken to evaluate the bone healing between PRF-treated and non-PRF-treated sockets. Also, periodontal evaluation was performed in the same control sessions. Dependent group t test for paired samples was used for statistical analysis. The average increase in technetium-99m methylene diphosphonate uptake as an indication of enhanced bone healing did not differ significantly between PRF-treated and non-PRF-treated sockets 30 and 90 days postoperatively. Radio-opacity that can show the bone healing on panoramic images were measured by Image J programme and they did not differ significantly. Also periodontal values did not differ significantly. PRF might not lead to enhanced bone healing in impacted mandibular third molar extraction sockets 30 and 90 days after surgery. It is thought that PRF has the potential characteristics of an autologous fibrin matrix and can accelerate the healing. To better understand the effects of PRF on healing, further research is warranted with larger sample sizes.

Comparative Study of Fibrin Sealent versus Use of Tackers in Inguinal Hernia Repair

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Wasim Qadir Kar

2015-09-01

Full Text Available Purpose: To determine role and benefit of fibrin glue over tackers for mesh fixation in laparoscopic inguinal hernia repair. Backgroud: Mesh fixation by tackers may lead to many complications peroperatively like bleeding, increased hospital stay and overall more cost and later on chronic groin pain. Material and Methods: 60 inguinal hernia with age more than 18 years were taken and were divided in two groups; 30 patient group who underwent TAPP and 30 patient group who underwent TEPP. In 15 patients in both groups tackers were used and in other half fibrin glue was used for fixation of mesh using a 3mm catheter (Duplotip: Baxter Healthcare, which fits the Tisseel syringe. Results: The use of fibrin sealent has a distinct advantage in laparoscopic treatment of inguinal hernias compared with use of tackers as a method of mesh fixation. The use of fibrin sealant reduces the risk of post- and intraoperative complications, such as bleeding, seroma, chronic pain, has a lower incidence of postoperative neuralgia and provides an early faster return to social life. The recurrence rates do not vary much, but the operative time is slightly longer if the preparation time of the fibrin sealant is taken into consideration. In our study, we found a marginal difference in the cost of the two groups, fibrin sealant and stapled tackers. [Cukurova Med J 2015; 40(3.000: 457-465

Acute fibrinous and organising pneumonia.

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Gonçalves, João Rocha; Marques, Ricardo; Serra, Paula; Cardoso, Leila

2017-09-07

Acute fibrinous and organising pneumonia (AFOP) is a rare histological pattern of interstitial lung disease. The authors describe a 60-year-old woman admitted to the hospital for sustained fever, presenting with an alveolar opacity on chest X-ray, with the presumed diagnosis of community-acquired pneumonia and the onset of antibiotics. Since serological results suggested that Legionella pneumophila was the infectious agent, she was discharged on levofloxacin. A week later, she was again admitted with fever. CT scan showed opacities with crescentic morphology and a central ground-glass area suggestive of cryptogenic organising pneumonia. Microbiological, serological and autoimmunity tests were negative. She underwent surgical lung biopsy that revealed inflammatory infiltrate, macrophage desquamation, fibroblasts proliferation and fibrin deposition in the alveolar spaces, consistent with AFOP. She started corticotherapy with good response. Disease relapsed after prednisolone discontinuation, 10 months later. Currently, the patient is on prednisolone 5 mg/day without clinical and radiological recurrence. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Excess Fibrin Deposits Decrease Fetal Weight of Pregnant Mice Infected by Plasmodium berghei

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Desy Andari

2014-05-01

Full Text Available Low birth weight is commonly attributed to malaria in pregnancy, but the cellular and molecular mechanisms that underlie this poor birth outcome are incompletely understood. A universally described histopathological feature of placental malaria is excessive deposition of fibrin, the end-product of the coagulation cascade. This study was conducted to compare fibrin deposit in pregnant mice that infected by Plasmodium berghei (treatment group to the normal pregnant mice (control group and its association with fetal weight. This research is in vivo experimental laboratory study that used 18 pregnant Balb/c mice which divided to the control the group (8 mice and treatment group (9 mice infected by P.berghei. Placentas were staining with Haematoxylin-Eosin (HE for fibrin deposits examination whereas fetal weight was performed with Mettler analytical balance AE 50. Fetal weight of the treatment group was lower than those of the control group (t test, p=0,002. Fibrin deposits were increased in the treatment group (t test, p=0,005 and influenced weight of fetuses (Spearman r= -0,586, p= 0,014. Weights of fetuses are interfered by fibrin deposits during malaria infection.

A model for cell migration in non-isotropic fibrin networks with an application to pancreatic tumor islets.

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Chen, Jiao; Weihs, Daphne; Vermolen, Fred J

2018-04-01

Cell migration, known as an orchestrated movement of cells, is crucially important for wound healing, tumor growth, immune response as well as other biomedical processes. This paper presents a cell-based model to describe cell migration in non-isotropic fibrin networks around pancreatic tumor islets. This migration is determined by the mechanical strain energy density as well as cytokines-driven chemotaxis. Cell displacement is modeled by solving a large system of ordinary stochastic differential equations where the stochastic parts result from random walk. The stochastic differential equations are solved by the use of the classical Euler-Maruyama method. In this paper, the influence of anisotropic stromal extracellular matrix in pancreatic tumor islets on T-lymphocytes migration in different immune systems is investigated. As a result, tumor peripheral stromal extracellular matrix impedes the immune response of T-lymphocytes through changing direction of their migration.

Plasminogen fragments K 1-3 and K 5 bind to different sites in fibrin fragment DD.

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Grinenko, T V; Kapustianenko, L G; Yatsenko, T A; Yusova, O I; Rybachuk, V N

2016-01-01

Specific plasminogen-binding sites of fibrin molecule are located in Аα148-160 regions of C-terminal domains. Plasminogen interaction with these sites initiates the activation process of proenzyme and subsequent fibrin lysis. In this study we investigated the binding of plasminogen fragments K 1-3 and K 5 with fibrin fragment DD and their effect on Glu-plasminogen interaction with DD. It was shown that the level of Glu-plasminogen binding to fibrin fragment DD is decreased by 50-60% in the presence of K 1-3 and K 5. Fragments K 1-3 and K 5 have high affinity to fibrin fragment DD (Kd is 0.02 for K 1-3 and 0.054 μМ for K 5). K 5 interaction is independent and K 1-3 is partly dependent on C-terminal lysine residues. K 1-3 interacts with complex of fragment DD-immobilized K 5 as well as K 5 with complex of fragment DD-immobilized K 1-3. The plasminogen fragments do not displace each other from binding sites located in fibrin fragment DD, but can compete for the interaction. The results indicate that fibrin fragment DD contains different binding sites for plasminogen kringle fragments K 1-3 and K 5, which can be located close to each other. The role of amino acid residues of fibrin molecule Аα148-160 region in interaction with fragments K 1-3 and K 5 is discussed.

Fibrin nanostructures for biomedical applications

Czech Academy of Sciences Publication Activity Database

Riedelová-Reicheltová, Zuzana; Brynda, Eduard; Riedel, Tomáš

2016-01-01

Roč. 65, Suppl. 2 (2016), S263-S272 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LQ1604 Institutional support: RVO:61389013 Keywords : fibrinogen * fibrin-bound thrombin * nanostructures Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.461, year: 2016 http://www.biomed.cas.cz/physiolres/pdf/65%20Suppl%202/65_S263.pdf

Synthesis of a cyclic fibrin-like peptide and its analysis by fast atom bombardment mass spectrometry

International Nuclear Information System (INIS)

Young, J.D.; Costello, C.E.; Langenhove, A. van; Haber, E.; Matsueda, G.R.

1983-01-01

For immunochemical purposes, a cyclic 12 peptide was synthesized to model the γ-γ-chain cross-link site in human fibrin. The model was based upon the structure proposed by Chen and Doolittle which is characterized by two reciprocating epsilon-(γ-Glu)Lys bonds between adjacent fibrin γ-chains oriented in an antiparallel manner. To achieve the antiparallel orientation of the peptide backbone, Pro and Gly were inserted at positions 6 and 7 of the linear 12-peptide: acetyl-Gly-Glu-Gln-His-His-Pro-Gly-Gly-Gly-Ala-Lys-Gly-amide. The insertions were made to facilitate a reverse turn of the peptide during the last synthetic step, which was formation of the epsilon-(γ-Glu)Lys bond between Glu at position 2 and Lys at position 11 with diphenylphosphorylazide. The resulting cyclic peptide represented half of the symmetrical cross-linked region in clotted fibrin. Following purification by HPLC, both linear and cyclic 12-peptides were analyzed by fast atom bombardment mass spectrometry. Abundant molecular protonated ions were observed for both peptides. In addition, the amino acid sequence of the linear peptide and the location of the epsilon-(γ-Glu)Lys bond in the cyclized peptide could be verified. (author)

Developing Mesoscale Model of Fibrin-Platelet Network Representing Blood Clotting =

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Sun, Yueyi; Nikolov, Svetoslav; Bowie, Sam; Alexeev, Alexander; Lam, Wilbur; Myers, David

Blood clotting disorders which prevent the body's natural ability to achieve hemostasis can lead to a variety of life threatening conditions such as, excessive bleeding, stroke, or heart attack. Treatment of these disorders is highly dependent on understanding the underlying physics behind the clotting process. Since clotting is a highly complex multi scale mechanism developing a fully atomistic model is currently not possible. We develop a mesoscale model based on dissipative particle dynamics (DPD) to gain fundamental understanding of the underlying principles controlling the clotting process. In our study, we examine experimental data on clot contraction using stacks of confocal microscopy images to estimate the crosslink density in the fibrin networks and platelet location. Using this data we reconstruct the platelet rich fibrin network and study how platelet-fibrin interactions affect clotting. Furthermore, we probe how different system parameters affect clot contraction. ANSF CAREER Award DMR-1255288.

Acute fibrinous and organising pneumonia: a case report and review of the literature.

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Tzouvelekis, Argyris; Koutsopoulos, Anastasios; Oikonomou, Anastasia; Froudarakis, Marios; Zarogoulidis, Pavlos; Steiropoulos, Paschalis; Mikroulis, Dimitrios; Antoniades, Antonis; Bouros, Demosthenes

2009-10-12

Organising pneumonia is a distinct histopathological entity characterized by intra-alveolar buds of granulation tissue, called Masson bodies, which mainly comprise of activated fibroblasts and loose connective tissue. This histopathologic pattern has been described in idiopathic cases, characterizing cryptogenic organising pneumonia as well as in the context of pulmonary infection, drug-induced pneumonitis and following lung transplantation. Although distinct as a clinical and pathological entity, community organising pneumonia may present with atypical clinical and pathological features, such as intra-alveolar fillings of fibrin balls and organising tissue that resembles acute respiratory distress syndrome or diffuse alveolar damage. The latter characteristics constitute a recently described anatomoclinical entity called acute fibrinous and organising pneumonia. Here, we describe a rare case of acute fibrinous and organising pneumonia, in an otherwise healthy 65-year-old Greek woman who complained of dry cough, fever, weight loss and progressive dyspnoea. She had never been a smoker. Her clinical symptoms showed a rapid deterioration in the two weeks before admission, despite a course of oral antibiotics. After excluding infection and malignancy with routine laboratory tests and flexible bronchoscopy, high resolution computed tomography and video assisted thoracoscopic lung biopsy were performed. Diagnosis was based on radiological features typical of community organising pneumonia coupled with pathologic features characteristic of acute fibrinous and organising pneumonia. The patient was treated with corticosteroids and showed excellent clinical and radiological response three months after treatment initiation. Acute fibrinous and organising pneumonia is an extremely rare pathologic entity, often misdiagnosed as typical community organising pneumonia. To our knowledge, this is the seventh case of acute fibrinous and organising pneumonia in the literature, with no

Interface between breast cancer cells and the tumor microenvironment using platelet-rich plasma to promote tumor angiogenesis - influence of platelets and fibrin bundles on the behavior of breast tumor cells.

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Andrade, Sheila Siqueira; Sumikawa, Joana Tomomi; Castro, Eloísa Dognani; Batista, Fabricio Pereira; Paredes-Gamero, Edgar; Oliveira, Lilian Carolina; Guerra, Izabel Monastério; Peres, Giovani Bravin; Cavalheiro, Renan Pelluzzi; Juliano, Luiz; Nazário, Afonso Pinto; Facina, Gil; Tsai, Siu Mui; Oliva, Maria Luiza Vilela; Girão, Manoel João Batista Castello

2017-03-07

Cancer progression is associated with an evolving tissue interface of direct epithelial-tumor microenvironment interactions. In biopsies of human breast tumors, extensive alterations in molecular pathways are correlated with cancer staging on both sides of the tumor-stroma interface. These interactions provide a pivotal paracrine signaling to induce malignant phenotype transition, the epithelial-mesenchymal transition (EMT). We explored how the direct contact between platelets-fibrin bundles primes metastasis using platelet-rich plasma (PRP) as a source of growth factors and mimics the provisional fibrin matrix between actively growing breast cancer cells and the tumor stroma. We have demonstrated PRP functions, modulating cell proliferation that is tumor-subtype and cancer cell-type-specific. Epithelial and stromal primary cells were prepared from breast cancer biopsies from 21 women with different cancer subtypes. Cells supplemented with PRP were immunoblotted with anti-phospho and total Src-Tyr-416, FAK-Try-925, E-cadherin, N-cadherin, TGF-β, Smad2, and Snail monoclonal antibodies. Breast tumor cells from luminal B and HER2 subtypes showed the most malignant profiles and the expression of thrombin and other classes of proteases at levels that were detectable through FRET peptide libraries. The angiogenesis process was investigated in the interface obtained between platelet-fibrin-breast tumor cells co-cultured with HUVEC cells. Luminal B and HER2 cells showed robust endothelial cell capillary-like tubes ex vivo. The studied interface contributes to the attachment of endothelial cells, provides a source of growth factors, and is a solid substrate. Thus, replacement of FBS supplementation with PRP supplementation represents an efficient and simple approach for mimicking the real multifactorial tumor microenvironment.

Novel aspects of the pathogenesis of aneurysms of the abdominal aorta in humans

DEFF Research Database (Denmark)

Michel, Jean-Baptiste; Martin-Ventura, José-Luis; Egido, Jesus

2011-01-01

and the adventitial response in the development of human AAA. The intraluminal thrombus exerts its pathogenic effect through platelet activation, fibrin formation, binding of plasminogen and its activators, and trapping of erythrocytes and neutrophils, leading to oxidative and proteolytic injury of the arterial wall...... arterial wall rupture. The roles of matrix metalloproteinases and plasmin generation in progression of AAA have been demonstrated both in animal models and in clinical studies. In the present review, we highlight recent studies addressing the role of the haemoglobin-rich, intraluminal thrombus...

Sealing of Gastrointestinal Anastomoses with a Fibrin Glue-Coated Collagen Patch: A Safety Study

DEFF Research Database (Denmark)

Nordentoft, Tyge; Rømer, John; Sørensen, Michael

2007-01-01

gastrointestinal anastomoses with a collagen patch coated with fibrin glue. The study is a prospective, experimental animal study comparing sealed and unsealed gastrointestinal anastomoses. Laparotomy was performed in 11 pigs under general anesthesia. In each pig two anastomoses were performed on the small......Sealing of anastomoses has previously been tested with several methods, including sealing with liquid fibrin glue. Sealing with a collagen patch coated with fibrin glue components has never been systematically examined. The aim of the present study was to determine the safety of sealing...... intestine. One of the anastomoses was sealed with a collagen patch coated with fibrin glue components (TachoSil). The other anastomosis contained no sealing. The pigs were observed for 1 to 6 weeks. The observation period was followed by in vivo examination under general anesthesia and included observation...

Role of pH Changes on Transforming Growth Factor-β1 Release and on the Fibrin Architecture of Platelet-rich Fibrin When Layered with Biodentine, Glass Ionomer Cement, and Intermediate Restorative Material.

Science.gov (United States)

Mullaguri, Harish; Suresh, Nandini; Surendran, Smitha; Velmurugan, Natanasabapathy; Chitra, Selvarajan

2016-05-01

The purpose of this study was to evaluate the influence of pH that is due to setting reaction of Biodentine, glass ionomer cement (GIC), and intermediate restorative material (IRM) on transforming growth factor-β1 (TGF-β1) release and on the fibrin architecture of platelet-rich fibrin (PRF). PRF was obtained from 8 volunteers and layered over the freshly prepared GIC, IRM, and Biodentine mixtures. TGF-β1 release was estimated by using enzyme-linked immunosorbent assay (ELISA), and fibrin structure of PRF was analyzed by using scanning electron microscope at 1 and 5 hours. Biodentine, GIC, and IRM increased the TGF-β1 release in comparison with that of control group (PRF alone) at both 1 and 5 hours. Biodentine released significantly more TGF-β1 than GIC and IRM at 1 hour. At 5 hours both GIC and Biodentine released significantly more TGF-β1 than IRM. The fibrin architecture of the Biodentine group was similar to that of control group at both 1 and 5 hours. In GIC and IRM groups the fibrillar structure of fibrin was collapsed, ill-defined, and cloudy with very thick fibers and irregularly reduced porosities. Biodentine induces larger amount of TGF-β1 release and also maintains the integrity of fibrin structure when compared with GIC and IRM when layered over PRF. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

[Eosinophilic pleural effusion possibly induced by fibrin sealant].

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Kambayashi, Takatoyo; Suzuki, Takashi

2012-02-01

A 74-year-old man underwent right upper lobectomy for the lung cancer and bullectomy of right lower lobe. Fibrin sealant was used for sealing the excision line. The increase of the pleural effusion with increasing C-reactive protein( CRP) and eosinophilia was noted at the 17th day after the operation. The pleural effusion was transparent and yellowish colored suggesting transudatory liquid. The eosinophil in the pleural effusion was as high as 14%. The drainage of the pleural effusion was performed for 2 days resulting in disappearing the abnormal accumulation without any additional treatment. The cause of pleural effusion was supposed to be fibrin sealant by a positive result of the drug lymphocyte stimulation test.

Nonuniform Internal Structure of Fibrin Fibers: Protein Density and Bond Density Strongly Decrease with Increasing Diameter

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Wei Li

2017-01-01

Full Text Available The major structural component of a blood clot is a meshwork of fibrin fibers. It has long been thought that the internal structure of fibrin fibers is homogeneous; that is, the protein density and the bond density between protofibrils are uniform and do not depend on fiber diameter. We performed experiments to investigate the internal structure of fibrin fibers. We formed fibrin fibers with fluorescently labeled fibrinogen and determined the light intensity of a fiber, I, as a function of fiber diameter, D. The intensity and, thus, the total number of fibrin molecules in a cross-section scaled as D1.4. This means that the protein density (fibrin per cross-sectional area, ρp, is not homogeneous but instead strongly decreases with fiber diameter as D-0.6. Thinner fibers are denser than thicker fibers. We also determined Young’s modulus, Y, as a function of fiber diameter. Y decreased strongly with increasing D; Y scaled as D-1.5. This implies that the bond density, ρb, also scales as D-1.5. Thinner fibers are stiffer than thicker fibers. Our data suggest that fibrin fibers have a dense, well-connected core and a sparse, loosely connected periphery. In contrast, electrospun fibrinogen fibers, used as a control, have a homogeneous cross-section.

Platelet-rich fibrin in the treatment of periodontal bone defects.

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Ranganathan, Aravindhan T; Chandran, Chitraa R

2014-05-01

Periodontitis is characterized by the formation of true pockets, bone loss and attachment loss. Various techniques have been attempted in the past to truly regenerate the lost periodontal structures, albeit with variable outcome. In this evolution, the technique being tried out widely is the use of platelet rich concentrates, namely platelet-rich fibrin (PRF). In this report, we present a case of surgical treatment of osseous bone defects namely two walled crater and dehiscence treated in posterior teeth with autologously prepared platelet rich fibrin mixed with hydroxy apatite bone graft and PRF in the form of a membrane. Our results showed clinical improvements in all the clinical parameters postoperatively namely the pocket depth reduction and gain in attachment level and hence, PRF can be used alone or in combination with the bone graft to yield successful clinical results in treating periodontal osseous defects. Platelet-rich fibrin is an effective alternative to platelet-rich plasma (PRP) in reconstructing bone defects.

Efficacy of leukocyte- and platelet-rich fibrin in wound healing: a randomized controlled clinical trial.

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Chignon-Sicard, Bérengère; Georgiou, Charalambos A; Fontas, Eric; David, Sylvain; Dumas, Pierre; Ihrai, Tarik; Lebreton, Elisabeth

2012-12-01

Application of platelet concentrates to wounds could speed healing. Leukocyte- and platelet-rich fibrin, a relatively recent development, stands out from the other preparations. This prospective, randomized, controlled clinical trial studied the rate of healing of postoperative hand wounds after a single application of leukocyte- and platelet-rich fibrin. Eligible patients were healthy individuals older than 18 years who had been scheduled for elective McCash (open palm) surgery for Dupuytren disease at the Plastic and Hand Surgery Department of Nice's University Hospital between August of 2007 and February of 2010. The control group received the reference care of petroleum jelly mesh (Vaselitulle), and test patients had leukocyte- and platelet-rich fibrin applied. The primary endpoint was healing delay measured in postoperative days. Secondary endpoints included pain, bleeding, and wound exudate. The trial was carried out as a single-blind trial. Among the 68 randomized patients, 33 patients in the leukocyte- and platelet-rich fibrin group and 31 in the Vaselitulle group were analyzed. Primary endpoint analysis showed a median healing delay of 24 days (interquartile range, 18 to 28 days) for the fibrin group and 29 days (interquartile range, 26 to 35 days) for the Vaselitulle group (p = 0.014, log-rank test). Postoperative pain assessment, bleeding, and exudate were always lower for the fibrin group, but not significantly so. The authors trial demonstrates that a single leukocyte- and platelet-rich fibrin application on fresh postoperative hand wounds shows a median improvement of 5 days in comparison with the standard treatment. Therapeutic, II.

Leukocyte- and platelet-rich fibrin (L-PRF) for long-term delivery of growth factor in rotator cuff repair: review, preliminary results and future directions.

Science.gov (United States)

Zumstein, Matthias A; Berger, Simon; Schober, Martin; Boileau, Pascal; Nyffeler, Richard W; Horn, Michael; Dahinden, Clemens A

2012-06-01

Surgical repair of the rotator cuff repair is one of the most common procedures in orthopedic surgery. Despite it being the focus of much research, the physiological tendon-bone insertion is not recreated following repair and there is an anatomic non-healing rate of up to 94%. During the healing phase, several growth factors are upregulated that induce cellular proliferation and matrix deposition. Subsequently, this provisional matrix is replaced by the definitive matrix. Leukocyte- and platelet-rich fibrin (L-PRF) contain growth factors and has a stable dense fibrin matrix. Therefore, use of LPRF in rotator cuff repair is theoretically attractive. The aim of the present study was to determine 1) the optimal protocol to achieve the highest leukocyte content; 2) whether L-PRF releases growth factors in a sustained manner over 28 days; 3) whether standard/gelatinous or dry/compressed matrix preparation methods result in higher growth factor concentrations. 1) The standard L-PRF centrifugation protocol with 400 x g showed the highest concentration of platelets and leukocytes. 2) The L-PRF clots cultured in medium showed a continuous slow release with an increase in the absolute release of growth factors TGF-β1, VEGF and MPO in the first 7 days, and for IGF1, PDGF-AB and platelet activity (PF4=CXCL4) in the first 8 hours, followed by a decrease to close to zero at 28 days. Significantly higher levels of growth factor were expressed relative to the control values of normal blood at each culture time point. 3) Except for MPO and the TGFβ-1, there was always a tendency towards higher release of growth factors (i.e., CXCL4, IGF-1, PDGF-AB, and VEGF) in the standard/gelatinous- compared to the dry/compressed group. L-PRF in its optimal standard/gelatinous-type matrix can store and deliver locally specific healing growth factors for up to 28 days and may be a useful adjunct in rotator cuff repair.

Effects of Plasma Rich in Growth Factors and Platelet-Rich Fibrin on Proliferation and Viability of Human Gingival Fibroblasts

Science.gov (United States)

Vahabi, Surena; Vaziri, Shahram; Torshabi, Maryam

2015-01-01

Objectives: Platelet preparations are commonly used to enhance bone and soft tissue regeneration. Considering the existing controversies on the efficacy of platelet products for tissue regeneration, more in vitro studies are required. The aim of the present study was to compare the in vitro effects of plasma rich in growth factors (PRGF) and platelet-rich fibrin (PRF) on proliferation and viability of human gingival fibroblasts (HGFs). Materials and Methods: Anitua’s PRGF and Choukran’s PRF were prepared according to the standard protocols. After culture periods of 24, 48 and 72 hours, proliferation of HGFs was evaluated by the methyl thiazol tetrazolium assay. Statistical analysis was performed using one-way ANOVA followed by Tukey-Kramer’s multiple comparisons and P-valuesPRGF treatment induced statistically significant (PPRGF than in PRF group (PPRGF had a strong stimulatory effect on HGF cell viability and proliferation compared to PRF. PMID:26877740

Cell-seeded polyurethane-fibrin structures – A possible system for intervertebral disc regeneration

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C Mauth

2009-10-01

Full Text Available Nowadays, intervertebral disc (IVD degeneration is one of the principal causes of low back pain involving high expense within the health care system. The long-term goal is the development of a medical treatment modality focused on a more biological regeneration of the inner nucleus pulposus (NP. Hence, interest in the endoscopic implantation of an injectable material took center stage in the recent past. We report on the development of a novel polyurethane (PU scaffold as a mechanically stable carrier system for the reimplantation of expanded autologous IVD-derived cells (disc cells to stimulate regenerative processes and restore the chondrocyte-like tissue within the NP. Primary human disc cells were seeded into newly developed PU spheroids which were subsequently encapsulated in fibrin hydrogel. The study aims to analyze adhesion properties, proliferation capacity and phenotypic characterization of these cells. Polymerase chain reaction was carried out to detect the expression of genes specifically expressed by native IVD cells. Biochemical analyses showed an increased DNA content, and a progressive enhancement of total collagen and glycosaminoglycans (GAG was observed during cell culture. The results suggest the synthesis of an appropriate extracellular matrix as well as a stable mRNA expression of chondrogenic and/or NP specific markers. In conclusion, the data presented indicate an alternative medical approach to current treatment options of degenerated IVD tissue.

Fibrinous pericarditis secondary to bacterial infection in a cat.

Science.gov (United States)

Tagawa, Michihito; Kurashima, Chihiro; Shimbo, Genya; Omura, Hiroshi; Koyama, Kenji; Horiuchi, Noriyuki; Kobayashi, Yoshiyasu; Kawamoto, Keiko; Miyahara, Kazuro

2017-06-10

A three-year-old spayed domestic short-haired cat presented for evaluation of weight loss, cardiomegaly and pleural effusion. Echocardiographic examination demonstrated a thickened pericardium with mild pericardial effusion and a large volume of pleural effusion characterized by exudate. Although the cat was treated with antibiotics, the clinical symptoms did not improve. The cat developed dyspnea and died on day 7. Necropsy revealed a large amount of modified transudates ascites, pleural effusion and markedly dilated pericardium. Histopathological examination revealed severe exudation of fibrin and granulation tissue in a thick layer of the epicardium. The cat was diagnosed with fibrinous pericarditis secondary to bacterial infection.

Platelet-rich fibrin or platelet-rich plasma – which one is better? an opinion

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Shweta Bansal

2017-01-01

Full Text Available The healing of hard and soft tissue in mediated by a wide range of intracellular and extracellular events that are regulated by signaling proteins. Platelets can play a crucial role in periodontal regeneration as they are the reservoirs of growth factors and cytokines which are the key factors for regeneration of bone and maturation of soft tissue. Platelet-rich plasma (PRP is first generation platelet concentrate. However, the short duration of cytokine release and its poor mechanical properties have resulted in search of new material. Platelet-rich fibrin (PRF is a natural fibrin-based biomaterial prepared from an anticoagulant-free blood harvest without any artificial biochemical modification (no bovine thrombin is required that allows obtaining fibrin membranes enriched with platelets and growth factors. The slow polymerization during centrifugation, fibrin-based structure, ease of preparation, minimal expense makes PRF somewhat superior in some aspect to PRP.

Tunneled dialysis catheter exchange with fibrin sheath disruption is not associated with increased rate of bacteremia.

Science.gov (United States)

Valliant, Amanda M; Chaudhry, Muhammad K; Yevzlin, Alexander S; Astor, Brad; Chan, Micah R

2015-01-01

Tunneled dialysis catheters are the most common form of vascular access among incident dialysis patients in the United States. Fibrin sheath formation is a frequent cause of late catheter dysfunction requiring an exchange procedure with balloon disruption of the fibrin sheath. It is unknown whether fibrin sheath disruption is associated with increased incidence of bacteremia or catheter failure. We reviewed all tunneled dialysis catheter exchange procedures at the University of Wisconsin between January 2008 and December 2011. The primary outcome was incidence of bacteremia, defined as positive blood cultures within 2 weeks of the procedure. Catheter failure, requiring intervention or replacement, was examined as a secondary outcome. Baseline characteristics examined included diabetic status, gender, race and age. A total of 163 procedures were reviewed; 67 (41.1%) had fibrin sheath disruption and 96 did not. Bacteremia occurred in 4.5% (3/67) of those with and 3.1% (3/97) of those without fibrin sheath disruption (p=0.65). Fibrin sheath disruption was not significantly associated with the risk of catheter failure (adjusted hazard ratio [aHR]=1.34; 95% confidence interval [CI]: 0.87-2.10; p=0.18). Diabetes was associated with greater risk of catheter failure (aHR=1.88; 95% CI: 1.19-2.95; p=0.006), whereas higher age was associated with a lower risk of catheter failure (aHR per 10 years=0.83; 95% CI: 0.72-0.96; p=0.01). This study demonstrates that there is no significant increase in bacteremia and subsequent catheter dysfunction rates after fibrin sheath disruption compared to simple over the wire exchange. These results are encouraging given the large numbers of patients utilizing tunneled catheters for initial hemodialysis access and the known rates of fibrin sheath formation leading to catheter failure.

Local and systemic effects of fibrin and cyanoacrylate adhesives on lung lesions in rabbits

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Marcus V.H. Carvalho

Full Text Available OBJECTIVES: Tissue adhesives can be used to prevent pulmonary air leaks, which frequently occur after lung interventions. The objective of this study is to evaluate local and systemic effects of fibrin and cyanoacrylate tissue adhesives on lung lesions in rabbits. METHODS: Eighteen rabbits were submitted to videothoracoscopy + lung incision alone (control or videothoracoscopy + lung incision + local application of fibrin or cyanoacrylate adhesive. Blood samples were collected and assessed for leukocyte, neutrophil and lymphocyte counts and interleukin-8 levels preoperatively and at 48 hours and 28 days post-operatively. After 28 days, the animals were euthanized for gross examination of the lung surface, and lung fragments were excised for histopathological analysis. RESULTS: Fibrin and cyanoacrylate produced similar adhesion scores of the lung to the parietal pleura. Microscopic analysis revealed uniform low-cellular tissue infiltration in the fibrin group and an intense tissue reaction characterized by dense inflammatory infiltration of granulocytes, giant cells and necrosis in the cyanoacrylate group. No changes were detected in the leukocyte, neutrophil or lymphocyte count at any time-point, while the interleukin-8 levels were increased in the fibrin and cyanoacrylate groups after 48 hours compared with the pre-operative control levels (p<0.01. CONCLUSION: Both adhesive agents promoted normal tissue healing, with a more pronounced local inflammatory reaction observed for cyanoacrylate. Among the serum markers of inflammation, only the interleukin-8 levels changed post-operatively, increasing after 48 hours and decreasing after 28 days to levels similar to those of the control group in both the fibrin and cyanoacrylate groups.

Percutaneous treatment of femoral pseudoaneurysms: comparison of fibrin sealant against thrombin

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Daniel Mendes Pinto

2013-12-01

Full Text Available INTRODUCTION: Femoral pseudoaneurysms are a complication that occurs in connection with up to 8% of percutaneous procedures. Of the available treatments, ultrasound guided thrombin injection has a high success rate and is well-tolerated by patients. The combination of thrombin and fibrinogen known as fibrin sealant forms a stable clot and can be used to treat pseudoaneurysms, particularly those with complex anatomy and larger size. OBJECTIVE: To compare the results of treating femoral pseudoaneurysm in two ways: Group T was treated with thrombin alone and Group T+F was treated with fibrin sealant (thrombin+fibrinogen. METHODS: A retrospective analysis was conducted of femoral pseudoaneurysm cases treated between January 2005 and December 2012. RESULTS: Twenty-eight patients were treated, 21 with thrombin alone and seven with fibrin sealant. All patients in group T were treated successfully, but only four patients in group T+F were treated successfully (57.1% success rate in Group T+F, p<0.01. The three cases of failure in group T+F needed surgery and in one of these cases the complication was embolization to the femoral bifurcation. The pseudoaneurysms that were treated with fibrin sealant were larger (25 cm3 in Group T and 57.7 cm3 in Group T+F, p=0.02 and required larger volumes of thrombin (0.5 mL in Group T and 1.0 mL in Group T+F, p<0.01. There was one complication in Group T and two complications in Group T+F (p<0.01. CONCLUSIONS: Irrespective of the small number of cases reviewed, treatment with thrombin alone was superior to treating with fibrin sealant, since it caused few complications and was more effective at correcting pseudoaneurysms.

Fibrin Clots Are Equilibrium Polymers That Can Be Remodeled Without Proteolytic Digestion

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Chernysh, Irina N.; Nagaswami, Chandrasekaran; Purohit, Prashant K.; Weisel, John W.

2012-01-01

Fibrin polymerization is a necessary part of hemostasis but clots can obstruct blood vessels and cause heart attacks and strokes. The polymerization reactions are specific and controlled, involving strong knob-into-hole interactions to convert soluble fibrinogen into insoluble fibrin. It has long been assumed that clots and thrombi are stable structures until proteolytic digestion. On the contrary, using the technique of fluorescence recovery after photobleaching, we demonstrate here that the...

Achilles Tendon Open Surgical Treatment With Platelet-Rich Fibrin Matrix Augmentation: Biomechanical Evaluation.

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Alviti, Federica; Gurzì, Michele; Santilli, Valter; Paoloni, Marco; Padua, Roberto; Bernetti, Andrea; Bernardi, Marco; Mangone, Massimiliano

The relationship between surgical technique and ankle biomechanical properties after surgery for acute rupture of the Achilles tendon (ATR) has not yet been fully investigated. Platelet-rich fibrin (PRF) matrices seem to play a central role in the complex processes of tendon healing. Our aim was to analyze the biomechanical characteristics, stiffness, and mechanical work of the ankle during walking in patients who had undergone surgery after ATR with and without PRF augmentation. We performed a retrospective review of all consecutive patients who had been treated with surgical repair after ATR. Of the 20 male subjects enrolled, 9 (45%) had undergone conventional open repair of the Achilles tendon using the Krackow technique (no-PRF) and 11 (55%) had undergone surgery with PRF augmentation. An additional 8 healthy subjects were included as a control group. A gait analysis evaluation was performed at 6 months after surgery. The percentage of the stance time of the operated leg, double-support time of the healthy leg, and net work of the ankle during the gait cycle showed statistically significant differences between the no-PRF and the healthy group (p < .005). No differences were found between the PRF and healthy groups. Treatment with suture and PRF augmentation could result in significant functional improvements in term of efficiency of motion. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Plasminogen activator activity and plasma-coagulum lysis measured by use of optimized fibrin gel structure preformed in microtiter plates

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Sidelmann, Johannes Jakobsen; Jespersen, J; Gram, J

1995-01-01

We introduce a new fibrin plate assay performed in microtiter plates. By means of spectroscopic studies we optimized the structure of the fibrin gel and then used the optimized fibrin gel to determine plasminogen activator activity. Plasminogen activator solutions were applied on top of the fibri...

Incorporation of vitronectin into fibrin clots. Evidence for a binding interaction between vitronectin and gamma A/gamma' fibrinogen.

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Podor, Thomas J; Campbell, Stephanie; Chindemi, Paul; Foulon, Denise M; Farrell, David H; Walton, Philip D; Weitz, Jeffrey I; Peterson, Cynthia B

2002-03-01

Vitronectin is an abundant plasma protein that regulates coagulation, fibrinolysis, complement activation, and cell adhesion. Recently, we demonstrated that plasma vitronectin inhibits fibrinolysis by mediating the interaction of type 1 plasminogen activator inhibitor with fibrin (Podor, T. J., Peterson, C. B., Lawrence, D. A., Stefansson, S., Shaughnessy, S. G., Foulon, D. M., Butcher, M., and Weitz, J. I. (2000) J. Biol. Chem. 275, 19788-19794). The current studies were undertaken to further examine the interactions between vitronectin and fibrin(ogen). Comparison of vitronectin levels in plasma with those in serum indicates that approximately 20% of plasma vitronectin is incorporated into the clot. When the time course of biotinylated-vitronectin incorporation into clots formed from (125)I-fibrinogen is monitored, vitronectin incorporation into the clot parallels that of fibrinogen in the absence or presence of activated factor XIII. Vitronectin binds specifically to fibrin matrices with an estimated K(d) of approximately 0.6 microm. Additional vitronectin subunits are assembled on fibrin-bound vitronectin multimers through self-association. Confocal microscopy of fibrin clots reveals the globular vitronectin aggregates anchored at intervals along the fibrin fibrils. This periodicity raised the possibility that vitronectin interacts with the gamma A/gamma' variant of fibrin(ogen) that represents about 10% of total fibrinogen. In support of this concept, the vitronectin which contaminates fibrinogen preparations co-purifies with the gamma A/gamma' fibrinogen fraction, and clots formed from gamma A/gamma' fibrinogen preferentially bind vitronectin. These studies reveal that vitronectin associates with fibrin during coagulation, and may thereby modulate hemostasis and inflammation.

[Use of fibrin glue in the prevention of leakage in pancreatico-jejunal anastomoses].

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Stojanović, M; Jeremic, M; Stojanović, P; Stojiljković, M; Gmijović, D; Stanojković, Z; Savić, V; Djordjević, V; Cvetković, Z; Kostov, M; Colović, R

2002-01-01

The aim of this study was to test the protective effects of fibrin sealing on the pancreatico-jejunostomy (PJA), the high-risk anastomosis following pancreas head resection. Experimental study was performed on the mongrel dogs, divided in two groups (20 animals each): Experimental group-with end to end "dunking" PJA, protected by temporary occlusion of the pancreatic duct with fibrin sealant/Tissucol/Immuno Ag/, while control group was without any protective procedure. The animals were followed 5 months in order to study: protective effects of such procedure on the PJA quantified with the percent of anastomotic leakage, effects of the exocrine secretion and effects the endocrine function Results: PJA leakage occurred in 13.33% in control group. No leakage was registered in experimental group. Biochemical, histological and electron microscopic study showed slight transitory elevation of amylase levels. Fibrin glue plug was dissolved and pancreatic juice output was reestablished 12th days postoperatively. Long term follow-up showed no damages of the endocrine and exocrine pancreas. Pancreatic duct occlusion with fibrin glue appeared to be an useful method in the prevention of pancreatico-jejunostomy leakage, without negative effects on the exocrine and endocrine pancreas.

Use of fibrin sealants for the localized, controlled release of cefazolin

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Tredwell, Stephen; Jackson, John K.; Hamilton, Donald; Lee, Vivian; Burt, Helen M.

2006-01-01

Background Fibrin sealants are used increasingly in surgery to reduce bleeding and improve wound healing. They have great potential as biocompatible, biodegradable drug delivery systems, because the sealant may adhere to the target tissue and allow controlled release of the drug over an extended period. We investigated the encapsulation, stability and controlled release of erythromycin and cefazolin from Beriplast fibrin sealants (Aventis Behring Canada). Methods Drug-loaded clots were cast in glass vials and allowed to set. We observed the clots for drug precipitation and aggregation, and we assessed the effect of drug encapsulation on clot strength. Drug stability and release from the clots in phosphate buffered saline (PBS) was quantified by ultraviolet and visible violet absorbance spectroscopy and high-performance liquid chromatography. Results Erythromycin was found to release slowly from the fibrin clots over the first 2 hours but then degrade rapidly. Cefazolin was found to be very stable in clots in PBS (97% stable at 2 d and 93% stable at 5 d). The drug released in a controlled manner over 2 days, with most being released during the first day. The dose of drug released could be varied by changing the amount placed in the thrombin solution. Clot thickness had no effect on the rate of cefazolin release. Conclusion Overall, the 2-day release profile and the excellent stability of the drug suggest that cefazolin-loaded fibrin sealants may offer an effective route of postoperative antibiotic delivery. PMID:17152573

Lyophilized Platelet-Rich Fibrin (PRF Promotes Craniofacial Bone Regeneration through Runx2

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Qi Li

2014-05-01

Full Text Available Freeze-drying is an effective means to control scaffold pore size and preserve its composition. The purpose of the present study was to determine the applicability of lyophilized Platelet-rich fibrin (LPRF as a scaffold for craniofacial tissue regeneration and to compare its biological effects with commonly used fresh Platelet-rich fibrin (PRF. LPRF caused a 4.8-fold ± 0.4-fold elevation in Runt-related transcription factor 2 (Runx2 expression in alveolar bone cells, compared to a 3.6-fold ± 0.2-fold increase when using fresh PRF, and a more than 10-fold rise of alkaline phosphatase levels and mineralization markers. LPRF-induced Runx2 expression only occurred in alveolar bone and not in periodontal or dental follicle cells. LPRF also caused a 1.6-fold increase in osteoblast proliferation (p < 0.001 when compared to fresh PRF. When applied in a rat craniofacial defect model for six weeks, LPRF resulted in 97% bony coverage of the defect, compared to 84% for fresh PRF, 64% for fibrin, and 16% without scaffold. Moreover, LPRF thickened the trabecular diameter by 25% when compared to fresh PRF and fibrin, and only LPRF and fresh PRF resulted in the formation of interconnected trabeculae across the defect. Together, these studies support the application of lyophilized PRF as a biomimetic scaffold for craniofacial bone regeneration and mineralized tissue engineering.

Protein nanocoatings on synthetic polymeric nanofibrous membranes designed as carriers for skin cells.

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Bacakova, Marketa; Pajorova, Julia; Stranska, Denisa; Hadraba, Daniel; Lopot, Frantisek; Riedel, Tomas; Brynda, Eduard; Zaloudkova, Margit; Bacakova, Lucie

2017-01-01

Protein-coated resorbable synthetic polymeric nanofibrous membranes are promising for the fabrication of advanced skin substitutes. We fabricated electrospun polylactic acid and poly(lactide- co -glycolic acid) nanofibrous membranes and coated them with fibrin or collagen I. Fibronectin was attached to a fibrin or collagen nanocoating, in order further to enhance the cell adhesion and spreading. Fibrin regularly formed a coating around individual nanofibers in the membranes, and also formed a thin noncontinuous nanofibrous mesh on top of the membranes. Collagen also coated most of the fibers of the membrane and randomly created a soft gel on the membrane surface. Fibronectin predominantly adsorbed onto a thin fibrin mesh or a collagen gel, and formed a thin nanofibrous structure. Fibrin nanocoating greatly improved the attachment, spreading, and proliferation of human dermal fibroblasts, whereas collagen nanocoating had a positive influence on the behavior of human HaCaT keratinocytes. In addition, fibrin stimulated the fibroblasts to synthesize fibronectin and to deposit it as an extracellular matrix. Fibrin coating also showed a tendency to improve the ultimate tensile strength of the nanofibrous membranes. Fibronectin attached to fibrin or to a collagen coating further enhanced the adhesion, spreading, and proliferation of both cell types.

Efficacy of fibrin-sealants in reducing biliary leakage following laparoscopic common bile duct exploration.

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Parra-Membrives, Pablo; Martínez-Baena, Darío; Lorente-Herce, José Manuel; Martín-Balbuena, Ramón

2018-05-21

In spite of the acquired experience with laparoscopic common bile duct exploration (LCBDE) for choledocholithiasis management, there is still a risk of biliary leakage of 5% to 15% following choledochotomy closure. We evaluate the usefulness of fibrin-collagen sealants to reduce the incidence of biliary fistula after laparoscopic choledochorrhaphy. We report a retrospective analysis of 96 patients undergoing LCBDE from March 2009 to March 2017, whose closure of the bile duct was completed by antegrade stenting and choledochorraphy or by performing a primary suture. The study population was divided into two groups according to whether they received a collagen-fibrin sealant covering the choledochorrhaphy or not, analyzing the incidence of postoperative biliary fistula in each group. Thirty-nine patients (41%) received a fibrin-collagen sponge while the bile duct closure was not covered in the remaining 57 patients (59%). The incidence of biliary fistula was 7.7% (3 patients) in the first group and 14% (8 patients) in the second group (P=.338). In patients who underwent primary choledochorraphy, the fibrin-collagen sealant reduced the incidence of biliary leakage significantly (4.5% vs. 33%, P=.020), which was a protective factor with an odds ratio of 10.5. Fibrin-collagen sealants may decrease the incidence of biliary fistula in patients who have undergone primary bile duct closure following LCBDE. Copyright © 2018 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

Autologous fibrin sealant (Vivostat®) in the neurosurgical practice: Part I: Intracranial surgical procedure

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Graziano, Francesca; Certo, Francesco; Basile, Luigi; Maugeri, Rosario; Grasso, Giovanni; Meccio, Flavia; Ganau, Mario; Iacopino, Domenico G.

2015-01-01

Background: Hemorrhages, cerebrospinal fluid (CSF) fistula and infections are the most challenging postoperative complications in Neurosurgery. In this study, we report our preliminary results using a fully autologous fibrin sealant agent, the Vivostat® system, in achieving hemostasis and CSF leakage repair during cranio-cerebral procedures. Methods: From January 2012 to March 2014, 77 patients were studied prospectively and data were collected and analyzed. Autologous fibrin sealant, taken from patient's blood, was prepared with the Vivostat® system and applied on the resection bed or above the dura mater to achieve hemostasis and dural sealing. The surgical technique, time to bleeding control and associated complications were recorded. Results: A total of 79 neurosurgical procedures have been performed on 77 patients. In the majority of cases (98%) the same autologous fibrin glue provided rapid hemostasis and dural sealing. No patient developed allergic reactions or systemic complications in association with its application. There were no cases of cerebral hematoma, swelling, infection, or epileptic seizures after surgery whether in the immediate or in late period follow-up. Conclusions: In this preliminary study, the easy and direct application of autologous fibrin sealant agent helped in controlling cerebral bleeding and in providing prompt and efficient dural sealing with resolution of CSF leaks. Although the use of autologous fibrin glue seems to be safe, easy, and effective, further investigations are strongly recommended to quantify real advantages and potential limitations. PMID:25984391

Fibrin glue on an aortic cusp detected by transesophageal echocardiography after valve-sparing aortic valve replacement: a case report.

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Nakahira, Junko; Ishii, Hisanari; Sawai, Toshiyuki; Minami, Toshiaki

2015-03-07

Fibrin glue is used commonly during cardiac surgery but can behave as an intracardiac abnormal foreign body following surgery. There have been few such cases reported, and they were typically noticed only because of the resulting catastrophic cardiac conditions, such as valvular malfunction. We report a case where, for the first time, transesophageal echocardiography was used to detected fibrin glue that was adherent to the ventricular side of a patient's aortic valve immediately after aortic declamping. A 45-year-old Japanese man with Marfan syndrome underwent an aortic valve-sparing operation to treat moderate aortic valve regurgitation resulting from enlargement of his right coronary cusp. Fibrin glue was lightly applied to the suture line between the previous and new grafts. Transesophageal echocardiography performed prior to weaning from the cardiopulmonary bypass revealed mild aortic valve regurgitation in addition to a mobile membranous structure attached to the ventricular side of his aortic valve. It was identified as fibrin glue. We resolved the regurgitation by removing the fibrin glue and repeating the aortic cusp plication. The patient had no complications during recovery. Fibrin glue can act as an intracardiac foreign body and lead to a potentially fatal embolism. We demonstrated the use of transesophageal echocardiography to detect a fibrin glue-derived intracardiac abnormal foreign body and to confirm its removal. To the best of our knowledge, this is the first case where fibrin glue adherent to the aortic valve was detected by transesophageal echocardiography. These findings demonstrate the importance of using transesophageal echocardiography during cardiac surgery that involves using biological glues.

Soft tissue regeneration using leukocyte-platelet rich fibrin after exeresis of hyperplastic gingival lesions: two case reports.

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di Lauro, A E; Abbate, D; Dell'Angelo, B; Iannaccone, G A; Scotto, F; Sammartino, G

2015-11-02

Leukocyte-platelet rich fibrin belongs to a second generation of platelet concentrates that does not need biochemical blood manipulation. It is used for tissue healing and regeneration in periodontal and oral-maxillofacial surgery. We report two cases of hyperplastic gingival lesions treated by exeresis and application of leukocyte-platelet rich fibrin membranes in order to improve and accelerate tissue healing. Two patients (a 78-year-old Caucasian woman and a 30-year-old Caucasian man) were treated for hyperplastic gingival lesions. They underwent to exeresis of lesions and application of leukocyte-platelet rich fibrin membranes. Tissue healing was clinically evaluated after 1, 3, 7, 14 and 30 postoperative days. No recurrences were observed after 2 years of semi-annual follow up. We obtained rapid and good healing of soft tissues probably due to the elevated content of leukocytes, platelets and growth factors in the leukocyte-platelet rich fibrin. Based on our results we suggest the use of leukocyte-platelet rich fibrin to cover wounds after exeresis of oral neoformations such as hyperplastic gingival lesions.

Construction of tissue-engineered small-diameter vascular grafts in fibrin scaffolds in 30 days.

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Gui, Liqiong; Boyle, Michael J; Kamin, Yishai M; Huang, Angela H; Starcher, Barry C; Miller, Cheryl A; Vishnevetsky, Michael J; Niklason, Laura E

2014-05-01

Tissue-engineered small-diameter vascular grafts have been developed as a promising alternative to native veins or arteries for replacement therapy. However, there is still a crucial need to improve the current approaches to render the tissue-engineered blood vessels more favorable for clinical applications. A completely biological blood vessel (3-mm inner diameter) was constructed by culturing a 50:50 mixture of bovine smooth muscle cells (SMCs) with neonatal human dermal fibroblasts in fibrin gels. After 30 days of culture under pulsatile stretching, the engineered blood vessels demonstrated an average burst pressure of 913.3±150.1 mmHg (n=6), a suture retention (53.3±15.4 g) that is suitable for implantation, and a compliance (3.1%±2.5% per 100 mmHg) that is comparable to native vessels. These engineered grafts contained circumferentially aligned collagen fibers, microfibrils and elastic fibers, and differentiated SMCs, mimicking a native artery. These promising mechanical and biochemical properties were achieved in a very short culture time of 30 days, suggesting the potential of co-culturing SMCs with fibroblasts in fibrin gels to generate functional small-diameter vascular grafts for vascular reconstruction surgery.

Effect of centrifugation time on growth factor and MMP release of an experimental platelet-rich fibrin-type product.

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Eren, Gülnihal; Gürkan, Ali; Atmaca, Harika; Dönmez, Ayhan; Atilla, Gül

2016-07-01

Platelet-rich fibrin (PRF) has a controlled release of growth factors due to the fibrin matrix structure. Different centrifugation protocols were suggested for PRF preparation. Since the derivation method of PRF can alter its contents, in the present study it is aimed to investigate the cell contents and transforming growth factor beta-1 (TGF-β1), platelet-derived growth factor (PDGF-AB), vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMP)-1 and-8 release from experimental PRF-type membranes obtained with different centrifugation times at 400 gravity. Three blood samples were collected from 20 healthy non-smoker volunteers. One tube was used for whole blood analyses. The other two tubes were centrifuged at 400 g for 10 minutes (group A) or 12 minutes (group B). Each experimental PRF-type membrane was placed in Dulbecco's Modified Eagle's Medium (DMEM)and at 1, 24 and 72 hours, TGF-β1, PDGF-AB, VEGF, MMP-1 and -8 release amounts were analysed by enzyme-linked immunosorbent assay (ELISA). The blood cell count of membranes was determined by subtracting plasma supernatant and red blood cell (RBC) mixture from the whole blood cell counts. At 72 hours, the VEGF level of group B was statistically higher than that of group A (p = 0.040). The centrifugation time was not found to influence the release of other growth factors, enzymes and cell counts. Within the limits of the present study, it might be suggested that centrifugation time at a constant gravity has a significant effect on the VEGF levels released from experimental PRF-type membrane. It can be concluded that due to the importance of VEGF in the tissue healing process, membranes obtained at 12-minute centrifugation time may show a superior potential in wound healing.

Comparison of commercial fibrin sealants in facelift surgery: a prospective study

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Botti G

2013-11-01

Full Text Available Giovanni Botti,1 Michele Pascali,2 Chiara Botti,1 Florian Bodog,3 Pietro Gentile,2 Valerio Cervelli2 1Villa Bella Clinic, Salò, 2Department of Plastic and Reconstructive Surgery, University of Rome Tor Vergata, Italy; 3University of Oradea, Oradea, Romania Background: The aim of this study was to compare the effects of two types of fibrin glue in patients undergoing facelift surgery. Methods: A prospective, controlled "right-left side" study was carried out in 20 patients. The two fibrin sealants used were Quixil® and Tissucol®. The two sealants were used at the same time, ie, one on one side of the face and the other on the contralateral side. Comparisons were made with regard to rates of hematoma and seroma, degree of induration, edema, ecchymosis, pain levels, and patient satisfaction. Results: The results were almost equivalent. The only exception was a significant (40 mL hematoma in a patient treated with Quixil. Bleeding was most likely due to a sudden rise in blood pressure during the immediate postoperative period. However, it must be emphasized that, while Tissucol actually seals the undermined area, thus virtually eliminating the dead space, Quixil acts differently, in that its effectiveness in preventing hematoma is linked mainly to its hemostatic effect. Conclusion: The two fibrin sealants used were nearly identical with regard to patient safety and quality of the result. Nevertheless, it is noted that, while Tissucol has both hemostatic and "gluing" effects, Quixil is mainly effective in securing hemostasis. Keywords: facelift surgery, rhytidectomy, fibrin sealants, hematoma

Application of fibrin glue with bandage contact lens in pterygium surgery

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Wei Liu

2014-05-01

Full Text Available AIM: To explore the efficacy of fibrin glue with bandage contact lens for pain relief after pterygium surgery performed with limbal autograft transplantation.METHODS: A prospective clinical trial was carried out in 52 patients(72 eyesoperated for primary nasal pterygium. All patients were randomly divided into the fibrin glue with bandage contact lens group(experimental group, 28 cases, 38 eyesand suture group(control group, 24 cases, 34 eyes. Autologous limbal graft taken from the superotemporal limbus was used to cover the sclera after pterygium excision under local anesthesia with 20g/L lidocaine. In experimental group, the transplant was attached to the sclera with fibrin tissue adhesive and in control group with 10-0 Virgin silk sutures. Experimental group weared bandage contact lens after surgery while the control group did not. The degree of pain after surgery was evaluated at 1, 2, 3, 5 and 7d after surgery. Follow-up was 6mo, matching degree of graft and complication such as infection, relapse, implant healing badness and subconjunctival cyst were mainly observed and recorded.RESULTS: The pain index scores of the experimental group were significantly less than those of control group(all P=0.000. In observation period, all conjunctival autografts in both groups were successfully attached and were intact without falling off, dissolution or recurrence and there were no complications such as infection, relapse, implant healing badness and subconjunctival cyst.CONCLUSION: Fibrin glue with bandage contact lens could significantly release pain response afterpterygium excision surgery.

Physical determinants of fibrinolysis in single fibrin fibers.

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Igal Bucay

Full Text Available Fibrin fibers form the structural backbone of blood clots; fibrinolysis is the process in which plasmin digests fibrin fibers, effectively regulating the size and duration of a clot. To understand blood clot dissolution, the influence of clot structure and fiber properties must be separated from the effects of enzyme kinetics and perfusion rates into clots. Using an inverted optical microscope and fluorescently-labeled fibers suspended between micropatterned ridges, we have directly measured the lysis of individual fibrin fibers. We found that during lysis 64 ± 6% of fibers were transected at one point, but 29 ± 3% of fibers increase in length rather than dissolving or being transected. Thrombin and plasmin dose-response experiments showed that the elongation behavior was independent of plasmin concentration, but was instead dependent on the concentration of thrombin used during fiber polymerization, which correlated inversely with fiber diameter. Thinner fibers were more likely to lyse, while fibers greater than 200 ± 30 nm in diameter were more likely to elongate. Because lysis rates were greatly reduced in elongated fibers, we hypothesize that plasmin activity depends on fiber strain. Using polymer physics- and continuum mechanics-based mathematical models, we show that fibers polymerize in a strained state and that thicker fibers lose their prestrain more rapidly than thinner fibers during lysis, which may explain why thick fibers elongate and thin fibers lyse. These results highlight how subtle differences in the diameter and prestrain of fibers could lead to dramatically different lytic susceptibilities.

The application of large amplitude oscillatory stress in a study of fully formed fibrin clots

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Lamer, T. F.; Thomas, B. R.; Curtis, D. J.; Badiei, N.; Williams, P. R.; Hawkins, K.

2017-12-01

The suitability of controlled stress large amplitude oscillatory shear (LAOStress) for the characterisation of the nonlinear viscoelastic properties of fully formed fibrin clots is investigated. Capturing the rich nonlinear viscoelastic behaviour of the fibrin network is important for understanding the structural behaviour of clots formed in blood vessels which are exposed to a wide range of shear stresses. We report, for the first time, that artefacts due to ringing exist in both the sample stress and strain waveforms of a LAOStress measurement which will lead to errors in the calculation of nonlinear viscoelastic properties. The process of smoothing the waveforms eliminates these artefacts whilst retaining essential rheological information. Furthermore, we demonstrate the potential of LAOStress for characterising the nonlinear viscoelastic properties of fibrin clots in response to incremental increases of applied stress up to the point of fracture. Alternating LAOStress and small amplitude oscillatory shear measurements provide detailed information of reversible and irreversible structural changes of the fibrin clot as a consequence of elevated levels of stress. We relate these findings to previous studies involving large scale deformations of fibrin clots. The LAOStress technique may provide useful information to help understand why some blood clots formed in vessels are stable (such as in deep vein thrombosis) and others break off (leading to a life threatening pulmonary embolism).

A Novel Technique Using a Protection Filter During Fibrin Sheath Removal for Implanted Venous Access Device Dysfunction

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Sotiriadis, Charalampos; Hajdu, Steven David [University Hospital of Lausanne, Cardiothoracic and Vascular Unit, Department of Radiology (Switzerland); Degrauwe, Sophie [University Hospital of Lausanne, Department of Cardiology (Switzerland); Barras, Heloise; Qanadli, Salah Dine, E-mail: salah.qanadli@chuv.ch [University Hospital of Lausanne, Cardiothoracic and Vascular Unit, Department of Radiology (Switzerland)

2016-08-15

With the increased use of implanted venous access devices (IVADs) for continuous long-term venous access, several techniques such as percutaneous endovascular fibrin sheath removal, have been described, to maintain catheter function. Most standard techniques do not capture the stripped fibrin sheath, which is subsequently released in the pulmonary circulation and may lead to symptomatic pulmonary embolism. The presented case describes an endovascular technique which includes stripping, capture, and removal of fibrin sheath using a novel filter device. A 64-year-old woman presented with IVAD dysfunction. Stripping was performed using a co-axial snare to the filter to capture the fibrin sheath. The captured fragment was subsequently removed for visual and pathological verification. No immediate complication was observed and the patient was discharged the day of the procedure.

Three-dimensional bone tissue substitute based on a human mesenchymal stem cell culture on a nanofiber carrier and inorganic matrix

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Martin Krbec

2016-01-01

Full Text Available The aim was to construct a composite structure for bone tissue substitute on the basis of a degradable composite of an organic nanofiber carrier and an inorganic matrix in 3D, and to achieve subsequent colonisation by differentiated human mesenchymal stem cells (hMSC towards osteocytes. We developed an active bone tissue substitute using nanofiber technology for a polycaprolactone (PCL scaffold with the addition of hydroxyapatite and the colonisation of both components with hMSC with the ability of differentiation towards osteocytes. The constructed composition included the components necessary for bone healing (inorganic and cellular and it also forms a spatially-oriented 3D structure. We used polycaprolactone Mw 70,000 with electrostatic spinning for the formation of nanofibers using a modified NanospiderTM method. For the inorganic component we used orthophosphate-calcium silicate with a crystal size of 1-2 mm which the nanofiber membrane was coated with. Both components were connected together with a tissue adhesive based of fibrin glue. Cultivated hMSC cells at a concentration of 1.2 × 104/cm2 were multiplied in vitro and then cultivated in the expansion medium. HMSC overgrew both the PCL membrane and the Si-CaP crystals. After colonisation with cultivated cells, this composite 3D structure can serve as a three-dimensional bone tissue replacement.

Identification of p63+ keratinocyte progenitor cells in circulation and their matrix-directed differentiation to epithelial cells.

Science.gov (United States)

Nair, Renjith P; Krishnan, Lissy K

2013-04-11

In the event of chronic diabetes or burn wounds, accomplishing skin regeneration is a major concern. Autologous skin grafting is the most effective remedy, but the tissue harvest may create more nonhealing wounds. Currently available skin substitutes have a limited clinical outcome because of immune reactions arising from the xenobiotic scaffold or allogenous cells. Autologous stem cells that can be collected without an additional injury may be a viable option for skin-tissue engineering. Presence of a low number of keratinocyte progenitor cells (KPCs) within the peripheral blood mononuclear cell (PBMNC) population has been indicated. Identification, isolation, expansion, and differentiation of KPCs is necessary before they are considered for skin regeneration, which is the focus of this study. Culture of isolated human PBMNCs on a cell-specific matrix was carried out to induce differentiation of KPCs. Flow cytometry and reverse transcriptase polymerase chain reaction were done for epithelial stem cell marker p63 and lineage markers cytokeratin 5 and cytokeratin 14, to track differentiation. Proliferation was confirmed by quantifying the proliferating cell nuclear antigen-expressing cells. Immunostaining with epithelial cell markers, involucrin and filaggrin, was carried out to establish terminal differentiation. Microscopic analysis confirmed growth and survival of KPCs on the dermal fibroblast monolayer and on a transplantable fibrin sheet. We demonstrated that KPCs are p63(+) and CD34-. The specifically designed composition of the extracellular matrix was found to support selective adhesion, proliferation, and differentiation of p63(+) KPCs. The PBMNC culture for 12 days under controlled conditions resulted in a homogenous population that expressed cytokeratins, and >90% of the cells were found to proliferate. Subculture for 5 days resulted in expression of filaggrin and involucrin, suggesting terminal differentiation. Transfer of matrix-selected KPCs to a

Binding of thrombin-activated platelets to a fibrin scaffold through α(IIb)β₃ evokes phosphatidylserine exposure on their cell surface.

Science.gov (United States)

Brzoska, Tomasz; Suzuki, Yuko; Mogami, Hideo; Sano, Hideto; Urano, Tetsumei

2013-01-01

Recently, by employing intra-vital confocal microscopy, we demonstrated that platelets expose phosphatidylserine (PS) and fibrin accumulate only in the center of the thrombus but not in its periphery. To address the question how exposure of platelet anionic phospholipids is regulated within the thrombus, an in-vitro experiment using diluted platelet-rich plasma was employed, in which the fibrin network was formed in the presence of platelets, and PS exposure on the platelet surface was analyzed using Confocal Laser Scanning Microscopy. Almost all platelets exposed PS after treatment with tissue factor, thrombin or ionomycin. Argatroban abrogated fibrin network formation in all samples, however, platelet PS exposure was inhibited only in tissue factor- and thrombin-treated samples but not in ionomycin-treated samples. FK633, an α(IIb)β₃ antagonist, and cytochalasin B impaired platelet binding to the fibrin scaffold and significantly reduced PS exposure evoked by thrombin. Gly-Pro-Arg-Pro amide abrogated not only fibrin network formation, but also PS exposure on platelets without suppressing platelet binding to fibrin/fibrinogen. These results suggest that outside-in signals in platelets generated by their binding to the rigid fibrin network are essential for PS exposure after thrombin treatment.

Fibrin hydrogels to deliver dental stem cells of the apical papilla for regenerative medicine.

Science.gov (United States)

Germain, Loïc; De Berdt, Pauline; Vanacker, Julie; Leprince, Julian; Diogenes, Anibal; Jacobs, Damien; Vandermeulen, Gaëlle; Bouzin, Caroline; Préat, Véronique; Dupont-Gillain, Christine; des Rieux, Anne

2015-01-01

Evaluation of survival, proliferation and neurodifferentiation of dental stem cells from the apical papilla (SCAP) in fibrin hydrogels. We hypothesized that fibrin composition will influence cell behavior. Modulus, pore and fiber size were measured. SCAP in vitro viability, proliferation and neural differentiation, as well as in vivo proliferation and angiogenesis were studied. Hydrogel moduli were influenced by fibrin formulation but not hydrogel morphology, SCAP in vitro viability and proliferation. In total 60% of SCAP expressed PanNeurofilament in vitro without induction in Fibrinogen50-Thrombin10. SCAP proliferated when implanted in vivo and stimulated host endothelial cell infiltration. Fibrinogen30-Thrombin10 or Thrombin50 would be more favorable to in vitro SCAP viability and in vivo proliferation, while Fibrinogen 50-Thrombin50 would be more adapted to neurodifferentiation.

Effect of Titanium-prepared Platelet-rich Fibrin Treatment on the ...

African Journals Online (AJOL)

Effect of Titanium-prepared Platelet-rich Fibrin Treatment on the Angiogenic Biomarkers in Gingival Crevicular Fluid in Infrabony Defects of Patients with Chronic Periodontitis: A Randomized Controlled Clinical Trial.

A Human Nuclear Shuttling Protein That Interacts with Human Immunodeficiency Virus Type 1 Matrix Is Packaged into Virions

Science.gov (United States)

Gupta, Kalpana; Ott, David; Hope, Thomas J.; Siliciano, Robert F.; Boeke, Jef D.

2000-01-01

Active nuclear import of the human immunodeficiency virus type 1 (HIV-1) preintegration complex (PIC) is essential for the productive infection of nondividing cells. Nuclear import of the PIC is mediated by the HIV-1 matrix protein, which also plays several critical roles during viral entry and possibly during virion production facilitating the export of Pr55Gag and genomic RNA. Using a yeast two-hybrid screen, we identified a novel human virion-associated matrix-interacting protein (VAN) that is highly conserved in vertebrates and expressed in most human tissues. Its expression is upregulated upon activation of CD4+ T cells. VAN is efficiently incorporated into HIV-1 virions and, like matrix, shuttles between the nucleus and cytoplasm. Furthermore, overexpression of VAN significantly inhibits HIV-1 replication in tissue culture. We propose that VAN regulates matrix nuclear localization and, by extension, both nuclear import of the PIC and export of Pr55Gag and viral genomic RNA during virion production. Our data suggest that this regulatory mechanism reflects a more global process for regulation of nucleocytoplasmic transport. PMID:11090181

Fibrin sealant for mesh fixation in laparoscopic groin hernia repair does not increase long-term recurrence

DEFF Research Database (Denmark)

Fenger, Andreas Qwist; Helvind, Neel Maria; Pommergaard, Hans-Christian

2016-01-01

BACKGROUND: Methods of groin hernia repair include laparoscopic techniques using tissue-penetrating mesh fixation or non-penetrating fixation. Concerns regarding hernia repair include postoperative chronic pain, sexual dysfunction, and recurrence. Earlier estimations of recurrence rates have......) laparoscopic groin hernia repair using either fibrin sealant or tacks for mesh fixation. METHODS: This study used data from the Danish Hernia Database to create the following cohort: All patients operated laparoscopically for primary groin hernia with a TAPP procedure using fibrin sealant for mesh fixation...... difference in long-term reoperation rates and clinical recurrences in patients undergoing TAPP repair with meshes fixated with fibrin sealant compared with tacks....

Nonexpansive immediate breast reconstruction using human acellular tissue matrix graft (AlloDerm).

Science.gov (United States)

Salzberg, C Andrew

2006-07-01

Immediate breast reconstruction has become a standard of care following mastectomy for cancer, largely due to improved esthetic and psychologic outcomes achieved with this technique. However, the current historical standards--transverse rectus abdominis myocutaneous flap reconstruction and expander--implant surgery-still have limitations as regards patient morbidity, short-term body-image improvements, and even cost. To address these shortcomings, we employ a novel concept of human tissue replacement to enhance breast shape and provide total coverage, enabling immediate mound reconstruction without the need for breast expansion prior to permanent implant placement. AlloDerm (human acellular tissue matrix) is a human-derived graft tissue with extensive experience in various settings of skin and soft tissue replacement surgery. This report describes the success using acellular tissue matrix to provide total coverage over the prosthesis in immediate reconstruction, with limited muscle dissection. In this population, 49 patients (76 breasts) successfully underwent the acellular tissue matrix-based immediate reconstruction, resulting in durable breast reconstruction with good symmetry. These findings may predict that acellular tissue matrix-supplemented immediate breast reconstruction will become a new technique for the immediate reconstruction of the postmastectomy breast.

Binding of Thrombin-Activated Platelets to a Fibrin Scaffold through αIIbβ3 Evokes Phosphatidylserine Exposure on Their Cell Surface

Science.gov (United States)

Brzoska, Tomasz; Suzuki, Yuko; Mogami, Hideo; Sano, Hideto; Urano, Tetsumei

2013-01-01

Recently, by employing intra-vital confocal microscopy, we demonstrated that platelets expose phosphatidylserine (PS) and fibrin accumulate only in the center of the thrombus but not in its periphery. To address the question how exposure of platelet anionic phospholipids is regulated within the thrombus, an in-vitro experiment using diluted platelet-rich plasma was employed, in which the fibrin network was formed in the presence of platelets, and PS exposure on the platelet surface was analyzed using Confocal Laser Scanning Microscopy. Almost all platelets exposed PS after treatment with tissue factor, thrombin or ionomycin. Argatroban abrogated fibrin network formation in all samples, however, platelet PS exposure was inhibited only in tissue factor- and thrombin-treated samples but not in ionomycin-treated samples. FK633, an αIIbβ3 antagonist, and cytochalasin B impaired platelet binding to the fibrin scaffold and significantly reduced PS exposure evoked by thrombin. Gly-Pro-Arg-Pro amide abrogated not only fibrin network formation, but also PS exposure on platelets without suppressing platelet binding to fibrin/fibrinogen. These results suggest that outside-in signals in platelets generated by their binding to the rigid fibrin network are essential for PS exposure after thrombin treatment. PMID:23383331

Binding of thrombin-activated platelets to a fibrin scaffold through α(IIbβ₃ evokes phosphatidylserine exposure on their cell surface.

Directory of Open Access Journals (Sweden)

Tomasz Brzoska

Full Text Available Recently, by employing intra-vital confocal microscopy, we demonstrated that platelets expose phosphatidylserine (PS and fibrin accumulate only in the center of the thrombus but not in its periphery. To address the question how exposure of platelet anionic phospholipids is regulated within the thrombus, an in-vitro experiment using diluted platelet-rich plasma was employed, in which the fibrin network was formed in the presence of platelets, and PS exposure on the platelet surface was analyzed using Confocal Laser Scanning Microscopy. Almost all platelets exposed PS after treatment with tissue factor, thrombin or ionomycin. Argatroban abrogated fibrin network formation in all samples, however, platelet PS exposure was inhibited only in tissue factor- and thrombin-treated samples but not in ionomycin-treated samples. FK633, an α(IIbβ₃ antagonist, and cytochalasin B impaired platelet binding to the fibrin scaffold and significantly reduced PS exposure evoked by thrombin. Gly-Pro-Arg-Pro amide abrogated not only fibrin network formation, but also PS exposure on platelets without suppressing platelet binding to fibrin/fibrinogen. These results suggest that outside-in signals in platelets generated by their binding to the rigid fibrin network are essential for PS exposure after thrombin treatment.

The impact of the centrifuge characteristics and centrifugation protocols on the cells, growth factors, and fibrin architecture of a leukocyte- and platelet-rich fibrin (L-PRF) clot and membrane.

Science.gov (United States)

Dohan Ehrenfest, David M; Pinto, Nelson R; Pereda, Andrea; Jiménez, Paula; Corso, Marco Del; Kang, Byung-Soo; Nally, Mauricio; Lanata, Nicole; Wang, Hom-Lay; Quirynen, Marc

2018-03-01

-PRF. All centrifugations were done using the original L-PRF centrifuge (Intra-Spin), as recommended by the two manufacturers. Half of the membranes were placed individually in culture media and transferred in a new tube at seven experimental times (up to 7 days). The releases of transforming growth factor β-1 (TGFβ-1), platelet derived growth factor AB (PDGF-AB), vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2) were quantified using ELISA kits at these seven experimental times. The remaining membranes were used to evaluate the initial quantity of growth factors of the L-PRF and A-PRF membranes, through forcible extraction. Very significant differences in the level of vibrations at each rotational speed were observed between the four tested centrifuges. The original L-PRF centrifuge (Intra-Spin) was by far the most stable machine in all configurations and always remained under the threshold of resonance, unlike the three other tested machines. At the classical speed of production of L-PRF, the level of undesirable vibrations on the original centrifuge was between 4.5 and 6 times lower than with other centrifuges. Intra-Spin showed the lowest temperature of the tubes. A-PRF and Salvin were both associated with a significant increase in temperature in the tube. Intra-Spin produced the heaviest clot and quantity of exudate among the four techniques. A-PRF and LW produced much lighter, shorter and narrower clots and membranes than the two other centrifuges. Light microscopy analysis showed relatively similar features for all L-PRF types (concentration of cell bodies in the first half). However, SEM illustrated considerable differences between samples. The original Intra-Spin L-PRF showed a strongly polymerized thick fibrin matrix and all cells appeared alive with a normal shape, including the textured surface aspect of activated lymphocytes. The A-PRF, Salvin and LW PRF-like membranes presented a lightly polymerized slim fibrin gel and most

Mechanical Stability and Fibrinolytic Resistance of Clots Containing Fibrin, DNA, and Histones*

Science.gov (United States)

Longstaff, Colin; Varjú, Imre; Sótonyi, Péter; Szabó, László; Krumrey, Michael; Hoell, Armin; Bóta, Attila; Varga, Zoltán; Komorowicz, Erzsébet; Kolev, Krasimir

2013-01-01

Neutrophil extracellular traps are networks of DNA and associated proteins produced by nucleosome release from activated neutrophils in response to infection stimuli and have recently been identified as key mediators between innate immunity, inflammation, and hemostasis. The interaction of DNA and histones with a number of hemostatic factors has been shown to promote clotting and is associated with increased thrombosis, but little is known about the effects of DNA and histones on the regulation of fibrin stability and fibrinolysis. Here we demonstrate that the addition of histone-DNA complexes to fibrin results in thicker fibers (increase in median diameter from 84 to 123 nm according to scanning electron microscopy data) accompanied by improved stability and rigidity (the critical shear stress causing loss of fibrin viscosity increases from 150 to 376 Pa whereas the storage modulus of the gel increases from 62 to 82 pascals according to oscillation rheometric data). The effects of DNA and histones alone are subtle and suggest that histones affect clot structure whereas DNA changes the way clots are lysed. The combination of histones + DNA significantly prolongs clot lysis. Isothermal titration and confocal microscopy studies suggest that histones and DNA bind large fibrin degradation products with 191 and 136 nm dissociation constants, respectively, interactions that inhibit clot lysis. Heparin, which is known to interfere with the formation of neutrophil extracellular traps, appears to prolong lysis time at a concentration favoring ternary histone-DNA-heparin complex formation, and DNase effectively promotes clot lysis in combination with tissue plasminogen activator. PMID:23293023

The use of snake venom derived fibrin glue in hysterorrhaphy of ovine caesarean surgery

OpenAIRE

CHALHOUB, M.; PRESTES, N. C.; LOPES, M. D.; ROCHA, N. S.; THOMAZINI-SANTOS, I. A.; MENDES-GIANNINI, M.J.

2000-01-01

Fibrin glue has been used on its own or in conjunction with suturing materials to promote hemostasis, reduce adherence, strengthen the wound site, and improve healing. Snake venom derived fibrin glue was evaluated as an alternative to conventional uterine suturing after ovine caesarean surgery. Twenty-eight pregnant ewes of known mating date were used. The animals submitted to conventional caesarean sections showed a better wound healing process. As expected, all the operated animals had reta...

Advanced platelet-rich fibrin: a new concept for cell-based tissue engineering by means of inflammatory cells.

Science.gov (United States)

Ghanaati, Shahram; Booms, Patrick; Orlowska, Anna; Kubesch, Alica; Lorenz, Jonas; Rutkowski, Jim; Landes, Constantin; Sader, Robert; Kirkpatrick, Cj; Choukroun, Joseph

2014-12-01

Choukroun's platelet-rich fibrin (PRF) is obtained from blood without adding anticoagulants. In this study, protocols for standard platelet-rich fibrin (S-PRF) (2700 rpm, 12 minutes) and advanced platelet-rich fibrin (A-PRF) (1500 rpm, 14 minutes) were compared to establish by histological cell detection and histomorphometrical measurement of cell distribution the effects of the centrifugal force (speed and time) on the distribution of cells relevant for wound healing and tissue regeneration. Immunohistochemistry for monocytes, T and B -lymphocytes, neutrophilic granulocytes, CD34-positive stem cells, and platelets was performed on clots produced from four different human donors. Platelets were detected throughout the clot in both groups, although in the A-PRF group, more platelets were found in the distal part, away from the buffy coat (BC). T- and B-lymphocytes, stem cells, and monocytes were detected in the surroundings of the BC in both groups. Decreasing the rpm while increasing the centrifugation time in the A-PRF group gave an enhanced presence of neutrophilic granulocytes in the distal part of the clot. In the S-PRF group, neutrophils were found mostly at the red blood cell (RBC)-BC interface. Neutrophilic granulocytes contribute to monocyte differentiation into macrophages. Accordingly, a higher presence of these cells might be able to influence the differentiation of host macrophages and macrophages within the clot after implantation. Thus, A-PRF might influence bone and soft tissue regeneration, especially through the presence of monocytes/macrophages and their growth factors. The relevance and feasibility of this tissue-engineering concept have to be proven through in vivo studies.

Pancreatic fistula after laparoscopic splenectomy in patients with hypersplenism due to liver cirrhosis: effect of fibrin glue and polyglycolic acid felt on prophylaxis of postoperative complications.

Science.gov (United States)

Tsutsumi, Norifumi; Tomikawa, Morimasa; Akahoshi, Tomohiko; Kawanaka, Hirofumi; Ota, Mitsuhiko; Sakaguchi, Yoshihisa; Kusumoto, Tetsuya; Ikejiri, Koji; Hashizume, Makoto; Maehara, Yoshihiko

2016-11-01

This study aimed to determine the effect of fibrin glue and polyglycolic acid (PGA) felt on prevention of pancreatic fistula (PF) after laparoscopic splenectomy in patients with hypersplenism due to liver cirrhosis. Fifty consecutive patients were enrolled in this prospective study. Twenty-three patients underwent laparoscopic splenectomy with a fibrin sheet (fibrin sheet group). The sealing ability of each treatment was evaluated by an ex vivo pressure test model. Based on the results from ex vivo experiments, 27 patients received prophylaxis using fibrin glue and PGA felt (PGA with fibrin group). The primary endpoint was the incidence of PF. Significantly more (5, 22%) patients developed PF in the fibrin sheet group than in the PGA with fibrin group (0%, P = .037). Our new application of fibrin glue and PGA felt is an effective prophylactic procedure for preventing development of PF after laparoscopic splenectomy. Copyright © 2016 Elsevier Inc. All rights reserved.

Simultaneous sinus lift and implantation using platelet-rich fibrin as sole grafting material.

Science.gov (United States)

Jeong, Seung-Mi; Lee, Chun-Ui; Son, Jeong-Seog; Oh, Ji-Hyeon; Fang, Yiqin; Choi, Byung-Ho

2014-09-01

Recently, several authors have shown that simultaneous sinus lift and implantation using autologous platelet-rich fibrin as the sole filling material is a reliable procedure promoting bone augmentation in the maxillary sinus. The aim of this study was to examine the effect of simultaneous sinus lift and implantation using platelet-rich fibrin as the sole grafting material on bone formation in a canine sinus model. An implant was placed after sinus membrane elevation in the maxillary sinus of six adult female mongrel dogs. The resulting space between the membrane and sinus floor was filled with autologous platelet-rich fibrin retrieved from each dog. The implants were left in place for six months. Bone tissue was seen at the lower part of the implants introduced into the sinus cavity. The height of the newly formed bone around the implants ranged from 0 mm to 4.9 mm (mean; 2.6 ± 2.0 mm) on the buccal side and from 0 mm to 4.2 mm (mean; 1.3 ± 1.8 mm) on the palatal side. The findings from this study suggest that simultaneous sinus lift and implantation using platelet-rich fibrin as sole grafting material is not a predictable and reproducible procedure, especially with respect to the bone formation around the implants in the sinus cavity. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. All rights reserved.

Matrix viscoplasticity and its shielding by active mechanics in microtissue models: experiments and mathematical modeling

Science.gov (United States)

Liu, Alan S.; Wang, Hailong; Copeland, Craig R.; Chen, Christopher S.; Shenoy, Vivek B.; Reich, Daniel H.

2016-01-01

The biomechanical behavior of tissues under mechanical stimulation is critically important to physiological function. We report a combined experimental and modeling study of bioengineered 3D smooth muscle microtissues that reveals a previously unappreciated interaction between active cell mechanics and the viscoplastic properties of the extracellular matrix. The microtissues’ response to stretch/unstretch actuations, as probed by microcantilever force sensors, was dominated by cellular actomyosin dynamics. However, cell lysis revealed a viscoplastic response of the underlying model collagen/fibrin matrix. A model coupling Hill-type actomyosin dynamics with a plastic perfectly viscoplastic description of the matrix quantitatively accounts for the microtissue dynamics, including notably the cells’ shielding of the matrix plasticity. Stretch measurements of single cells confirmed the active cell dynamics, and were well described by a single-cell version of our model. These results reveal the need for new focus on matrix plasticity and its interactions with active cell mechanics in describing tissue dynamics. PMID:27671239

Effect of Titanium-prepared Platelet-rich Fibrin Treatment on the ...

African Journals Online (AJOL)

2018-02-07

Feb 7, 2018 ... Defects of Patients with Chronic Periodontitis: A Randomized. Controlled ... Faculty of Dentistry Department of Periodontology, Kirikkale. University ..... using leukocyte and platelet-rich fibrin: A report of a case. Case. Rep Dent ...

The hydraulic permeability of blood clots as a function of fibrin and platelet density.

Science.gov (United States)

Wufsus, A R; Macera, N E; Neeves, K B

2013-04-16

Interstitial fluid flow within blood clots is a biophysical mechanism that regulates clot growth and dissolution. Assuming that a clot can be modeled as a porous medium, the physical property that dictates interstitial fluid flow is the hydraulic permeability. The objective of this study was to bound the possible values of the hydraulic permeability in clots formed in vivo and present relationships that can be used to estimate clot permeability as a function of composition. A series of clots with known densities of fibrin and platelets, the two major components of a clot, were formed under static conditions. The permeability was calculated by measuring the interstitial fluid velocity through the clots at a constant pressure gradient. Fibrin gels formed with a fiber volume fraction of 0.02-0.54 had permeabilities of 1.2 × 10(-1)-1.5 × 10(-4)μm(2). Platelet-rich clots with a platelet volume fraction of 0.01-0.61 and a fibrin volume fraction of 0.03 had permeabilities over a range of 1.1 × 10(-2)-1.5 × 10(-5)μm(2). The permeability of fibrin gels and of clots with platelet volume fraction of platelet volume fraction of >0.2 were modeled as a Brinkman medium of coarse solids (platelets) embedded in a mesh of fine fibers (fibrin). Our data suggest that the permeability of clots formed in vivo can vary by up to five orders of magnitude, with pore sizes that range from 4 to 350 nm. These findings have important implications for the transport of coagulation zymogens/enzymes in the interstitial spaces during clot formation, as well as the design of fibrinolytic drug delivery strategies. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Ultrastructure and growth factor content of equine platelet-rich fibrin gels.

Science.gov (United States)

Textor, Jamie A; Murphy, Kaitlin C; Leach, J Kent; Tablin, Fern

2014-04-01

To compare fiber diameter, pore area, compressive stiffness, gelation properties, and selected growth factor content of platelet-rich fibrin gels (PRFGs) and conventional fibrin gels (FGs). PRFGs and conventional FGs prepared from the blood of 10 healthy horses. Autologous fibrinogen was used to form conventional FGs. The PRFGs were formed from autologous platelet-rich plasma of various platelet concentrations (100 × 10³ platelets/μL, 250 × 10³ platelets/μL, 500 × 10³ platelets/μL, and 1,000 × 10³ platelets/μL). All gels contained an identical fibrinogen concentration (20 mg/mL). Fiber diameter and pore area were evaluated with scanning electron microscopy. Maximum gelation rate was assessed with spectrophotometry, and gel stiffness was determined by measuring the compressive modulus. Gel weights were measured serially over 14 days as an index of contraction (volume loss). Platelet-derived growth factor-BB and transforming growth factor-β1 concentrations were quantified with ELISAs. Fiber diameters were significantly larger and mean pore areas were significantly smaller in PRFGs than in conventional FGs. Gel weight decreased significantly over time, differed significantly between PRFGs and conventional FGs, and was significantly correlated with platelet concentration. Platelet-derived growth factor-BB and transforming growth factor-β1 concentrations were highest in gels and releasates derived from 1,000 × 10³ platelets/μL. The inclusion of platelets in FGs altered the architecture and increased the growth factor content of the resulting scaffold. Platelets may represent a useful means of modifying these gels for applications in veterinary and human regenerative medicine.

Conformational changes in fragments D and double-D from human fibrin(ogen) upon binding the peptide ligand Gly-His-Arg-Pro-amide.

Science.gov (United States)

Everse, S J; Spraggon, G; Veerapandian, L; Doolittle, R F

1999-03-09

The structure of fragment double-D from human fibrin has been solved in the presence and absence of the peptide ligands that simulate the two knobs exposed by the removal of fibrinopeptides A and B, respectively. All told, six crystal structures have been determined, three of which are reported here for the first time: namely, fragments D and double-D with the peptide GHRPam alone and double-D in the absence of any peptide ligand. Comparison of the structures has revealed a series of conformational changes that are brought about by the various knob-hole interactions. Of greatest interest is a moveable "flap" of two negatively charged amino acids (Glubeta397 and Aspbeta398) whose side chains are pinned back to the coiled coil with a calcium atom bridge until GHRPam occupies the beta-chain pocket. Additionally, in the absence of the peptide ligand GPRPam, GHRPam binds to the gamma-chain pocket, a new calcium-binding site being formed concomitantly.

Ginsenoside Rg1 and platelet-rich fibrin enhance human breast adipose-derived stem cells function for soft tissue regeneration

Science.gov (United States)

Li, Hong-Mian; Peng, Qi-Liu; Huang, Min-Hong; Li, De-Quan; Liang, Yi-Dan; Chi, Gang-Yi; Li, De-Hui; Yu, Bing-Chao; Huang, Ji-Rong

2016-01-01

Adipose-derived stem cells (ASCs) can be used to repair soft tissue defects, wounds, burns, and scars and to regenerate various damaged tissues. The cell differentiation capacity of ASCs is crucial for engineered adipose tissue regeneration in reconstructive and plastic surgery. We previously reported that ginsenoside Rg1 (G-Rg1 or Rg1) promotes proliferation and differentiation of ASCs in vitro and in vivio. Here we show that both G-Rg1 and platelet-rich fibrin (PRF) improve the proliferation, differentiation, and soft tissue regeneration capacity of human breast adipose-derived stem cells (HBASCs) on collagen type I sponge scaffolds in vitro and in vivo. Three months after transplantation, tissue wet weight, adipocyte number, intracellular lipid, microvessel density, and gene and protein expression of VEGF, HIF-1α, and PPARγ were higher in both G-Rg1- and PRF-treated HBASCs than in control grafts. More extensive new adipose tissue formation was evident after treatment with G-Rg1 or PRF. In summary, G-Rg1 and/or PRF co-administration improves the function of HBASCs for soft tissue regeneration engineering. PMID:27191987

Lyophilized platelet-rich fibrin (PRF) promotes craniofacial bone regeneration through Runx2.

Science.gov (United States)

Li, Qi; Reed, David A; Min, Liu; Gopinathan, Gokul; Li, Steve; Dangaria, Smit J; Li, Leo; Geng, Yajun; Galang, Maria-Therese; Gajendrareddy, Praveen; Zhou, Yanmin; Luan, Xianghong; Diekwisch, Thomas G H

2014-05-14

Freeze-drying is an effective means to control scaffold pore size and preserve its composition. The purpose of the present study was to determine the applicability of lyophilized Platelet-rich fibrin (LPRF) as a scaffold for craniofacial tissue regeneration and to compare its biological effects with commonly used fresh Platelet-rich fibrin (PRF). LPRF caused a 4.8-fold±0.4-fold elevation in Runt-related transcription factor 2 (Runx2) expression in alveolar bone cells, compared to a 3.6-fold±0.2-fold increase when using fresh PRF, and a more than 10-fold rise of alkaline phosphatase levels and mineralization markers. LPRF-induced Runx2 expression only occurred in alveolar bone and not in periodontal or dental follicle cells. LPRF also caused a 1.6-fold increase in osteoblast proliferation (pfibrin, and 16% without scaffold. Moreover, LPRF thickened the trabecular diameter by 25% when compared to fresh PRF and fibrin, and only LPRF and fresh PRF resulted in the formation of interconnected trabeculae across the defect. Together, these studies support the application of lyophilized PRF as a biomimetic scaffold for craniofacial bone regeneration and mineralized tissue engineering.

Successful Endoscopic Management of Non-Healing Perforated Duodenal Ulcer with Polyglycolic Acid Sheet and Fibrin Glue.

Science.gov (United States)

Mishiro, Tsuyoshi; Shibagaki, Kotaro; Matsuda, Kayo; Fukuyama, Chika; Okada, Mayumi; Mikami, Hironobu; Izumi, Daisuke; Yamashita, Noritsugu; Okimoto, Eiko; Fukuda, Naoki; Aimi, Masahito; Fukuba, Nobuhiko; Oshima, Naoki; Takanashi, Toshihiro; Matsubara, Takeshi; Ishimura, Norihisa; Ishihara, Shunji; Kinoshita, Yoshikazu

2016-08-01

In recent years, treatment techniques in which polyglycolic acid sheets are applied to various situations with fibrin glue have exhibited great clinical potential, and previous studies have reported safety and efficacy. We describe closure of a non-healing perforated duodenal ulcer with the use of a polyglycolic acid sheet and fibrin glue in an elderly patient who was not a candidate for surgery.

The use of fibrin and poly(lactic-co-glycolic acid hybrid scaffold for articular cartilage tissue engineering: an in vivo analysis

Directory of Open Access Journals (Sweden)

S Munirah

2008-02-01

Full Text Available Our preliminary results indicated that fibrin and poly(lactic-co-glycolic acid (PLGA hybrid scaffold promoted early chondrogenesis of articular cartilage constructs in vitro. The aim of this study was to evaluate in vivo cartilaginous tissue formation by chondrocyte-seeded fibrin/PLGA hybrid scaffolds. PLGA scaffolds were soaked carefully, in chondrocyte-fibrin suspension, and polymerized by dropping thrombin-calcium chloride (CaCl2 solution. PLGA-seeded chondrocytes were used as a control. Resulting constructs were implanted subcutaneously, at the dorsum of nude mice, for 4 weeks. Macroscopic observation, histological evaluation, gene expression and sulphated-glycosaminoglycan (sGAG analyses were performed at each time point of 1, 2 and 4 weeks post-implantation. Cartilaginous tissue formation in fibrin/PLGA hybrid construct was confirmed by the presence of lacunae and cartilage-isolated cells embedded within basophilic ground substance. Presence of proteoglycan and glycosaminoglycan (GAG in fibrin/PLGA hybrid constructs was confirmed by positive Safranin O and Alcian Blue staining. Collagen type II exhibited intense immunopositivity at the pericellular matrices. Chondrogenic properties were further demonstrated by the expression of gene encoded cartilage-specific markers, collagen type II and aggrecan core protein. The sGAG production in fibrin/PLGA hybrid constructs was higher than in the PLGA group. In conclusion, fibrin/PLGA hybrid scaffold promotes cartilaginous tissue formation in vivo and may serve as a potential cell delivery vehicle and a structural basis for articular cartilage tissue-engineering.

Long-Standing Motor and Sensory Recovery following Acute Fibrin Sealant Based Neonatal Sciatic Nerve Repair

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Natalia Perussi Biscola

2016-01-01

Full Text Available Brachial plexus lesion results in loss of motor and sensory function, being more harmful in the neonate. Therefore, this study evaluated neuroprotection and regeneration after neonatal peripheral nerve coaptation with fibrin sealant. Thus, P2 neonatal Lewis rats were divided into three groups: AX: sciatic nerve axotomy (SNA without treatment; AX+FS: SNA followed by end-to-end coaptation with fibrin sealant derived from snake venom; AX+CFS: SNA followed by end-to-end coaptation with commercial fibrin sealant. Results were analyzed 4, 8, and 12 weeks after lesion. Astrogliosis, microglial reaction, and synapse preservation were evaluated by immunohistochemistry. Neuronal survival, axonal regeneration, and ultrastructural changes at ventral spinal cord were also investigated. Sensory-motor recovery was behaviorally studied. Coaptation preserved synaptic covering on lesioned motoneurons and led to neuronal survival. Reactive gliosis and microglial reaction decreased in the same groups (AX+FS, AX+CFS at 4 weeks. Regarding axonal regeneration, coaptation allowed recovery of greater number of myelinated fibers, with improved morphometric parameters. Preservation of inhibitory synaptic terminals was accompanied by significant improvement in the motor as well as in the nociceptive recovery. Overall, the present data suggest that acute repair of neonatal peripheral nerves with fibrin sealant results in neuroprotection and regeneration of motor and sensory axons.

In vivo extracellular matrix protein expression by human periodontal ...

African Journals Online (AJOL)

It is well known that the orthodontic force applied to teeth generates a series of events that remodel the periodontal ligament (PDL). Extracellular matrix proteins (ECM) are described as molecular regulators of these events. However, the exact contribution of these proteins in human PDL modeling by orthodontic force ...

Association Between Disruption of Fibrin Sheaths Using Percutaneous Transluminal Angioplasty Balloons and Late Onset of Central Venous Stenosis

International Nuclear Information System (INIS)

Ni, Nina; Mojibian, Hamid; Pollak, Jeffrey; Tal, Michael

2011-01-01

To compare the rates of central venous stenosis in patients undergoing hemodialysis who underwent disruption of fibrin sheath with percutaneous transluminal angioplasty balloons and those who underwent over-the-wire catheter exchange. This study is a retrospective review of 209 percutaneous transluminal angioplasty balloon disruption and 1304 over-the-wire catheter exchange procedures performed in 753 patients. Approval from the Human Investigations Committee was obtained for this study. Up to 10-year follow-up was performed. A χ 2 test was used to compare the rates of central venous stenosis after balloon disruption versus catheter exchange. A t-test was used to compare time to central venous stenosis development. Of the 753 patients in the study, 127 patients underwent balloon disruption of fibrin sheath and 626 had catheter exchange. Within the balloon disruption group, 18 (14.2%) of 127 patients subsequently developed central venous stenosis, compared with 44 (7.0%) of 626 in the catheter exchange group (P 2 test). Time to central venous stenosis development was approximately 3 years in both groups and not significantly different (1371 and 1010 days, P = 0.20). A total of 25.2% of patients in the balloon disruption group had four or more subsequent catheter exchanges, versus 12.6% in the catheter exchange group (P 2 test). In conclusions, there is a possible association between percutaneous transluminal angioplasty balloon disruption of fibrin sheath and late-onset central venous stenosis. Because venography was not routinely performed in catheter exchange patients, future randomized studies are necessary to confirm these findings.

Nano-fibrin stabilized CaSO4 crystals incorporated injectable chitin composite hydrogel for enhanced angiogenesis & osteogenesis.

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Arun Kumar, R; Sivashanmugam, A; Deepthi, S; Bumgardner, Joel D; Nair, Shantikumar V; Jayakumar, R

2016-04-20

Calcium sulfate (CaSO4), an excellent biodegradable bone forming agent that is an ideal choice as additive in gels, however, its disadvantage being poor gel rheology and angiogenesis. Here, we have synthesized chitin-CaSO4-nano-fibrin based injectable gel system which shows improved rheology and angiogenic potential. Rheological studies showed that the composite gel was a shear thinning gel with elastic modulus of 15.4±0.275kPa; a 1.67 fold increase over chitin control. SEM and XRD analyses revealed the effect of nano-fibrin (nFibrin) in transforming CaSO4 crystal shape from needle to hexagonal. It also masked the retarding effect of CaSO4 towards in vitro early cell attachment and angiogenesis using rabbit adipose derived mesenchymal stem cells (rASCs) and HUVECs, respectively. rASCs osteogenesis was confirmed by spectrophotometric endpoint assay, which showed 6-fold early increase in alkaline phosphatase levels and immuno-cytochemistry analysis. These in vitro results highlight the potential of injectable chitin-CaSO4-nFibrin gel for osteo-regeneration via enhanced angiogenesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Crosslinking of fihrinogen by factor XIHa exposes fibrin-specific epitopes and induces enhanced plasminogen activation by t-PA

NARCIS (Netherlands)

Nieuwenhuizen, W.; Voskuilen, M.; Kevin, R.; Siebenlis; Michael, W.; Mosesson

1996-01-01

'Fibrin-specific'epitopes 'Aαl48-160' and 'γ312-324' are exposed when fibrinogen (Fbg) is converted to fibrin (Fb). Particularly, polymerized Fb enhances the t-PA-mediated plasminogen activation. Fb polymerization involves 'D:E' assembly, end-to-end self-association ('D:D') and interactions between

CT-guided percutaneous injection of the fibrin glue by 'double needle' technique for the treatment of sacral cysts

International Nuclear Information System (INIS)

Wang Ganggang; Chen Long; Yang Chao; Ni Caifang

2013-01-01

Objective: To analyze the efficacy and safety of CT-guided percutaneous injection of the fibrin glue by 'double needle' technique to treat sacral cyst. Methods: Clinical data of 20 cases with 'double-needle' injection of fibrin glue technology to treat sacral cyst were retrospectively analyzed. All patients had varying degrees of sacral nerve root compression symptoms. The treatment for sacral cyst was carried out after clear diagnosis was made. On the basis of CT-guided percutaneous injection of fibrin glue, the improved CT-guided percutaneous injection of fibrin glue by 'double-needle' technique was used to treat these patients. The average dose of fibrin glue was (5.9 ± 2.4) ml. The clinical results of improvement as to pain and neurological function were evaluated after follow-up of an average of 17 months. The assessment criteria were as follows: excellent, complete resolution of signs and symptoms, with the patient returning to his or her regular employment and no recurrence of cysts during 1 year of follow-up, good, symptoms and signs in the legs and perineal region resolved but with persistent pain in the lumbosacral region, which did not interfere with the patient's regular work (the cysts did not recur for 6 months during follow-up), fair, no improvement in clinical symptoms, but a decrease in cyst size on the imaging study, poor, no improvement in clinical symptoms and no observed changes in cyst size in imaging studies or recurrence. Results: Most patients experienced some degree of pain relief and functional improvement after fibrin glue therapy, with most experiencing complete or marked resolution of clinical symptoms. Nine patients reported excellent recovery, 8 reported good recovery, 2 reported fair recovery, and 1 reported poor recovery. The overall percentage of positive outcomes (excellent and good recovery) was 85%. No serious postoperative complications were discovered. Conclusions: CT guided percutaneous injection of the fibrin glue by

Detection of von Willebrand factor and tissue factor in platelets-fibrin rich coronary thrombi in acute myocardial infarction.

Science.gov (United States)

Yamashita, Atsushi; Sumi, Takahiro; Goto, Shinya; Hoshiba, Yasunari; Nishihira, Kensaku; Kawamoto, Riichirou; Hatakeyama, Kinta; Date, Haruhiko; Imamura, Takuroh; Ogawa, Hisao; Asada, Yujiro

2006-01-01

The rapid closure of coronary arteries due to occlusive thrombi is the major cause of acute myocardial infarction. However, the mechanisms of coronary thrombus formation have not been elucidated. We immunohistochemically assessed the localizations and their changes over time of glycoprotein IIb/IIIa, fibrin, von Willebrand factor (vWF), and tissue factor (TF), after the onset of chest pain (platelets, fibrin, vWF, and TF from the early phase of onset, and glycoprotein IIb/IIIa and fibrin were closely associated with vWF and TF, respectively. vWF and/or TF may contribute to occlusive thrombus formation and be novel therapeutic candidates for treating patients with coronary thrombosis.

Clinical experience of intrapleural administration of fibrin glue for secondary pneumothorax with advanced lung cancer

International Nuclear Information System (INIS)

Nishino, Takeshi; Takizawa, Hiromitsu; Yoshida, Mitsuteru; Kawakami, Yukikiyo; Sakiyama, Shoji; Kondo, Kazuya

2014-01-01

Secondary pneumothorax with advanced lung cancer is an intractable and serious pathosis, which directly aggravates patients' Quality of Life (QOL) and prognosis. We first select the intrapleural administration of fibrin glue for secondary pneumothorax with advanced lung cancer. From April 2009 to May 2012, we encountered 5 patients who developed secondary pneumothorax during treatment for advanced lung cancer. Their average age was 60.8 years old, and 4 of them had squamous cell carcinoma, 1 had adenocarcinoma, and all had unresectable advanced lung cancer. In 4 of them, the point of air leakage could be detected by pleurography, and leakage could be stopped by the intrapleural administration of fibrin glue. All of them could receive chemotherapy or radiotherapy after treatment for secondary pneumothorax. The intrapleural administration of fibrin glue may be an effective and valid treatment for intractable secondary pneumothorax with advanced lung cancer. (author)

Chondrocyte secreted CRTAC1: a glycosylated extracellular matrix molecule of human articular cartilage.

Science.gov (United States)

Steck, Eric; Bräun, Jessica; Pelttari, Karoliina; Kadel, Stephanie; Kalbacher, Hubert; Richter, Wiltrud

2007-01-01

Cartilage acidic protein 1 (CRTAC1), a novel human marker which allowed discrimination of human chondrocytes from osteoblasts and mesenchymal stem cells in culture was so far studied only on the RNA-level. We here describe its genomic organisation and detect a new brain expressed (CRTAC1-B) isoform resulting from alternate last exon usage which is highly conserved in vertebrates. In humans, we identify an exon sharing process with the neighbouring tail-to-tail orientated gene leading to CRTAC1-A. This isoform is produced by cultured human chondrocytes, localized in the extracellular matrix of articular cartilage and its secretion can be stimulated by BMP4. Of five putative O-glycosylation motifs in the last exon of CRTAC1-A, the most C-terminal one is modified according to exposure of serial C-terminal deletion mutants to the O-glycosylation inhibitor Benzyl-alpha-GalNAc. Both isoforms contain four FG-GAP repeat domains and an RGD integrin binding motif, suggesting cell-cell or cell-matrix interaction potential. In summary, CRTAC1 acquired an alternate last exon from the tail-to-tail oriented neighbouring gene in humans resulting in the glycosylated isoform CRTAC1-A which represents a new extracellular matrix molecule of articular cartilage.

Staple line reinforcement with fleece-coated fibrin glue (TachoComb) after thoracoscopic bullectomy for the treatment of spontaneous pneumothorax

International Nuclear Information System (INIS)

Muramatsu, Takashi; Ohmori, Kazumitsu; Shimamura, Mie; Furuichi, Motohiko; Takeshita, Shinji; Negishi, Nanao

2007-01-01

We investigated the cause of pneumothorax recurrence after thoracoscopic surgery and the effectiveness of staple line reinforcement with fleece-coated fibrin glue (TachoComb) in the prevention of postoperative pneumothorax recurrence. From April 3, 1992 to the end of December 2005, thoracoscopic bullectomy was performed on 499 patients of primary spontaneous pneumothorax. The causes of recurrence were investigated on 39 patients on the basis of surgical observations, preoperative chest computed tomography, and so on. The most common cause was new bulla formation (37 cases), 19 of which were apparently related to the staple line (within 1 cm of the staple lines) and 15 of which were not related to the staple line. After 2000, we stopped using forceps to grasp lungs and we have reinforced the staple line by applying fleece-coated fibrin glue. The staple line reinforced with fleece-coated fibrin glue, or sprayed with fibrin glue solution and the untreated group (bullectomy only with staples) were compared, and the recurrence rates were 1.22%, 7.25%, and 10.00%, respectively (P=0.0006021). The recurrence rate after thoracoscopic bullectomy with fleece-coated fibrin glue was significantly lowered and we consider this procedure to be the treatment of choice for the management of spontaneous pneumothorax. (author)

Clinical evaluations of complete autologous fibrin glue, produced by the CryoSeal® FS system, and polyglycolic acid sheets as wound coverings after oral surgery.

Science.gov (United States)

Kouketsu, Atsumu; Nogami, Shinnosuke; Yamada-Fujiwara, Minami; Nagai, Hirokazu; Yamauchi, Kensuke; Mori, Shiro; Miyashita, Hitoshi; Kawai, Tadashi; Matsui, Aritsune; Kataoka, Yoshihiro; Satomi, Norihisa; Ezoe, Yushi; Abe, Satoko; Takeda, Yuri; Tone, Takeshi; Hirayama, Bunnichi; Kurobane, Tsuyoshi; Tashiro, Kazuki; Yanagisawa, Yuta; Takahashi, Tetsu

2017-09-01

The CryoSeal ® FS System has been recently introduced as an automated device for the production of complete fibrin glue from autologous plasma, rather than from pool allogenic or cattle blood, to prevent viral infection and allergic reaction. We evaluated the effectiveness of complete autologous fibrin glue and polyglycolic acid (PGA) sheet wound coverings in mucosa defect oral surgery. Postoperative pain, scar contracture, ingestion, tongue dyskinesia, and postoperative bleeding were evaluated in 12 patients who underwent oral (including the tongue) mucosa excision, and received a PGA sheet and an autologous fibrin glue covering. They were compared with 12 patients who received a PGA sheet and commercial allogenic fibrin glue. All cases in the complete autologous fibrin glue group demonstrated good wound healing without complications such as local infection or incomplete cure. All evaluated clinical measures in this group were similar or superior to the commercial allogenic fibrin glue group. Coagulation and adhesion quality achieved with this method was comparable to that with a PGA sheet and commercial fibrin glue. Covering oral surgery wounds with complete autologous fibrin glue produced by an automated device was convenient, safe, and reduced the risk of viral infection and allergic reaction associated with conventional techniques. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

IMMEDIATE AND DISTANT EFFECTS OF THE PANCREATIC DUCT OCCLUSION BY THE FIBRIN ADHESIVE

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Vojin Savić

2002-05-01

Full Text Available The paper represent an experimental study whose aim was to determine immediate consequences of the pancreatic duct occlusion by the fibrin adhesive upon the pancreas parenchyma as well as distant negative effects upon the exocrine and endocrine pancreatic secretion.The experiment was carried out on the dogs divided into two groups of twenty animals, namely, into the experimental group of those animals that were subdued to the pancreas resection with the PJA formation and the anastomosis protection by means of the pancreatic duct occlusion with the fibrin adhesive (Tissucol - Immuno AG and the control group that was, under the same conditions, subdued to the pancreas resection and the PJA with no anastomosis protection. In the post-operative course the animals cere monitored for five months and during that time they were subjected to the clinic, biochemical, pathohistological, histochemical, immunocito-chemical and scanning electronic-microscopic examination.The fibrin cork lyse was noticed since the fifth post-operative day while it was fully completed on the thirteenth post-operative day. The statistical analysis of the biochemical parameters as well as pathohistological and scanning-electronic exami-nations have revealed the signs of easier, sub-clinic forms of edematose pancreatitis with a short-term increase of the amylase level. The examinations after 150 days have shown the preserved morphology and the functional integrity of the exocrine and en-docrine pancreas.The authors conclude that the fibrin adhesive application in preventing the loosening up of the pancreatic jejuna anastomosis represents a simple and efficient procedure with no negative effects upon the exocrine and endocrine function and the pancreas morphology.

Polyethylene glycol–polylactic acid nanoparticles modified with cysteine–arginine–glutamic acid–lysine–alanine fibrin-homing peptide for glioblastoma therapy by enhanced retention effect

Directory of Open Access Journals (Sweden)

Wu J

2014-11-01

Full Text Available Junzhu Wu,1,2,* Jingjing Zhao,1,3,* Bo Zhang,1 Yong Qian,1 Huile Gao,1 Yuan Yu,1 Yan Wei,1 Zhi Yang,1 Xinguo Jiang,1 Zhiqing Pang1 1Key Laboratory of Smart Drug Delivery, Ministry of Education, Department of Pharmaceutics, School of Pharmacy, Fudan University, Shanghai, 2School of Pharmacy, Dali University, Xiaguan, 3School of Pharmacy, China Pharmaceutical University, Nanjing, People’s Republic of China *These authors contributed equally to this work Abstract: For a nanoparticulate drug-delivery system, crucial challenges in brain-glioblastoma therapy are its poor penetration and retention in the glioblastoma parenchyma. As a prevailing component in the extracellular matrix of many solid tumors, fibrin plays a critical role in the maintenance of glioblastoma morphology and glioblastoma cell differentiation and proliferation. We developed a new drug-delivery system by conjugating polyethylene glycol–polylactic acid nanoparticles (NPs with cysteine–arginine–glutamic acid–lysine–alanine (CREKA; TNPs, a peptide with special affinity for fibrin, to mediate glioblastoma-homing and prolong NP retention at the tumor site. In vitro binding tests indicated that CREKA significantly enhanced specific binding of NPs with fibrin. In vivo fluorescence imaging of glioblastoma-bearing nude mice, ex vivo brain imaging, and glioblastoma distribution demonstrated that TNPs had higher accumulation and longer retention in the glioblastoma site over unmodified NPs. Furthermore, pharmacodynamic results showed that paclitaxel-loaded TNPs significantly prolonged the median survival time of intracranial U87 glioblastoma-bearing nude mice compared with controls, Taxol, and NPs. These findings suggested that TNPs were able to target the glioblastoma and enhance retention, which is a valuable strategy for tumor therapy. Keywords: CREKA peptide, nanoparticles, retention effect, paclitaxel, glioblastoma

Chylothorax after mediastinal ganglioneuroma resection treated with fibrin sealant patch: a case report

Science.gov (United States)

Chiarelli, Marco; Achilli, Pietro; Guttadauro, Angelo; Vertemati, Giuseppe; Terragni, Sabina; De Simone, Matilde

2017-01-01

Chylothorax is a severe condition resulting from the accumulation of chyle into the pleural space. We report the treatment of postoperative chylothorax after resection of mediastinal ganglioneuroma in a 17-year-old boy. Since conservative measures were not effective, we performed direct ligation of lymphatic vessels and pleurodesis. At subsequent surgical re-exploration for persisting chylothorax, accurate inspection of pleural cavity revealed residual chyle leakage. Fibrin sealant patches (TachoSil®) were placed over the source of leak with complete resolution of chylous effusion. To our knowledge, this is the first report of postoperative chylothorax successfully treated by the use of a fibrin sealant patch. PMID:29221335

Clinical observation on fibrin glue technique in pterygium surgery performed with limbal autograft transplantation

Directory of Open Access Journals (Sweden)

Hui Liu

2013-07-01

Full Text Available AIM: To compare the efficiency and safety of fibrin glue to suture technique in pterygium surgery performed with limbal autograft.METHODS: A prospective randomized clinical trial was carried out in 60 eyes of 48 patients operated for primary nasal pterygium. Autologous limbal graft taken from the superotemporal limbus was used to cover the sclera after pterygium excision under local anesthesia with 2% lidocaine. In 22 cases(30 eyes, the transplant was attached to the sclera with a fibrin tissue adhesive(group 1and in 26 cases(30 eyeswith 10-0 Virgin silk sutures(group 2. Patients were followed up at least for 3 months. Time of operation, matching degree of graft and visual analogue scale(VASscore were mainly observed and recorded. RESULTS: Patient symptoms were significantly less and biomicroscopic findings were better in group 1. Pterygium recurrence was seen in 1 case of group 1, and 1 case of group 2. Average surgery time was shorter(PCONCLUSION: Using fibrin glue for graft fixation in pterygium surgery causes significantly less postoperative pain and shortens surgery time significantly.

A Combined In Vitro Imaging and Multi-Scale Modeling System for Studying the Role of Cell Matrix Interactions in Cutaneous Wound Healing.

Directory of Open Access Journals (Sweden)

Aribet M De Jesus

Full Text Available Many cell types remodel the extracellular matrix of the tissues they inhabit in response to a wide range of environmental stimuli, including mechanical cues. Such is the case in dermal wound healing, where fibroblast migrate into and remodel the provisional fibrin matrix in a complex manner that depends in part on the local mechanical environment and the evolving multi-scale mechanical interactions of the system. In this study, we report on the development of an image-based multi-scale mechanical model that predicts the short-term (24 hours, structural reorganization of a fibrin gel by fibroblasts. These predictive models are based on an in vitro experimental system where clusters of fibroblasts (i.e., explants were spatially arranged into a triangular geometry onto the surface of fibrin gels that were subjected to either Fixed or Free in-plane mechanical constraints. Experimentally, regional differences in short-term structural remodeling and cell migration were observed for the two gel boundary conditions. A pilot experiment indicated that these small differences in the short-term remodeling of the fibrin gel translate into substantial differences in long-term (4 weeks remodeling, particularly in terms of collagen production. The multi-scale models were able to predict some regional differences in remodeling and qualitatively similar reorganization patterns for the two boundary conditions. However, other aspects of the model, such as the magnitudes and rates of deformation of gel, did not match the experiments. These discrepancies between model and experiment provide fertile ground for challenging model assumptions and devising new experiments to enhance our understanding of how this multi-scale system functions. These efforts will ultimately improve the predictions of the remodeling process, particularly as it relates to dermal wound healing and the reduction of patient scarring. Such models could be used to recommend patient

HPLC-MS/MS method optimisation for matrix metalloproteinase 3 and matrix metalloproteinase 9 determination in human blood serum using target analysis.

Science.gov (United States)

Kotnik, Petra; Krajnc, Metka Koren; Pahor, Artur; Finšgar, Matjaž; Knez, Željko

2018-02-20

A quantitative analysis of zinc endopeptidases matrix metalloproteinase 9 (MMP9) and matrix metalloproteinase 3 (MMP3) from human blood serum are presented. Both matrix metalloproteinases (MMP) are present in human blood serum and can be used as biomarkers for different diseases. The analysis was performed using LC-MS/MS with a triple quadrupole mass spectrometer, based on two specific peptides of each MMP in comparison with an enzyme-linked immunosorbent assay (ELISA). While the conditions for the LC-MS/MS analysis of MMP9 peptides were previously reported for bronchoalveolar lavage fluid, the analysis of MMP3 peptides was newly quantified for human blood serum herein for the first time. For MMP3, the linear behaviour was determined in the concentration range from 1.0-200.0ng/mL (R 2 =0.997) with an LLOD of 0.5ng/mL. For MMP9, linearity was determined in the concentration range from 6.5-65.0ng/mL (R 2 =0.995) with an LLOD of 2.0ng/mL. Copyright © 2017 Elsevier B.V. All rights reserved.

In search of a consensus terminology in the field of platelet concentrates for surgical use: platelet-rich plasma (PRP), platelet-rich fibrin (PRF), fibrin gel polymerization and leukocytes.

Science.gov (United States)

Dohan Ehrenfest, David M; Bielecki, Tomasz; Mishra, Allan; Borzini, Piero; Inchingolo, Francesco; Sammartino, Gilberto; Rasmusson, Lars; Everts, Peter A

2012-06-01

In the field of platelet concentrates for surgical use, most products are termed Platelet-Rich Plasma (PRP). Unfortunately, this term is very general and incomplete, leading to many confusions in the scientific database. In this article, a panel of experts discusses this issue and proposes an accurate and simple terminology system for platelet concentrates for surgical use. Four main categories of products can be easily defined, depending on their leukocyte content and fibrin architecture: Pure Platelet-Rich Plasma (P-PRP), such as cell separator PRP, Vivostat PRF or Anitua's PRGF; Leukocyteand Platelet-Rich Plasma (L-PRP), such as Curasan, Regen, Plateltex, SmartPReP, PCCS, Magellan, Angel or GPS PRP; Pure Plaletet-Rich Fibrin (P-PRF), such as Fibrinet; and Leukocyte- and Platelet-Rich Fibrin (L-PRF), such as Choukroun's PRF. P-PRP and L-PRP refer to the unactivated liquid form of these products, their activated versions being respectively named P-PRP gels and L-PRP gels. The purpose of this search for a terminology consensus is to plead for a more serious characterization of these products. Researchers have to be aware of the complex nature of these living biomaterials, in order to avoid misunderstandings and erroneous conclusions. Understanding the biomaterials or believing in the magic of growth factors ? From this choice depends the future of the field.

Postsynaptic density protein 95 in the striosome and matrix compartments of the human neostriatum.

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Ryoma eMorigaki

2015-11-01

Full Text Available The human neostriatum consists of two functional subdivisions referred to as the striosome (patch and matrix compartments. The striosome-matrix dopamine systems play a central role in cortico-thalamo-basal ganglia circuits, and their involvement is thought to underlie the genesis of multiple movement and behavioral disorders, and of drug addiction. Human neuropathology also has shown that striosomes and matrix have differential vulnerability patterns in several striatal neurodegenerative diseases. Postsynaptic density protein 95 (PSD-95, also known as DLG4, is a major scaffolding protein in the postsynaptic densities of dendritic spines. PSD-95 is now known to negatively regulate not only N-methyl-D-aspartate glutamate signaling, but also dopamine D1 signals at sites of postsynaptic transmission. Accordingly, a neuroprotective role for PSD-95 against dopamine D1 receptor (D1R-mediated neurotoxicity in striatal neurodegeneration also has been suggested. Here, we used a highly sensitive immunohistochemistry technique to show that in the human neostriatum, PSD-95 is differentially concentrated in the striosome and matrix compartments, with a higher density of PSD-95 labeling in the matrix compartment than in the striosomes. This compartment-specific distribution of PSD-95 was strikingly complementary to that of D1R. In addition to the possible involvement of PSD-95-mediated synaptic function in compartment-specific dopamine signals, we suggest that the striosomes might be more susceptible to D1R-mediated neurotoxicity than the matrix compartment. This notion may provide new insight into the compartment-specific vulnerability of MSNs in striatal neurodegeneration.

Gallium67 scintigraphy in fibrinous pericarditis associated with bacterial endocarditis

International Nuclear Information System (INIS)

Martin, P.; Verhas, M.; Devriendt, J.; Goffin, Y.

1982-01-01

An 80-year-old man presented with pyrexia, progressive cardiac failure and inflammation. A diagnosis of pericarditisd associated with bacterial endocarditis was suggested from Gallium 67 scintigraphy and confirmed at autpsy. This case of fibrinous pericarditis without effusion could not be diagnosed by echography or routine cardiopulmonary scintigraphy. (orig.)

Safety and hemostatic efficacy of fibrin pad in partial nephrectomy: Results of an open-label Phase I and a randomized, standard-of-care-controlled Phase I/II study

Directory of Open Access Journals (Sweden)

Nativ Ofer

2012-11-01

Full Text Available Abstract Background Bleeding severity, anatomic location, tissue characteristics, and visibility are common challenges encountered while managing intraoperative bleeding, and conventional hemostatic measures (suture, ligature, and cautery may sometimes be ineffective or impractical. While topical absorbable hemostats (TAH are useful hemostatic adjuvants, each TAH has associated disadvantages. Methods We evaluated the safety and hemostatic efficacy of a new advanced biologic combination product―fibrin pad―to potentially address some gaps associated with TAHs. Fibrin pad was assessed as adjunctive hemostat in open partial nephrectomy in single-center, open-label, Phase I study (N = 10, and as primary hemostat in multicenter, single-blind, randomized, standard-of-care (SOC-controlled Phase I/II study (N = 7 in Israel. It was used to control mild-to-moderate bleeding in Phase I and also spurting arterial bleeding in Phase I/II study. Phase I study assessed safety and Phase I/II study, proportion of successes at 10 min following randomization, analyzed by Fisher exact tests at 5% significance level. Results Phase I (N = 10: All patients completed the study. Hemostasis was achieved within 3–4 min (average = 3.1 min of a single application in all patients. Fibrin pad was found to be safe for human use, with no product-related adverse events reported. Phase I/II (N = 7: Hemostatic success at 10 min (primary endpoint was achieved in 3/4 patients treated with fibrin pad versus 0/3 patients treated with SOC. No clinically significant change in laboratory or coagulation parameters was recorded, except a case of post-procedural hemorrhage with fibrin pad, which was considered serious and related to the fibrin pad treatment, and required re-operation. Although Data Safety Monitoring Board authorized trial continuation, the sponsor decided against proceeding toward an indication for primary treatment of severe arterial

HGF potentiates extracellular matrix-driven migration of human myoblasts: involvement of matrix metalloproteinases and MAPK/ERK pathway.

Science.gov (United States)

González, Mariela Natacha; de Mello, Wallace; Butler-Browne, Gillian S; Silva-Barbosa, Suse Dayse; Mouly, Vincent; Savino, Wilson; Riederer, Ingo

2017-10-10

The hepatocyte growth factor (HGF) is required for the activation of muscle progenitor cells called satellite cells (SC), plays a role in the migration of proliferating SC (myoblasts), and is present as a soluble factor during muscle regeneration, along with extracellular matrix (ECM) molecules. In this study, we aimed at determining whether HGF is able to interact with ECM proteins, particularly laminin 111 and fibronectin, and to modulate human myoblast migration. We evaluated the expression of the HGF-receptor c-Met, laminin, and fibronectin receptors by immunoblotting, flow cytometry, or immunofluorescence and used Transwell assays to analyze myoblast migration on laminin 111 and fibronectin in the absence or presence of HGF. Zymography was used to check whether HGF could modulate the production of matrix metalloproteinases by human myoblasts, and the activation of MAPK/ERK pathways was evaluated by immunoblotting. We demonstrated that human myoblasts express c-Met, together with laminin and fibronectin receptors. We observed that human laminin 111 and fibronectin have a chemotactic effect on myoblast migration, and this was synergistically increased when low doses of HGF were added. We detected an increase in MMP-2 activity in myoblasts treated with HGF. Conversely, MMP-2 inhibition decreased the HGF-associated stimulation of cell migration triggered by laminin or fibronectin. HGF treatment also induced in human myoblasts activation of MAPK/ERK pathways, whose specific inhibition decreased the HGF-associated stimulus of cell migration triggered by laminin 111 or fibronectin. We demonstrate that HGF induces ERK phosphorylation and MMP production, thus stimulating human myoblast migration on ECM molecules. Conceptually, these data state that the mechanisms involved in the migration of human myoblasts comprise both soluble and insoluble moieties. This should be taken into account to optimize the design of therapeutic cell transplantation strategies by improving

Co-effects of matrix low elasticity and aligned topography on stem cell neurogenic differentiation and rapid neurite outgrowth

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Yao, Shenglian; Liu, Xi; Yu, Shukui; Wang, Xiumei; Zhang, Shuming; Wu, Qiong; Sun, Xiaodan; Mao, Haiquan

2016-05-01

The development of novel biomaterials that deliver precise regulatory signals to direct stem cell fate for nerve regeneration is the focus of current intensive research efforts. In this study, a hierarchically aligned fibrillar fibrin hydrogel (AFG) that was fabricated through electrospinning and the concurrent molecular self-assembly process mimics both the soft and oriented features of nerve tissue, thus providing hybrid biophysical cues to instruct cell behavior in vitro and in vivo. The electrospun hydrogels were examined by scanning electron microscopy (SEM), polarized light microscopy, small angle X-ray scattering assay and atomic force microscopy (AFM), showing a hierarchically linear-ordered structure from the nanoscale to the macroscale with a soft elastic character (elasticity ~1 kPa). We found that this low elasticity and aligned topography of AFG exhibit co-effects on promoting the neurogenic differentiation of human umbilical cord mesenchymal stem cells (hUMSCs) in comparison to random fibrin hydrogel (RFG) and tissue culture plate (TCP) control after two week cell culture in growth medium lacking supplementation with soluble neurogenic induction factors. In addition, AFG also induces dorsal root ganglion (DRG) neurons to rapidly project numerous long neurite outgrowths longitudinally along the AFG fibers for a total neurite extension distance of 1.96 mm in three days in the absence of neurotrophic factor supplementation. Moreover, the AFG implanted in a rat T9 dorsal hemisection spinal cord injury model was found to promote endogenous neural cell fast migration and axonal invasion along AFG fibers, resulting in aligned tissue cables in vivo. Our results suggest that matrix stiffness and aligned topography may instruct stem cell neurogenic differentiation and rapid neurite outgrowth, providing great promise for biomaterial design for applications in nerve regeneration.The development of novel biomaterials that deliver precise regulatory signals to

The use of 125I-labelled fibrinogen for determination of fibrin trapping in the lungs in patients developing the microembolism syndrome

International Nuclear Information System (INIS)

Busch, C.; Dahlgren, S.; Jakobson, S.; Jung, B.; Modig, J.; Saldeen, T.

1975-01-01

The microembolism syndrome occurred in four patients out of a series of 15 patients with multiple injuries who were considered to run a risk of developing this syndrome. These four patients showed signs of fibrin trapping in the lungs, as demonstrated by the use of 125 I-labelled fibrinogen and external detection over the lungs. It is, therefore, considered that this method can be used for diagnosing the microembolism syndrome. The fibrin trapping occurred at the onset of the progressive respiratory insufficiency. The time relation between the uptake of fibrin and the onset of the progressive respiratory insufficiency supports the theory af a causal connection between fibrin and pulmonary damage. Measurements of different coagulation and fibrinolysis factors in the blood were not able to discriminate between patients who developed the microembolism syndrome and those who did not. (author)

Matrix Stiffness Corresponding to Strictured Bowel Induces a Fibrogenic Response in Human Colonic Fibroblasts

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Johnson, Laura A.; Rodansky, Eva S.; Sauder, Kay L.; Horowitz, Jeffrey C.; Mih, Justin D.; Tschumperlin, Daniel J.; Higgins, Peter D.

2013-01-01

Background Crohn’s disease is characterized by repeated cycles of inflammation and mucosal healing which ultimately progress to intestinal fibrosis. This inexorable progression towards fibrosis suggests that fibrosis becomes inflammation-independent and auto-propagative. We hypothesized that matrix stiffness regulates this auto-propagation of intestinal fibrosis. Methods The stiffness of fresh ex vivo samples from normal human small intestine, Crohn’s disease strictures, and the unaffected margin were measured with a microelastometer. Normal human colonic fibroblasts were cultured on physiologically normal or pathologically stiff matrices corresponding to the physiological stiffness of normal or fibrotic bowel. Cellular response was assayed for changes in cell morphology, α-smooth muscle actin (αSMA) staining, and gene expression. Results Microelastometer measurements revealed a significant increase in colonic tissue stiffness between normal human colon and Crohn’s strictures as well as between the stricture and adjacent tissue margin. In Ccd-18co cells grown on stiff matrices corresponding to Crohn’s strictures, cellular proliferation increased. Pathologic stiffness induced a marked change in cell morphology and increased αSMA protein expression. Growth on a stiff matrix induced fibrogenic gene expression, decreased matrix metalloproteinase and pro-inflammatory gene expression, and was associated with nuclear localization of the transcriptional cofactor MRTF-A. Conclusions Matrix stiffness, representative of the pathological stiffness of Crohn’s strictures, activates human colonic fibroblasts to a fibrogenic phenotype. Matrix stiffness affects multiple pathways suggesting the mechanical properties of the cellular environment are critical to fibroblast function and may contribute to autopropagation of intestinal fibrosis in the absence of inflammation, thereby contributing to the intractable intestinal fibrosis characteristic of Crohn’s disease. PMID

Elevated NT-proBNP is associated with unfavorably altered plasma fibrin clot properties in atrial fibrillation.

Science.gov (United States)

Matusik, Paweł T; Matusik, Patrycja S; Kornacewicz-Jach, Zdzisława; Małecka, Barbara; Ząbek, Andrzej; Undas, Anetta

2017-09-15

Dense fibrin clot formation and hypofibrinolysis have been reported in atrial fibrillation (AF). It is unclear which factors affect fibrin clot properties in AF. We investigated plasma fibrin clot permeability (K s ), clot lysis time (CLT), endogenous thrombin potential (ETP) as well as other coagulation and fibrinolysis parameters along with N-terminal pro-B-type natriuretic peptide (NT-proBNP) in 160 AF patients (median age, 70.5years). Previous stroke (n=15; 9.4%) was associated with decreased K s (P=0.04) and longer CLT (P=0.005), together with higher antiplasmin (P=0.03) and lower tissue-type plasminogen activator (P=0.01). Lower K s (P=0.04) and tendency towards longer CLT (P=0.10) were observed in patients with a left atrium diameter>40mm. Patients with a CHA 2 DS 2 -VASc score of 3 or more (82.5%) were characterized by higher thrombin-activatable fibrinolysis inhibitor antigen (P=0.009). K s was inversely correlated with log NT-proBNP (r=-0.34, PCLT was positively correlated with log NT-proBNP (R=0.61, PCLT (the top quartile,≥109min). In AF patients prothrombotic fibrin clot properties assessed ex vivo are determined by PAI-1 and NT-proBNP and this phenotype is associated with prior ischemic stroke. Copyright © 2017 Elsevier B.V. All rights reserved.

Use of fibrin glue in the management of recurrent pterygium by conjunctival autograft

International Nuclear Information System (INIS)

Virendra K. Malik; Sandeep Kumar

2010-01-01

To evaluate whether use of fibrin glue instead of sutures for the treatment of recurrent pterygium with conjunctival auto-graft (CAG) further decreases its recurrence. A prospective, clinical open trial of 50 eyes of 50 patients with recurrent pterygium, who were randomly assigned to either, pterygium excision and CAG with fibrin glue (Group 1) or with 6 interrupted sutures (Group 2), was carried out from January 2009 to July 2010 at the outpatient department of Subharti Medical College, Meerut, North India. Both groups had 25 patients each. The groups were compared with regards to the surgical time taken, development of recurrence, postoperative symptoms (irritation, watering, and redness), and complications. Recurrence was seen in one (4%) eye in group I, and 3 (12%) eyes in group II after 9-13 months of follow up. The difference between the 2 groups was not statistically significant. The surgical time was significantly reduced, and postoperative inflammation and complications were less in group I. Postoperative symptoms were significantly more in group II patients. While conjunctival autograft with sutures for management of recurrent pterygium appears to be a safe and feasible modality, fibrin glue fixation of the autograft is a more viable option in terms of surgical ease, less time consuming, less postoperative complications, and less recurrence (Author).

In vitro human periodontal ligament-like tissue formation with porous poly-L-lactide matrix

International Nuclear Information System (INIS)

Liao, Wen; Okada, Masahiro; Sakamoto, Fumito; Okita, Naoya; Inami, Kaoru; Nishiura, Aki; Hashimoto, Yoshiya; Matsumoto, Naoyuki

2013-01-01

This study aimed to establish an in vitro human periodontal ligament-like tissue (HPdLLT) by three-dimensional culturing of human periodontal ligament fibroblasts (HPdLFs) in a porous poly-L-lactide (PLLA) matrix modified hydrophilically with ammonia solution. After ammonia modification, the surface roughness and culture-medium-soaking-up ability of the PLLA matrix increased, whereas the contact angle of water drops decreased. The thickness, porosity, and pore size of the PLLA matrix were 400 ± 50 μm, 83.3%, and 75–150 μm, respectively. HPdLFs (1 × 10 5 cells) were seeded on the modified PLLA matrix and centrifuged to facilitate seeding into its interior and cultured for 14 days. Scanning electron microscope (SEM) observation, proliferation assay, picrosirius-red staining, and real-time polymerase chain reaction (RT-PCR) for type-1 collagen (COL1), periodontal ligament associated protein-1 (PLAP-1), fibroblast growth factor-2 (FGF-2), and alkaline phosphatase (ALP) mRNA were conducted on days 1, 3, 7, and 14. HPdLFs were observed entirely from the surface to the rear side of the matrix. Cell proliferation analysis, SEM observation, and picrosirius-red staining showed both progressive growth of 3D-cultured HPdLFs and extracellular matrix maturation by the secretion of COL1 and type 3 collagen (COL3) from days 1 to 14. Expressions of COL1, PLAP-1, and FGF-2 mRNA suggested the formation of cellular components and supplementation of extracellular components. Expressions of ALP, COL1, and PLAP-1 mRNA suggested the osteogenic potential of the HPdLLT. The results indicated in vitro HPdLLT formation, and it could be used in future periodontal ligament tissue engineering to achieve optimal periodontal regeneration. - Highlights: • First report on ammonia treated PLLA matrix for in vitro human periodontal ligament-like tissue generation. • Good combination of matrix thickness, pore size, and porosity. • Biodegradable PLLA is also possible to be used in vivo

In vitro human periodontal ligament-like tissue formation with porous poly-L-lactide matrix

Energy Technology Data Exchange (ETDEWEB)

Liao, Wen [Graduate School of Dentistry, Department of Orthodontics, Osaka Dental University, 8-1 Kuzuha-hanazono-cho, Hirakata-shi, Osaka-fu 573-1121 (Japan); Okada, Masahiro [Department of Biomaterials, Osaka Dental University, 8-1 Kuzuha-hanazono-cho, Hirakata-shi, Osaka-fu 573-1121 (Japan); Sakamoto, Fumito; Okita, Naoya [Graduate School of Dentistry, Department of Orthodontics, Osaka Dental University, 8-1 Kuzuha-hanazono-cho, Hirakata-shi, Osaka-fu 573-1121 (Japan); Inami, Kaoru; Nishiura, Aki [Department of Orthodontics, Osaka Dental University, 8-1 Kuzuha-hanazono-cho, Hirakata-shi, Osaka-fu 573-1121 (Japan); Hashimoto, Yoshiya, E-mail: yoshiya@cc.osaka-dent.ac.jp [Department of Biomaterials, Osaka Dental University, 8-1 Kuzuha-hanazono-cho, Hirakata-shi, Osaka-fu 573-1121 (Japan); Matsumoto, Naoyuki [Department of Orthodontics, Osaka Dental University, 8-1 Kuzuha-hanazono-cho, Hirakata-shi, Osaka-fu 573-1121 (Japan)

2013-08-01

This study aimed to establish an in vitro human periodontal ligament-like tissue (HPdLLT) by three-dimensional culturing of human periodontal ligament fibroblasts (HPdLFs) in a porous poly-L-lactide (PLLA) matrix modified hydrophilically with ammonia solution. After ammonia modification, the surface roughness and culture-medium-soaking-up ability of the PLLA matrix increased, whereas the contact angle of water drops decreased. The thickness, porosity, and pore size of the PLLA matrix were 400 ± 50 μm, 83.3%, and 75–150 μm, respectively. HPdLFs (1 × 10{sup 5} cells) were seeded on the modified PLLA matrix and centrifuged to facilitate seeding into its interior and cultured for 14 days. Scanning electron microscope (SEM) observation, proliferation assay, picrosirius-red staining, and real-time polymerase chain reaction (RT-PCR) for type-1 collagen (COL1), periodontal ligament associated protein-1 (PLAP-1), fibroblast growth factor-2 (FGF-2), and alkaline phosphatase (ALP) mRNA were conducted on days 1, 3, 7, and 14. HPdLFs were observed entirely from the surface to the rear side of the matrix. Cell proliferation analysis, SEM observation, and picrosirius-red staining showed both progressive growth of 3D-cultured HPdLFs and extracellular matrix maturation by the secretion of COL1 and type 3 collagen (COL3) from days 1 to 14. Expressions of COL1, PLAP-1, and FGF-2 mRNA suggested the formation of cellular components and supplementation of extracellular components. Expressions of ALP, COL1, and PLAP-1 mRNA suggested the osteogenic potential of the HPdLLT. The results indicated in vitro HPdLLT formation, and it could be used in future periodontal ligament tissue engineering to achieve optimal periodontal regeneration. - Highlights: • First report on ammonia treated PLLA matrix for in vitro human periodontal ligament-like tissue generation. • Good combination of matrix thickness, pore size, and porosity. • Biodegradable PLLA is also possible to be used in vivo.

Re: Fibrin Glue Injections: A Minimally Invasive and Cost-Effective Treatment for Post-Renal Transplant Lymphoceles and Lymph Fistulas

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Presser N

2016-03-01

Full Text Available In this retrospective study, 46 (2.7% patients out of 1662 kidney transplant recipients had developed symptomatic lymphocele/lymph fistula requiring intervention over an 11-year period. Open surgical drainage (22, laparoscopic surgical drainage (11 and percutaneous fibrin glue injections into the drained lymphocele cavity (13 were used to treat this complication. Besides being effective both on the early and late developed lymphoceles, significantly lower recurrence rates by fibrin glue injections and lower median treatment costs were observed when compared with the other two surgical modalities. It has also the advantage of an outpatient procedure that can be performed using fluoroscopic guidance, under local anesthesia. However, due to era effect, most of the open and laparoscopic surgical recipients were treated with sirolimus, a well-known antiproliferative immunosuppressive agent, which can promote development of lymphoceles and surgical failure. However, the majority of fibrin glue-treated cases were with tacrolimus-based regimens, but this study, in its nature, is far from giving the answer for decreased number of recurrences with fibrin glue

Cartilage oligomeric matrix protein enhances matrix assembly during chondrogenesis of human mesenchymal stem cells.

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Haleem-Smith, Hana; Calderon, Raul; Song, Yingjie; Tuan, Rocky S; Chen, Faye H

2012-04-01

Cartilage oligomeric matrix protein/thrombospondin-5 (COMP/TSP5) is an abundant cartilage extracellular matrix (ECM) protein that interacts with major cartilage ECM components, including aggrecan and collagens. To test our hypothesis that COMP/TSP5 functions in the assembly of the ECM during cartilage morphogenesis, we have employed mesenchymal stem cell (MSC) chondrogenesis in vitro as a model to examine the effects of COMP over-expression on neo-cartilage formation. Human bone marrow-derived MSCs were transfected with either full-length COMP cDNA or control plasmid, followed by chondrogenic induction in three-dimensional pellet or alginate hydrogel culture. MSC chondrogenesis and ECM production was estimated based on quantitation of sulfated glycosaminoglycan (sGAG) accumulation, immunohistochemistry of the presence and distribution of cartilage ECM proteins, and real-time RT-PCR analyis of mRNA expression of cartilage markers. Our results showed that COMP over-expression resulted in increased total sGAG content during the early phase of MSC chondrogenesis, and increased immuno-detectable levels of aggrecan and collagen type II in the ECM of COMP-transfected pellet and alginate cultures, indicating more abundant cartilaginous matrix. COMP transfection did not significantly increase the transcript levels of the early chondrogenic marker, Sox9, or aggrecan, suggesting that enhancement of MSC cartilage ECM was effected at post-transcriptional levels. These findings strongly suggest that COMP functions in mesenchymal chondrogenesis by enhancing cartilage ECM organization and assembly. The action of COMP is most likely mediated not via direct changes in cartilage matrix gene expression but via interactions of COMP with other cartilage ECM proteins, such as aggrecan and collagens, that result in enhanced assembly and retention.

CARTILAGE OLIGOMERIC MATRIX PROTEIN ENHANCES MATRIX ASSEMBLY DURING CHONDROGENESIS OF HUMAN MESENCHYMAL STEM CELLS

Science.gov (United States)

Haleem-Smith, Hana; Calderon, Raul; Song, Yingjie; Tuan, Rocky S.; Chen, Faye H.

2011-01-01

Cartilage oligomeric matrix protein/thrombospondin-5 (COMP/TSP5) is an abundant cartilage extracellular matrix (ECM) protein that interacts with major cartilage ECM components, including aggrecan and collagens. To test our hypothesis that COMP/TSP5 functions in the assembly of the ECM during cartilage morphogenesis, we have employed mesenchymal stem cell (MSC) chondrogenesis in vitro as a model to examine the effects of COMP over-expression on neo-cartilage formation. Human bone marrow-derived MSCs were transfected with either full-length COMP cDNA or control plasmid, followed by chondrogenic induction in three-dimensional pellet or alginate-hydrogel culture. MSC chondrogenesis and ECM production was estimated based on quantitation of sulfated glycosaminoglycan (sGAG) accumulation, immunohistochemistry of the presence and distribution of cartilage ECM proteins, and real-time RT-PCR analyis of mRNA expression of cartilage markers. Our results showed that COMP over-expression resulted in increased total sGAG content during the early phase of MSC chondrogenesis, and increased immuno-detectable levels of aggrecan and collagen type II in the ECM of COMP-transfected pellet and alginate cultures, indicating more abundant cartilaginous matrix. COMP transfection did not significantly increase the transcript levels of the early chondrogenic marker, Sox9, or aggrecan, suggesting that enhancement of MSC cartilage ECM was effected at post-transcriptional levels. These findings strongly suggest that COMP functions in mesenchymal chondrogenesis by enhancing cartilage ECM organization and assembly. The action of COMP is most likely mediated not via direct changes in cartilage matrix gene expression but via interactions of COMP with other cartilage ECM proteins, such as aggrecan and collagens, that result in enhanced assembly and retention. PMID:22095699

Efficacy, Reliability, and Safety of Completely Autologous Fibrin Glue in Neurosurgical Procedures: Single-Center Retrospective Large-Number Case Study.

Science.gov (United States)

Nakayama, Noriyuki; Yano, Hirohito; Egashira, Yusuke; Enomoto, Yukiko; Ohe, Naoyuki; Kanemura, Nobuhiro; Kitagawa, Junichi; Iwama, Toru

2018-01-01

Commercially available fibrin glue (Com-FG), which is used commonly worldwide, is produced with pooled human plasma from multiple donors. However, it has added bovine aprotinin, which involves the risk of infection, allogenic immunity, and allergic reactions. We evaluate the efficacy, reliability, and safety of completely autologous fibrin glue (CAFG). From August 2014 to February 2016, prospective data were collected and analyzed from 153 patients. CAFG was prepared with the CryoSeal System using autologous blood and was applied during neurosurgical procedures. Using CAFG-soaked oxidized regenerated cellulose and/or polyglycolic acid sheets, we performed a pinpoint hemostasis, transposed the offending vessels in a microvascular decompression, and covered the dural incision to prevent cerebrospinal fluid leakage. The CryoSeal System had generated up to a mean of 4.51 mL (range, 3.0-8.4 mL) of CAFG from 400 mL autologous blood. Com-FG products were not used in our procedures. Only 6 patients required an additional allogeneic blood transfusion. The hemostatic effective rate was 96.1% (147 of 153 patients). Only 1 patient who received transsphenoidal surgery for a pituitary adenoma presented with the complication of delayed postoperative cerebrospinal fluid leakage (0.65%). No patient developed allergic reactions or systemic complications associated with the use of CAFG. CAFG effectively provides hemostatic, adhesive, and safety performance. The timing and three-dimensional shape of CAFG-soaked oxidized regenerated cellulose and/or polyglycolic acid sheets solidification can be controlled with slow fibrin formation. The cost to prepare CAFG is similar compared with Com-FG products, and it can therefore be easily used at most institutions. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of fibrin-gelatin hydrogel as biopaper for application in skin bioprinting: An in-vitro study.

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Hakam, Mohammad Sadjad; Imani, Rana; Abolfathi, Nabiollah; Fakhrzadeh, Hossein; Sharifi, Ali Mohammad

2016-01-01

Recent advances in tissue engineering have led to the development of the concept of bioprinting as an interesting alternative to traditional tissue engineering approaches. Biopaper, a biomimetic hydrogel, is an essential component of the bioprinting process. The aim of this work was to synthesize a biopaper made of fibrin-gelatin hybrid hydrogel for application in skin bioprinting. Different composition percentages of the two biopolymer hydrogels, fibrin-gelatin, have been studied for the construction of the biopaper and were examined in terms of water absorption, biodegradability, glucose absorption, mechanical properties and water vapor transmission. Subsequently, tissue fusion study was performed on prepared 3T3 fibroblast cell line pellets embedded into the hydrogel. Based on the obtained results, fibrin-gelatin blend hydrogel with the same proportion of two components provides a natural scaffold for fibroblast-based bioink embedding and culture. The suggested optimized hydrogel was a suitable candidate as a biopaper for skin bioprinting technology.

Cytocompatibility and biologic characteristics of synthetic scaffold materials of rabbit acellular vascular matrix combining with human-like collagen I.

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Liu, Xuqian; Wang, Jie; Dong, Fusheng; Song, Peng; Tian, Songbo; Li, Hexiang; Hou, Yali

2017-10-01

Scaffold material provides a three-dimensional growing environment for seed cells in the research field of tissue engineering. In the present study, rabbit arterial blood vessel cells were chemically removed with trypsin and Triton X-100 to prepare rabbit acellular vascular matrix scaffold material. Observation by He&Masson staining revealed that no cellular components or nuclei existed in the vascular intima and media after decellularization. Human-like collagen I was combined with acellular vascular matrix by freeze-drying to prepare an acellular vascular matrix-0.25% human-like collagen I scaffold to compensate for the extracellular matrix loss during the decellularization process. We next performed a series of experiments to test the water absorbing quality, biomechanics, pressure resistance, cytotoxicity, and ultra-micro structure of the acellular vascular matrix composite material and natural rabbit artery and found that the acellular vascular matrix-0.25% human-like collagen I material behaved similarly to natural rabbit artery. In conclusion, the acellular vascular matrix-0.25% human-like collagen I composite material provides a new approach and lays the foundation for novel scaffold material research into tissue engineering of blood vessels.

Management of an extrasphincteric fistula in an HIV-positive patient by using fibrin glue: a case report with tips and tricks

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Sapalidis Konstantinos

2010-02-01

Full Text Available Abstract Background Individuals with impaired immunity are at higher risk of perianal diseases. Concerning complex anal fistulas impaired healing and complication rates are also higher. Definitive treatment of a fistula aims controlling the purulent discharge and prevents its recurrence. It depends mainly on the trajectory of the fistula and the underlying disease. We present a case of a HIV-positive patient with a complex extrasphincteric anal fistula who was treated successfully with fibrin glue application. We further, discuss tips and tricks when applying fibrin glue as plugging material in complex anal fistulas. Case presentation A sixty-one-year-old HIV-positive male referred to us for warts and extrasphincteric fistula. Because of the patients' immunological status, we opted against surgery and recommended fibrin glue plugging. The patient was discharged the same day. A follow-up examination was performed 5 days after the initial fibrin glue application showing that the fistula canal was obstructed. Three months and a year post-intervention the fistula tract remains closed. Conclusion The best treatment for a disease gives at least the same result with the other treatments with minimised risk for the life of the patient and minimal application effort. Conservative closure of fistula with fibrin plugging is simple, safe and with less morbidity than surgery. Our patient was successfully treated without endangering his life despite his precarious medical state. Not everybody believes in the effectiveness of fibrin glue application, however we consider this solution in cases of complex fistulas at least as primary procedure in special populations such as the immunosupressed.

Fixation of split-thickness skin graft using fast-clotting fibrin glue containing undiluted high-concentration thrombin or sutures: a comparison study.

Science.gov (United States)

Han, Hyun Ho; Jun, Daiwon; Moon, Suk-Ho; Kang, In Sook; Kim, Min Cheol

2016-01-01

For skin defects caused by full-thickness burns, trauma, or tumor tissue excision, skin grafting is one of the most convenient and useful treatment methods. In this situation, graft fixation is important in skin grafting. This study was performed to compare the effectiveness of skin graft fixation between high-concentration fibrin sealant and sutures. There have been numerous studies using fibrin sealant for graft fixation, but they utilized slow-clotting fibrin sealant containing less than 10 IU/mL thrombin. Twenty-five patients underwent split-thickness skin grafting using fast-clotting fibrin sealant containing 400 IU/mL thrombin, while 30 patients underwent grafting using sutures. Rates of hematoma/seroma formation, graft dislocation, graft necrosis, and graft take were investigated postoperatively. The graft surface area was calculated using Image J software (National Institutes of Health, Bethesda, MD, USA). After 5 days, rates of hematoma/seroma formation and graft dislocation were 7.84 and 1.29% in group I, and 9.55 and 1.45% in group II, respectively. After 30 days, rates of graft necrosis and graft take were 1.86 and 98.14% in group I, and 4.65 and 95.35% in group II. Undiluted fibrin sealant showed significantly superior results for all rates ( p  < 0.05) except graft dislocation. When high-concentration fast-clotting fibrin sealant was applied to skin grafts without dilution, no difficulty was experienced during surgery. Sealant showed superior results compared with sutures and had an excellent graft take rate. II.

Fibrin d-dimer concentration, deep vein thrombosis symptom duration, and venous thrombus volume.

Science.gov (United States)

Kurklinsky, Andrew K; Kalsi, Henna; Wysokinski, Waldemar E; Mauck, Karen F; Bhagra, Anjali; Havyer, Rachel D; Thompson, Carrie A; Hayes, Sharonne N; McBane, Robert D

2011-04-01

To determine the relationship between fibrin D-dimer levels, symptom duration, and thrombus volume, consecutive patients with incident deep venous thrombosis (DVT) were evaluated. In a cross-sectional study design, patient symptom onset was determined by careful patient questioning. Venous thrombosis was confirmed by compression duplex ultrasonography. Thrombus volume was estimated based on patient's femur length using a forensic anthropology method. Fibrin D-dimer was measured by latex immunoassay. 72 consecutive patients with confirmed leg DVT agreed to participate. The median symptom duration at the time of diagnosis was 10 days. The median D-dimer concentration was 1050 ng/dL. The median thrombus volume was 12.92 cm(3). D-Dimer levels correlated with estimated thrombus volume (P venous thrombosis and correlates with thrombus volume.

Complete horizontal skin cell resurfacing and delayed vertical cell infiltration into porcine reconstructive tissue matrix compared to bovine collagen matrix and human dermis.

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Mirastschijski, Ursula; Kerzel, Corinna; Schnabel, Reinhild; Strauss, Sarah; Breuing, Karl-Heinz

2013-10-01

Xenogenous dermal matrices are used for hernia repair and breast reconstruction. Full-thickness skin replacement is needed after burn or degloving injuries with exposure of tendons or bones. The authors used a human skin organ culture model to study whether porcine reconstructive tissue matrix (Strattice) is effective as a dermal tissue replacement. Skin cells or split-thickness skin grafts were seeded onto human deepidermized dermis, Strattice, and Matriderm. Cellular resurfacing and matrix infiltration were monitored by live fluorescence imaging, histology, and electron microscopy. Proliferation, apoptosis, cell differentiation, and adhesion were analyzed by immunohistochemistry. Epithelial resurfacing and vertical proliferation were reduced and delayed with both bioartificial matrices compared with deepidermized dermis; however, no differences in apoptosis, cell differentiation, or basement membrane formation were found. Vertical penetration was greatest on Matriderm, whereas no matrix infiltration was found on Strattice in the first 12 days. Uncompromised horizontal resurfacing was greatest with Strattice but was absent with Matriderm. Strattice showed no stimulatory effect on cellular inflammation. Matrix texture and surface properties governed cellular performance on tissues. Although dense dermal compaction delayed vertical cellular ingrowth for Strattice, it allowed uncompromised horizontal resurfacing. Dense dermal compaction may slow matrix decomposition and result in prolonged biomechanical stability of the graft. Reconstructive surgeons should choose the adequate matrix substitute depending on biomechanical requirements at the recipient site. Strattice may be suitable as a dermal replacement at recipient sites with high mechanical load requirements.

Study of some parameters of the fibrinogen - fibrin transformation reaction

International Nuclear Information System (INIS)

Hollard, D.; Suscillon, M.; Marcille, G.; Rambaud, F.; Baloyan, M.

1966-01-01

The authors studied the action of some parameters on the reaction of transformation fibrinogen-fibrin. The five parameters studied are: the concentration of substratum: a certain quantity of enzyme determines an optimum quantity of fibrinogen; the concentration of enzyme: a certain quantity of substratum defines an optimum quantity of enzyme, beyond which the excess of enzyme is unable to act, the substratum being saturated by the enzyme; the concentration of Ca ions: between 0,07 and 0,10 mg of Ca by mg of fibrinogen, the reaction appears with a great speed. Between 0,02 and 0,40 mg of Ca by mg of fibrinogen the fibrin stabilisation is possible, the FSF can act only inside the definite bounds; the ph of the solution: the reaction of the transformation appears with its maximum intensity on physiological ph, the polymerisation is not possible on acid ph; the temperature has an effect which could not really be verified owing to the fact that the technical realisation is difficult. (author) [fr

A New Method to Develop Human Dental Pulp Cells and Platelet-rich Fibrin Complex.

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He, Xuan; Chen, Wen-Xia; Ban, Guifei; Wei, Wei; Zhou, Jun; Chen, Wen-Jin; Li, Xian-Yu

2016-11-01

Platelet-rich fibrin (PRF) has been used as a scaffold material in various tissue regeneration studies. In the previous methods to combine seed cells with PRF, the structure of PRF was damaged, and the manipulation time in vitro was also increased. The objective of this in vitro study was to explore an appropriate method to develop a PRF-human dental pulp cell (hDPC) complex to maintain PRF structure integrity and to find out the most efficient part of PRF. The PRF-hDPC complex was developed at 3 different time points during PRF preparation: (1) the before centrifugation (BC) group, the hDPC suspension was added to the venous blood before blood centrifugation; (2) the immediately after centrifugation (IAC) group, the hDPC suspension was added immediately after blood centrifugation; (3) the after centrifugation (AC) group, the hDPC suspension was added 10 minutes after blood centrifugation; and (4) the control group, PRF without hDPC suspension. The prepared PRF-hDPC complexes were cultured for 7 days. The samples were fixed for histologic, immunohistochemistry, and scanning electron microscopic evaluation. Real-time polymerase chain reaction was performed to evaluate messenger RNA expression of alkaline phosphatase and dentin sialophosphoprotein. Enzyme-linked immunosorbent assay quantification for growth factors was performed within the different parts of the PRF. Histologic, immunohistochemistry, and scanning electron microscopic results revealed that hDPCs were only found in the BC group and exhibited favorable proliferation. Real-time polymerase chain reaction revealed that alkaline phosphatase and dentin sialophosphoprotein expression increased in the cultured PRF-hDPC complex. The lower part of the PRF released the maximum quantity of growth factors. Our new method to develop a PRF-hDPCs complex maintained PRF structure integrity. The hDPCs were distributed in the buffy coat, which might be the most efficient part of PRF. Copyright © 2016 American

Crestal Approach to Sinus Floor Elevation for Atrophic Maxilla Using Platelet-Rich Fibrin as the Only Grafting Material: A 1-Year Prospective Study.

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Kanayama, Takeo; Horii, Koichiro; Senga, Yasuko; Shibuya, Yasuyuki

2016-02-01

Platelet-rich fibrin (PRF) has been recently used as the sole grafting material in sinus floor elevation procedures. The aim of this prospective study was to measure the bone gain around the dental implant after using the crestal approach to sinus floor elevation using platelet-rich fibrin as the only grafting material in atrophic posterior maxillae with residual bone height platelet-rich fibrin promoted endosinus bone gain when used as the grafting material in the crestal approach to sinus floor elevation.

Fibrinogen and thrombin concentrations are critical for fibrin glue adherence in rat high-risk colon anastomoses

Directory of Open Access Journals (Sweden)

Eliseo Portilla-de Buen

2014-04-01

Full Text Available OBJECTIVE: Fibrin glues have not been consistently successful in preventing the dehiscence of high-risk colonic anastomoses. Fibrinogen and thrombin concentrations in glues determine their ability to function as sealants, healers, and/or adhesives. The objective of the current study was to compare the effects of different concentrations of fibrinogen and thrombin on bursting pressure, leaks, dehiscence, and morphology of high-risk ischemic colonic anastomoses using fibrin glue in rats. METHODS: Colonic anastomoses in adult female Sprague-Dawley rats (weight, 250-350 g treated with fibrin glue containing different concentrations of fibrinogen and thrombin were evaluated at post-operative day 5. The interventions were low-risk (normal or high-risk (ischemic end-to-end colonic anastomoses using polypropylene sutures and topical application of fibrinogen at high (120 mg/mL or low (40 mg/mL concentrations and thrombin at high (1000 IU/mL or low (500 IU/mL concentrations. RESULTS: Ischemia alone, anastomosis alone, or both together reduced the bursting pressure. Glues containing a low fibrinogen concentration improved this parameter in all cases. High thrombin in combination with low fibrinogen also improved adherence exclusively in low-risk anastomoses. No differences were detected with respect to macroscopic parameters, histopathology, or hydroxyproline content at 5 days post-anastomosis. CONCLUSIONS: Fibrin glue with a low fibrinogen content normalizes the bursting pressure of high-risk ischemic left-colon anastomoses in rats at day 5 after surgery.

Silver-Stained Fibrin Zymography: Separation of Proteases and Activity Detection Using a Single Substrate-Containing Gel.

Science.gov (United States)

Park, Chang-Su; Kang, Dae-Ook; Choi, Nack-Shick

2017-01-01

Silver-stained fibrin zymography for separation of protease bands and activity detection using a single substrate gel was designed. The method takes advantage of the nano-scale sensitivity of both zymography and silver staining. After sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE) in a gel containing fibrin (protease substrate), the gel was incubated in enzyme reaction buffer and the zymogram gel was silver-stained. Bands with protease activity were stained with silver in clear areas where the protein substrate had been degraded. The molecular sizes of proteases were accurately determined.

Preliminary report of a sutureless onlay technique for incisional hernia repair using fibrin glue alone for mesh fixation.

Science.gov (United States)

Stoikes, Nathaniel; Webb, David; Powell, Ben; Voeller, Guy

2013-11-01

The Rives repair for ventral/incisional (V/I) hernias involves sublay mesh placement requiring retrorectus dissection and transfascial stitches. Chevrel described a repair by onlaying mesh after a unique primary fascial closure. Although Chevrel fixated mesh to the anterior fascia with sutures, he used fibrin glue for fascial closure reinforcement. We describe an onlay technique with mesh fixated to the anterior fascia solely with fibrin glue without suture fixation. From January 2010 to January 2012, 50 patients underwent a V/I hernia onlay technique with fibrin glue mesh fixation. Records were reviewed for technical details, demographics, mesh characteristics, and postoperative outcomes. Primary fascial closure with interrupted permanent suture was done with or without myofascial advancement flaps. Onlay polypropylene mesh was placed providing 8 cm of overlap. Fibrin glue was applied over the prosthesis and subcutaneous drains were placed. Mean age was 62.4 years. Mean body mass index was 30.1 kg/m(2). Average mesh size was 14.5 cm × 19.1 cm. Mean operative time was 144.4 minutes (range, 38 to 316 minutes). Mean discharge was postoperative Day 2.9 (range, 0 to 15 days). Morbidity included eight seromas, one hematoma, and three wound infections. Seventeen patients required components separation. Mean follow-up was 19.5 months with no recurrences. This is the first series describing fibrin glue alone for mesh fixation for V/I hernia repair. It allows for immediate prosthesis fixation to the anterior fascia. Early results are promising. Potential advantages include less operative time, less technical difficulty, and less long-term pain. A prospective trial is needed to evaluate this approach.

Gallium/sup 67/ scintigraphy in fibrinous pericarditis associated with bacterial endocarditis

Energy Technology Data Exchange (ETDEWEB)

Martin, P; Verhas, M; Devriendt, J; Goffin, Y

1982-04-01

An 80-year-old man presented with pyrexia, progressive cardiac failure and inflammation. A diagnosis of pericarditis associated with bacterial endocarditis was suggested from Gallium 67 scintigraphy and confirmed at autopsy. This case of fibrinous pericarditis without effusion could not be diagnosed by echography or routine cardiopulmonary scintigraphy.

Low-thrombogenic fibrin-heparin coating promotes in vitro endothelialization

Czech Academy of Sciences Publication Activity Database

Kaplan, Ondřej; Hierlemann, T.; Krajewski, S.; Kurz, J.; Nevoralová, Martina; Houska, Milan; Riedel, Tomáš; Riedelová, Zuzana; Zárubová, Jana; Wendel, H. P.; Brynda, Eduard

2017-01-01

Roč. 105, č. 11 (2017), s. 2995-3005 ISSN 1549-3296 R&D Projects: GA MZd(CZ) NV15-29153A Institutional support: RVO:61389013 ; RVO:67985823 Keywords : fibrin-heparin coating * hemocompatibility * endothelialization Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery; FA - Cardiovascular Diseases incl. Cardiotharic Surgery (FGU-C) OBOR OECD: Cardiac and Cardiovascular systems; Cardiac and Cardiovascular systems (FGU-C) Impact factor: 3.076, year: 2016

Fixation of osteochondral fractures in rabbit knees. A comparison of Kirschner wires, fibrin sealant, and polydioxanone pins.

Science.gov (United States)

Plaga, B R; Royster, R M; Donigian, A M; Wright, G B; Caskey, P M

1992-03-01

We compared fibrin sealant, polydioxanone (PDS) pins and Kirschner wires in the fixation of osteochondral fractures in rabbit knees. Standardised osteochondral fractures of the right medial femoral condyle were made in 56 adult New Zealand white rabbits. There were equal groups of control knees, and those which had Kirschner-wire, fibrin-sealant or PDS-pin fixation. No external immobilisation was used. One animal from each group was killed at two, three and four weeks. The remaining rabbits were killed at six weeks. A fracture which healed with less than 1 mm of displacement was considered a success. There was successful healing in 29% of the control group, in all of the Kirschner-wire group, in 50% of the fibrin-sealant group, and in 86% of the PDS-pin group. The use of PDS pins appears to be a reliable alternative to the use of metal in the fixation of osteochondral fractures in rabbits.

Fibrin sealants or cell saver eliminate the need for autologous blood donation in anemic patients undergoing primary total knee arthroplasty.

Science.gov (United States)

Bou Monsef, Jad; Buckup, Johannes; Waldstein, Wenzel; Cornell, Charles; Boettner, Friedrich

2014-01-01

Reducing allogeneic blood transfusions remains a challenge in total knee arthroplasty. Patients with preoperative anemia have a particularly high risk for perioperative blood transfusions. 176 anemic patients (Hb < 13.5 g/dl) undergoing total knee replacement were prospectively evaluated to compare the effect of a perioperative cell saver (26 patients), intraoperative fibrin sealants (5 ml Evicel, Johnson & Johnson Wound Management, Ethicon, Somerville, NJ) (45 patients), preoperative autologous blood donation (PABD) (21 patients), the combination of fibrin sealants and preoperative autologous blood donation (44) and no intervention (40 patients) on perioperative blood loss and transfusion requirements. All protocols resulted in significant reduction of allogeneic blood transfusions. Transfusion rates were similar with the use of PABD (19%), Evicel (18%), and cell saver (19%), all significantly lower than the control group (38 %, p < 0.05). Combining Evicel with PABD resulted in significantly higher wastage of autologous units (p < 0.05) with no significant reduction in allogeneic transfusion rate (14%). The use of fibrin sealant resulted in a significant reduction of blood loss compared to the PABD group (603 vs. 810 ml, p < 0.005) as well as the control group (603 vs. 822 ml, p < 0.005). While PABD proved to be the most cost-effective treatment option in anemic patients, fibrin sealants and cell saver show similar reduction in allogeneic transfusion rates compared to controls. The combination of fibrin sealants and PABD is not cost-effective and increases the number of wasted units.

Comparison of mechanical compressive properties of commercial and autologous fibrin glues for tissue engineering applications.

Science.gov (United States)

Cravens, Matthew G; Behn, Anthony W; Dragoo, Jason L

2017-11-01

Fibrin glues are widely used in orthopedic surgery as adhesives and hemostatic agents. We evaluated the compressive properties of selected fibrin glues in order to identify which are appropriate for tissue regeneration applications subject to compression. Uniaxial unconfined compression tests were performed on fibrin gels prepared from commercial and autologous products: (1) Evicel (Ethicon), (2) Tisseel (Baxter), (3) Angel (Arthrex), and (4) ProPlaz (Biorich). Cyclic loads were applied from 0 to 30% strain for 100cycles at 0.5Hz. Following cyclic testing, specimens were subjected to ramp displacement of 1% strain per second to 80% strain. Throughout cyclic loading, Evicel and Tisseel deformed (shortened) less than Angel at all but one time point, and deformed less than ProPlaz at cycles 10 and 20. The dynamic moduli, peak stress, and strain energy were significantly greater in Tisseel than all other groups. Evicel displayed significantly greater dynamic moduli, peak stress, and strain energy than Angel and ProPlaz. Following cyclic testing, Tisseel and Evicel were significantly less deformed than Angel. No specimens exhibited gross failure during ramp loading to 80% strain. Ramp loading trends mirrored those of cyclic loading. The tested commercial glues were significantly more resistant to compression than the autologous products. The compressive properties of Tisseel were approximately twice those of Evicel. All preparations displayed moduli multiple orders of magnitude less than that of native articular cartilage. We conclude that in knee surgeries requiring fibrin glue to undergo compression of daily activity, commercial products are preferable to autologous preparations from platelet-poor plasma, though both will deform significantly. Copyright © 2017 Elsevier Ltd. All rights reserved.

Clot retraction is mediated by factor XIII-dependent fibrin-αIIbβ3-myosin axis in platelet sphingomyelin-rich membrane rafts.

Science.gov (United States)

Kasahara, Kohji; Kaneda, Mizuho; Miki, Toshiaki; Iida, Kazuko; Sekino-Suzuki, Naoko; Kawashima, Ikuo; Suzuki, Hidenori; Shimonaka, Motoyuki; Arai, Morio; Ohno-Iwashita, Yoshiko; Kojima, Soichi; Abe, Mitsuhiro; Kobayashi, Toshihide; Okazaki, Toshiro; Souri, Masayoshi; Ichinose, Akitada; Yamamoto, Naomasa

2013-11-07

Membrane rafts are spatially and functionally heterogenous in the cell membrane. We observed that lysenin-positive sphingomyelin (SM)-rich rafts are identified histochemically in the central region of adhered platelets where fibrin and myosin are colocalized on activation by thrombin. The clot retraction of SM-depleted platelets from SM synthase knockout mouse was delayed significantly, suggesting that platelet SM-rich rafts are involved in clot retraction. We found that fibrin converted by thrombin translocated immediately in platelet detergent-resistant membrane (DRM) rafts but that from Glanzmann's thrombasthenic platelets failed. The fibrinogen γ-chain C-terminal (residues 144-411) fusion protein translocated to platelet DRM rafts on thrombin activation, but its mutant that was replaced by A398A399 at factor XIII crosslinking sites (Q398Q399) was inhibited. Furthermore, fibrin translocation to DRM rafts was impaired in factor XIII A subunit-deficient mouse platelets, which show impaired clot retraction. In the cytoplasm, myosin translocated concomitantly with fibrin translocation into the DRM raft of thrombin-stimulated platelets. Furthermore, the disruption of SM-rich rafts by methyl-β-cyclodextrin impaired myosin activation and clot retraction. Thus, we propose that clot retraction takes place in SM-rich rafts where a fibrin-αIIbβ3-myosin complex is formed as a primary axis to promote platelet contraction.

Novel sulfated xylogalactoarabinans from green seaweed Cladophora falklandica: Chemical structure and action on the fibrin network.

Science.gov (United States)

Arata, Paula X; Quintana, Irene; Raffo, María Paula; Ciancia, Marina

2016-12-10

The water-soluble sulfated xylogalactoarabinans from green seaweed Cladophora falklandica are constituted by a backbone of 4-linked β-l-arabinopyranose units partially sulfated mainly on C3 and also on C2. Besides, partial glycosylation mostly on C2 with single stubs of β-d-xylopyranose, or single stubs of β-d-galactofuranose or short chains comprising (1→5)- and/or (1→6)-linkages, was also found. These compounds showed anticoagulant activity, although much lower than that of heparin. The effect of a purified fraction (F1) on the fibrin network was studied in detail. It modifies the kinetics of fibrin formation, suggesting an impaired polymerization process. Scanning electron microscopy showed a laxer conformation, with larger interstitial pores than the control. Accordingly, this network was lysed more easily. These fibrin properties would reduce the time of permanence of the clot in the blood vessel, inducing a lesser thrombogenic state. One of the possible mechanisms of its anticoagulant effect is direct thrombin inhibition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Transient Expression of Lumbrokinase (PI239 in Tobacco (Nicotiana tabacum Using a Geminivirus-Based Single Replicon System Dissolves Fibrin and Blood Clots

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Alexia Dickey

2017-01-01

Full Text Available Lumbrokinases, a group of fibrinolytic enzymes extracted from earthworm, have been widely used to prevent and treat various cardiovascular diseases. They specifically target fibrin to effectively degrade thrombi without major side effects. Plant expression systems are becoming potential alternative expression platforms for producing pharmaceutical proteins. In this work, a lumbrokinase (PI239 was produced from a plant system. Both wild-type (WT and plant codon-optimized (OP PI239 gene sequences were synthesized and cloned into a geminivirus-based single-vector DNA replicon system. Both vectors were independently expressed in tobacco (Nicotiana tabacum leaves transiently by agroinfiltration. Overexpressed PI239 resulted in sudden tissue necrosis 3 days after infiltration. Remaining proteins were purified through His-tag affinity chromatography and analyzed with SDS-PAGE and Western blot methods. Purified PI239 successfully degraded artificial fibrin with relative activity of 13,400 U/mg when compared with commercial lumbrokinase product. In vitro tests demonstrated that plant-derived PI239 dissolved human blood clots and that the plant expression system is capable of producing functional PI239.

Three-Dimensional In Vitro Skin and Skin Cancer Models Based on Human Fibroblast-Derived Matrix.

Science.gov (United States)

Berning, Manuel; Prätzel-Wunder, Silke; Bickenbach, Jackie R; Boukamp, Petra

2015-09-01

Three-dimensional in vitro skin and skin cancer models help to dissect epidermal-dermal and tumor-stroma interactions. In the model presented here, normal human dermal fibroblasts isolated from adult skin self-assembled into dermal equivalents with their specific fibroblast-derived matrix (fdmDE) over 4 weeks. The fdmDE represented a complex human extracellular matrix that was stabilized by its own heterogeneous collagen fiber meshwork, largely resembling a human dermal in vivo architecture. Complemented with normal human epidermal keratinocytes, the skin equivalent (fdmSE) thereof favored the establishment of a well-stratified and differentiated epidermis and importantly allowed epidermal regeneration in vitro for at least 24 weeks. Moreover, the fdmDE could be used to study the features of cutaneous skin cancer. Complementing fdmDE with HaCaT cells in different stages of malignancy or tumor-derived cutaneous squamous cell carcinoma cell lines, the resulting skin cancer equivalents (fdmSCEs) recapitulated the respective degree of tumorigenicity. In addition, the fdmSCE invasion phenotypes correlated with their individual degree of tissue organization, disturbance in basement membrane organization, and presence of matrix metalloproteinases. Together, fdmDE-based models are well suited for long-term regeneration of normal human epidermis and, as they recapitulate tumor-specific growth, differentiation, and invasion profiles of cutaneous skin cancer cells, also provide an excellent human in vitro skin cancer model.

Enhancement of the repair of dog alveolar cleft by an autologous iliac bone, bone marrow-derived mesenchymal stem cell, and platelet-rich fibrin mixture.

Science.gov (United States)

Yuanzheng, Chen; Yan, Gao; Ting, Li; Yanjie, Fu; Peng, Wu; Nan, Bai

2015-05-01

Autologous bone graft has been regarded as the criterion standard for the repair of alveolar cleft. However, the most prominent issue in alveolar cleft treatment is the high absorption rate of the bone graft. The authors' objective was to investigate the effects of an autologous iliac bone, bone marrow-derived mesenchymal stem cell, and platelet-rich fibrin mixture on the repair of dog alveolar cleft. Twenty beagle dogs with unilateral alveolar clefts created by surgery were divided randomly into four groups: group A underwent repair with an autologous iliac bone, bone marrow-derived mesenchymal stem cell, and platelet-rich fibrin mixture; group B underwent repair with autologous iliac bone and bone marrow-derived mesenchymal stem cells; group C underwent repair with autologous iliac bone and platelet-rich fibrin; and group D underwent repair with autologous iliac bone as the control. One day and 6 months after transplantation, the transplant volumes and bone mineral density were assessed by quantitative computed tomography. All of the transplants were harvested for hematoxylin and eosin staining 6 months later. Bone marrow-derived mesenchymal stem cells and platelet-rich fibrin transplants formed the greatest amounts of new bone among the four groups. The new bone formed an extensive union with the underlying maxilla in groups A, B, and C. Transplants with the bone marrow-derived mesenchymal stem cells, platelet-rich fibrin, and their mixture retained the majority of their initial volume, whereas the transplants in the control group showed the highest absorption rate. Bone mineral density of transplants with the bone marrow-derived mesenchymal stem cells, platelet-rich fibrin, and their mixture 6 months later was significantly higher than in the control group (p platelet-rich fibrin mixed transplants. Hematoxylin and eosin staining showed that the structure of new bones formed the best in group A. Both bone marrow-derived mesenchymal stem cells and platelet

Randomized clinical trial of fibrin sealant versus titanium tacks for mesh fixation in laparoscopic umbilical hernia repair

DEFF Research Database (Denmark)

Eriksen, J R; Bisgaard, T; Assaadzadeh, S

2011-01-01

The use of tacks for mesh fixation may induce pain after surgery for ventral hernia. The aim of this study was to compare postoperative pain after laparoscopic ventral hernia repair (LVHR) with conventional mesh fixation using titanium tacks versus fibrin sealant (FS).......The use of tacks for mesh fixation may induce pain after surgery for ventral hernia. The aim of this study was to compare postoperative pain after laparoscopic ventral hernia repair (LVHR) with conventional mesh fixation using titanium tacks versus fibrin sealant (FS)....

Fibrin- versus Plasma-Gel Scaffolds - und der Einfluss von TGF-ß und bFGF auf Myofibroblasten und die Gewebeneogenese

OpenAIRE

Dietrich, Maren

2015-01-01

One central aspect in tissue engineering is the scaffold. Due to its properties and the direct contact to cells, it strongly influences the development of the tissue engineered construct. Especially attractive are autologous materials, like fibrin. To optimize autologous PFP- and fibrin-scaffolds this work compared the basic materials platelet free plasma (PFP), platelet poor plasma (PPP), and platelet rich plasma (PRP) as autologous materials for scaffold production. Three differently concen...

Unfavorably Altered Fibrin Clot Properties in Patients with Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Syndrome): Association with Thrombin Generation and Eosinophilia.

Science.gov (United States)

Mastalerz, Lucyna; Celińska-Lӧwenhoff, Magdalena; Krawiec, Piotr; Batko, Bogdan; Tłustochowicz, Witold; Undas, Anetta

2015-01-01

Given reports on the increased prevalence of thromboembolic incidents in patients with eosinophilic granulomatosis with polyangiitis (EGPA; Churg-Strauss syndrome), we investigated whether fibrin clot properties are unfavorably altered in EGPA. Ex vivo plasma fibrin clot characteristics, including clot permeability, turbidimetry and efficiency of fibrinolysis using two assays, were investigated in 34 consecutive patients with remission in EGPA according to the Birmingham Vasculitis Activity Score version 3 (23 female, 11 male), aged 48 (range, 21-80) years. The control group comprised 34 age- and sex- matched volunteers. Compared with controls, patients with EGPA were characterized by denser fiber clots (estimated pore size, Ks, 7.30±0.93 vs 10.14±1.07 10-9 cm2), faster fibrin polymerization (lag phase in a turbidimetric curve, 41.8±3.6 vs 47.4±2.9 s), thicker fibrin fibers (maximum absorbance, ΔAbs, 0.87±0.09 vs 0.72±0.07), higher maximum levels of D-dimer released from clots (DDmax 4.10±0.46 vs 3.54±0.35 mg/L), and prolonged clot lysis time (t50%; 9.50±1.45 vs 7.56±0.87 min); all p<0.0001. Scanning electron microscopy images confirmed denser plasma fibrin networks composed of thinner fibers formed in EGPA. Antineutrophil cytoplasmic antibody status and C-reactive protein did not affect clot variables. Multivariate analysis adjusted for fibrinogen showed that Ks was predicted by eosinophil count, peak thrombin generation, factor VIII, and soluble CD40 ligand, whereas eosinophil count, peak thrombin generation and antiplasmin predicted t50%. This study is the first to show that EGPA is associated with prothrombotic plasma fibrin clot phenotype, which may contribute to thromboembolic manifestations reported in this disease.

Unfavorably Altered Fibrin Clot Properties in Patients with Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Syndrome: Association with Thrombin Generation and Eosinophilia.

Directory of Open Access Journals (Sweden)

Lucyna Mastalerz

Full Text Available Given reports on the increased prevalence of thromboembolic incidents in patients with eosinophilic granulomatosis with polyangiitis (EGPA; Churg-Strauss syndrome, we investigated whether fibrin clot properties are unfavorably altered in EGPA.Ex vivo plasma fibrin clot characteristics, including clot permeability, turbidimetry and efficiency of fibrinolysis using two assays, were investigated in 34 consecutive patients with remission in EGPA according to the Birmingham Vasculitis Activity Score version 3 (23 female, 11 male, aged 48 (range, 21-80 years. The control group comprised 34 age- and sex- matched volunteers.Compared with controls, patients with EGPA were characterized by denser fiber clots (estimated pore size, Ks, 7.30±0.93 vs 10.14±1.07 10-9 cm2, faster fibrin polymerization (lag phase in a turbidimetric curve, 41.8±3.6 vs 47.4±2.9 s, thicker fibrin fibers (maximum absorbance, ΔAbs, 0.87±0.09 vs 0.72±0.07, higher maximum levels of D-dimer released from clots (DDmax 4.10±0.46 vs 3.54±0.35 mg/L, and prolonged clot lysis time (t50%; 9.50±1.45 vs 7.56±0.87 min; all p<0.0001. Scanning electron microscopy images confirmed denser plasma fibrin networks composed of thinner fibers formed in EGPA. Antineutrophil cytoplasmic antibody status and C-reactive protein did not affect clot variables. Multivariate analysis adjusted for fibrinogen showed that Ks was predicted by eosinophil count, peak thrombin generation, factor VIII, and soluble CD40 ligand, whereas eosinophil count, peak thrombin generation and antiplasmin predicted t50%.This study is the first to show that EGPA is associated with prothrombotic plasma fibrin clot phenotype, which may contribute to thromboembolic manifestations reported in this disease.

Narrow-band imaging can increase the visibility of fibrin caps after bleeding of esophageal varices: a case with extensive esophageal candidiasis.

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Furuichi, Yoshihiro; Kasai, Yoshitaka; Takeuchi, Hirohito; Yoshimasu, Yuu; Kawai, Takashi; Sugimoto, Katsutoshi; Kobayashi, Yoshiyuki; Nakamura, Ikuo; Itoi, Takao

2017-08-01

A 58-year-old man with hepatitis B cirrhosis noticed black stools and underwent an endoscopy at a community hospital. The presence of esophageal varices (EVs) was confirmed, but the bleeding point was not found. He was referred to our institution and underwent a second endoscopy. Extensive white patches of esophageal candidiasis were visible on endoscopy by white-light imaging (WLI), but it was difficult to find the fibrin cap of the EVs. This was easier under narrow-band imaging (NBI), however, as the color turned red from absorption by hemoglobin adhered to it. We retrospectively measured the color differences (CD) between the fibrin cap and the surrounding mucosa 10 times using the CIE (L*a*b*) color space method. The median value of CD increased after NBI (13.9 → 43.0, p candidiasis, but the increased visibility of the fibrin cap by NBI enabled it to be found more easily. This is the first report of a case in which NBI was helpful in locating a fibrin cap of EVs.

Platelet factor XIII increases the fibrinolytic resistance of platelet-rich clots by accelerating the crosslinking of alpha 2-antiplasmin to fibrin

Science.gov (United States)

Reed, G. L.; Matsueda, G. R.; Haber, E.

1992-01-01

Platelet clots resist fibrinolysis by plasminogen activators. We hypothesized that platelet factor XIII may enhance the fibrinolytic resistance of platelet-rich clots by catalyzing the crosslinking of alpha 2-antiplasmin (alpha 2AP) to fibrin. Analysis of plasma clot structure by polyacrylamide gel electrophoresis and immunoblotting revealed accelerated alpha 2AP-fibrin crosslinking in platelet-rich compared with platelet-depleted plasma clots. A similar study of clots formed with purified fibrinogen (depleted of factor XIII activity), isolated platelets, and specific factor XIII inhibitors indicated that this accelerated crosslinking was due to the catalytic activity of platelet factor XIII. Moreover, when washed platelets were aggregated by thrombin, there was evidence of platelet factor XIII-mediated crosslinking between platelet alpha 2AP and platelet fibrin(ogen). Specific inhibition (by a monoclonal antibody) of the alpha 2AP associated with washed platelet aggregates accelerated the fibrinolysis of the platelet aggregate. Thus in platelet-rich plasma clots, and in thrombin-induced platelet aggregates, platelet factor XIII actively formed alpha 2AP-fibrin crosslinks, which appeared to enhance the resistance of platelet-rich clots to fibrinolysis.

Matrix production and organization by endothelial colony forming cells in mechanically strained engineered tissue constructs.

Directory of Open Access Journals (Sweden)

Nicky de Jonge

Full Text Available AIMS: Tissue engineering is an innovative method to restore cardiovascular tissue function by implanting either an in vitro cultured tissue or a degradable, mechanically functional scaffold that gradually transforms into a living neo-tissue by recruiting tissue forming cells at the site of implantation. Circulating endothelial colony forming cells (ECFCs are capable of differentiating into endothelial cells as well as a mesenchymal ECM-producing phenotype, undergoing Endothelial-to-Mesenchymal-transition (EndoMT. We investigated the potential of ECFCs to produce and organize ECM under the influence of static and cyclic mechanical strain, as well as stimulation with transforming growth factor β1 (TGFβ1. METHODS AND RESULTS: A fibrin-based 3D tissue model was used to simulate neo-tissue formation. Extracellular matrix organization was monitored using confocal laser-scanning microscopy. ECFCs produced collagen and also elastin, but did not form an organized matrix, except when cultured with TGFβ1 under static strain. Here, collagen was aligned more parallel to the strain direction, similar to Human Vena Saphena Cell-seeded controls. Priming ECFC with TGFβ1 before exposing them to strain led to more homogenous matrix production. CONCLUSIONS: Biochemical and mechanical cues can induce extracellular matrix formation by ECFCs in tissue models that mimic early tissue formation. Our findings suggest that priming with bioactives may be required to optimize neo-tissue development with ECFCs and has important consequences for the timing of stimuli applied to scaffold designs for both in vitro and in situ cardiovascular tissue engineering. The results obtained with ECFCs differ from those obtained with other cell sources, such as vena saphena-derived myofibroblasts, underlining the need for experimental models like ours to test novel cell sources for cardiovascular tissue engineering.

Source of fibrin/fibrinogen degradation products in the CSF after subarachnoid hemorrhage

NARCIS (Netherlands)

Vermeulen, M.; van Vliet, H. H.; Lindsay, K. W.; Hijdra, A.; van Gijn, J.

1985-01-01

In 48 patients with a subarachnoid hemorrhage, levels of fibrin/fibrinogen degradation products (FDP's), total protein, and plasminogen were measured in the cerebrospinal fluid (CSF) between Days 9 and 15 after the bleed. Of these 48 patients, 22 received tranexamic acid. Despite a significant

A comparative study of the regenerative effect of sinus bone grafting with platelet-rich fibrin-mixed Bio-Oss® and commercial fibrin-mixed Bio-Oss®: an experimental study.

Science.gov (United States)

Xuan, Feng; Lee, Chun-Ui; Son, Jeong-Seog; Jeong, Seung-Mi; Choi, Byung-Ho

2014-06-01

Anorganic bovine bone (Bio-Oss®) particles are one of the most popular grafting materials. The particles are often mixed with platelet-rich fibrin (PRF) or a commercial fibrin (Tisseel®) to form a mouldable graft material. The objective of this study was to compare the potentials of PRF-mixed Bio-Oss® and Tisseel®-mixed Bio-Oss® to enhance bone regeneration in a canine sinus model. Six mongrel dogs were used in this study. After elevating the sinus membrane in both maxillary sinus cavities, an implant was placed into the sinus cavity. In one of the sinus cavities, the PRF/Bio-Oss® composite was grafted, and the Tisseel®/Bio-Oss® composite was grafted in the other sinus cavity. After a 6 month healing period, bone formation in the graft sites and bone-implant contact were evaluated. The mean osseointegration rate was 43.5 ± 12.4% and new bone formation rate 41.8 ± 5.9% in the PRF/Bio-Oss® composite sites. In the Tisseel®/Bio-Oss® composite sites they were 30.7 ± 7.9% and 31.3 ± 6.4%. There were statistically significant differences between the groups. The findings from this study suggest that when platelet-rich fibrin is used as an adjunct to Bio-Oss® particles for bone augmentation in the maxillary sinus, bone formation in the graft sites is significantly greater than when Tisseel® is used. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Equibiaxial cyclic stretch stimulates fibroblasts to rapidly remodel fibrin.

Science.gov (United States)

Balestrini, Jenna Leigh; Billiar, Kristen Lawrence

2006-01-01

Understanding the effects of the mechanical environment on wound healing is critical for developing more effective treatments to reduce scar formation and contracture. The aim of this study was to investigate the effects of dynamic mechanical stretch on cell-mediated early wound remodeling independent of matrix alignment which obscures more subtle remodeling mechanisms. Cyclic equibiaxial stretch (16% stretch at 0.2 Hz) was applied to fibroblast-populated fibrin gel in vitro wound models for eight days. Compaction, density, tensile strength, and collagen content were quantified as functional measures of remodeling. Stretched samples were approximately ten times stronger, eight-fold more dense, and eight times thinner than statically cultured samples. These changes were accompanied by a 15% increase in net collagen but no significant differences in cell number or viability. When collagen crosslinking was inhibited in stretched samples, the extensibility increased and the strength decreased. The apparent weakening was due to a reduction in compaction rather than a decrease in ability of the tissue to withstand tensile forces. Interestingly, inhibiting collagen crosslinking had no measurable effects on the statically cultured samples. These results indicate that amplified cell-mediated compaction and even a slight addition in collagen content play substantial roles in mechanically induced wound strengthening. These findings increase our understanding of how mechanical forces guide the healing response in skin, and the methods employed in this study may also prove valuable tools for investigating stretch-induced remodeling of other planar connective tissues and for creating mechanically robust engineered tissues.

Clot friction variation with fibrin content; implications for resistance to thrombectomy.

Science.gov (United States)

Gunning, Gillian M; McArdle, Kevin; Mirza, Mahmood; Duffy, Sharon; Gilvarry, Michael; Brouwer, Patrick A

2018-01-01

Despite significant advancements in the procedural efficacy of mechanical thrombectomy in patients with ischemic stroke in recent years, there still remains a portion of the population that does not achieve good recanalization. The reasons for this may be varied. We hypothesized that static friction between the clot and the vessel, or catheter wall might contribute to the difficulty in removing the clot. To determine if there is a relationship between clot composition and the resistance to sliding (friction) which might contribute to resistance to clot removal. As clot composition can vary significantly, we investigated five different types of clot in order to measure their respective frictional properties. To do this, a custom-made testing apparatus was created, consisting of various replaceable low-friction surfaces on which the clots could be placed. The surface was then gradually tilted until the clots began to slide; the angle at which this occurred is related to the coefficient of friction of the clots. The experiment was repeated on a bovine aortic surface in order to confirm the results. We found that fibrin-rich clots (friction than clots with a red blood cell content >20%. This result was confirmed by repeating the experiment on a bovine aortic surface as a representation of the interaction between clots and the arterial wall. The friction properties of clots were found to be related to the content ratio of fibrin to red blood cells. Future imaging techniques that could show fibrin and red blood cell content might help us to predict the 'stickiness' of a clot. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Evaluation of the effect of platelet-rich fibrin on the alveolar osteitis ...

African Journals Online (AJOL)

Evaluation of the effect of platelet-rich fibrin on the alveolar osteitis incidence and periodontal probing depth after extracting partially erupted mandibular third ... Conclusions: PRF significantly reduced the AO incidence among smokers and had a positive effect on postoperative pain levels but not on periodontal healing.

Neutrophil-Derived MMP-8 Drives AMPK-Dependent Matrix Destruction in Human Pulmonary Tuberculosis

Science.gov (United States)

Ong, Catherine W. M.; Elkington, Paul T.; Brilha, Sara; Ugarte-Gil, Cesar; Tome-Esteban, Maite T.; Tezera, Liku B.; Pabisiak, Przemyslaw J.; Moores, Rachel C.; Sathyamoorthy, Tarangini; Patel, Vimal; Gilman, Robert H.; Porter, Joanna C.; Friedland, Jon S.

2015-01-01

Pulmonary cavities, the hallmark of tuberculosis (TB), are characterized by high mycobacterial load and perpetuate the spread of M. tuberculosis. The mechanism of matrix destruction resulting in cavitation is not well defined. Neutrophils are emerging as key mediators of TB immunopathology and their influx are associated with poor outcomes. We investigated neutrophil-dependent mechanisms involved in TB-associated matrix destruction using a cellular model, a cohort of 108 patients, and in separate patient lung biopsies. Neutrophil-derived NF-kB-dependent matrix metalloproteinase-8 (MMP-8) secretion was up-regulated in TB and caused matrix destruction both in vitro and in respiratory samples of TB patients. Collagen destruction induced by TB infection was abolished by doxycycline, a licensed MMP inhibitor. Neutrophil extracellular traps (NETs) contain MMP-8 and are increased in samples from TB patients. Neutrophils lined the circumference of human pulmonary TB cavities and sputum MMP-8 concentrations reflected TB radiological and clinical disease severity. AMPK, a central regulator of catabolism, drove neutrophil MMP-8 secretion and neutrophils from AMPK-deficient patients secrete lower MMP-8 concentrations. AMPK-expressing neutrophils are present in human TB lung biopsies with phospho-AMPK detected in nuclei. These data demonstrate that neutrophil-derived MMP-8 has a key role in the immunopathology of TB and is a potential target for host-directed therapy in this infectious disease. PMID:25996154

Neutrophil-Derived MMP-8 Drives AMPK-Dependent Matrix Destruction in Human Pulmonary Tuberculosis.

Science.gov (United States)

Ong, Catherine W M; Elkington, Paul T; Brilha, Sara; Ugarte-Gil, Cesar; Tome-Esteban, Maite T; Tezera, Liku B; Pabisiak, Przemyslaw J; Moores, Rachel C; Sathyamoorthy, Tarangini; Patel, Vimal; Gilman, Robert H; Porter, Joanna C; Friedland, Jon S

2015-05-01

Pulmonary cavities, the hallmark of tuberculosis (TB), are characterized by high mycobacterial load and perpetuate the spread of M. tuberculosis. The mechanism of matrix destruction resulting in cavitation is not well defined. Neutrophils are emerging as key mediators of TB immunopathology and their influx are associated with poor outcomes. We investigated neutrophil-dependent mechanisms involved in TB-associated matrix destruction using a cellular model, a cohort of 108 patients, and in separate patient lung biopsies. Neutrophil-derived NF-kB-dependent matrix metalloproteinase-8 (MMP-8) secretion was up-regulated in TB and caused matrix destruction both in vitro and in respiratory samples of TB patients. Collagen destruction induced by TB infection was abolished by doxycycline, a licensed MMP inhibitor. Neutrophil extracellular traps (NETs) contain MMP-8 and are increased in samples from TB patients. Neutrophils lined the circumference of human pulmonary TB cavities and sputum MMP-8 concentrations reflected TB radiological and clinical disease severity. AMPK, a central regulator of catabolism, drove neutrophil MMP-8 secretion and neutrophils from AMPK-deficient patients secrete lower MMP-8 concentrations. AMPK-expressing neutrophils are present in human TB lung biopsies with phospho-AMPK detected in nuclei. These data demonstrate that neutrophil-derived MMP-8 has a key role in the immunopathology of TB and is a potential target for host-directed therapy in this infectious disease.

Steric Interference of Adhesion Supports In-Vitro Chondrogenesis of Mesenchymal Stem Cells on Hydrogels for Cartilage Repair

OpenAIRE

Goldshmid, Revital; Cohen, Shlomit; Shachaf, Yonatan; Kupershmit, Ilana; Sarig-Nadir, Offra; Seliktar, Dror; Wechsler, Roni

2015-01-01

Recent studies suggest the presence of cell adhesion motifs found in structural proteins can inhibit chondrogenesis. In this context, the current study aims to determine if a polyethylene glycol (PEG)-modified fibrinogen matrix could support better chondrogenesis of human bone marrow mesenchymal stem cells (BM-MSC) based on steric interference of adhesion, when compared to a natural fibrin matrix. Hydrogels used as substrates for two-dimensional (2D) BM-MSC cultures under chondrogenic conditi...

Fibrinous anterior uveitis following laser in situ keratomileusis

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Parmar Pragya

2009-01-01

Full Text Available A 29-year-old woman who underwent laser in situ keratomileusis (LASIK for myopic astigmatism in both eyes presented with severe pain, photophobia and decreased visual acuity in the left eye eight days after surgery. Examination revealed severe anterior uveitis with fibrinous exudates in the anterior chamber, flap edema and epithelial bullae. Laboratory investigations for uveitis were negative and the patient required systemic and intensive topical steroids with cycloplegics to control the inflammation. This case demonstrates that severe anterior uveitis may develop after LASIK and needs prompt and vigorous management for resolution.

Chin Symphysis Bone, Allograft, and Platelet-Rich Fibrin: Is the Combination Effective in Repair of Alveolar Cleft?

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Movahedian Attar, Bijan; Naghdi, Navid; Etemadi Sh, Milad; Mehdizadeh, Mojdeh

2017-05-01

Secondary grafting of alveolar defects with iliac crest bone is a common treatment method in cleft patients. The aim of this study was to evaluate the effectiveness of the combination of symphysis bone, allograft, and platelet-rich fibrin in regeneration of alveolar defects compared with iliac bone graft. In this randomized clinical trial, patients with unilateral alveolar defects were divided randomly into two categories. Group A comprised patients in whom the combination of chin symphysis bone plus allogeneic bone material plus leukocyte- and platelet-rich fibrin was considered for treatment. Group B comprised patients in whom iliac bone graft was considered. Cone beam computed tomography before treatment and 1 year postoperatively was used for measurement of bone formation (bone volume in cubic centimeters). The data were analyzed by paired t and χ 2 tests via SPSS software (version 23; IBM, Armonk, NY). P platelet-rich fibrin is a proper combination for bone regeneration in alveolar defects with a small to moderate volume range. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Multisite Thrombus Imaging and Fibrin Content Estimation With a Single Whole-Body PET Scan in Rats.

Science.gov (United States)

Blasi, Francesco; Oliveira, Bruno L; Rietz, Tyson A; Rotile, Nicholas J; Naha, Pratap C; Cormode, David P; Izquierdo-Garcia, David; Catana, Ciprian; Caravan, Peter

2015-10-01

Thrombosis is a leading cause of morbidity and mortality worldwide. Current diagnostic strategies rely on imaging modalities that are specific for distinct vascular territories, but a thrombus-specific whole-body imaging approach is still missing. Moreover, imaging techniques to assess thrombus composition are underdeveloped, although therapeutic strategies may benefit from such technology. Therefore, our goal was to test whether positron emission tomography (PET) with the fibrin-binding probe (64)Cu-FBP8 allows multisite thrombus detection and fibrin content estimation. Thrombosis was induced in Sprague-Dawley rats (n=32) by ferric chloride application on both carotid artery and femoral vein. (64)Cu-FBP8-PET/CT imaging was performed 1, 3, or 7 days after thrombosis to detect thrombus location and to evaluate age-dependent changes in target uptake. Ex vivo biodistribution, autoradiography, and histopathology were performed to validate imaging results. Arterial and venous thrombi were localized on fused PET/CT images with high accuracy (97.6%; 95% confidence interval, 92-100). A single whole-body PET/MR imaging session was sufficient to reveal the location of both arterial and venous thrombi after (64)Cu-FBP8 administration. PET imaging showed that probe uptake was greater in younger clots than in older ones for both arterial and venous thrombosis (P<0.0001). Quantitative histopathology revealed an age-dependent reduction of thrombus fibrin content (P<0.001), consistent with PET results. Biodistribution and autoradiography further confirmed the imaging findings. We demonstrated that (64)Cu-FBP8-PET is a feasible approach for whole-body thrombus detection and that molecular imaging of fibrin can provide, noninvasively, insight into clot composition. © 2015 American Heart Association, Inc.

Chondrogenic potential of physically treated bovine cartilage matrix derived porous scaffolds on human dermal fibroblast cells.

Science.gov (United States)

Moradi, Ali; Ataollahi, Forough; Sayar, Katayoun; Pramanik, Sumit; Chong, Pan-Pan; Khalil, Alizan Abdul; Kamarul, Tunku; Pingguan-Murphy, Belinda

2016-01-01

Extracellular matrices have drawn attention in tissue engineering as potential biomaterials for scaffold fabrication because of their bioactive components. Noninvasive techniques of scaffold fabrication and cross-linking treatments are believed to maintain the integrity of bioactive molecules while providing proper architectural and mechanical properties. Cartilage matrix derived scaffolds are designed to support the maintenance of chondrocytes and provide proper signals for differentiation of chondroinducible cells. Chondroinductive potential of bovine articular cartilage matrix derived porous scaffolds on human dermal fibroblasts and the effect of scaffold shrinkage on chondrogenesis were investigated. An increase in sulfated glycosaminoglycans production along with upregulation of chondrogenic genes confirmed that physically treated cartilage matrix derived scaffolds have chondrogenic potential on human dermal fibroblasts. © 2015 Wiley Periodicals, Inc.

Human endothelium on vascular prostheses modified by extracellular matrix proteins in a flow experiment

Czech Academy of Sciences Publication Activity Database

Chlupáč, Jaroslav; Filová, Elena; Riedel, Tomáš; Brynda, Eduard; Remy-Zolghadri, M.; Bareille, R.; Fernandez, P.; Daculsi, R.; Bordenave, L.; Bačáková, Lucie

2006-01-01

Roč. 9, č. 58-60 (2006), s. 10-13 ISSN 1429-7248 R&D Projects: GA AV ČR(CZ) IAA5011301; GA AV ČR(CZ) IAA4050202; GA AV ČR(CZ) IAA400500507; GA AV ČR(CZ) 1QS500110564 Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z40500505 Keywords : bioartificial vascular prostheses * laminin * fibrin Subject RIV: EI - Biotechnology ; Bionics

Characterisation of cell cycle arrest and terminal differentiation in a maximally proliferative human epithelial tissue: Lessons from the human hair follicle matrix.

Science.gov (United States)

Purba, Talveen S; Brunken, Lars; Peake, Michael; Shahmalak, Asim; Chaves, Asuncion; Poblet, Enrique; Ceballos, Laura; Gandarillas, Alberto; Paus, Ralf

2017-09-01

Human hair follicle (HF) growth and hair shaft formation require terminal differentiation-associated cell cycle arrest of highly proliferative matrix keratinocytes. However, the regulation of this complex event remains unknown. CIP/KIP family member proteins (p21 CIP1 , p27 KIP1 and p57 KIP2 ) regulate cell cycle progression/arrest, endoreplication, differentiation and apoptosis. Since they have not yet been adequately characterized in the human HF, we asked whether and where CIP/KIP proteins localise in the human hair matrix and pre-cortex in relation to cell cycle activity and HF-specific epithelial cell differentiation that is marked by keratin 85 (K85) protein expression. K85 expression coincided with loss or reduction in cell cycle activity markers, including in situ DNA synthesis (EdU incorporation), Ki-67, phospho-histone H3 and cyclins A and B1, affirming a post-mitotic state of pre-cortical HF keratinocytes. Expression of CIP/KIP proteins was found abundantly within the proliferative hair matrix, concomitant with a role in cell cycle checkpoint control. p21 CIP1 , p27 KIP1 and cyclin E persisted within post-mitotic keratinocytes of the pre-cortex, whereas p57 KIP2 protein decreased but became nuclear. These data imply a supportive role for CIP/KIP proteins in maintaining proliferative arrest, differentiation and anti-apoptotic pathways, promoting continuous hair bulb growth and hair shaft formation in anagen VI. Moreover, post-mitotic hair matrix regions contained cells with enlarged nuclei, and DNA in situ hybridisation showed cells that were >2N in the pre-cortex. This suggests that CIP/KIP proteins might counterbalance cyclin E to control further rounds of DNA replication in a cell population that has a propensity to become tetraploid. These data shed new light on the in situ-biography of human hair matrix keratinocytes on their path of active cell cycling, arrest and terminal differentiation, and showcase the human HF as an excellent, clinically

Binding of Thrombin-Activated Platelets to a Fibrin Scaffold through ?IIb?3 Evokes Phosphatidylserine Exposure on Their Cell Surface

OpenAIRE

Brzoska, Tomasz; Suzuki, Yuko; Mogami, Hideo; Sano, Hideto; Urano, Tetsumei

2013-01-01

Recently, by employing intra-vital confocal microscopy, we demonstrated that platelets expose phosphatidylserine (PS) and fibrin accumulate only in the center of the thrombus but not in its periphery. To address the question how exposure of platelet anionic phospholipids is regulated within the thrombus, an in-vitro experiment using diluted platelet-rich plasma was employed, in which the fibrin network was formed in the presence of platelets, and PS exposure on the platelet surface was analyz...

The effect of fibrin sealant on bioactive glass S53P4 particles – pH impact and dissolution characteristics in vitro

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Jussi Sarin

2016-12-01

Full Text Available Fibrin glue, a two-component tissue adhesive, has a range of clinical indications. Bioactive glass (BG S53P4 has been approved for clinical use in several craniomaxillofacial and orthopedic applications. Although sometimes used simultaneously, there is no data available regarding the possible interaction of these two biocompatible substances. In this in vitro study, using a BG particle concentration of 4 mg/ml, a 0.4 unit pH increment (p < 0.001 was observed in simulated body fluid (SBF after a 7-day incubation period. The addition of fibrin glue (0.13 g, SD 0.04; or 3.7 mg/ml on top of the BG particles raised further the pH by 0.5 units (p < 0.001. The difference between these groups was statistically significant (p = 0.008. With a BG concentration of 25 mg/ml and a fibrin glue concentration of 18 mg/ml during a 14-day incubation period, a pH increment of 0.6 units and SBF ion concentration change of Ca, K, Mg, Na, P and Si ions was seen. Moreover, a penetration depth between 4 and 6 mm was observed when fibrin glue was applied on top of a bed of BG particles. Conclusions: Fibrin glue is not likely to have a distracting effect on BG-induced pH increase of the SBF although it might delay early BG surface reactions based on ion concentration measurements. Fibrin glue penetrated to the interparticle space to some extent, binding the particles together for easy clinical use of BG.

Dual function of a bee venom serine protease: prophenoloxidase-activating factor in arthropods and fibrin(ogen)olytic enzyme in mammals.

Science.gov (United States)

Choo, Young Moo; Lee, Kwang Sik; Yoon, Hyung Joo; Kim, Bo Yeon; Sohn, Mi Ri; Roh, Jong Yul; Je, Yeon Ho; Kim, Nam Jung; Kim, Iksoo; Woo, Soo Dong; Sohn, Hung Dae; Jin, Byung Rae

2010-05-03

Bee venom contains a variety of peptides and enzymes, including serine proteases. While the presence of serine proteases in bee venom has been demonstrated, the role of these proteins in bee venom has not been elucidated. Furthermore, there is currently no information available regarding the melanization response or the fibrin(ogen)olytic activity of bee venom serine protease, and the molecular mechanism of its action remains unknown. Here we show that bee venom serine protease (Bi-VSP) is a multifunctional enzyme. In insects, Bi-VSP acts as an arthropod prophenoloxidase (proPO)-activating factor (PPAF), thereby triggering the phenoloxidase (PO) cascade. Bi-VSP injected through the stinger induces a lethal melanization response in target insects by modulating the innate immune response. In mammals, Bi-VSP acts similarly to snake venom serine protease, which exhibits fibrin(ogen)olytic activity. Bi-VSP activates prothrombin and directly degrades fibrinogen into fibrin degradation products, defining roles for Bi-VSP as a prothrombin activator, a thrombin-like protease, and a plasmin-like protease. These findings provide a novel view of the mechanism of bee venom in which the bee venom serine protease kills target insects via a melanization strategy and exhibits fibrin(ogen)olytic activity.

Effectiveness of Fibrin Sealant Patch in Reducing Drain Volume after Pelvic Lymph Node Dissection in Women with Gynecologic Malignancy

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Hwa Cheong Kim

2017-01-01

Full Text Available Background. The goal of this study was to evaluate the effectiveness of fibrin sealant in decreasing postoperative lymphatic drainage in women after pelvic lymphadenectomy and/or para-aortic lymphadenectomy during gynecologic cancer surgery. Methods. This study is a retrospective case-control study. Forty-five patients who underwent staging surgery were enrolled. Twenty-seven patients were in the fibrin sealant group (group A and 18 in the control group (group B. The two groups were compared for the total volume of drain, hospital stay, harvested lymph node, and incidence of asymptomatic lymphocele. Lymphocele formation was evaluated by computed tomography (CT on 3 months after surgery. Results. There were no significant differences in patient demographics between group A and B with respect to age, BMI, and harvested lymph nodes. Patients who received fibrin sealants had reduced total volume of drainage from postoperative days 2 to 5 compared to the control group (group A versus group B: 994.819±745.85 ml versus 1847.89±1241.41 ml; P=0.015. However no differences were observed in hospital stay (P=0.282, duration of drain (P=0.207, and incidence of asymptomatic lymphocele at 3 months (P=0.126. Conclusion. The results of this study indicate that the application of fibrin sealants after pelvic and/or para-aortic lymphadenectomy may reduce lymphatic drainage in gynecologic malignancy.

Bee venom induces apoptosis and suppresses matrix metaloprotease-2 expression in human glioblastoma cells

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Mohsen Sisakht

Full Text Available Abstract Glioblastoma is the most common malignant brain tumor representing with poor prognosis, therapy resistance and high metastasis rate. Increased expression and activity of matrix metalloproteinase-2, a member of matrix metalloproteinase family proteins, has been reported in many cancers including glioblastoma. Inhibition of matrix metalloproteinase-2 expression has resulted in reduced aggression of glioblastoma tumors in several reports. In the present study, we evaluated effect of bee venom on expression and activity of matrix metalloproteinase-2 as well as potential toxicity and apoptogenic properties of bee venom on glioblastoma cells. Human A172 glioblastoma cells were treated with increasing concentrations of bee venom. Then, cell viability, apoptosis, matrix metalloproteinase-2 expression, and matrix metalloproteinase-2 activity were measured using MMT assay, propidium iodide staining, real time-PCR, and zymography, respectively. The IC50 value of bee venom was 28.5 µg/ml in which it leads to decrease of cell viability and induction of apoptosis. Incubation with bee venom also decreased the expression of matrix metalloproteinase-2 in this cell line (p < 0.05. In zymography, there was a reverse correlation between bee venom concentration and total matrix metalloproteinase-2 activity. Induction of apoptosis as well as inhibition of matrix metalloproteinase-2 activity and expression can be suggested as molecular mechanisms involved in cytotoxic and antimetastatic effects of bee venom against glioblastoma cells.

The formation of human auricular cartilage from microtic tissue: An in vivo study.

Science.gov (United States)

Ishak, Mohamad Fikeri bin; See, Goh Bee; Hui, Chua Kien; Abdullah, Asma bt; Saim, Lokman bin; Saim, Aminuddin bin; Idrus, Ruszymah bt Haji

2015-10-01

This study aimed to isolate, culture-expand and characterize the chondrocytes isolated from microtic cartilage and evaluate its potential as a cell source for ear cartilage reconstruction. Specific attention was to construct the auricular cartilage tissue by using fibrin as scaffold. Cell culture experiment with the use of microtic chondrocytes. Cell culture experiment with the use of microtic chondrocytes. After ear reconstructive surgery at the Universiti Kebangsaan Malaysia Medical Center, chondrocytes were isolated from microtic cartilage. Chondrocytes isolated from the tissue were cultured expanded until passage 4 (P4). Upon confluency at P4, chondrocytes were harvested and tissue engineered constructs were made with human plasma polymerized to fibrin. Constructs formed later is implanted at the dorsal part of nude mice for 8 weeks, followed by post-implantation evaluation with histology staining (Hematoxylin and Eosin (H&E) and Safranin O), immunohistochemistry and RT-PCR for chondrogenic associated genes expression level. Under gross assessment, the construct after 8 weeks of implantation showed similar physical characteristics that of cartilage. Histological staining showed abundant lacunae cells embedded in extracellular matrix similar to that of native cartilage. Safranin O staining showed positive staining which indicates the presence of proteoglycan-rich matrix. Immunohistochemistry analysis showed the strong positive staining for collagen type II, the specific collagen type in the cartilage. Gene expression quantification showed no significant differences in the expression of chondrogenic gene used which is collagen type I, collagen type II, aggrecan core protein (ACP), elastin and sox9 genes when compared to construct formed from normal auricular tissue. Chondrocytes isolated from microtia cartilage has the potential to be used as an alternative cell source for external ear reconstruction in future clinical application. Copyright © 2015 Elsevier

No difference in sexual dysfunction after transabdominal preperitoneal (TAPP) approach for inguinal hernia with fibrin sealant or tacks for mesh fixation

DEFF Research Database (Denmark)

Pommergaard, H C; Burcharth, J; Andresen, K

2017-01-01

BACKGROUND: Postoperative sexual dysfunction in relation to laparoscopic groin hernia surgery may be related to methods of mesh fixation. However, this has not been investigated earlier. Moreover, results regarding sexual dysfunction in females have not been reported systematically. The aim...... of this study was to compare fibrin sealant versus tacks for fixation of mesh regarding sexual dysfunction in males and females. METHODS: Using the Danish Hernia Database, patients operated laparoscopically for groin hernia with a transabdominal preperitoneal (TAPP) procedure with fibrin sealant or tacks...... for mesh fixation were sent a questionnaire regarding sexual dysfunction. Sexually active patients without recurrence were evaluated in this study. RESULTS: Pain during sexual activity was present in 115 of 1019 (11.3 %) males and 17 of 147 (11.6 %) females. There was no difference between fibrin sealant...

The conversion of fibrinogen to fibrin: A brief history of some key events.

Science.gov (United States)

Doolittle, Russell F

2017-07-01

The conversion of fibrinogen to fibrin is a process that has long fascinated an army of researchers. In this brief review some early break-through observations are noted and a few later unexpected results described. Copyright © 2016 Elsevier B.V. All rights reserved.

In vivo near infrared (NIRS) sensor attachment using fibrin bioadhesive

Science.gov (United States)

Macnab, Andrew; Pagano, Roberto; Kwon, Brian; Dumont, Guy; Shadgan, Babak

2018-02-01

Background: `Tisseel' (Baxter Healthcare, Deerfield, IL) is a fibrin-based sealant that is commonly used during spine surgery to augment dural repairs. We wish to intra-operatively secure a near infrared spectroscopy (NIRS) sensor to the dura in order to monitor the tissue hemodynamics of the underlying spinal cord. To determine if `Tisseel' sealant adversely attenuates NIR photon transmission. Methods: We investigated `Tisseel' in both an in vitro and in vivo paradigm. For in vitro testing, we used a 1 mm pathlength cuvette containing either air or `Tisseel' interposed between a NIR light source (760 and 850 nm) and a photodiode detector and compared transmittance. For in vivo testing, a continuous wave (760 and 850 nm) spatiallyresolved NIRS device was placed over the triceps muscle using either conventional skin apposition (overlying adhesive bandage) or bioadhesion with `Tisseel'. Raw optical data and tissue saturation index (TSI%) collected at rest were compared. Results: In-vitro NIR light absorption by `Tisseel' was very high, with transmittance reduced by 95% compared to air. In-vivo muscle TSI% values were 80% with conventional attachment and 20% using fibrin glue. Conclusion: The optical properties of `Tisseel' significantly attenuate NIR light during in-vitro transmittance and critically compromise photon transmission in-vivo.

Platelet-Rich Fibrin Accelerates Skin Wound Healing in Diabetic Mice.

Science.gov (United States)

Ding, Yinjia; Cui, Lei; Zhao, Qiming; Zhang, Weiqiang; Sun, Huafeng; Zheng, Lijun

2017-09-01

Diabetic foot ulcers (DFUs) are associated with an increased risk of secondary infection and amputation. Platelet-rich fibrin (PRF), a platelet and leukocyte concentrate containing several cytokines and growth factors, is known to promote wound healing. However, the effect of PRF on diabetic wound healing has not been adequately investigated. The aim of the study was to investigate the effect of PRF on skin wound healing in a diabetic mouse model. Platelet-rich fibrin was prepared from whole blood of 8 healthy volunteers. Two symmetrical skin wounds per mouse were created on the back of 16 diabetic nude mice. One of the 2 wounds in each mouse was treated with routine dressings (control), whereas the other wound was treated with PRF in addition to routine dressings (test), each for a period of 14 days. Skin wound healing rate was calculated.Use of PRF was associated with significantly improved skin wound healing in diabetic mice. On hematoxylin and eosin and CD31 staining, a significant increase in the number of capillaries and CD31-positive cells was observed, suggesting that PRF may have promoted blood vessel formation in the skin wound. In this study, PRF seemed to accelerate skin wound healing in diabetic mouse models, probably via increased blood vessel formation.

Coverage of Megaprosthesis with Human Acellular Dermal Matrix after Ewing's Sarcoma Resection: A Case Report

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Robert M. Whitfield

2011-01-01

Full Text Available A 23-year-old female with Ewing's Sarcoma underwent tibial resection and skeletal reconstruction using proximal tibial allograft prosthetic reconstruction with distal femur endoprosthetic reconstruction and rotating hinge. Human acellular dermal matrix, (Alloderm, LifeCell, Branchburg, NJ, USA, was used to wrap the skeletal reconstruction. Soft tissue reconstruction was completed with a rotational gastrocnemius muscle flap and skin graft. Despite prolonged immobilization, the patient quickly regained full range of motion of her skeletal reconstruction. Synthetic mesh, tapes and tubes are used to perform capsule reconstruction of megaprosthesis. This paper describes the role of human acellular dermal matrix in capsule reconstruction around a megaprosthesis.

Effect of topical autologous platelet-rich fibrin versus no intervention on epithelialization of donor sites and meshed split-thickness skin autografts: a randomized clinical trial

DEFF Research Database (Denmark)

Danielsen, P.; Jorgensen, B.; Jorgensen, L.N.

2008-01-01

BACKGROUND: Autologous platelet-rich fibrin contains multiple growth factors. The aim of this randomized clinical trial was to study the effect of topical platelet-rich fibrin on epithelialization of donor sites and meshed split-thickness skin autografts. METHODS: Twenty consecutive leg ulcer pat...

Subfractions of enamel matrix derivative differentially influence cytokine secretion from human oral fibroblasts

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Oscar Villa

2015-03-01

Full Text Available Enamel matrix derivative is used to promote periodontal regeneration during the corrective phase of the treatment of periodontal defects. Our main goal was to analyze the bioactivity of different molecular weight fractions of enamel matrix derivative. Enamel matrix derivative, a complex mixture of proteins, was separated into 13 fractions using size-exclusion chromatography and characterized by sodium dodecyl sulfate–polyacrylamide gel electrophoresis and liquid chromatography–electrospray ionization–tandem mass spectrometry. Human periodontal ligament fibroblasts were treated with either enamel matrix derivative or the different fractions. Proliferation and cytokine secretion to the cell culture medium were measured and compared to untreated cells. The liquid chromatography–electrospray ionization–tandem mass spectrometry analyses revealed that the most abundant peptides were amelogenin and leucine-rich amelogenin peptide related. The fractions containing proteins above 20 kDa induced an increase in vascular endothelial growth factor and interleukin-6 secretion, whereas lower molecular weight fractions enhanced proliferation and secretion of interleukin-8 and monocyte chemoattractant protein-1 and reduced interleukin-4 release. The various molecular components in the enamel matrix derivative formulation might contribute to reported effects on tissue regeneration through their influence on vascularization, the immune response, and chemotaxis.

Intraoperative use of fibrin glue dyed with methylene blue in surgery for branchial cleft anomalies.

Science.gov (United States)

Piccioni, Michela; Bottazzoli, Marco; Nassif, Nader; Stefini, Stefania; Nicolai, Piero

2016-09-01

We present a new method of optimizing the results of surgery for branchial cleft anomalies based on the intraoperative injection of fibrin glue combined with methylene blue dye. Retrospective single-center cohort study. The method was applied in 17 patients suffering from branchial anomalies. Six (35.29%) had a preauricular lesion; three (17.65%) had lesions derived from the first arch/pouch/groove (type I), four (23.53%) had lesions derived from the first (type II), one (5.88%) had lesions derived from the second, one (5.88%) had lesions derived from the third, and two (11.76%) had lesions derived from the fourth. The median and mean age at surgery were 10 and 10.6 years, respectively. All patients were followed by periodic clinical and ultrasonographic examination. The combination of fibrin glue with methylene blue facilitated the correct assessment of the extension of the lesions and their intraoperative manipulation. After a mean follow-up of 47.8 months, all patients were free of disease. Intraoperative injection of branchial fistulae and cysts by a mixture of fibrin glue and methylene blue is an effective, easy, and safe tool to track lesions and achieve radical resection. The technique requires a definitive validation on a large cohort with adequate stratification of patients. 4 Laryngoscope, 126:2147-2150, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

High-throughput proteomic characterization of plasma rich in growth factors (PRGF-Endoret)-derived fibrin clot interactome.

Science.gov (United States)

Anitua, Eduardo; Prado, Roberto; Azkargorta, Mikel; Rodriguez-Suárez, Eva; Iloro, Ibon; Casado-Vela, Juan; Elortza, Felix; Orive, Gorka

2015-11-01

Plasma rich in growth factors (PRGF®-Endoret®) is an autologous technology that contains a set of proteins specifically addressed to wound healing and tissue regeneration. The scaffold formed by using this technology is a clot mainly composed of fibrin protein, forming a three-dimensional (3D) macroscopic network. This biomaterial is easily obtained by biotechnological means from blood and can be used in a range of situations to help wound healing and tissue regeneration. Although the main constituent of this clot is the fibrin scaffold, little is known about other proteins interacting in this clot that may act as adjuvants in the healing process. The aim of this study was to characterize the proteins enclosed by PRGF-Endoret scaffold, using a double-proteomic approach that combines 1D-SDS-PAGE approach followed by LC-MS/MS, and 2-DE followed by MALDI-TOF/TOF. The results presented here provide a description of the catalogue of key proteins in close contact with the fibrin scaffold. The obtained lists of proteins were grouped into families and networks according to gene ontology. Taken together, an enrichment of both proteins and protein families specifically involved in tissue regeneration and wound healing has been found. Copyright © 2013 John Wiley & Sons, Ltd.

Percutaneous sclerotherapy of sialoceles after parotidectomy with fibrin glue, OK-432, and bleomycin.

Science.gov (United States)

Chen, Wei-liang; Zhang, Li-ping; Huang, Zhi-quan; Zhou, Bin

2013-12-01

We evaluated the curative effect of fibrin glue combined with OK-432 (streptococcal pyrogenic exotoxin A, Picibanil™) and bleomycin on 9 patients with sialoceles after parotidectomy. The primary lesions included pleomorphic adenomas in 6 cases and Warthin's tumours in 3 cases. After a sialocele had been diagnosed each patient had repeated aspirations and pressure dressings for 3-4 weeks, but these treatments failed. The patients were then treated with percutaneous sclerotherapy with the injection of fibrin glue 8-10 ml combined with OK-432 5 mg and bleomycin 15 mg. All the sialoceles disappeared completely after a single procedure in 2-3 weeks. The patients have been followed up for more than 6 months with no evidence of recurrent sialocele or injury to the facial nerve related to sclerotherapy. This simple, safe technique can be successfully used to treat sialoceles after parotidectomy. Copyright © 2013 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Monitoring sinew contraction during formation of tissue-engineered fibrin-based ligament constructs.

Science.gov (United States)

Paxton, Jennifer Z; Wudebwe, Uchena N G; Wang, Anqi; Woods, Daniel; Grover, Liam M

2012-08-01

The ability to study the gross morphological changes occurring during tissue formation is vital to producing tissue-engineered structures of clinically relevant dimensions in vitro. Here, we have used nondestructive methods of digital imaging and optical coherence tomography to monitor the early-stage formation and subsequent maturation of fibrin-based tissue-engineered ligament constructs. In addition, the effect of supplementation with essential promoters of collagen synthesis, ascorbic acid (AA) and proline (P), has been assessed. Contraction of the cell-seeded fibrin gel occurs unevenly within the first 5 days of culture around two fixed anchor points before forming a longitudinal ligament-like construct. AA+P supplementation accelerates gel contraction in the maturation phase of development, producing ligament-like constructs with a higher collagen content and distinct morphology to that of unsupplemented constructs. These studies highlight the importance of being able to control the methods of tissue formation and maturation in vitro to enable the production of tissue-engineered constructs with suitable replacement tissue characteristics for repair of clinical soft-tissue injuries.

Polylactic-co-glycolic acid mesh coated with fibrin or collagen and biological adhesive substance as a prefabricated, degradable, biocompatible, and functional scaffold for regeneration of the urinary bladder wall.

Science.gov (United States)

Salem, Salah Abood; Hwei, Ng Min; Bin Saim, Aminuddin; Ho, Christopher C K; Sagap, Ismail; Singh, Rajesh; Yusof, Mohd Reusmaazran; Md Zainuddin, Zulkifili; Idrus, Ruszymah Bt Hj

2013-08-01

The chief obstacle for reconstructing the bladder is the absence of a biomaterial, either permanent or biodegradable, that will function as a suitable scaffold for the natural process of regeneration. In this study, polylactic-co-glycolic acid (PLGA) plus collagen or fibrin was evaluated for its suitability as a scaffold for urinary bladder construct. Human adipose-derived stem cells (HADSCs) were cultured, followed by incubation in smooth muscle cells differentiation media. Differentiated HADSCs were then seeded onto PLGA mesh supported with collagen or fibrin. Evaluation of cell-seeded PLGA composite immersed in culture medium was performed under a light and scanning microscope. To determine if the composite is compatible with the urodynamic properties of urinary bladder, porosity and leaking test was performed. The PLGA samples were subjected to tensile testing was pulled until PLGA fibers break. The results showed that the PLGA composite is biocompatible to differentiated HADSCs. PLGA-collagen mesh appeared to be optimal as a cell carrier while the three-layered PLGA-fibrin composite is better in relation to its leaking/ porosity property. A biomechanical test was also performed for three-layered PLGA with biological adhesive and three-layered PLGA alone. The tensile stress at failure was 30.82 ± 3.80 (MPa) and 34.36 ± 2.57 (MPa), respectively. Maximum tensile strain at failure was 19.42 ± 2.24 (mm) and 23.06 ± 2.47 (mm), respectively. Young's modulus was 0.035 ± 0.0083 and 0.043 ± 0.012, respectively. The maximum load at break was 58.55 ± 7.90 (N) and 65.29 ± 4.89 (N), respectively. In conclusion, PLGA-Fibrin fulfils the criteria as a scaffold for urinary bladder reconstruction. Copyright © 2013 Wiley Periodicals, Inc.

Motor recovery and synaptic preservation after ventral root avulsion and repair with a fibrin sealant derived from snake venom.

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Roberta Barbizan

Full Text Available BACKGROUND: Ventral root avulsion is an experimental model of proximal axonal injury at the central/peripheral nervous system interface that results in paralysis and poor clinical outcome after restorative surgery. Root reimplantation may decrease neuronal degeneration in such cases. We describe the use of a snake venom-derived fibrin sealant during surgical reconnection of avulsed roots at the spinal cord surface. The present work investigates the effects of this fibrin sealant on functional recovery, neuronal survival, synaptic plasticity, and glial reaction in the spinal motoneuron microenvironment after ventral root reimplantation. METHODOLOGY/PRINCIPAL FINDINGS: Female Lewis rats (7 weeks old were subjected to VRA and root replantation. The animals were divided into two groups: 1 avulsion only and 2 replanted roots with fibrin sealant derived from snake venom. Post-surgical motor performance was evaluated using the CatWalk system twice a week for 12 weeks. The rats were sacrificed 12 weeks after surgery, and their lumbar intumescences were processed for motoneuron counting and immunohistochemistry (GFAP, Iba-1 and synaptophysin antisera. Array based qRT-PCR was used to evaluate gene regulation of several neurotrophic factors and receptors as well as inflammatory related molecules. The results indicated that the root reimplantation with fibrin sealant enhanced motor recovery, preserved the synaptic covering of the motoneurons and improved neuronal survival. The replanted group did not show significant changes in microglial response compared to VRA-only. However, the astroglial reaction was significantly reduced in this group. CONCLUSIONS/SIGNIFICANCE: In conclusion, the present data suggest that the repair of avulsed roots with snake venom fibrin glue at the exact point of detachment results in neuroprotection and preservation of the synaptic network at the microenvironment of the lesioned motoneurons. Also such procedure reduced the

Motor Recovery and Synaptic Preservation after Ventral Root Avulsion and Repair with a Fibrin Sealant Derived from Snake Venom

Science.gov (United States)

Barbizan, Roberta; Castro, Mateus V.; Rodrigues, Antônio C.; Barraviera, Benedito; Ferreira, Rui S.; Oliveira, Alexandre L. R.

2013-01-01

Background Ventral root avulsion is an experimental model of proximal axonal injury at the central/peripheral nervous system interface that results in paralysis and poor clinical outcome after restorative surgery. Root reimplantation may decrease neuronal degeneration in such cases. We describe the use of a snake venom-derived fibrin sealant during surgical reconnection of avulsed roots at the spinal cord surface. The present work investigates the effects of this fibrin sealant on functional recovery, neuronal survival, synaptic plasticity, and glial reaction in the spinal motoneuron microenvironment after ventral root reimplantation. Methodology/Principal Findings Female Lewis rats (7 weeks old) were subjected to VRA and root replantation. The animals were divided into two groups: 1) avulsion only and 2) replanted roots with fibrin sealant derived from snake venom. Post-surgical motor performance was evaluated using the CatWalk system twice a week for 12 weeks. The rats were sacrificed 12 weeks after surgery, and their lumbar intumescences were processed for motoneuron counting and immunohistochemistry (GFAP, Iba-1 and synaptophysin antisera). Array based qRT-PCR was used to evaluate gene regulation of several neurotrophic factors and receptors as well as inflammatory related molecules. The results indicated that the root reimplantation with fibrin sealant enhanced motor recovery, preserved the synaptic covering of the motoneurons and improved neuronal survival. The replanted group did not show significant changes in microglial response compared to VRA-only. However, the astroglial reaction was significantly reduced in this group. Conclusions/Significance In conclusion, the present data suggest that the repair of avulsed roots with snake venom fibrin glue at the exact point of detachment results in neuroprotection and preservation of the synaptic network at the microenvironment of the lesioned motoneurons. Also such procedure reduced the astroglial reaction and

Human Homeostatic Control Matrix in Norm

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Alexander G. Kruglov

2016-09-01

Full Text Available We undertook our research to study and systemize the relationship between hemodynamics and biochemical parameters of arterial and venous blood in healthy people. Hemodynamic and biochemical characteristics were obtained through a probe by using catheterization in various vascular areas (aorta, brain, heart, lungs, and liver. Correlation and factor analyses were conducted to study the relationship between the obtained characteristics of the regional and systemic blood flow. Due to the nature of the correlation analysis, the significant (p<0.05 relation signs (+, 0, - without regard to their power were considered. The obtained results suggested that there are sets of both intra-organ and system regulatory relationships between metabolic and hemodynamic characteristics. The complex of relationships among the studied parameters makes it possible to maintain the homeostatic equilibrium in the body. The psychophysiological control system includes the subsystems we described: 1 the cardiac-hepatic-pulmonary complex having properties of the metabolic and hemodynamic information field providing biological stability of the homeostasis; any significant imbalance of its elements triggers afferent information flows actualizing an afferent synthesis; 2 the mind forming gradient patterns of targeted behavior to eliminate metabolic imbalance, to achieve goals both as coded biological parameters and as the highest forms of behavior, to reach the ultimate goal: parametric, homeostatic equilibrium in the “biosphere” of the human body. By using the results of our research and the complex of dynamic relationships in human homeostasis, we built a homeostatic control matrix (HCM.

Influência do selante de fibrina na cicatrização das pregas vocais de suínos Influence of selant fibrin on the wound healing of the pigs vocal folds

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Karla Palma Portes

2012-02-01

Full Text Available Os selantes de fibrina ou cola de fibrina são produtos originários de proteínas do plasma humano que mimetizam a via final da rede de coagulação. Sua aplicação para estimular a cicatrização tem sido motivo de discussão na literatura mundial. O uso do selante de fibrina em fonocirurgia tem sido realizado de modo empírico. Não há trabalhos que investiguem a ação do selante de fibrina no espaço de Reinke. OBJETIVOS: Avaliar a interferência do uso da cola de fibrina no processo de cicatrização gerado pela manipulação cirúrgica em pregas vocais de suínos. MATERIAIS E MÉTODOS: Estudo prospectivo e experimental. Seis animais tiveram ambas as pregas vocais incisadas e em apenas uma delas foi aplicado o selante, sendo que a outra serviu de controle. Após 3 meses, os animais foram sacrificados e a contagem de colágenos realizada. RESULTADOS: O lado com aplicação de cola teve média de 27,8% contra 20,4% do lado sem aplicação de cola. CONCLUSÃO: A concentração de colágeno nas amostras onde o selante de fibrina foi aplicado é significativamente maior do que nas amostras onde não houve a aplicação. Portanto, a presença do selante de fibrina estimula a fibrogênese neste tecido.Fibrin sealants or fibrin glue are products made from human plasma proteins, which mimic the final pathway of the coagulation cascade. Its application to stimulate the healing process has been a topic of debate in the literature. The use of fibrin sealants in phonosurgery has been empirical; there have been no studies that investigate the action of fibrin sealant in Reinke's space. AIM: To evaluate the effect of fibrin glue in healing of the vocal folds of pigs after surgical manipulation. MATERIALS AND METHODS: This was a prospective and experimental study. Six animals had both vocal folds incised. Sealant was applied in one of them; the other served as a control. After three months, the animals were sacrificed and a collagen count was carried

Thyroid Dysfunction and Fibrin Network Structure: A Mechanism for Increased Thrombotic Risk in Hyperthyroid Individuals

NARCIS (Netherlands)

Hooper, J. M. W.; Stuijver, D. J. F.; Orme, S. M.; van Zaane, B.; Hess, K.; Gerdes, V. E.; Phoenix, F.; Rice, P.; Smith, K. A.; Alzahrani, S. H.; Standeven, K. F.; Ajjan, R. A.

2012-01-01

Context: Hyperthyroidism is associated with increased thrombosis risk, and fibrin clot structure determines susceptibility to vascular thrombotic events. Objective: Our objective was to investigate clot formation and lysis in hyperthyroidism using observational and interventional studies. Design: Ex

A PEGylated Fibrin-Based Wound Dressing with Antimicrobial and Angiogenic Activity

Science.gov (United States)

2011-04-13

activity SSD–CSM particles were impregnated in polyethylene glycol (PEGylated) fibrin gels. In vitro drug release studies showed that a burst release of...promote revascularization. Silver sulfadiazine (SSD) is a broad spectrum antimicrobial agent that controls yeasts, molds, other types of fungi , and...site is currently thought to be a crucial early event in the tissue regeneration process [23]. We have recently shown that a polyethylene glycol-based

Identification of transcriptional macromolecular associations in human bone using browser based in silico analysis in a giant correlation matrix.

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Reppe, Sjur; Sachse, Daniel; Olstad, Ole K; Gautvik, Vigdis T; Sanderson, Paul; Datta, Harish K; Berg, Jens P; Gautvik, Kaare M

2013-03-01

Intracellular signaling is critically dependent on gene regulatory networks comprising physical molecular interactions. Presently, there is a lack of comprehensive databases for most human tissue types to verify such macromolecular interactions. We present a user friendly browser which helps to identify functional macromolecular interactions in human bone as significant correlations at the transcriptional level. The molecular skeletal phenotype has been characterized by transcriptome analysis of iliac crest bone biopsies from 84 postmenopausal women through quantifications of ~23,000 mRNA species. When the signal levels were inter-correlated, an array containing >260 million correlations was generated, thus recognizing the human bone interactome at the RNA level. The matrix correlation and p values were made easily accessible by a freely available online browser. We show that significant correlations within the giant matrix are reproduced in a replica set of 13 male vertebral biopsies. The identified correlations differ somewhat from transcriptional interactions identified in cell culture experiments and transgenic mice, thus demonstrating that care should be taken in extrapolating such results to the in vivo situation in human bone. The current giant matrix and web browser are a valuable tool for easy access to the human bone transcriptome and molecular interactions represented as significant correlations at the RNA-level. The browser and matrix should be a valuable hypothesis generating tool for identification of regulatory mechanisms and serve as a library of transcript relationships in human bone, a relatively inaccessible tissue. Copyright © 2012 Elsevier Inc. All rights reserved.

Use of fibrin glue derived from snake venom in the repair of deep corneal ulcers: experimental study in dogs (Canis familiaris, Linnaeus, 1758

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R. L. Sampaio

2007-01-01

Full Text Available Fibrin glue has been researched as an alternative method for tissue synthesis and is known for its capability to promote hemostasis at the application site, good approximation of wound edges and fast healing. The current study consisted in the application of fibrin glue derived from snake venom as treatment for experimental corneal ulcers. Twenty-one dogs had their corneas experimentally prepared through lamellar keratectomy (of standardized diameter and depth. Animals were divided into seven groups of three animals each. Six experimental groups were periodically evaluated and collection was carried out on the 1st, 3rd, 7th, 15th, 30th and 60th post-operative days, whereas one control group was evaluated throughout the experiment. Analyses consisted in the clinical evolution and in the histopathological study of all operated on eyes. Results indicated that fibrin glue was efficient in repairing keratectomy wounds in dogs and contributed to an earlier healing phenomenon, avoiding edema formation and keeping corneal clearness. The use of fibrin glue derived from snake venom showed to be easy to apply, feasible with animal models and of low cost, avoiding the lesion progress and allowing fast and appropriate corneal healing.

Muscarinic receptor agonists stimulate matrix metalloproteinase 1-dependent invasion of human colon cancer cells

International Nuclear Information System (INIS)

Raufman, Jean-Pierre; Cheng, Kunrong; Saxena, Neeraj; Chahdi, Ahmed; Belo, Angelica; Khurana, Sandeep; Xie, Guofeng

2011-01-01

Highlights: ► Muscarinic receptor agonists stimulated robust human colon cancer cell invasion. ► Anti-matrix metalloproteinase1 antibody pre-treatment blocks cell invasion. ► Bile acids stimulate MMP1 expression, cell migration and MMP1-dependent invasion. -- Abstract: Mammalian matrix metalloproteinases (MMPs) which degrade extracellular matrix facilitate colon cancer cell invasion into the bloodstream and extra-colonic tissues; in particular, MMP1 expression correlates strongly with advanced colon cancer stage, hematogenous metastasis and poor prognosis. Likewise, muscarinic receptor signaling plays an important role in colon cancer; muscarinic receptors are over-expressed in colon cancer compared to normal colon epithelial cells. Muscarinic receptor activation stimulates proliferation, migration and invasion of human colon cancer cells. In mouse intestinal neoplasia models genetic ablation of muscarinic receptors attenuates carcinogenesis. In the present work, we sought to link these observations by showing that MMP1 expression and activation plays a mechanistic role in muscarinic receptor agonist-induced colon cancer cell invasion. We show that acetylcholine, which robustly increases MMP1 expression, stimulates invasion of HT29 and H508 human colon cancer cells into human umbilical vein endothelial cell monolayers – this was abolished by pre-incubation with atropine, a non-selective muscarinic receptor inhibitor, and by pre-incubation with anti-MMP1 neutralizing antibody. Similar results were obtained using a Matrigel chamber assay and deoxycholyltaurine (DCT), an amidated dihydroxy bile acid associated with colon neoplasia in animal models and humans, and previously shown to interact functionally with muscarinic receptors. DCT treatment of human colon cancer cells resulted in time-dependent, 10-fold increased MMP1 expression, and DCT-induced cell invasion was also blocked by pre-treatment with anti-MMP1 antibody. This study contributes to understanding

Muscarinic receptor agonists stimulate matrix metalloproteinase 1-dependent invasion of human colon cancer cells

Energy Technology Data Exchange (ETDEWEB)

Raufman, Jean-Pierre, E-mail: jraufman@medicine.umaryland.edu [Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD (United States); Cheng, Kunrong; Saxena, Neeraj; Chahdi, Ahmed; Belo, Angelica; Khurana, Sandeep; Xie, Guofeng [Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, MD (United States)

2011-11-18

Highlights: Black-Right-Pointing-Pointer Muscarinic receptor agonists stimulated robust human colon cancer cell invasion. Black-Right-Pointing-Pointer Anti-matrix metalloproteinase1 antibody pre-treatment blocks cell invasion. Black-Right-Pointing-Pointer Bile acids stimulate MMP1 expression, cell migration and MMP1-dependent invasion. -- Abstract: Mammalian matrix metalloproteinases (MMPs) which degrade extracellular matrix facilitate colon cancer cell invasion into the bloodstream and extra-colonic tissues; in particular, MMP1 expression correlates strongly with advanced colon cancer stage, hematogenous metastasis and poor prognosis. Likewise, muscarinic receptor signaling plays an important role in colon cancer; muscarinic receptors are over-expressed in colon cancer compared to normal colon epithelial cells. Muscarinic receptor activation stimulates proliferation, migration and invasion of human colon cancer cells. In mouse intestinal neoplasia models genetic ablation of muscarinic receptors attenuates carcinogenesis. In the present work, we sought to link these observations by showing that MMP1 expression and activation plays a mechanistic role in muscarinic receptor agonist-induced colon cancer cell invasion. We show that acetylcholine, which robustly increases MMP1 expression, stimulates invasion of HT29 and H508 human colon cancer cells into human umbilical vein endothelial cell monolayers - this was abolished by pre-incubation with atropine, a non-selective muscarinic receptor inhibitor, and by pre-incubation with anti-MMP1 neutralizing antibody. Similar results were obtained using a Matrigel chamber assay and deoxycholyltaurine (DCT), an amidated dihydroxy bile acid associated with colon neoplasia in animal models and humans, and previously shown to interact functionally with muscarinic receptors. DCT treatment of human colon cancer cells resulted in time-dependent, 10-fold increased MMP1 expression, and DCT-induced cell invasion was also blocked by pre

Co-effects of matrix low elasticity and aligned topography on stem cell neurogenic differentiation and rapid neurite outgrowth.

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Yao, Shenglian; Liu, Xi; Yu, Shukui; Wang, Xiumei; Zhang, Shuming; Wu, Qiong; Sun, Xiaodan; Mao, Haiquan

2016-05-21

The development of novel biomaterials that deliver precise regulatory signals to direct stem cell fate for nerve regeneration is the focus of current intensive research efforts. In this study, a hierarchically aligned fibrillar fibrin hydrogel (AFG) that was fabricated through electrospinning and the concurrent molecular self-assembly process mimics both the soft and oriented features of nerve tissue, thus providing hybrid biophysical cues to instruct cell behavior in vitro and in vivo. The electrospun hydrogels were examined by scanning electron microscopy (SEM), polarized light microscopy, small angle X-ray scattering assay and atomic force microscopy (AFM), showing a hierarchically linear-ordered structure from the nanoscale to the macroscale with a soft elastic character (elasticity ∼1 kPa). We found that this low elasticity and aligned topography of AFG exhibit co-effects on promoting the neurogenic differentiation of human umbilical cord mesenchymal stem cells (hUMSCs) in comparison to random fibrin hydrogel (RFG) and tissue culture plate (TCP) control after two week cell culture in growth medium lacking supplementation with soluble neurogenic induction factors. In addition, AFG also induces dorsal root ganglion (DRG) neurons to rapidly project numerous long neurite outgrowths longitudinally along the AFG fibers for a total neurite extension distance of 1.96 mm in three days in the absence of neurotrophic factor supplementation. Moreover, the AFG implanted in a rat T9 dorsal hemisection spinal cord injury model was found to promote endogenous neural cell fast migration and axonal invasion along AFG fibers, resulting in aligned tissue cables in vivo. Our results suggest that matrix stiffness and aligned topography may instruct stem cell neurogenic differentiation and rapid neurite outgrowth, providing great promise for biomaterial design for applications in nerve regeneration.

Microbicidal properties of Leukocyte- and Platelet-Rich Plasma/Fibrin (L-PRP/L-PRF): new perspectives.

Science.gov (United States)

Cieslik-Bielecka, A; Dohan Ehrenfest, D M; Lubkowska, A; Bielecki, T

2012-01-01

Platelets, as main actors of the first stage of the healing process, play an important role in tissue repair. Their granules contain many active substances, particularly over 30 growth factors with significant effects on the resident cells at the site of injury, such as mesenchymal stem cells, chondrocytes, fibroblasts, osteoblasts. This potential may be increased by the concentration of the platelets, using platelet-rich plasma/fibrin products. In the four families of platelet concentrates, 2 families contain also significant concentrations of leukocytes: L-PRP (Leukocyte- and Platelet-Rich Plasma) and L-PRF (Leukocyte- and Platelet-Rich Fibrin). Inductive properties of platelet concentrates were widely described. However, they present also antimicrobial effects. The antibacterial effects of L-PRP were highlighted in only a few in vitro studies. Strong activity comparable to gentamicin and oxacillin for L-PRP against methicillin susceptible Staphylococcus aureus (MSSA) was already demonstrated. L-PRP also inhibited the growth of methicillin resistant Staphylococcus aureus (MRSA) and Escherichia coli. Some authors also reported clinical observations about the reduction of infections and the induction of healing processes after the use of platelet concentrates in cardiac, orthopaedic, oral and maxillofacial surgery. However, very little is yet known about the antibacterial effects of these concentrates. In this manuscript, the current data about the antimicrobial agents and cells present in the platelet-rich plasma/fibrin are highlighted and discussed, in order to introduce this new key chapter of the platelet concentrate technology history.

In vivo evaluation of titanium-prepared platelet-rich fibrin (T-PRF): a new platelet concentrate.

Science.gov (United States)

Tunalı, Mustafa; Özdemir, Hakan; Küçükodacı, Zafer; Akman, Serhan; Fıratlı, Erhan

2013-07-01

We have developed a new, titanium-prepared, platelet-rich fibrin (T-PRF) together with the protocol for forming it, which is based on the hypothesis that titanium tubes may be more effective at activating platelets than the glass tubes used by Chouckroun in his platelet-rich fibrin (PRF) method. The aim of this study was to find a suitable animal model in which to evaluate the method and to investigate the efficacy of T-PRF for wound healing. Blood samples from 6 rabbits were used to confirm the protocol for formation of T-PRF. We evaluated T-PRF or T-PRF-like clots morphologically using scanning electron microscopy (EM). Blood samples from 5 rabbits were used to develop an experiment in which to evaluate the effects of T-PRF on wound healing. The mucoperiosteal flaps were filled with autologous T-PRF membranes from the vestibule in the anterior mandibular regions. Samples collected from the surgical sites were stained with haematoxylin and eosin. We found a mature fibrin network in T-PRF clots that had been centrifuged for 15 min at 3500 rpm and, 15 days after placement of the membrane, we found newly-forming connective tissue and islets of bony tissue in the T-PRF membrane. These results show that T-PRF could induce the formation of new bone with new connective tissue in a rabbit model of wound healing within 30 days of treatment. Published by Elsevier Ltd.

Morphogen and proinflammatory cytokine release kinetics from PRGF-Endoret fibrin scaffolds: evaluation of the effect of leukocyte inclusion.

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Anitua, E; Zalduendo, M M; Prado, R; Alkhraisat, M H; Orive, G

2015-03-01

The potential influence of leukocyte incorporation in the kinetic release of growth factors from platelet-rich plasma (PRP) may explain the conflicting efficiency of leukocyte platelet-rich plasma (L-PRP) scaffolds in tissue regeneration. To assess this hypothesis, leukocyte-free (PRGF-Endoret) and L-PRP fibrin scaffolds were prepared, and both morphogen and proinflammatory cytokine release kinetics were analyzed. Clots were incubated with culture medium to monitor protein release over 8 days. Furthermore, the different fibrin scaffolds were morphologically characterized. Results show that leukocyte-free fibrin matrices were homogenous while leukocyte-containing ones were heterogeneous, loose and cellular. Leukocyte incorporation produced a significant increase in the contents of proinflammatory cytokines interleukin (IL)-1β and IL-16 but not in the platelet-derived growth factors release (PRGF-Endoret, the inclusion of leukocytes induced a major increase in these cytokines, which was characterized by the presence of a latent period. The PRGF-Endoret matrices were stable during the 8 days of incubation. The inclusion of leukocytes alters the growth factors release profile and also increased the dose of proinflammatory cytokines. © 2014 Wiley Periodicals, Inc.

A Practical Method ‘Discussion using Matrix Diagram’ , ConnectingHuman Base-Liberal-and Engineering Base-Professional-

Science.gov (United States)

Shimada, Wataru

In order to bring up talented people, it is a most important subject how to awake ‘Emotional Human Power’ , which is the origin of Autonomy and Creativity. A Practical Method ‘Discussion using Matrix Diagram’ developed for improving ‘Emotional Human Power’ including ‘Communication Skill’ , is confirmed to be useful for connecting Human Base-Liberal-and Engineering Base-Professional-.

Laminin-111-derived peptide conjugated fibrin hydrogel restores salivary gland function.

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Kihoon Nam

Full Text Available Hyposalivation reduces the patient quality of life, as saliva is important for maintaining oral health. Current treatments for hyposalivation are limited to medications such as the muscarinic receptor agonists, pilocarpine and cevimeline. However, these therapies only provide temporary relief. Therefore, alternative therapies are essential to restore salivary gland function. An option is to use bioengineered scaffolds to promote functional salivary gland regeneration. Previous studies demonstrated that the laminin-111 protein is critical for intact salivary gland cell cluster formation and organization. However, laminin-111 protein as a whole is not suitable for clinical applications as some protein domains may contribute to unwanted side effects such as degradation, tumorigenesis and immune responses. Conversely, the use of synthetic laminin-111 peptides makes it possible to minimize the immune reactivity or pathogen transfer. In addition, it is relatively simple and inexpensive as compared to animal-derived proteins. Therefore, the goal of this study was to demonstrate whether a 20 day treatment with laminin-111-derived peptide conjugated fibrin hydrogel promotes tissue regeneration in submandibular glands of a wound healing mouse model. In this study, laminin-111-derived peptide conjugated fibrin hydrogel significantly accelerated formation of salivary gland tissue. The regenerated gland tissues displayed not only structural but also functional restoration.

Incorporation of albumin fusion proteins into fibrin clots in vitro and in vivo: comparison of different fusion motifs recognized by factor XIIIa

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Sheffield William P

2011-12-01

Full Text Available Abstract Background The transglutaminase activated factor XIII (FXIIIa acts to strengthen pathological fibrin clots and to slow their dissolution, in part by crosslinking active α2-antiplasmin (α2AP to fibrin. We previously reported that a yeast-derived recombinant fusion protein comprising α2AP residues 13-42 linked to human serum albumin (HSA weakened in vitro clots but failed to become specifically incorporated into in vivo clots. In this study, our aims were to improve both the stability and clot localization of the HSA fusion protein by replacing α2AP residues 13-42 with shorter sequences recognized more effectively by FXIIIa. Results Expression plasmids were prepared encoding recombinant HSA with the following N-terminal 23 residue extensions: H6NQEQVSPLTLLAG4Y (designated XL1; H6DQMMLPWAVTLG4Y (XL2; H6WQHKIDLPYNGAG4Y (XL3; and their 17 residue non-His-tagged equivalents (XL4, XL5, and XL6. The HSA moiety of XL4- to XL6-HSA proteins was C-terminally His-tagged. All chimerae were efficiently secreted from transformed Pichia pastoris yeast except XL3-HSA, and following nickel chelate affinity purification were found to be intact by amino acid sequencing, as was an N-terminally His-tagged version of α2AP(13-42-HSA. Of the proteins tested, XL5-HSA was cross-linked to biotin pentylamine (BPA most rapidly by FXIIIa, and was the most effective competitor of α2AP crosslinking not only to BPA but also to plasma fibrin clots. In the mouse ferric chloride vena cava thrombosis model, radiolabeled XL5-HSA was retained in the clot to a greater extent than recombinant HSA. In the rabbit jugular vein stasis thrombosis model, XL5-HSA was also retained in the clot, in a urea-insensitive manner indicative of crosslinking to fibrin, to a greater extent than recombinant HSA. Conclusions Fusion protein XL5-HSA (DQMMLPWAVTLG4Y-HSAH6 was found to be more active as a substrate for FXIIIa-mediated transamidation than seven other candidate fusion proteins in

Acute fibrinous and organising pneumonia: a rare histopathological variant of chemotherapy-induced lung injury.

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Gupta, Arjun; Sen, Shiraj; Naina, Harris

2016-04-06

Bleomycin-induced lung injury is the most common chemotherapy-associated lung disease, and is linked with several histopathological patterns. Acute fibrinous and organising pneumonia (AFOP) is a relatively new and rare histological pattern of diffuse lung injury. We report the first known case of bleomycin-induced AFOP. A 36-year-old man with metastatic testicular cancer received three cycles of bleomycin, etoposide and cisplatin, before being transitioned to paclitaxel, ifosfamide and cisplatin. He subsequently presented with exertional dyspnoea, cough and pleuritic chest pain. CT of the chest demonstrated bilateral ground glass opacities with peribronchovascular distribution and pulmonary function tests demonstrated a restrictive pattern of lung disease with impaired diffusion. Transbronchial biopsy revealed intra-alveolar fibrin deposits with organising pneumonia, consisting of intraluminal loose connective tissue consistent with AFOP. The patient received high-dose corticosteroids with symptomatic and radiographic improvement. AFOP should be recognised as a histopathological variant of bleomycin-induced lung injury. 2016 BMJ Publishing Group Ltd.

Platelet rich fibrin (Prf) and β-tricalcium phosphate with coronally advanced flap for the management of grade-II furcation defect.

Science.gov (United States)

Sambhav, Jain; Rohit, Rai; Ranjana, Mohan; Shalabh, Mehrotra

2014-07-01

Multirooted teeth offer unique and challenging problems due to the furcation area, creates situations in which routine periodontal procedures are somewhat limited and special procedures are generally required. The present case was showing the management of grade II furcation defect by platelet rich fibrin (PRF) and β-Tricalcium phosphate with coronally advanced flap. Platelet rich fibrin and β-Tricalcium phosphate with coronally advanced flap have been shown to be a promising and successful approach for the treatment of furcation defect. Its gaining clinical attachment significantly manages both the gingival recession and furcation involvement simultaneously.

Influence of oxidative stress onto fibrin net formation, architecture and lysis

Czech Academy of Sciences Publication Activity Database

Štikarová, J.; Kotlín, R.; Suttnar, J.; Riedel, T.; Šácha, Pavel; Májek, P.; Chrastinová, L.; Hlaváčková, A.; Dyr, J. E.

2015-01-01

Roč. 13, Suppl 2 (2015), s. 837-838 ISSN 1538-7933. [ISTH 2015. Congress of the International Society on Thrombosis and Haemostasis /25./ and Annual SSC Meeting /61./. 20.06.2015-25.06.2015, Toronto] Grant - others:GA ČR(CZ) GBP205/12/G118; OPPK(CZ) CZ.2.16/3.1.00/24001 Program:GB Institutional support: RVO:61388963 Keywords : fibrinogen modification * fibrin net * oxidative stress Subject RIV: CE - Biochemistry

Acute Fibrinous and Organizing Pneumonia Associated With Allogenic Hematopoietic Stem Cell Transplant Successfully Treated With Corticosteroids

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Lam-Phuong Nguyen DO

2016-04-01

Full Text Available Acute fibrinous and organizing pneumonia (AFOP is an extremely rare, relatively new, and distinct histological pattern of acute lung injury characterized predominately by the presence of intra-alveolar fibrin and associated organizing pneumonia. AFOP may be idiopathic or associated with a wide spectrum of clinical conditions. It has a variable clinical presentation from mild respiratory symptoms to that similar to the acute respiratory distress syndrome. Currently there is no consensus on treatment, and corticosteroids previously were of unclear benefit. To date, there are less than 40 cases of AFOP reported in the literature and only one has been linked to hematopoietic stem cell transplantation. Here we report the first case series of 2 patients who developed AFOP following allogenic stem cell transplant that were successfully treated with high-dose corticosteroids.

Effects of annulus defects and implantation of poly(lactic-co-glycolic acid) (PLGA)/fibrin gel scaffolds on nerves ingrowth in a rabbit model of annular injury disc degeneration.

Science.gov (United States)

Xin, Long; Xu, Weixing; Yu, Leijun; Fan, Shunwu; Wang, Wei; Yu, Fang; Wang, Zhenbin

2017-05-12

Growth of nerve fibers has been shown to occur in a rabbit model of intravertebral disc degeneration (IVD) induced by needle puncture. As nerve growth may underlie the process of chronic pain in humans affected by disc degeneration, we sought to investigate the factors underlying nerve ingrowth in a minimally invasive annulotomy rabbit model of IVD by comparing the effects of empty disc defects with those of defects filled with poly(lactic-co-glycolic acid)/fibrin gel (PLGA) plugs. New Zealand white rabbits (n = 24) received annular injuries at three lumbar levels (L3/4, L4/5, and L5/6). The discs were randomly assigned to four groups: (a) annular defect (1.8-mm diameter; 4-mm depth) by mini-trephine, (b) annular defect implanted with a PLGA scaffold containing a fibrin gel, (c) annular puncture by a 16G needle (5-mm depth), and (d) uninjured L2/3 disc (control). Disc degeneration was evaluated by radiography, MRI, histology, real-time PCR, and analysis of proteoglycan (PG) content. Nerve ingrowth into the discs was assessed by immunostaining with the nerve marker protein gene product 9.5. Injured discs showed a progressive disc space narrowing with significant disc degeneration and proteoglycan loss, as confirmed by imaging results, molecular and compositional analysis, and histological examinations. In 16G punctured discs, nerve ingrowth was observed on the surface of scar tissue. In annular defects, nerve fibers were found to be distributed along small fissures within the fibrocartilaginous-like tissue that filled the AF. In discs filled with PLGA/ fibrin gel, more nerve fibers were observed growing deeper into the inner AF along the open annular track.  In addition, innervations scores showed significantly higher than those of punctured discs and empty defects. A limited vascular proliferation was found in the injured sites and regenerated tissues. Nerve ingrowth was significantly higher in PLGA/fibrin-filled discs than in empty defects. Possible

Effects of Plasma Rich in Growth Factors and Platelet-Rich Fibrin on Proliferation and Viability of Human Gingival Fibroblasts

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Surena Vahabi

2016-01-01

Full Text Available Objectives: Platelet preparations are commonly used to enhance bone and soft tissue regeneration. Considering the existing controversies on the efficacy of platelet products for tissue regeneration, more in vitro studies are required. The aim of the present study was to compare the in vitro effects of plasma rich in growth factors (PRGF and platelet-rich fibrin (PRF on proliferation and viability of human gingival fibroblasts (HGFs.Materials and Methods: Anitua's PRGF and Choukran's PRF were prepared according to the standard protocols. After culture periods of 24, 48 and 72 hours, proliferation of HGFs was evaluated by the methyl thiazol tetrazolium assay. Statistical analysis was performed using one-way ANOVA followed by Tukey-Kramer’s multiple comparisons and P-values<0.05 were considered statistically significant.Results: PRGF treatment induced statistically significant (P<0.001 proliferation of HGF cells compared to the negative control (100% viability at 24, 48 and 72 hours in values of 123%±2.25%, 102%±2.8% and 101%±3.92%, respectively. The PRF membrane treatment of HGF cells had a statistically significant effect on cell proliferation (21%±1.73%, P<0.001 at 24 hours compared to the negative control. However, at 48 and 72 hours after treatment, PRF had a negative effect on HGF cell proliferation and caused 38% and 60% decrease in viability and proliferation compared to the negative control, respectively. The HGF cell proliferation was significantly higher in PRGF than in PRF group (P< 0.001.Conclusion: This study demonstrated that PRGF had a strong stimulatory effect on HGF cell viability and proliferation compared to PRF.

FIBRIN-TYPE FIBRINOID IN HUMAN PLACENTA: A STEREOLOGICAL ANALYSIS OF ITS ASSOCIATION WITH INTERVILLOUS VOLUME AND VILLOUS SURFACE AREA

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Terry M Mayhew

2011-05-01

Full Text Available Stereological methods were used to examine fibrin-type fibrinoid deposition in the intervillous spaces of human placentas collected during gestation (12-41 weeks and from term pregnancies at low (400 m and high (3.6 km altitude. The main aim was to test predictions about the relationships between fibrinoid deposits and either the volume of intervillous space or the surface area of (intermediate + terminal villi. Fields of view on Masson trichrome-stained paraffin sections were selected as part of a systematic sampling design which randomised section location and orientation. Relative and absolute volumes were estimated by test point counting and surfaces by intersection counting. Apparent differences were tested by analyses of variance and relationships by correlation and regression analysis. Fibrinoid volume increased during gestation and correlated positively with intervillous volume and villous surface area. However, relative to intervillous volume, the main increase in fibrinoid occurred towards term (36-41 weeks. At high altitude, placentas contained more intervillous space but less fibrinoid. At both altitudes, there were significant correlations between fibrinoid volume and villous surface area. In all cases, changes in fibrinoid volume were commensurate with changes in villous surface area. Whilst findings lend support to the notion that fibrinoid deposition during normal gestation is influenced by the quality of vascular perfusion, they also emphasise that the extent of the villous surface is a more generally important factor. The villous surface may influence the steady state between coagulation and fibrinolysis since some pro-coagulatory events operate at the trophoblastic epithelium. They occur notably at sites of trophoblast de-epithelialisation and these arise following trauma or during the extrusion phase of normal epithelial turnover.

Extracellular matrix components expression in human pluripotent stem cell-derived retinal organoids recapitulates retinogenesis in vivo and reveals an important role for IMPG1 and CD44 in the development of photoreceptors and interphotoreceptor matrix.

Science.gov (United States)

Felemban, Majed; Dorgau, Birthe; Hunt, Nicola Claire; Hallam, Dean; Zerti, Darin; Bauer, Roman; Ding, Yuchun; Collin, Joseph; Steel, David; Krasnogor, Natalio; Al-Aama, Jumana; Lindsay, Susan; Mellough, Carla; Lako, Majlinda

2018-05-17

The extracellular matrix (ECM) plays an important role in numerous processes including cellular proliferation, differentiation, migration, maturation, adhesion guidance and axonal growth. To date, there has been no detailed analysis of the ECM distribution during retinal ontogenesis in humans and the functional importance of many ECM components is poorly understood. In this study, the expression of key ECM components in adult mouse and monkey retina, developing and adult human retina and retinal organoids derived from human pluripotent stem cells was studied. Our data indicate that basement membrane ECMs (Fibronectin and Collagen IV) were expressed in Bruch's membrane and the inner limiting membrane of the developing human retina, whilst the hyalectins (Versican and Brevican), cluster of differentiation 44 (CD44), photoreceptor-specific ECMs Interphotoreceptor Matrix Proteoglycan 1 (IMPG1) and Interphotoreceptor Matrix Proteoglycan 2 (IMPG2) were detected in the developing interphotoreceptor matrix (IPM). The expression of IMPG1, Versican and Brevican in the developing IPM was conserved between human developing retina and human pluripotent stem cell-derived retinal organoids. Blocking the action of CD44 and IMPG1 in pluripotent stem cell derived retinal organoids affected the development of photoreceptors, their inner/outer segments and connecting cilia and disrupted IPM formation, with IMPG1 having an earlier and more significant impact. Together, our data suggest an important role for IMPG1 and CD44 in the development of photoreceptors and IPM formation during human retinogenesis. The expression and the role of many extracellular matrix (ECM) components during human retinal development is not fully understood. In this study, expression of key ECM components (Collagen IV, Fibronectin, Brevican, Versican, IMPG1 and IMPG2) was investigated during human retinal ontogenesis. Collagen IV and Fibronectin were expressed in Bruch's membrane; whereas Brevican, Versican

Impaired platelet adhesion to lysed fibrin, whereas neutrophil adhesion remains intact under conditions of flow

NARCIS (Netherlands)

Remijn, Jasper A.; da Costa Martins, Paula; Ijsseldijk, Martin J. W.; Sixma, Jan J.; de Groot, Philip G.; Zwaginga, Jaap J.

2006-01-01

Vessel wall injury induces the formation of a haemostatic plug. Restoration of vascular integrity should involve cessation of further platelet and fibrin deposition and subsequent removal of these thrombi by both the fibrinolytic system and proteases delivered by infiltrating inflammatory cells. We

Histological assessment of titanium and polypropylene fiber mesh implantation with and without fibrin tissue glue.

NARCIS (Netherlands)

Hallers, E.J.O. ten; Jansen, J.A.; Marres, H.A.M.; Rakhorst, G.; Verkerke, G.J.

2007-01-01

Polypropylene (PP) and titanium (Ti) meshes are well-known surgical implants that provoke a relative low foreign body reaction. Firm stabilization of the implant is important to prevent migration and subsequent failure of the operation. Fibrin tissue glues are commercially available adhesives and

Histological assessment of titanium and polypropylene fiber mesh implantation with and without fibrin tissue glue

NARCIS (Netherlands)

ten Hallers, E.J. Olivier; Jansen, John A.; Marres, Henri A.M.; Rakhorst, Gerhard; Verkerke, Gijsbertus Jacob

2007-01-01

Polypropylene (PP) and titanium (Ti) meshes are well-known surgical implants that provoke a relative low foreign body reaction. Firm stabilization of the implant is important to prevent migration and subsequent failure of the operation. Fibrin tissue glues are commercially available adhesives and

Histological assessment of titanium and polypropylene fiber mesh implantation with and without fibrin tissue glue

NARCIS (Netherlands)

ten Hallers, E. J. Olivier; Jansen, John A.; Marres, Henri A. M.; Rakhorst, Gerhard; Verkerke, Gijsbertus J.

Polypropylene (PP) and titanium (Ti) meshes are well-known surgical implants that provoke a relative low foreign body reaction. Firm stabilization of the implant is important to prevent migration and subsequent failure of the operation. Fibrin tissue glues are commercially available adhesives and

Tracheal anastomosis with the diode laser and fibrin tissue adhesive: an in vitro and in vivo investigation.

Science.gov (United States)

Gleich, L L; Wang, Z; Pankratov, M M; Aretz, H T; Shapshay, S M

1995-05-01

Absorbable sutures have been advocated for tracheal anastomosis to reduce fibrosis and foreign body reaction leading to recurrent stenosis. Fibrin tissue adhesive (FTA) and diode laser welding with indocyanine green-dyed fibrinogen were evaluated in tracheal anastomosis to reduce the number of sutures and to improve healing. In vitro studies demonstrated strong anastomoses with a combination of laser welding and FTA with minimal tissue damage. In a controlled in vivo study, circumferential resections of canine tracheas were repaired with laser welding and FTA augmented with a few stay sutures. These anastomoses had less fibrosis and tissue damage than anastomoses in control animals repaired with sutures alone. This study supports investigation of laser welding and FTA in human beings for tracheal anastomosis and other procedures in which suturing may be difficult.

Soluble fibrin inhibits monocyte adherence and cytotoxicity against tumor cells: implications for cancer metastasis

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Patel Shonak

2006-08-01

Full Text Available Abstract Background Soluble fibrin (sFn is a marker for disseminated intravascular coagulation and may have prognostic significance, especially in metastasis. However, a role for sFn in the etiology of metastatic cancer growth has not been extensively studied. We have reported that sFn cross-linked platelet binding to tumor cells via the major platelet fibrin receptor αIIbβ3, and tumor cell CD54 (ICAM-1, which is the receptor for two of the leukocyte β2 integrins (αLβ2 and aMβ2. We hypothesized that sFn may also affect leukocyte adherence, recognition, and killing of tumor cells. Furthermore, in a rat experimental metastasis model sFn pre-treatment of tumor cells enhanced metastasis by over 60% compared to untreated cells. Other studies have shown that fibrin(ogen binds to the monocyte integrin αMβ2. This study therefore sought to investigate the effect of sFn on β2 integrin mediated monocyte adherence and killing of tumor cells. Methods The role of sFn in monocyte adherence and cytotoxicity against tumor cells was initially studied using static microplate adherence and cytotoxicity assays, and under physiologically relevant flow conditions in a microscope perfusion incubator system. Blocking studies were performed using monoclonal antibodies specific for β2 integrins and CD54, and specific peptides which inhibit sFn binding to these receptors. Results Enhancement of monocyte/tumor cell adherence was observed when only one cell type was bound to sFn, but profound inhibition was observed when sFn was bound to both monocytes and tumor cells. This effect was also reflected in the pattern of monocyte cytotoxicity. Studies using monoclonal blocking antibodies and specific blocking peptides (which did not affect normal coagulation showed that the predominant mechanism of fibrin inhibition is via its binding to αMβ2 on monocytes, and to CD54 on both leukocytes and tumor cells. Conclusion sFn inhibits monocyte adherence and cytotoxicity of

Plasma fibrin clot properties in the G20210A prothrombin mutation carriers following venous thromboembolism: the effect of rivaroxaban.

Science.gov (United States)

Janion-Sadowska, Agnieszka; Natorska, Joanna; Siudut, Jakub; Ząbczyk, Michal; Stanisz, Andrzej; Undas, Anetta

2017-08-30

We sought to investigate whether the G20210A prothrombin mutation modifies plasma fibrin clot properties in patients after venous thromboembolism (VTE) and how rivaroxaban treatment affects these alterations. We studied 34 prothrombin mutation heterozygous carriers and sex- and age-matched 34 non-carriers, all at least three months since the first VTE episode, before and during treatment with rivaroxaban. Clot permeability (K s ) and clot lysis time (CLT) with or without elimination of thrombin activatable fibrinolysis inhibitor (TAFI) were assessed at baseline, 2-6 hours (h) after and 20-25 h after intake of rivaroxaban (20 mg/day). At baseline, the prothrombin mutation group formed denser clots (K s -12 %, p=0.0006) and had impaired fibrinolysis (CLT +14 %, p=0.004, and CLT-TAFI +13 %, p=0.03) compared with the no mutation group and were similar to those observed in 15 healthy unrelated prothrombin mutation carriers. The G20210A prothrombin mutation was the independent predictor for K s and CLT before rivaroxaban intake. At 2-6 h after rivaroxaban intake, clot properties improved in both G20210A carriers and non-carriers (K s +38 %, and +37 %, CLT -25 % and -25 %, CLT-TAFI -20 % and -24 %, respectively, all pCLT +17 %, CLT-TAFI +13 %, all p<0.001). Rivaroxaban concentration correlated with fibrin clot properties. After 20-25 h since rivaroxaban intake most clot properties returned to baseline. Rivaroxaban-related differences in clot structure were confirmed by scanning electron microscopy images. In conclusion, rivaroxaban treatment, though improves fibrin clot properties, cannot abolish more prothrombotic fibrin clot phenotype observed in prothrombin mutation carriers following VTE.

The control of epidermal stem cells (holoclones) in the treatment of massive full-thickness burns with autologous keratinocytes cultured on fibrin.

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Pellegrini, G; Ranno, R; Stracuzzi, G; Bondanza, S; Guerra, L; Zambruno, G; Micali, G; De Luca, M

1999-09-27

Cell therapy is an emerging therapeutic strategy aimed at replacing or repairing severely damaged tissues with cultured cells. Epidermal regeneration obtained with autologous cultured keratinocytes (cultured autografts) can be life-saving for patients suffering from massive full-thickness burns. However, the widespread use of cultured autografts has been hampered by poor clinical results that have been consistently reported by different burn units, even when cells were applied on properly prepared wound beds. This might arise from the depletion of epidermal stem cells (holoclones) in culture. Depletion of holoclones can occur because of (i) incorrect culture conditions, (ii) environmental damage of the exposed basal layer of cultured grafts, or (iii) use of new substrates or culture technologies not pretested for holoclone preservation. The aim of this study was to show that, if new keratinocyte culture technologies and/or "delivery systems" are proposed, a careful evaluation of epidermal stem cell preservation is essential for the clinical performance of this life-saving technology. Fibrin was chosen as a potential substrate for keratinocyte cultivation. Stem cells were monitored by clonal analysis using the culture system originally described by Rheinwald and Green as a reference. Massive full-thickness burns were treated with the composite allodermis/cultured autograft technique. We show that: (i) the relative percentage of holoclones, meroclones, and paraclones is maintained when keratinocytes are cultivated on fibrin, proving that fibrin does not induce clonal conversion and consequent loss of epidermal stem cells; (ii) the clonogenic ability, growth rate, and long-term proliferative potential are not affected by the new culture system; (iii) when fibrin-cultured autografts bearing stem cells are applied on massive full-thickness burns, the "take" of keratinocytes is high, reproducible, and permanent; and (iv) fibrin allows a significant reduction of the cost

Local and global deformations in a strain-stiffening fibrin gel

Energy Technology Data Exchange (ETDEWEB)

Wen Qi [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Basu, Anindita [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Winer, Jessamine P [Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104 (United States); Yodh, Arjun [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Janmey, Paul A [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States)

2007-11-15

Extracellular matrices composed of filamentous biopolymers like collagen and fibrin have viscoelastic properties that differ from those of rubberlike elastomers or hydrogels formed by flexible polymers. Compared to flexible polymer gels, filamentous biopolymer networks generally have larger elastic moduli, a striking increase in elastic modulus with increasing strain, and a pronounced negative normal stress when deformed in simple shear. All three of these unusual features can be accounted for by a theory that extends concepts of entropic elasticity to a regime where the polymer chains are already significantly extended in the absence of external forces because of their finite bending stiffness. An essential assumption of the theories that relate microscopic structural parameters such as persistence length and mesh size of biopolymer gels to their macroscopic rheology is that the deformation of these materials is affine: that is, the macroscopic strain of the bulk material is equal to the local strain within the material at each point. The validity of this assumption for the dilute open meshworks of most biopolymer gels has been experimentally tested by embedding micron diameter fluorescent beads within the networks formed by fibrin and quantifying their displacements as the macroscopic samples are deformed in a rheometer. Measures of non-affine deformation are small at small strains and decrease as strain increases and the sample stiffens. These results are consistent with the entropic model for non-linear elasticity of semiflexible polymer networks and show that strain-stiffening does not require non-affine deformations.

Fibrinogen Vicenza and Genova II: two new cases of congenital dysfibrinogenemia with isolated defect of fibrin monomer polymerization and inhibitory activity on normal coagulation.

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Rodeghiero, F; Castaman, G C; Dal Belin Peruffo, A; Dini, E; Galletti, A; Barone, E; Gastaldi, G

1987-06-03

Two new cases of congenital dysfibrinogenemia are presented in which defective fibrin monomer polymerization and inhibitory activity on normal coagulation were observed. They have been tentatively called fibrinogen Vicenza and Genova II. The first was discovered in a family with mild bleeding diathesis, the second in an asymptomatic family. In almost all reported cases of fibrinogens with defective fibrin monomer polymerization, additional functional or structural defects have been detected. In our cases, on the contrary, detailed investigations failed to show any other abnormality. Fibrinogen Genova II is apparently identical to fibrinogen Baltimore IV, whereas fibrinogen Vicenza is similar to fibrinogen Troyes and Genova I, but also exerts an evident inhibitory activity on normal coagulation and differs from fibrinogen Genova II and Baltimore IV showing a different kinetic pattern of fibrin monomer polymerization.

Steric Interference of Adhesion Supports In-Vitro Chondrogenesis of Mesenchymal Stem Cells on Hydrogels for Cartilage Repair.

Science.gov (United States)

Goldshmid, Revital; Cohen, Shlomit; Shachaf, Yonatan; Kupershmit, Ilana; Sarig-Nadir, Offra; Seliktar, Dror; Wechsler, Roni

2015-09-28

Recent studies suggest the presence of cell adhesion motifs found in structural proteins can inhibit chondrogenesis. In this context, the current study aims to determine if a polyethylene glycol (PEG)-modified fibrinogen matrix could support better chondrogenesis of human bone marrow mesenchymal stem cells (BM-MSC) based on steric interference of adhesion, when compared to a natural fibrin matrix. Hydrogels used as substrates for two-dimensional (2D) BM-MSC cultures under chondrogenic conditions were made from cross-linked PEG-fibrinogen (PF) and compared to thrombin-activated fibrin. Cell morphology, protein expression, DNA and sulfated proteoglycan (GAG) content were correlated to substrate properties such as stiffness and adhesiveness. Cell aggregation and chondrogenic markers, including collagen II and aggrecan, were observed on all PF substrates but not on fibrin. Shielding fibrinogen's adhesion domains and increasing stiffness of the material are likely contributing factors that cause the BM-MSCs to display a more chondrogenic phenotype. One composition of PF corresponding to GelrinC™--a product cleared in the EU for cartilage repair--was found to be optimal for supporting chondrogenic differentiation of BM-MSC while minimizing hypertrophy (collagen X). These findings suggest that semi-synthetic biomaterials based on ECM proteins can be designed to favourably affect BM-MSC towards repair processes involving chondrogenesis.

Effect of fibrin glue derived from snake venom on the viability of autogenous split-thickness skin graft

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S.C. Rahal

2004-01-01

Full Text Available The aim of this study was to analyze the effect of snake venom derived from fibrin glue on the viability of split-thickness skin graft. Nine crossbreed dogs were used. Full-thickness skin segments measuring 4 x 4 cm were bilaterally excised from the proximal radial area on each dog. A split-thickness skin graft was harvestedfrom left lateral thoracic area using a freehand graft knife, and was secured to the left recipient bed using several simple interrupted sutures of 3-0 nylon (sutured graft. A split-thickness skin graft was harvested from the right lateral thoracic area using a graft knife. Fibrin glue derived from snake venom was applied to the recipient bed, and 8 equidistant simple interrupted sutures of 3-0 nylon were used to secure the skin graft (glued graft. Viable and nonviable areas were traced on a transparent sheet and measured using a Nikon Photomicroscope connected to a KS-300 image analysis system. The skin graft and recipient bed were collected from three dogs at day 7, 15, and 30 postoperative. The glued grafts had statistically higher graft viability than sutured grafts. Histological examination showed that the tissue repair process in the glued grafts was more accentuated than sutured grafts. It was possible to conclude that fibrin glue derived from snake venom increased survival of autogenous split-thickness skin graft.

Microbiology and pathology of fibrinous pericarditis in Danish slaughter pigs

DEFF Research Database (Denmark)

Buttenschøn, J.; Friis, N.F.; Aalbaek, B.

1997-01-01

The prevalence of fibrinous pericarditis detected at slaughter in Danish slaughter pigs is approximately 0.02 %. The microbiology and pathology of this disorder was studied through 46 field cases collected at slaughter from May 1994 to August 1995. Mycoplasmas (Mycoplasma hyopneumoniae, M...... from the pericardium in three cases. The pericardium was sterile in three cases and contained a low grade mixed flora in two; the latter is believed to be a result of the slaughter procedure rather than an infection. No chlamydiae were found in connection with the microbiological examination...

Selective abrogation of the uPA-uPAR interaction in vivo reveals a novel role in suppression of fibrin-associated inflammation

DEFF Research Database (Denmark)

Connolly, Brian M; Choi, Eun Young; Gårdsvoll, Henrik

2010-01-01

the interaction between endogenous uPA and uPAR is selectively abrogated, whereas other functions of both the protease and its receptor are retained. Specifically, we introduced 4 amino acid substitutions into the growth factor domain (GFD) of uPA that abrogate uPAR binding while preserving the overall structure...... a principal in vivo role of the uPA-uPAR interaction in cell-associated fibrinolysis critical for suppression of fibrin accumulation and fibrin-associated inflammation and provides a valuable model for further exploration of this multifunctional receptor....

Oxidation modifies the structure and function of the extracellular matrix generated by human coronary artery endothelial cells.

Science.gov (United States)

Chuang, Christine Y; Degendorfer, Georg; Hammer, Astrid; Whitelock, John M; Malle, Ernst; Davies, Michael J

2014-04-15

ECM (extracellular matrix) materials, such as laminin, perlecan, type IV collagen and fibronectin, play a key role in determining the structure of the arterial wall and the properties of cells that interact with the ECM. The aim of the present study was to investigate the effect of peroxynitrous acid, an oxidant generated by activated macrophages, on the structure and function of the ECM laid down by HCAECs (human coronary artery endothelial cells) in vitro and in vivo. We show that exposure of HCAEC-derived native matrix components to peroxynitrous acid (but not decomposed oxidant) at concentrations >1 μM results in a loss of antibody recognition of perlecan, collagen IV, and cell-binding sites on laminin and fibronectin. Loss of recognition was accompanied by decreased HCAEC adhesion. Real-time PCR showed up-regulation of inflammation-associated genes, including MMP7 (matrix metalloproteinase 7) and MMP13, as well as down-regulation of the laminin α2 chain, in HCAECs cultured on peroxynitrous acid-treated matrix compared with native matrix. Immunohistochemical studies provided evidence of co-localization of laminin with 3-nitrotyrosine, a biomarker of peroxynitrous acid damage, in type II-III/IV human atherosclerotic lesions, consistent with matrix damage occurring during disease development in vivo. The results of the present study suggest a mechanism through which peroxynitrous acid modifies endothelial cell-derived native ECM proteins of the arterial basement membrane in atherosclerotic lesions. These changes to ECM and particularly perlecan and laminin may be important in inducing cellular dysfunction and contribute to atherogenesis.

Effects of matrix elasticity and cell density on human mesenchymal stem cells differentiation.

Science.gov (United States)

Xue, Ruyue; Li, Julie Yi-Shuan; Yeh, Yiting; Yang, Li; Chien, Shu

2013-09-01

Human mesenchymal stem cells (hMSCs) can differentiate into various cell types, including osteogenic and chondrogenic cells. The matrix elasticity and cell seeding density are important factors in hMSCs differentiation. We cultured hMSCs at different seeding densities on polyacrylamide hydrogels with different stiffness corresponding to Young's moduli of 1.6 ± 0.3 and 40 ± 3.6 kPa. The promotion of osteogenic marker expression by hard gel is overridden by a high seeding density. Cell seeding density, however, did not influence the chondrogenic marker expressions induced by soft gel. These findings suggest that interplays between cell-matrix and cell-cell interactions contribute to hMSCs differentiation. The promotion of osteogenic differentiation on hard matrix was shown to be mediated through the Ras pathway. Inhibition of Ras (RasN17) significantly decreased ERK, Smad1/5/8 and AKT activation, and osteogenic markers expression. However, constitutively active Ras (RasV12) had little effect on osteogenic marker expression, suggesting that the Ras pathways are necessary but not sufficient for osteogenesis. Taken together, our results indicate that matrix elasticity and cell density are important microenvironmental cues driving hMSCs proliferation and differentiation. Copyright © 2013 Orthopaedic Research Society.

Comparison of vasovasostomy with conventional microsurgical suture and fibrin adhesive in rats

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Wilson F. Busato Junior

2007-12-01

Full Text Available OBJECTIVE: Microsurgical procedures are currently the gold standard for vasovasostomy with excellent results, but it takes an increased operative time demanding special training and experience in microsurgery. The objective of this study is to reach the same results with reduced operative time. MATERIALS AND METHODS: Male adults Wistar rats were divided into 3 groups: I 20 rats in control group, II 20 with conventional one-layer microsuture and III 20 with fibrin glue. After four weeks each rat was left for two weeks with two female rats. RESULTS: The fertility rates were 80% in group I, 70% in group II and 65% in group III (p > 0.05. In group II granuloma was found in 75% of the rats, while in group III in 85% (p 0.05. Overall operative time was 41.7 ± 2.49 and 28.55 ± 1.14 minutes in groups II and III (p < 0.05 and the time to anastomosis of 24.6 ± 1.8 and 9.35 ± 0.78 minutes (p < 0.05, respectively. CONCLUSIONS: We can conclude that vasovasostomy with fibrin adhesive has the same results of the conventional microsurgery technique but with a reduced operative time and a simplified procedure.

Comparative evaluation of coronally advanced flap using amniotic membrane and platelet-rich fibrin membrane in gingival recession: An 18-month clinical study

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Mohd Rehan

2018-01-01

Full Text Available Background: An amnion membrane is a placenta-derived tissue that consists of numerous growth factors, proteins, and stem cell reserves which help in accelerated wound healing and regeneration. Platelet-rich fibrin (PRF also releases growth factors after activation from the platelets and gets trapped within fibrin matrix which has been shown to stimulate the mitogenic response in the periosteum for bone repair and regeneration during normal wound healing. This preliminary, controlled, randomized clinical trial with an 18-month follow-up was aimed to evaluate the effectiveness of coronally advanced flap (CAF with either PRF membrane or bioresorbable amniotic membrane (AM in treatment of localized gingival recession defects. Materials and Methods: Sixteen healthy adult patients presenting with Miller Class I recession defects were treated surgically with CAF along with AM (Group I or PRF (Group II for coverage of the recession defects. For all patients, plaque index, gingival index, bleeding on probing, clinical attachment level, depth of recession, width of recession, width of attached gingiva, and gingival thickness were evaluated at 6 months and 18 months postoperatively. Statistical analysis was done using paired t-test, repeated measure analysis of variance test, Bonferroni test for intragroup comparison and unpaired t-test for intergroup comparison. Results: The results showed statistically nonsignificant (P < 0.01 difference in all clinical parameters at the 6- and 18-month follow-ups in both groups. Gingival recession in both PRF and amnion group when evaluated individually, significantly reduced from baseline to 6 months (P = 0.000 and from baseline to 18 months (P = 0.000. However, the mean value from 6 months to 18 months was statistically nonsignificant. Conclusion: The present study demonstrated that both CAF + PRF and CAF + AM are equally effective in providing clinically significant outcomes with respect to root coverage with AM

Expression of matrix metrallproteinase-2 in human tears fluid after LASIK

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Ai-Wei Chen

2014-12-01

Full Text Available AIM: To monitor long-term changes of matrix metalloproteinase-2(MMP-2in human tears fluid after laser in situ keratomileusis(LASIK. METHODS: Thirty-two myopia cases(64 eyesunderwent uneventful LASIK were enrolled in the study. Tear fluid were collected and MMP-2 expression was analyzed by Western-bolt assay preoperatively and postoperatively on 15d, at 1, 3mo, and 1a. RESULTS: LASIK increased the concentration of MMP-2 in human tear fluid. At 15d postoperatively, the magnitude of MMP-2 was 1.4 times that of preoperative, thereafter subsided, but didn't return to preoperative level by 3mo(PP>0.05. CONCLUSION: MMP-2 is significantly expressed in human tear fluid after LASIK, then subsided with time, but didn't return to preoperative level by 3mo and almost recovered up to 1a, indicating wound healing of LASIK would continue up at least 3mo after surgery and almost recovered 1a postoperatively.

Protein crystallization with microseed matrix screening: application to human germline antibody Fabs

International Nuclear Information System (INIS)

Obmolova, Galina; Malia, Thomas J.; Teplyakov, Alexey; Sweet, Raymond W.; Gilliland, Gary L.

2014-01-01

The power of microseed matrix screening is demonstrated in the crystallization of a panel of antibody Fab fragments. The crystallization of 16 human antibody Fab fragments constructed from all pairs of four different heavy chains and four different light chains was enabled by employing microseed matrix screening (MMS). In initial screening, diffraction-quality crystals were obtained for only three Fabs, while many Fabs produced hits that required optimization. Application of MMS, using the initial screens and/or refinement screens, resulted in diffraction-quality crystals of these Fabs. Five Fabs that failed to give hits in the initial screen were crystallized by cross-seeding MMS followed by MMS optimization. The crystallization protocols and strategies that resulted in structure determination of all 16 Fabs are presented. These results illustrate the power of MMS and provide a basis for developing future strategies for macromolecular crystallization

Decellularized matrix from tumorigenic human mesenchymal stem cells promotes neovascularization with galectin-1 dependent endothelial interaction.

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Jorge S Burns

Full Text Available BACKGROUND: Acquisition of a blood supply is fundamental for extensive tumor growth. We recently described vascular heterogeneity in tumours derived from cell clones of a human mesenchymal stem cell (hMSC strain (hMSC-TERT20 immortalized by retroviral vector mediated human telomerase (hTERT gene expression. Histological analysis showed that cells of the most vascularized tumorigenic clone, -BD11 had a pericyte-like alpha smooth muscle actin (ASMA+ and CD146+ positive phenotype. Upon serum withdrawal in culture, -BD11 cells formed cord-like structures mimicking capillary morphogenesis. In contrast, cells of the poorly tumorigenic clone, -BC8 did not stain for ASMA, tumours were less vascularized and serum withdrawal in culture led to cell death. By exploring the heterogeneity in hMSC-TERT20 clones we aimed to understand molecular mechanisms by which mesenchymal stem cells may promote neovascularization. METHODOLOGY/PRINCIPAL FINDINGS: Quantitative qRT-PCR analysis revealed similar mRNA levels for genes encoding the angiogenic cytokines VEGF and Angiopoietin-1 in both clones. However, clone-BD11 produced a denser extracellular matrix that supported stable ex vivo capillary morphogenesis of human endothelial cells and promoted in vivo neovascularization. Proteomic characterization of the -BD11 decellularized matrix identified 50 extracellular angiogenic proteins, including galectin-1. siRNA knock down of galectin-1 expression abrogated the ex vivo interaction between decellularized -BD11 matrix and endothelial cells. More stable shRNA knock down of galectin-1 expression did not prevent -BD11 tumorigenesis, but greatly reduced endothelial migration into -BD11 cell xenografts. CONCLUSIONS: Decellularized hMSC matrix had significant angiogenic potential with at least 50 angiogenic cell surface and extracellular proteins, implicated in attracting endothelial cells, their adhesion and activation to form tubular structures. hMSC -BD11 surface galectin-1

Decellularized Matrix from Tumorigenic Human Mesenchymal Stem Cells Promotes Neovascularization with Galectin-1 Dependent Endothelial Interaction

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Burns, Jorge S.; Kristiansen, Malthe; Kristensen, Lars P.; Larsen, Kenneth H.; Nielsen, Maria O.; Christiansen, Helle; Nehlin, Jan; Andersen, Jens S.; Kassem, Moustapha

2011-01-01

Background Acquisition of a blood supply is fundamental for extensive tumor growth. We recently described vascular heterogeneity in tumours derived from cell clones of a human mesenchymal stem cell (hMSC) strain (hMSC-TERT20) immortalized by retroviral vector mediated human telomerase (hTERT) gene expression. Histological analysis showed that cells of the most vascularized tumorigenic clone, -BD11 had a pericyte-like alpha smooth muscle actin (ASMA+) and CD146+ positive phenotype. Upon serum withdrawal in culture, -BD11 cells formed cord-like structures mimicking capillary morphogenesis. In contrast, cells of the poorly tumorigenic clone, -BC8 did not stain for ASMA, tumours were less vascularized and serum withdrawal in culture led to cell death. By exploring the heterogeneity in hMSC-TERT20 clones we aimed to understand molecular mechanisms by which mesenchymal stem cells may promote neovascularization. Methodology/Principal Findings Quantitative qRT-PCR analysis revealed similar mRNA levels for genes encoding the angiogenic cytokines VEGF and Angiopoietin-1 in both clones. However, clone-BD11 produced a denser extracellular matrix that supported stable ex vivo capillary morphogenesis of human endothelial cells and promoted in vivo neovascularization. Proteomic characterization of the -BD11 decellularized matrix identified 50 extracellular angiogenic proteins, including galectin-1. siRNA knock down of galectin-1 expression abrogated the ex vivo interaction between decellularized -BD11 matrix and endothelial cells. More stable shRNA knock down of galectin-1 expression did not prevent -BD11 tumorigenesis, but greatly reduced endothelial migration into -BD11 cell xenografts. Conclusions Decellularized hMSC matrix had significant angiogenic potential with at least 50 angiogenic cell surface and extracellular proteins, implicated in attracting endothelial cells, their adhesion and activation to form tubular structures. hMSC -BD11 surface galectin-1 expression was

The role of titanium-prepared platelet-rich fibrin in palatal mucosal wound healing and histoconduction.

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Ustaoğlu, Gülbahar; Ercan, Esra; Tunali, Mustafa

2016-10-01

We aimed to determine the clinical effects of titanium-prepared, platelet-rich fibrin (T-PRF) on human palatal mucosal wound healing (PMWH) and to identify its effect on time-dependent changes in palatal soft-tissue thickness (PSTT) in terms of histoconduction, which is a new concept. Free gingival graft (FGG) donor sites were treated with T-PRF and compared with an untreated control group. The results of colour match and H 2 O 2 -bubbling tests for complete wound epithelization (CWE) were recorded on days 3, 7, 14 and 21. Pain level, number of analgesics used and bleeding status were recorded for the first 7 days. PSTT was measured at baseline and after 1 and 6 months. Colour match scores of the test group were significantly higher than those of the control group at 7 and 14 days. CWE was observed at a higher frequency in the test group than in the control group on day 14. Post-operative bleeding prevalence was lower in the test group than in the control group for the first 2 days. A time-dependent decrease in PSTT was observed at 1 and 6 months in the control group compared with baseline (baseline, 4.23 ± 0.62 mm; 1 month, 4.01 ± 0.68 mm; and 6 months, 3.93 ± 0.69 mm). However, no significant difference was found in the test group (baseline, 4.29 ± 0.64 mm; 1 month, 4.61 ± 0.51 mm; and 6 months, 4.51 ± 0.58 mm). The T-PRF membrane exhibited positive effects on PMWH. T-PRF, which is a promising autogenous matrix for histoconduction, may also be preferred as an autogenous alternative to connective tissue grafts in the treatment of gingival recessions and peri-implant mucosal recessions.

Selective inhibition by a synthetic hirudin peptide of fibrin-dependent thrombosis in baboons

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Cadroy, Y.; Hanson, S.R.; Harker, L.A.; Maraganore, J.M.

1991-01-01

To determine the importance of the thrombin substrate recognition exosite for fibrinogen binding in the formation of both arterial and venous thrombi the authors evaluated the antithrombotic effects of the tyrosine-sulfated dodecapeptide from residues 53-64 of hirudin (H peptide) in a nonhuman primate model. This peptide was studied because it inhibits thrombin cleavages of fibrinogen by simple competition without blocking enzyme catalytic-site function. When an exteriorized arteriovenous access shunt model was used in baboons (Papio anubis), thrombus formation was induced by placing a thrombogenic device made of (i) a segment of tubing coated covalently with type I collagen, which generated platelet-rich thrombi under arterial flow conditions, and (ii) two subsequent annular regions of flow expansion that produced fibrin-rich thrombi typically associated with venous valves and veins. Thrombus formation was quantified by measurements of 111 In-labeled platelet and 125 I-labeled fibrinogen deposition in both arterial-flow and venous-flow portions of the device. These finding suggest that, by competitive inhibition of fibrinogen binding to thrombin, fibrin-rich venous-type thrombus formation may be selectively prevented. This strategy may be therapeutically attractive for preserving normal platelet function when conventional anticoagulant therapy is contraindicated

The effect of sibutramine, a serotonin-norepinephrine reuptake inhibitor, on platelets and fibrin networks of male Sprague-Dawley rats: a descriptive study.

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van der Schoor, Ciska; Oberholzer, Hester Magdalena; Bester, Megan Jean; van Rooy, Mia-Jeanne

2014-12-01

Sibutramine is used in the treatment of obesity due to its ability to influence feelings of hunger and satiety by inhibiting the re-uptake of serotonin and noradrenalin in the central nervous system (CNS). Sibutramine use has been associated with numerous adverse events in particular cardiovascular complications possibly due to the formation of thrombi. This ultrastructural descriptive study investigated the effect of sibutramine on blood coagulation, specifically the effect on morphology of platelets and fibrin networks using scanning electron microscopy. Male Sprague-Dawley rats treated with either a recommended therapeutic dose [low dosage 1.32 mg/kg] or a toxicological higher dose [high dosage 13.2 mg/kg] of sibutramine for 28 days were used and compared to control animals. Blood samples were collected and plasma smears were prepared for platelet evaluation. Following the addition of thrombin to the plasma samples, the morphology of the fibrin clots was evaluated. Platelet evaluation by scanning electron microscopy revealed morphology typical of a prothrombotic state with a characteristic excessive platelet activation in both low-dose (LD) and high-dose (HD) rats. The fibrin clots of sibutramine-treated rats, LD and HD revealed fused thick fibers with thin fibers forming a net-like structure over the thick fibers which differ considerably from the organized structure of the control animals. It can be concluded that sibutramine alters the ultrastructure of platelets and fibrin networks creating a prothrombotic state.

An ibuprofen-antagonized plasmin inhibitor released by human endothelial cells.

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Rockwell, W B; Ehrlich, H P

1991-02-01

Serum-free culture medium harvested from endothelial cell monolayer cultures derived from human scars and dermis was examined for inhibition of fibrinolysis using a fibrin plate assay. Human cultured fibroblasts and smooth muscle cells did not produce any detectable inhibitory activity. The inhibitor is spontaneously released from the cultured endothelial cells over time. In the fibrin plate assay of plasmin-induced fibrinolysis, one nonsteroidal antiinflammatory (NSAI) drug, ibuprofen, was demonstrated to antagonize the inhibition of fibrinolysis. The antagonistic activity of ibuprofen appears unrelated to its NSAI drug activity because other NSAI drugs such as indomethacin and tolmetin have minimal antagonistic activity. Heating the cultured endothelial cells to 42 degrees C stimulates greater release of the inhibitor in a shorter period of time. This plasmin inhibitor, which is produced by endothelial cells, may contribute to postburn vascular occlusion, leading to secondary progressive necrosis in burn-traumatized patients.

Subconjunctival PRGF Fibrin Membrane as an Adjuvant to Nonpenetrating Deep Sclerectomy: A 2-Year Pilot Study.

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Rodríguez-Agirretxe, Iñaki; Freire, Vanesa; Muruzabal, Francisco; Orive, Gorka; Anitua, Eduardo; Díez-Feijóo, Elio; Acera, Arantxa

2018-01-01

To evaluate the potential role of the autologous PRGF (plasma rich in growth factors) fibrin membrane in tissue regeneration after glaucoma filtering surgery. Ten patients with medically uncontrolled primary open-angle glaucoma underwent nonpenetrating deep sclerectomy and were treated with PRGF fibrin membrane as adjuvant. Intraocular pressure reduction was the primary outcome. This variable was measured preoperatively and also at each follow-up visit. Secondary outcomes included the number of antiglaucoma medications, anterior segment optical coherence tomography bleb examination, photographic bleb evaluation, and subjective clinical symptomatology evaluation. The surgical technique showed a significant reduction (p PRGF-Endoret treatment could promote ocular surface regeneration after glaucoma surgery, enhancing the surgery success rates and reducing the need for postoperative medications. It is important to highlight that this is a preliminary study and some large clinical studies are necessary to verify these results. © 2017 S. Karger AG, Basel.

Clinical and morphological evaluation of snake venom derived fibrin glue on the tendon healing in dogs

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G. C. Ferraro

2005-12-01

Full Text Available The aim of this study was to evaluate the effect of snake venom derived fibrin glue on the healing of the deep digital flexor tendon, during three periods. The tendon of the 2nd digit of 30 thoracic limbs of dogs was partially sectioned for glue application. Biopsies were performed 7, 15, and 30 days post surgery for the clinical and morphological study of tendons. Analysis of the results showed that 73.3% of the tendons showed stump retraction and 16.6% moderate to excessive adherence, which affected sliding. There was a significant difference in the number of inflammatory cells among the three studied periods, being the highest on day 15. The morphological analysis revealed a typical tendon healing process with a lower level of inflammation in the acute phase, facilitating the cicatricial maturation phase. Snake venom derived fibrin glue promotes the healing in dog flexor tendon.

Treatment of venous ulcers with fibrin sealant derived from snake venom

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MAN Gatti

2011-01-01

Full Text Available Venous ulcers of the lower limbs complicated by infection or chronicity represent a serious public health problem. The elevated number of those afflicted burdens the health services, interferes in quality of life and causes absenteeism. Although there are 2,500 items on the market, ranging from the simplest dressing up to the most complex types of dressing, treatment remains a challenge. Among the substances used, fibrin sealant is the one that promotes diminution of bacterial colonization and of edema, controls hemorrhaging, alters the pain threshold by protecting the nerve endings, hydrates the wound bed and forms granulation tissue that favors healing. Its disadvantages include higher cost and utilization of human fibrinogen that can transmit infectious diseases. The Center for the Study of Venoms and Venomous Animals (CEVAP at São Paulo State University (UNESP developed a new sealant made up of fibrinogen extracted from large animals and from an enzyme obtained from snake venom. The present study, developed in the Health Education Clinic (CEPS of Sacred Heart University (USC aimed to evaluate the effect of the new sealant on the healing process of venous ulcers in 24 adult patients, seven of whom were male and 17 female. Two study groups were formed as follows: Group 1 (G1 - control group of 11 patients treated with essential fatty acid (EFA and Unna's boot, and Group 2 (G2 - 13 patients treated with essential fatty acid (EFA, fibrin sealant and Unna's boot. The follow-up lasted eight weeks and the sealant was applied at only the first and fourth weeks. The results showed that Group 2 presented worse lesion conditions as to healing, but, when comparing the two groups, it was noteworthy that the the sealant was effective in healing venous ulcers. There is evidence that the new sealant is recommended for leg ulcers with the following advantages: ease of application, preparation of the wound bed, diminution of pain and a higher number of

Acute fibrinous organising pneumonia: a manifestation of trimethoprim-sulfamethoxazole pulmonary toxicity.

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Jamous, Fady; Ayaz, Syed Zain; Choate, Jacquelyn

2014-10-29

A 50-year-old man was treated with trimethoprim-sulfamethoxazole (TMP-SMX) for acute arthritis of his right big toe. Within a few days, he developed dyspnoea, hypoxaemia and diffuse pulmonary infiltrates. Symptoms improved with discontinuation of the antibiotic but worsened again with its reintroduction. An open lung biopsy was performed. We describe the workup performed and the factors that pointed to a final diagnosis of TMP-SMX-related pulmonary toxicity in the form of acute fibrinous organising pneumonia. 2014 BMJ Publishing Group Ltd.

Comparison of standard fibrinogen measurement methods with fibrin clot firmness assessed by thromboelastometry in patients with cirrhosis.

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Vucelic, Dragica; Jesic, Rada; Jovicic, Snezana; Zivotic, Maja; Grubor, Nikica; Trajkovic, Goran; Canic, Ivana; Elezovic, Ivo; Antovic, Aleksandra

2015-06-01

The Clauss fibrinogen method and thrombin clotting time (TCT) are still routinely used in patients with cirrhosis to define fibrinogen concentration and clotting potential. The thromboelastometric functional fibrinogen FIBTEM assay evaluates the strength of fibrin-based clots in whole blood, providing information on both quantitative deficit and fibrin polymerization disorders. To compare these three methods of assessing fibrinogen in patients with cirrhosis of different aetiologies, characterized by impairment in fibrinogen concentration as well as functional aberrance. Sixty patients with alcoholic and 24 patients with cholestatic cirrhosis were included (Child-Pugh score (CPs)A, n=24; B, n=32; C, n=28). All parameters were compared with those from a control group. Maximum clot firmness (MCF) in the FIBTEM test was assessed in regard to its relevance in detection of qualitative fibrinogen disorders in comparison with results obtained by standard measurement methods, i.e. the Clauss fibrinogen method and TCT. With increased cirrhosis severity, fibrinogen and FIBTEM-MCF levels significantly declined (p=0.002), while TCT was significantly prolonged (p=0.002). In all CPs groups, fibrinogen strongly correlated with FIBTEM-MCF (r=0.77, r=0.72, r=0.74; pmeasurement in cirrhotic patients, especially in evaluating fibrin polymerization disorders in these patients. Further studies are needed to evaluate the usefulness of this assay in predicting bleeding complications in cirrhotic patients as well as monitoring replacement treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Platelet rich fibrin - a novel acumen into regenerative endodontic therapy

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Kavita Hotwani

2014-02-01

Full Text Available Research into regenerative dentistry has added impetus onto the field of molecular biology. It can be documented as a prototype shift in the therapeutic armamentarium for dental disease. Regenerative endodontic procedures are widely being added to the current armamentarium of pulp therapy procedures. The regenerative potential of platelets has been deliberated. A new family of platelet concentrates called the platelet rich fibrin (PRF has been recently used by several investigators and has shown application in diverse disciplines of dentistry. This paper is intended to add light on the various prospects of PRF and clinical insights to regenerative endodontic therapy.

Assessment of Pain and Quality of Life in Lichtenstein Hernia Repair Using a New Monofilament PTFE Mesh: Comparison of Suture vs. Fibrin-Sealant Mesh Fixation.

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Fortelny, René H; Petter-Puchner, Alexander H; Redl, Heinz; May, Christopher; Pospischil, Wolfgang; Glaser, Karl

2014-01-01

Inguinal hernia repair is one of the most common operations in general surgery. The Lichtenstein tension-free operation has become the gold standard in open inguinal hernia repair. Despite the low recurrence rates, pain and discomfort remain a problem for a large number of patients. The aim of this study was to compare suture fixation vs. fibrin sealing by using a new monofilament PTFE mesh, i.e., the Infinit(®) mesh by W. L. Gore & Associates. This study was designed as a controlled prospective single-center two-cohort study. A total of 38 patients were enrolled and operated in Lichtenstein technique either standard suture mesh fixation or fibrin-sealant mesh fixation were used as described in the TIMELI trial. Primary outcome parameters were postoperative complications with the new mesh (i.e., seroma, infection), pain, and quality of life evaluated by the VAS and the SF-36 questionnaire. Secondary outcome was recurrence assessed by ultrasound and physical examination. Follow-up time was 1 year. Significantly, less postoperative pain was reported in the fibrin-sealant group compared to the suture group at 6 weeks (P = 0.035), 6 months (P = 0.023), and 1 year (P = 0.011) postoperatively. Additionally, trends toward a higher postoperative quality of life, a faster surgical procedure, and a shorter hospital stay were seen in the fibrin-sealant group. Fibrin-sealant mesh fixation in Lichtenstein hernioplasty effectively reduces acute and chronic postoperative pain. Monofilament, macro-porous, knitted PTFE meshes seem to be a practicable alternative to commonly used polypropylene meshes in open inguinal hernia repair.

Assessment of pain and quality of life in Lichtenstein hernia repair using a new monofilament PTFE mesh: comparison of suture vs. fibrin sealant mesh fixation

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René H Fortelny

2014-11-01

Full Text Available Background: Inguinal hernia repair is one of the most common operations in general surgery. The Lichtenstein tension-free operation has become the gold standard in open inguinal hernia repair. Despite the low recurrence rates, pain and discomfort remain a problem for a large number of patients. The aim of this study was to compare suture fixation vs. fibrin sealing by using a new monofilament PTFE mesh, i.e. the Infinit® mesh by W. L. Gore & Associates. Methods: This study was designed as a controlled prospective single-centre two cohort study. A total of 38 patients were enrolled and operated in Lichtenstein technique either standard suture mesh fixation or fibrin sealant mesh fixation were used as described in the TIMELI trial. Primary outcome parameters were postoperative complications with the new mesh (i.e. seroma, infection, pain and quality of life evaluated by the VAS and the SF-36 questionnaire. Secondary outcome was recurrence assessed by ultrasound and physical examination. Follow-up time was 1 year.Results: Significantly less postoperative pain was reported in the fibrin sealant group compared to the suture group at 6 weeks (P=0.035, 6 months (P=0.023 and 1 year (P=0.011 postoperatively. Additionally trends towards a higher postoperative quality of life, a faster surgical procedure and a shorter hospital stay were seen in the fibrin sealant group.Conclusion: Fibrin sealant mesh fixation in Lichtenstein hernioplasty effectively reduces acute and chronic postoperative pain. Monofilament, macro-porous, knitted PTFE meshes seem to be a practicable alternative to commonly used polypropylene meshes in open inguinal hernia repair.

Design of a Novel Two-Component Hybrid Dermal Scaffold for the Treatment of Pressure Sores.

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Sharma, Vaibhav; Kohli, Nupur; Moulding, Dale; Afolabi, Halimat; Hook, Lilian; Mason, Chris; García-Gareta, Elena

2017-11-01

The aim of this study is to design a novel two-component hybrid scaffold using the fibrin/alginate porous hydrogel Smart Matrix combined to a backing layer of plasma polymerized polydimethylsiloxane (Sil) membrane to make the fibrin-based dermal scaffold more robust for the treatment of the clinically challenging pressure sores. A design criteria are established, according to which the Sil membranes are punched to avoid collection of fluid underneath. Manual peel test shows that native silicone does not attach to the fibrin/alginate component while the plasma polymerized silicone membranes are firmly bound to fibrin/alginate. Structural characterization shows that the fibrin/alginate matrix is intact after the addition of the Sil membrane. By adding a Sil membrane to the original fibrin/alginate scaffold, the resulting two-component scaffolds have a significantly higher shear or storage modulus G'. In vitro cell studies show that dermal fibroblasts remain viable, proliferate, and infiltrate the two-component hybrid scaffolds during the culture period. These results show that the design of a novel two-component hybrid dermal scaffold is successful according to the proposed design criteria. To the best of the authors' knowledge, this is the first study that reports the combination of a fibrin-based scaffold with a plasma-polymerized silicone membrane. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Extracellular Matrix Molecular Remodeling in Human Liver Fibrosis Evolution.

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Andrea Baiocchini

Full Text Available Chronic liver damage leads to pathological accumulation of ECM proteins (liver fibrosis. Comprehensive characterization of the human ECM molecular composition is essential for gaining insights into the mechanisms of liver disease. To date, studies of ECM remodeling in human liver diseases have been hampered by the unavailability of purified ECM. Here, we developed a decellularization method to purify ECM scaffolds from human liver tissues. Histological and electron microscopy analyses demonstrated that the ECM scaffolds, devoid of plasma and cellular components, preserved the three-dimensional ECM structure and zonal distribution of ECM components. This method has been then applied on 57 liver biopsies of HCV-infected patients at different stages of liver fibrosis according to METAVIR classification. Label-free nLC-MS/MS proteomics and computation biology were performed to analyze the ECM molecular composition in liver fibrosis progression, thus unveiling protein expression signatures specific for the HCV-related liver fibrotic stages. In particular, the ECM molecular composition of liver fibrosis was found to involve dynamic changes in matrix stiffness, flexibility and density related to the dysregulation of predominant collagen, elastic fibers and minor components with both structural and signaling properties. This study contributes to the understanding of the molecular bases underlying ECM remodeling in liver fibrosis and suggests new molecular targets for fibrolytic strategies.

Platelet-rich fibrin-mediated revitalization of immature necrotic tooth

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Navin Mishra

2013-01-01

Full Text Available Contemporary studies have shown that the regeneration of tissues and root elongation is possible in necrotic immature permanent teeth. The purpose of this case report is to add a new vista in regenerative endodontic therapy by using platelet rich fibrin for revitalization of immature non vital tooth. An 11year old boy with the history of trauma was diagnosed with the pulpal necrosis and symptomatic apical periodontitis in tooth #21. Intra oral periapical radiograph showed open apex and associated immature supernumerary tooth with respect to tooth #21. Access preparation and minimal instrumentation was done to remove necrotic debris under copious irrigation with 2.5% sodium hypochlorite. Triple antibiotic paste was packed in the canal for four weeks. During second visit, 5 mL of whole blood was drawn from the medial cubital vein of the patient and blood was then subjected to centrifugation at 2400 rpm for 12 minutes for the preparation of Platelet rich fibrin (PRF utilizing Choukroun′s method. Triple antibiotic paste was removed and canal was dried. PRF clot was pushed to the apical region of tooth #21 using hand pluggers. Three milimetres of Mineral trioxide (MTA was placed in cervical part of the root canal and permanent restoration was done three days later. Clinical examination at 6 and 12 months revealed no sensitivity to percussion and palpation in tooth #21and it responded positively to both electric pulp and cold tests. Radiographic examination showed resolution of periapical rarefaction, further root development and apical closure of the tooth #21 and its associated supernumerary tooth. On the basis of successful outcome of the present case it can be stated that PRF clot may serve as a scaffold for regeneration of necrotic immature teeth.

Use of photoactivated disinfection and platelet-rich fibrin in regenerative Endodontics

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Johns, Dexton Antony; Shivashankar, Vasundara Yayathi; Krishnamma, Shoba; Johns, Manu

2014-01-01

Aim: Photoactivated disinfection has been used as an adjunct to conventional endodontic treatment. Its use in regenerative endodontics is not reported in literature. The aim of this case report was to describe a new proposal for pulp revascularization with disinfection of pulp canal space using a unique combination of a photosensitizer solution and low-power laser light. Materials and Methods: A 9-year-old boy came with the chief complaint of discolored upper central incisors (#8, #9). A diagnosis of pulp necrosis was made on the basis of clinical and radiographic findings. The canal was irrigated with 5.25% sodium hypochlorite solution and dried with paper points. Photodynamic therapy was used to disinfect the root canal and platelet-rich fibrin was used to revitalize the pulp. Three millimeters of gray mineral trioxide aggregate was placed directly over the platelet-rich plasma clot. Three days later, the tooth was double-sealed with permanent filling materials. Results: Clinical examination revealed no sensitivity to percussion or palpation tests. Radiograph revealed continued thickening of the dentinal walls, root lengthening, regression of the peri-apical lesion and apical closure. Both the roots showed complete apical closure at the 10-month follow-up. However, the teeth were not responsive to electric pulp test. Conclusion: This report of pulp revascularization shows that disinfection with photodynamic therapy combined with platelet-rich fibrin leads to satisfactory root development in necrotic immature teeth. PMID:25298655

Measurement of human tissue-type plasminogen activator by a two-site immunoradiometric assay

International Nuclear Information System (INIS)

Rijken, D.C.; Juhan-Vague, I.; De Cock, F.; Collen, D.

1983-01-01

A two-site immunoradiometric assay for human extrinsic (tissue-type) plasminogen activator was developed by using rabbit antibodies raised against plasminogen activator purified from human melanoma cell culture fluid. Samples of 100 μl containing 1 to 100 ng/ml plasminogen activator were incubated in the wells of polyvinyl chloride microtiter plates coated with antibody. The amount of bound extrinsic plasminogen activator was quantitated by the subsequent binding of 125 I-labeled affinospecific antibody. The mean level of plasma samples taken at rest was 6.6 +/- 2.9 ng/ml (n = 54). This level increased approximately threefold by exhaustive physical exercise, venous occlusion, or infusion of DDAVP. Extrinsic plasminogen activator in plasma is composed of a fibrin-adsorbable and active component (1.9 +/- 1.1 ng/ml, n = 54, in resting conditions) and an inactive component that does not bind to a fibrin clot (probably extrinsic plasminogen activator-proteinase inhibitor complexes). The fibrin-adsorbable fraction increased approximately fivefold to eightfold after physical exercise, venous occlusion, or DDAVP injections. Potential applications of the immunoradiometric assay are illustrated by the measurement of extrinsic plasminogen activator in different tissue extracts, body fluids, and cell culture fluids and in oocyte translation products after injection with mRNA for plasminogen activator

Platelet-rich fibrin: a boon in regenerative endodontics.

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Rebentish, Priyanka D; Umashetty, Girish; Kaur, Harpreet; Doizode, Trupthi; Kaslekar, Mithun; Chowdhury, Shouvik

2016-12-01

Research into regenerative dentistry has contributed momentum to the field of molecular biology. Periapical surgery aims at removing periapical pathology to achieve complete wound healing and regeneration of bone and periodontal tissue. Regenerative endodontic procedures are widely being added to the current armamentarium of pulp therapy procedures. The regenerative potential of platelets has been deliberated. Platelet-rich fibrin (PRF) is a wonderful tissue-engineering product and has recently gained much popularity due its promising results in wound healing bone induction. The features of this product are an attribute of platelets which, after cellular interactions, release growth factors and have shown application in diverse disciplines of dentistry. This paper is intended to shed light onto the various prospects of PRF and to provide clinical insight into regenerative endodontic therapy.

Platelet-rich-fibrin: A novel root coverage approach

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Anilkumar K

2009-01-01

Full Text Available Treatment of gingival recession has become an important therapeutic issue due to increasing cosmetic demand. Multiple surgical procedures have been developed to obtain predictable esthetic root coverage. More specifically, after periodontal regenerative surgery, the aim is to achieve complete wound healing and regeneration of the periodontal unit. A recent innovation in dentistry is the preparation and use of platelet-rich plasma (PRP, a concentrated suspension of the growth factors, found in platelets. These growth factors are involved in wound healing and postulated as promoters of tissue regeneration. This paper reports the use of PRF membrane for root coverage on the labial surfaces of the mandibular anterior teeth. This was accomplished using laterally displaced flap technique with platelet rich fibrin (PRF membrane at the recipient site.

A collagen-fibrin patch for the prevention of symptomatic lymphoceles after pelvic lymphadenectomy in women with gynecologic malignancies: A randomized clinical trial.

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Grimm, Christoph; Polterauer, Stephan; Helmy-Bader, Samir; Zikan, Michal; Cibula, David; Heitz, Florian; Harter, Philipp; Giese, Arnd; Reinthaller, Alexander; Tempfer, Clemens

2018-04-01

To evaluate the efficacy of a collagen-fibrin patch for the prevention of symptomatic lymphoceles after pelvic lymphadenectomy in women with gynecologic malignancies. In a multicenter, randomized, clinical trial, 164 women with pelvic lymphadenectomy were allocated either to bilateral pelvic application of two collagen-fibrin patches or no intervention. Main outcome was efficacy, defined as reduction of symptomatic lymphocele rate diagnosed within four weeks after surgery. Secondary outcomes were asymptomatic lymphoceles and subsequent interventions. Sample size was based on the assumption that application of a collagen-fibrin patch reduces the prevalence of symptomatic lymphoceles by at least 66%. The study was single-blinded, i.e., patients and primary outcome assessors, but not surgeons, were blinded to the treatment allocation. A total of 75 women were randomized to the intervention and 89 to the control group. All women received the allocated intervention. In total, 42 (27.4%) lymphoceles and 8 (5.2%) symptomatic lymphoceles were observed. Symptomatic lymphoceles were observed in 5/68 (7.4%) women in the intervention group and 3/85 (3.5%) women in the control group (p = 0.47). Asymptomatic lymphoceles were observed in 16 (23.5%) women in the intervention group compared to 18 (21.2%) in the control group (p = 0.85). In a multivariate logistic regression model, no independent risk factor for the development of a symptomatic lymphocele was ascertained. Intraoperative application of collagen-fibrin patches to the pelvic side walls does not reduce the incidence of symptomatic lymphoceles in women with gynecologic malignancies undergoing pelvic lymphadenectomy. Copyright © 2018. Published by Elsevier Inc.

Platelet rich fibrin in jaw defects

Science.gov (United States)

Nica, Diana; Ianes, Emilia; Pricop, Marius

2016-03-01

Platelet rich fibrin (PRF) is a tissue product of autologous origin abundant in growth factors, widely used in regenerative procedures. Aim of the study: Evaluation of the regenerative effect of PRF added in the bony defects (after tooth removal or after cystectomy) Material and methods: The comparative nonrandomized study included 22 patients divided into 2 groups. The first group (the test group) included 10 patients where the bony defects were treated without any harvesting material. The second group included 12 patients where the bony defects were filled with PRF. The bony defect design was not critical, with one to two walls missing. After the surgeries, a close clinically monitoring was carried out. The selected cases were investigated using both cone beam computer tomography (CBCT) and radiographic techniques after 10 weeks postoperatively. Results: Faster bone regeneration was observed in the bony defects filled with PRF comparing with the not grafted bony defects. Conclusions: PRF added in the bony defects accelerates the bone regeneration. This simplifies the surgical procedures and decreases the economic costs.

Heparan sulfate proteoglycan from the extracellular matrix of human lung fibroblasts. Isolation, purification, and core protein characterization

International Nuclear Information System (INIS)

Heremans, A.; Cassiman, J.J.; Van den Berghe, H.; David, G.

1988-01-01

Confluent cultured human lung fibroblasts were labeled with 35SO4(2-). After 48 h of labeling, the pericellular matrix was prepared by Triton X-100 and deoxycholate extraction of the monolayers. Heparan sulfate proteoglycan (HSPG) accounted for nearly 80% of the total matrix [35S]proteoglycans. After solubilization in 6 M guanidinium HCl and cesium chloride density gradient centrifugation, the majority (78%) of these [35S] HSPG equilibrated at an average buoyant density of 1.35 g/ml. This major HSPG fraction was purified by ion-exchange chromatography on Mono Q and by gel filtration on Sepharose CL-4B, and further characterized by gel electrophoresis and immunoblotting. Intact [35S]HSPG eluted with Kav 0.1 from Sepharose CL-4B, whereas the protein-free [35S]heparan sulfate chains, obtained by alkaline borohydride treatment of the proteoglycan fractions, eluted with Kav 0.45 (Mr approximately 72,000). When analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography, core (protein) preparations, obtained by heparitinase digestion of 125I-labeled HSPG fractions, yielded one major labeled band with apparent molecular mass of approximately 300 kDa. Reduction with beta-mercaptoethanol slightly increased the apparent Mr of the labeled band, suggesting a single polypeptide structure and the presence of intrachain disulfide bonds. Immunoadsorption experiments and immunostaining of electrophoretically separated heparitinase-digested core proteins with monoclonal antibodies raised against matrix and cell surface-associated HSPG suggested that the major matrix-associated HSPG of cultured human lung fibroblasts is distinct from the HSPG that are anchored in the membranes of these cells. Binding studies suggested that this matrix HSPG interacts with several matrix components, both through its glycosaminoglycan chains and through its heparitinase-resistant core. (Abstract Truncated)

Synthesis of embryonic tendon-like tissue by human marrow stromal/mesenchymal stem cells requires a three-dimensional environment and transforming growth factor β3.

Science.gov (United States)

Kapacee, Zoher; Yeung, Ching-Yan Chloé; Lu, Yinhui; Crabtree, David; Holmes, David F; Kadler, Karl E

2010-10-01

Tendon-like tissue generated from stem cells in vitro has the potential to replace tendons and ligaments lost through injury and disease. However, thus far, no information has been available on the mechanism of tendon formation in vitro and how to accelerate the process. We show here that human mesenchymal stem cells (MSCs) and bone marrow-derived mononuclear cells (BM-MNCs) can generate tendon-like tissue in 7days mediated by transforming growth factor (TGF) β3. MSCs cultured in fixed-length fibrin gels spontaneously synthesized narrow-diameter collagen fibrils and exhibited fibripositors (actin-rich, collagen fibril-containing plasma membrane protrusions) identical to those that occur in embryonic tendon. In contrast, BM-MNCs did not synthesize tendon-like tissue under these conditions. We performed real-time PCR analysis of MSCs and BM-MNCs. MSCs upregulated genes encoding type I collagen, TGFβ3, and Smad2 at the time of maximum contraction of the tendon-like tissue (7days). Western blot analysis showed phosphorylation of Smad2 at maximum contraction. The TGFβ inhibitor SB-431542, blocked the phosphorylation of Smad2 and stopped the formation of tendon-like tissue. Quantitative PCR showed that BM-MNCs expressed very low levels of TGFβ3 compared to MSCs. Therefore we added exogenous TGFβ3 protein to BM-MNCs in fibrin gels, which resulted in phosphorylation of Smad2, synthesis of collagen fibrils, the appearance of fibripositors at the plasma membrane, and the formation of tendon-like tissue. In conclusion, MSCs that self-generate TGFβ signaling or the addition of TGFβ3 protein to BM-MNCs in fixed-length fibrin gels spontaneously make embryonic tendon-like tissue in vitro within 7days. Copyright © 2010 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.

Assembly of fibronectin into the extracellular matrix of early and late passage human skin fibroblasts

International Nuclear Information System (INIS)

Mann, D.M.

1987-01-01

The specific binding of soluble 125 I-human plasma fibronectin ( 125 I-HFN-P) to confluent cultures of early and late passage human skin fibroblasts was investigated. Previous studies HFN-P bound to fibroblast cell layers indicated that HNF-P was present in the cultures in two separate pools, distinguishable on the basis of their solubility in 1% deoxycholate. Examination of the kinetics of 125 I-HFN-P binding to Pool I of early and late passage cultures revealed that both cultures required 2-4 h to approach steady-state conditions. Other kinetic studies showed that the rates of low of 125 I-HFN-P from either Pool I or Pool II were similar for both cultures. Further, Scatchard analysis revealed a single class of Pool I binding sites with apparent dissociation constants (K/sub d/) of 5.3 x 10 -8 M (early passage) and 4.2 x 10 -8 M (late passage). These results indicate that early and late passage cultures of human fibroblasts exhibit differences in the number of cell surface biding sites for soluble fibronectin, and in the extent to which they incorporate soluble fibronectin into the extracellular matrix. Parameters which affect the fibronectin matrix assembly system of human skin fibroblasts were also examined. In addition, several monoclonal anti-fibronectin antibodies were characterized and developed as experimental probes for fibronectin structure and function

Extracellular matrix alterations in human corneas with bullous keratopathy

DEFF Research Database (Denmark)

Ljubimov, A V; Burgeson, R E; Butkowski, R J

1996-01-01

PURPOSE. To uncover abnormalities of extracellular matrix (ECM) distribution in human corneas with pseudophakic and aphakic bullous keratopathy (PBK/ABK). METHODS. Indirect immunofluorescence with antibodies to 27 ECM components was used on frozen sections of 14 normal and 20 PBK/ABK corneas...... in some cases, correlated with decreased visual acuity. In normal central corneas, tenascin was never found. Other major ECM abnormalities in PBK/ABK corneas compared to normals included: discontinuous epithelial BM straining for laminin-1 (alpha 1 beta 1 gamma 1), entactin/nidogen and fibronectin......; accumulation of fibronectin and alpha 1-alpha 2 type IV collagen on the endothelial face of the Descemet's membrane; and abnormal deposition of stromal ECM (tenascin, fibronectin, decorin, types I, III, V, VI, VIII, XII, XIV collagen) and BM components (type IV, collagen, perlecan, bamacan, laminin-1, entactin...

Uso de fibrinógeno humano en la generación de soportes para la obtención de equivalentes tisulares

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Dionisio Malagón

2011-07-01

Full Text Available Título en ingles: Use of human fibrinogen in the generation of scaffold for obtaining Tissue equivalents Resumen Desde sus orígenes, la Ingeniería de Tejidos ha buscado diversos materiales que puedan ser utilizados para la generación de soportes que sirvan para el anclaje, proliferación y diferenciación celular que conduzcan a la obtención de tejidos humanos. Muchos materiales de tipo cerámico, polimérico y metálico se han evaluado, pero hasta la fecha muchos de ellos han sido rechazados por diversas razones, entre otras su escasa biocompatibilidad y biodegradabilidad, la respuesta inmune generada, la baja resistencia mecánica o el riesgo de transmisión de virus o priones. El fibrinógeno es una proteína presente en el plasma sanguíneo que puede ser utilizada para la generación de soportes tridimensionales que favorezcan el crecimiento de células; se obtiene a partir del propio paciente, bancos de sangre o como proteína purificada (Tisseel® o Tissucol®, Laboratorios Baxter. El fibrinógeno evita el desencadenamiento de una respuesta inmunológica y el uso de productos xenogénicos. Debido a la estructura proteica, la adhesión y proliferación celular se ven favorecidas dando excelentes resultados en la generación de equivalentes de piel, cartílago, córnea y reemplazos cardiacos en aplicaciones in vitro e in vivo. Como desventajas presenta su rápida degradación y su baja resistencia mecánica; sin embargo, en los últimos años se han venido evaluando mezclas con algunos biopolímeros como ácido poliláctico (PLLA, ácido poli-glicólico (PGA y alginato de sodio. Esta revisión presenta algunas de las principales aplicaciones del fibrinógeno en Ingeniería de Tejidos. Palabras clave: fibrina, cultivos celulares, biomaterial, hidrogel, proteína. Abstract Since its origin, Tissue Engineering has sought various materials that can be used for generation of scaffolds that serve to anchor, proliferation and cell

Growth factor and proteinase profile of Vivostat® platelet-rich fibrin linked to tissue repair

DEFF Research Database (Denmark)

Ågren, Sven Per Magnus; Rasmussen, Karina; Pakkenberg, Bente

2014-01-01

. Leucocyte, erythrocyte and platelet counts in whole blood and fibrin-I were determined by automated haematology analyser. Platelet concentration in PRF was quantified manually by stereologic analysis of Giemsa-stained tissue sections, and the total content of five growth factors and MMP-9 by enzyme......·001]. MMP-9 was reduced 139-fold (P tissue regenerative applications....

The potential applications of fibrin-coated electrospun polylactide nanofibers in skin tissue engineering

Czech Academy of Sciences Publication Activity Database

Bačáková, Markéta; Musílková, Jana; Riedel, Tomáš; Stránská, D.; Brynda, Eduard; Žaloudková, Margit; Bačáková, Lucie

2016-01-01

Roč. 11, č. 2016 (2016), s. 771-789 E-ISSN 1178-2013 R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:67985823 ; RVO:61389013 ; RVO:67985891 Keywords : electrospun nanofibers * nanocoating * skin tissue engineering * fibroblasts * fibrin Subject RIV: EI - Biotechnology ; Bionics; CD - Macromolecular Chemistry (UMCH-V); JI - Composite Materials (USMH-B) Impact factor: 4.300, year: 2016

Platelet-rich fibrin: Evolution of a second-generation platelet concentrate

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Sunitha Raja V

2008-01-01

Full Text Available Platelet-rich plasma (PRP is a platelet concentrate that has been used widely to accelerate soft-tissue and hard-tissue healing. The preparation of PRP has been described by several authors. Platelet-rich fibrin (PRF was first described by Choukroun et al. in France. It has been referred to as a second-generation platelet concentrate, which has been shown to have several advantages over traditionally prepared PRP. Its chief advantages include ease of preparation and lack of biochemical handling of blood, which makes this preparation strictly autologous. This article describes the evolution of this novel platelet concentrate, referred to as PRF.

Peeping into human renal calcium oxalate stone matrix: characterization of novel proteins involved in the intricate mechanism of urolithiasis.

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Kanu Priya Aggarwal

Full Text Available BACKGROUND: The increasing number of patients suffering from urolithiasis represents one of the major challenges which nephrologists face worldwide today. For enhancing therapeutic outcomes of this disease, the pathogenic basis for the formation of renal stones is the need of hour. Proteins are found as major component in human renal stone matrix and are considered to have a potential role in crystal-membrane interaction, crystal growth and stone formation but their role in urolithiasis still remains obscure. METHODS: Proteins were isolated from the matrix of human CaOx containing kidney stones. Proteins having MW>3 kDa were subjected to anion exchange chromatography followed by molecular-sieve chromatography. The effect of these purified proteins was tested against CaOx nucleation and growth and on oxalate injured Madin-Darby Canine Kidney (MDCK renal epithelial cells for their activity. Proteins were identified by Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF MS followed by database search with MASCOT server. In silico molecular interaction studies with CaOx crystals were also investigated. RESULTS: Five proteins were identified from the matrix of calcium oxalate kidney stones by MALDI-TOF MS followed by database search with MASCOT server with the competence to control the stone formation process. Out of which two proteins were promoters, two were inhibitors and one protein had a dual activity of both inhibition and promotion towards CaOx nucleation and growth. Further molecular modelling calculations revealed the mode of interaction of these proteins with CaOx at the molecular level. CONCLUSIONS: We identified and characterized Ethanolamine-phosphate cytidylyltransferase, Ras GTPase-activating-like protein, UDP-glucose:glycoprotein glucosyltransferase 2, RIMS-binding protein 3A, Macrophage-capping protein as novel proteins from the matrix of human calcium oxalate stone which play a critical role in kidney stone

Extracellular Matrix-Mediated Maturation of Human Pluripotent Stem Cell-Derived Cardiac Monolayer Structure and Electrophysiological Function.

Science.gov (United States)

Herron, Todd J; Rocha, Andre Monteiro Da; Campbell, Katherine F; Ponce-Balbuena, Daniela; Willis, B Cicero; Guerrero-Serna, Guadalupe; Liu, Qinghua; Klos, Matt; Musa, Hassan; Zarzoso, Manuel; Bizy, Alexandra; Furness, Jamie; Anumonwo, Justus; Mironov, Sergey; Jalife, José

2016-04-01

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) monolayers generated to date display an immature embryonic-like functional and structural phenotype that limits their utility for research and cardiac regeneration. In particular, the electrophysiological function of hPSC-CM monolayers and bioengineered constructs used to date are characterized by slow electric impulse propagation velocity and immature action potential profiles. Here, we have identified an optimal extracellular matrix for significant electrophysiological and structural maturation of hPSC-CM monolayers. hPSC-CM plated in the optimal extracellular matrix combination have impulse propagation velocities ≈2× faster than previously reported (43.6±7.0 cm/s; n=9) and have mature cardiomyocyte action potential profiles, including hyperpolarized diastolic potential and rapid action potential upstroke velocity (146.5±17.7 V/s; n=5 monolayers). In addition, the optimal extracellular matrix promoted hypertrophic growth of cardiomyocytes and the expression of key mature sarcolemmal (SCN5A, Kir2.1, and connexin43) and myofilament markers (cardiac troponin I). The maturation process reported here relies on activation of integrin signaling pathways: neutralization of β1 integrin receptors via blocking antibodies and pharmacological blockade of focal adhesion kinase activation prevented structural maturation. Maturation of human stem cell-derived cardiomyocyte monolayers is achieved in a 1-week period by plating cardiomyocytes on PDMS (polydimethylsiloxane) coverslips rather than on conventional 2-dimensional cell culture formats, such as glass coverslips or plastic dishes. Activation of integrin signaling and focal adhesion kinase is essential for significant maturation of human cardiac monolayers. © 2016 American Heart Association, Inc.

Fibrin Glue Does Not Improve Healing of Gastrointestinal Anastomoses

DEFF Research Database (Denmark)

Nordentoft, Tyge; Pommergaard, Hans-Christian; Rosenberg, Jacob

2015-01-01

BACKGROUND/AIM: Anastomotic leakage remains a frequent and serious complication in gastrointestinal surgery. In order to reduce its incidence, several clinical and experimental studies on anastomotic sealing have been performed. In a number of these studies, the sealing material has been fibrin...... glue (FG), and the results in individual studies have been varying. The positive effect of anastomotic sealing with FG might be due to the mechanical/physical properties, the increased healing of the anastomoses or both. The aim of this systematic review was to evaluate the existing evidence....... It is consequently plausible that the positive effect of FG sealing of gastrointestinal anastomoses, if there is any, may be due to a mechanical sealing effect rather than due to improved healing per se....

Bulk physicochemical, interconnectivity, and mechanical properties of calcium phosphate cements-fibrin glue composites for bone substitute applications

NARCIS (Netherlands)

Lopez-Heredia, M.A.; Pattipeilohy, J.; Hsu, S.; Grykien, M.; Weijden, B. van der; Leeuwenburgh, S.C.G.; Salmon, P.; Wolke, J.G.C.; Jansen, J.A.

2013-01-01

Calcium phosphate cements (CPCs) and fibrin glue (FG) are used for surgical applications. Their combination is promising to create bone substitutes able to promote cell attachment and bone remodeling. This study proposes a novel approach to create CPC-FG composites by simultaneous CPC setting and FG

Dermatopontin interacts with fibronectin, promotes fibronectin fibril formation, and enhances cell adhesion.

Science.gov (United States)

Kato, Aiko; Okamoto, Osamu; Ishikawa, Kazushi; Sumiyoshi, Hideaki; Matsuo, Noritaka; Yoshioka, Hidekatsu; Nomizu, Motoyoshi; Shimada, Tatsuo; Fujiwara, Sakuhei

2011-04-29

We report that dermatopontin (DP), an abundant dermal extracellular matrix protein, is found in the fibrin clot and in the wound fluid, which comprise the provisional matrix at the initial stage of wound healing. DP was also found in the serum but at a lower concentration than that in wound fluid. DP co-localized with both fibrin and fibronectin on fibrin fibers and interacted with both proteins. Both normal fibroblast and HT1080 cell adhesion to the fibrin-fibronectin matrix were dose-dependently enhanced by DP, and the adhesion was mediated by α5β1 integrin. The cytoskeleton was more organized in the cells that adhered to the fibrin-fibronectin-DP complex. When incubated with DP, fibronectin formed an insoluble complex of fibronectin fibrils as visualized by electron microscopy. The interacting sites of fibronectin with DP were the first, thirteenth, and fourteenth type III repeats (III(1), III(13), and III(14)), with III(13) and III(14) assumed to be the major sites. The interaction between III(2-3) and III(12-14) was inhibited by DP, whereas the interaction between I(1-5) and III(12-14) was specifically and strongly enhanced by DP. Because the interaction between III(2-3) and III(12-14) is involved in forming a globular conformation of fibronectin, and that between I(1-5) and III(12-14) is required for forming fibronectin fibrils, DP promotes fibronectin fibril formation probably by changing the fibronectin conformation. These results suggest that DP has an accelerating role in fibroblast cell adhesion to the provisional matrix in the initial stage of wound healing.

Platelet rich fibrin combined with decalcified freeze-dried bone allograft for the treatment of human intrabony periodontal defects: a randomized split mouth clinical trail.

Science.gov (United States)

Agarwal, Ashish; Gupta, Narinder Dev; Jain, Avikal

2016-01-01

Polypeptide growth factors of platelet rich fibrin (PRF) have the potential to regenerate periodontal tissues. Osteoinductive property of demineralized freeze-dried bone allograft (DFDBA) has been successfully utilized in periodontal regeneration. The aim of the present randomized, split mouth, clinical trial was to determine the additive effects of PRF with a DFDBA in the treatment of human intrabony periodontal defects. Sixty interproximal infrabony defects in 30 healthy, non-smoker patients diagnosed with chronic periodontitis were randomly assigned to PRF/DFDBA group or the DFDBA/saline. Clinical [pocket depth (PD), clinical attachment level (CAL) and gingival recession (REC)] and radiographic (bone fill, defect resolution and alveolar crest resorption) measurements were made at baseline and at a 12-month evaluation. Compared with baseline, 12-month results indicated that both treatment modalities resulted in significant changes in all clinical and radiographic parameters. However, the PRP/DFDBA group exhibited statistically significantly greater changes compared with the DFDBA/saline group in PD (4.15 ± 0.84 vs 3.60 ± 0.51 mm), CAL (3.73 ± 0.74 vs 2.61 ± 0.68 mm), REC (0.47 ± 0.56 vs 1.00 ± 0.61 mm), bone fill (3.50 ± 0.67 vs 2.49 ± 0.64 mm) and defect resolution (3.73 ± 0.63 vs 2.75 ± 0.57 mm). Observations indicate that a combination of PRF and DFDBA is more effective than DFDBA with saline for the treatment of infrabony periodontal defects.

Analysing uncertainty around costs of innovative medical technologies: the case of fibrin sealant (QUIXIL) for total knee replacement.

NARCIS (Netherlands)

Steuten, Lotte Maria Gertruda; Vallejo-Torres, Laura; Bastide, Philippe; Buxton, Martin J.

2009-01-01

This paper presents a relatively simple cost model comparing the costs of using a commercial fibrin sealant (QUIXIL®) in addition to conventional haemostatic treatment vs. conventional treatment alone in total knee replacement (TKR) surgery, and demonstrates and discusses how one- and two-way

Antimicrobial properties of single-donor-derived, platelet-leukocyte fibrin for fistula occlusion: An in vitro study.

Science.gov (United States)

Wu, Xiuwen; Ren, Jianan; Yuan, Yujie; Luan, Jianfeng; Yao, Genhong; Li, Jieshou

2013-01-01

Fibrin glue is a promising alternative for low-output enterocutaneous fistula closure. Bacterial flora colonizing inside the fistula tract, however, may limit the glue application. Single-donor-derived, platelet-rich materials were hypothesized in this study to have antimicrobial activity against Gram-negative microorganisms. Platelet-leukocyte fibrin (PLF), platelet-rich plasma (PRP), and platelet-poor plasma (PPP) were obtained from healthy volunteers. The amounts of platelet, leukocyte, and complement/antibody were determined. In vitro laboratory susceptibility to PLF and plasmas was determined by the Kirby-Bauer disc-diffusion method. Antimicrobial activity of PLF, PRP, and PPP against three Gram-negative ATCC strains was determined in a bacterial kill assay. Levels of complement and antibody did not significantly differ among PLF, PRP, and PPP (p > 0.05), while platelet and leukocyte counts in platelet-rich biomaterials were significantly higher than those in PPP (p platelets and leukocytes may play an important role in bacterial defense. This is the first study to demonstrate the antibacterial properties of single-unit PLF for fistula closure, presenting a new opportunity for glue sealing.

Percutaneous sclerotherapy of massive macrocystic lymphatic malformations of the face and neck using fibrin glue with OK-432 and bleomycin.

Science.gov (United States)

Chen, W-l; Huang, Z-q; Chai, Q; Zhang, D-m; Wang, Y-y; Wang, H-j; Wang, L; Fan, S

2011-06-01

Picibanil (OK-432) and bleomycin have been used as alternative sclerosing agents for lymphatic malformations. This study evaluated the clinical curative effect of sclerotherapy using fibrin glue combined with OK-432 and bleomycin for the treatment of macrocystic lymphatic malformations of the face and neck. Fifteen paediatric patients (6 males; 9 females, aged 13 months to 14 years) who had received percutaneous sclerotherapy for massive macrocystic lymphatic malformations of the face and neck were retrospectively reviewed. Affected regions included the neck, parotid region and parapharynx, mouth floor, face and cheek, and orbital regions. All patients showed preoperative symptoms of space-occupying lesions between 4 cm × 5 cm and 12 cm × 16 cm in size. Fibrin glue with OK-432 and bleomycin was injected under general anaesthesia. All patients received preoperative and follow-up CT scans. Outcomes were assessed by three surgeons. All patients exhibited mid-facial swelling for 3-4 weeks after surgery, but no major complications. Follow-up periods ranged from 8 to 16 months. Eight lesions were completely involuted, five were mostly involuted, and two were partially involuted. Percutaneous sclerotherapy using fibrin glue with OK-432 and bleomycin provided a simple, safe, and reliable alternative treatment for massive macrocystic lymphatic malformations of the face and neck. Copyright © 2011 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Grooved surface topography alters matrix-metalloproteinase production by human fibroblasts

Energy Technology Data Exchange (ETDEWEB)

Brydone, Alistair S; Dominic Meek, R M [Department of Orthopaedics, Southern General Hospital, 1345 Govan Road, Glasgow G51 4TF (United Kingdom); Dalby, Matthew J; Berry, Catherine C; McNamara, Laura E, E-mail: alibrydone@gmail.com [Centre for Cell Engineering, Joseph Black Building, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

2011-06-15

Extracellular matrix (ECM) remodelling is an essential physiological process in which matrix-metalloproteinases (MMPs) have a key role. Manipulating the manner in which cells produce MMPs and ECMs may enable the creation of a desired tissue type, i.e. effect repair, or the prevention of tissue invasion (e.g. metastasis). The aim of this project was to determine if culturing fibroblasts on grooved topography altered collagen deposition or MMP production. Human fibroblasts were seeded on planar or grooved polycaprolactone substrates (grooves were 12.5 {mu}m wide with varying depths of 240 nm, 540 nm or 2300 nm). Cell behaviour and collagen production were studied using fluorescence microscopy and the spent culture medium was assessed using gel zymography to detect MMPs. Total collagen deposition was high on the 240 nm deep grooves, but decreased as the groove depth increased, i.e. as cell contact guidance decreased. There was an increase in gelatinase on the 2300 nm deep grooved topography and there was a difference in the temporal expression of MMP-3 observed on the planar surface compared to the 540 nm and 2300 nm topographies. These results show that topography can alter collagen and MMP production. A fuller understanding of these processes may permit the design of surfaces tailored to tissue regeneration e.g. tendon repair.

Grooved surface topography alters matrix-metalloproteinase production by human fibroblasts

International Nuclear Information System (INIS)

Brydone, Alistair S; Dominic Meek, R M; Dalby, Matthew J; Berry, Catherine C; McNamara, Laura E

2011-01-01

Extracellular matrix (ECM) remodelling is an essential physiological process in which matrix-metalloproteinases (MMPs) have a key role. Manipulating the manner in which cells produce MMPs and ECMs may enable the creation of a desired tissue type, i.e. effect repair, or the prevention of tissue invasion (e.g. metastasis). The aim of this project was to determine if culturing fibroblasts on grooved topography altered collagen deposition or MMP production. Human fibroblasts were seeded on planar or grooved polycaprolactone substrates (grooves were 12.5 μm wide with varying depths of 240 nm, 540 nm or 2300 nm). Cell behaviour and collagen production were studied using fluorescence microscopy and the spent culture medium was assessed using gel zymography to detect MMPs. Total collagen deposition was high on the 240 nm deep grooves, but decreased as the groove depth increased, i.e. as cell contact guidance decreased. There was an increase in gelatinase on the 2300 nm deep grooved topography and there was a difference in the temporal expression of MMP-3 observed on the planar surface compared to the 540 nm and 2300 nm topographies. These results show that topography can alter collagen and MMP production. A fuller understanding of these processes may permit the design of surfaces tailored to tissue regeneration e.g. tendon repair.

Use of platelet rich fibrin in a fenestration defect around an implant

Directory of Open Access Journals (Sweden)

R Vijayalakshmi

2012-01-01

Full Text Available Guided bone regeneration (GBR in implant therapy is especially useful for implant placement with dehiscence defects or fenestration defects. In alveolar ridges with marked facial/buccal depressions or in knifeedge alveolar crests, the position and direction of fixture placement is restricted. Improvement of alveolar ridge morphology becomes possible with GBR. This article describes a case in which the fenestration defect around an implant was treated by the application of platelet rich fibrin, a second generation platelet concentrate along with bone graft, and guided tissue regeneration membrane.

Knockdown of asporin affects transforming growth factor-β1-induced matrix synthesis in human intervertebral annulus cells

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Xu Jiang

2016-10-01

Conclusion: Our results have verified a functional feedback loop between TGF-β1 and asporin in human intervertebral annulus cells indicating that TGF-β1-induced annulus matrix biosynthesis can be significantly upregulated by knockdown of asporin. Therefore, asporin could be a potential new therapeutic target and inhibition of asporin could be adopted to enhance the anabolic effect of TGF-β1 in human intervertebral annulus cells in degenerative IVD diseases.

Proliferation and extracellular matrix synthesis of smooth muscle cells cultured from human coronary atherosclerotic and restenotic lesions

NARCIS (Netherlands)

D.C. MacLeod (Donald); B.H. Strauss (Bradley); J. Escaned (Javier); V.A.W.M. Umans (Victor); R-J. van Suylen (Robert-Jan); A. Verkerk (Anton); P.J. de Feyter (Pim); P.W.J.C. Serruys (Patrick); M. de Jong (Marcel)

1994-01-01

textabstractOBJECTIVES. The purpose of this study was to examine the proliferative capacity and extracellular matrix synthesis of human coronary plaque cells in vitro. BACKGROUND. Common to both primary atherosclerosis and restenosis are vascular smooth muscle cell proliferation and production of

Evaluation of Fibrin Sealants and Tissue Adhesives in Oral Surgery for Patients with Bleeding Disorders

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Gülsüm Ak

2012-03-01

Full Text Available OBJECTIVE: The aim of this study was to evaluate the efficiency of two local haemostatic agents administered together with preoperative dose of replacement therapy for oral surgical procedures in patients with bleeding disorders METHODS: Twenty-one patients were divided into three groups randomly. Patients in Group 1 (n=7 received preoperative replacement therapy with postoperative fibrin sealant application in the surgical site. Patients in Group 2 (n=7 received preoperative replacement therapy with postoperative tissue adhesive application in the surgical site. Patients in Group 3 (n=7 were given total dose of replacement therapy pre- and postoperatively. RESULTS: No postoperative bleeding was observed in 17 patients including five patients in Group 1 (71.42%, six patients in Group 2 (85.71% and six patients in Group 3 (85.71%. Haemorrhagic complication was observed in only four patients among all groups. CONCLUSION: We conclude that utilization of fibrin sealants and tissue adhesives in oral surgery is beneficial due to the lessened amount of factor concentrates used for replacement therapy and the rapid haemostasis at the operation side to perform serial surgical procedures in the same session.

Human 2'-phosphodiesterase localizes to the mitochondrial matrix with a putative function in mitochondrial RNA turnover

DEFF Research Database (Denmark)

Poulsen, Jesper Buchhave; Andersen, Kasper Røjkjær; Kjær, Karina Hansen

2011-01-01

. Interestingly, 2′-PDE shares both functionally and structurally characteristics with the CCR4-type exonuclease–endonuclease–phosphatase family of deadenylases. Here we show that 2′-PDE locates to the mitochondrial matrix of human cells, and comprise an active 3′–5′ exoribonuclease exhibiting a preference...

Matrix Metalloproteinase Enzyme Family

Directory of Open Access Journals (Sweden)

Ozlem Goruroglu Ozturk

2013-04-01

Full Text Available Matrix metalloproteinases play an important role in many biological processes such as embriogenesis, tissue remodeling, wound healing, and angiogenesis, and in some pathological conditions such as atherosclerosis, arthritis and cancer. Currently, 24 genes have been identified in humans that encode different groups of matrix metalloproteinase enzymes. This review discuss the members of the matrix metalloproteinase family and their substrate specificity, structure, function and the regulation of their enzyme activity by tissue inhibitors. [Archives Medical Review Journal 2013; 22(2.000: 209-220

Mesenchymal stromal cells improve human islet function through released products and extracellular matrix.

Science.gov (United States)

Arzouni, Ahmed A; Vargas-Seymour, Andreia; Rackham, Chloe L; Dhadda, Paramjeet; Huang, Guo-Cai; Choudhary, Pratik; Nardi, Nance; King, Aileen J F; Jones, Peter M

2017-12-01

The aims of the present study were (i) to determine whether the reported beneficial effects of mesenchymal stromal cells (MSCs) on mouse islet function extend to clinically relevant human tissues (islets and MSCs), enabling translation into improved protocols for clinical human islet transplantation; and (ii) to identify possible mechanisms through which human MSCs influence human islet function. Human islets were co-cultured with human adipose tissue-derived MSCs (hASCs) or pre-treated with its products - extracellular matrix (ECM) and annexin A1 (ANXA1). Mouse islets were pre-treated with mouse MSC-derived ECM. Islet insulin secretory function was assessed in vitro by radioimmunoassay. Quantitative RT-PCR was used to screen human adipMSCs for potential ligands of human islet G-protein-coupled receptors. We show that co-culture with hASCs improves human islet secretory function in vitro , as measured by glucose-stimulated insulin secretion, confirming previous reports using rodent tissues. Furthermore, we demonstrate that these beneficial effects on islet function can be partly attributed to the MSC-derived products ECM and ANXA1. Our results suggest that hASCs have the potential to improve the quality of human islets isolated for transplantation therapy of Type 1 diabetes. Furthermore, it may be possible to achieve improvements in human islet quality in a cell-free culture system by using the MSC-derived products ANXA1 and ECM. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Culture temperature affects redifferentiation and cartilaginous extracellular matrix formation in dedifferentiated human chondrocytes.

Science.gov (United States)

Ito, Akira; Aoyama, Tomoki; Iijima, Hirotaka; Tajino, Junichi; Nagai, Momoko; Yamaguchi, Shoki; Zhang, Xiangkai; Kuroki, Hiroshi

2015-05-01

To date, there have been few studies on how temperature affects the phenotype and metabolism of human chondrocytes. Thus, the purpose of this study was to elucidate the effects of culture temperature on chondrocyte redifferentiation and extracellular matrix (ECM) formation using dedifferentiated mature human chondrocytes in vitro. Dedifferentiated chondrocytes were cultured in a pellet culture system for up to 21 days. The pellets were randomly divided into three groups with different culture temperature (32, 37, and 41°C). Chondrocyte redifferentiation and ECM formation were evaluated by wet weight, messenger ribonucleic acid (mRNA), histological, and biochemical analyses. The results showed that the wet weight and the mRNA expressions of collagen type II A1 and cartilage oligomeric matrix protein at 37°C were higher than the corresponding values at 32°C. The histological and biochemical analyses revealed that the syntheses of type II collagen and proteoglycan were promoted at 37°C compared to those at 32°C, whereas they were considerably inhibited at 41°C. In conclusion, the results obtained herein indicated that temperature affects chondrocyte redifferentiation and ECM formation, and modulation of temperature might thus represent an advantageous means to regulate the phenotype and biosynthetic activity of chondrocytes. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Demineralized bone matrix and human cancellous bone enhance fixation of titanium implants

DEFF Research Database (Denmark)

Babiker, Hassan; Ding, Ming; Overgaard, Søren

Best Poster 5Demineralized bone matrix and human cancellous bone enhance fixation of titanium implants AuthorsBabiker , H.; Ding M.; Overgaard S.InstitutionOrthopaedic Research Laboratory, Department of Orthopaedic Surgery, Odense University Hospital, Clinical Institute, University of Southern...... from human tissue were included (IsoTis OrthoBiologics, Inc. USA). Both materials are commercially available. Titanium alloy implants (Biomet Inc.) of 10 mm in length and 10 mm in diameter were inserted bilaterally into the femoral condyles of 8 skeletally mature sheep. Thus four implants...... with a concentric gap of 2 mm were implanted in each sheep. The gap was filled with: DBM; DBM/CB with ratio of 1/3; DBM/allograft with ratio of 1/3; or allograft (Gold standard), respectively. Standardised surgical procedure was used1. At sacrifice, 6 weeks after surgery, both distal femurs were harvested...

Deposition of fibrinogen on the surface of in vitro thrombi prevents platelet adhesion.

Science.gov (United States)

Owaynat, Hadil; Yermolenko, Ivan S; Turaga, Ramya; Lishko, Valeryi K; Sheller, Michael R; Ugarova, Tatiana P

2015-12-01

The initial accumulation of platelets after vessel injury is followed by thrombin-mediated generation of fibrin which is deposited around the plug. While numerous in vitro studies have shown that fibrin is highly adhesive for platelets, the surface of experimental thrombi in vivo contains very few platelets suggesting the existence of natural anti-adhesive mechanisms protecting stabilized thrombi from platelet accumulation and continuous thrombus propagation. We previously showed that adsorption of fibrinogen on pure fibrin clots results in the formation of a nonadhesive matrix, highlighting a possible role of this process in surface-mediated control of thrombus growth. However, the deposition of fibrinogen on the surface of blood clots has not been examined. In this study, we investigated the presence of intact fibrinogen on the surface of fibrin-rich thrombi generated from flowing blood and determined whether deposited fibrinogen is nonadhesive for platelets. Stabilized fibrin-rich thrombi were generated using a flow chamber and the time that platelets spend on the surface of thrombi was determined by video recording. The presence of fibrinogen and fibrin on the surface of thrombi was analyzed by confocal microscopy using specific antibodies. Examination of the spatial distribution of two proteins revealed the presence of intact fibrinogen on the surface of stabilized thrombi. By manipulating the surface of thrombi to display either fibrin or intact fibrinogen, we found that platelets adhere to fibrin- but not to fibrinogen-coated thrombi. These results indicate that the fibrinogen matrix assembled on the outer layer of stabilized in vitro thrombi protects them from platelet adhesion. Copyright © 2015 Elsevier Ltd. All rights reserved.

Survival of Lactobacillus rhamnosus strains inoculated in cheese matrix during simulated human digestion.

Science.gov (United States)

Pitino, Iole; Randazzo, Cinzia L; Cross, Kathryn L; Parker, Mary L; Bisignano, Carlo; Wickham, Martin S J; Mandalari, Giuseppina; Caggia, Cinzia

2012-08-01

Survival of probiotic bacteria during transit through the gastrointestinal (GI) tract is influenced by a number of environmental variables including stomach acidity, bile salts, digestive enzymes and food matrix. This study assessed survival of seven selected Lactobacillus rhamnosus strains delivered within a model cheese system to the human upper GI tract using a dynamic gastric model (DGM). Good survival rates for all tested strains were recorded during both simulated gastric and duodenal digestion. Strains H12, H25 and N24 demonstrated higher survival capacities during gastric digestion than L. rhamnosus GG strain used as control, with H12 and N24 continuing to grow during duodenal digestion. Strains L. rhamnosus F17, N24 and R61 showed adhesion properties to both HT-29 and Caco-2 cells. The ability to attach to the cheese matrix during digestion was confirmed by scanning electron microscopy, also indicating production of extracellular polysaccharides as a response to acid stress. Copyright © 2012 Elsevier Ltd. All rights reserved.

Food Matrix Effects of Polyphenol Bioaccessibility from Almond Skin during Simulated Human Digestion

Science.gov (United States)

Mandalari, Giuseppina; Vardakou, Maria; Faulks, Richard; Bisignano, Carlo; Martorana, Maria; Smeriglio, Antonella; Trombetta, Domenico

2016-01-01

The goal of the present study was to quantify the rate and extent of polyphenols released in the gastrointestinal tract (GIT) from natural (NS) and blanched (BS) almond skins. A dynamic gastric model of digestion which provides a realistic simulation of the human stomach was used. In order to establish the effect of a food matrix on polyphenols bioaccessibility, NS and BS were either digested in water (WT) or incorporated into home-made biscuits (HB), crisp-bread (CB) and full-fat milk (FM). Phenolic acids were the most bioaccessible class (68.5% release from NS and 64.7% from BS). WT increased the release of flavan-3-ols (p digestion, whereas CB and HB were better vehicles for BS. FM lowered the % recovery of polyphenols, the free total phenols and the antioxidant status in the digestion medium, indicating that phenolic compounds could bind protein present in the food matrix. The release of bioactives from almond skins could explain the beneficial effects associated with almond consumption. PMID:27649239

Thrombus imaging with indium-111 and iodine-131-labeled fibrin-specific monoclonal antibody and its F(ab')2 and Fab fragments

International Nuclear Information System (INIS)

Rosebrough, S.F.; Grossman, Z.D.; McAfee, J.G.

1988-01-01

We have previously reported successful imaging of fresh (2-4 hr old) and aged (1-5 days old) canine thrombi with 131 I-labeled intact monoclonal antibody (MAb) specific for fibrin. We now report thrombus imaging with 131 I-labeled F(ab')2 and Fab and 111 In-labeled intact MAb, F(ab')2, and Fab. Indium-111-labeled F(ab')2 proved to be the best imaging agent due to less nonspecific binding in the liver than whole IgG. Image quality was improved by the higher administered dose permissible with 111 In and its better physical characteristics for imaging, compared to 131 I. Immunofluorescence of fresh human histologic sections showed intact MAb and F(ab')2 binding to thrombi, pulmonary emboli, and atherosclerotic plaques, strengthening the feasibility of clinical thrombus imaging

Comparison of four decontamination treatments on porcine renal decellularized extracellular matrix structure, composition, and support of human renal cortical tubular epithelium cells.

Science.gov (United States)

Poornejad, Nafiseh; Nielsen, Jeffery J; Morris, Ryan J; Gassman, Jason R; Reynolds, Paul R; Roeder, Beverly L; Cook, Alonzo D

2016-03-01

Engineering whole organs from porcine decellularized extracellular matrix and human cells may lead to a plentiful source of implantable organs. Decontaminating the porcine decellularized extracellular matrix scaffolds is an essential step prior to introducing human cells. However, decontamination of whole porcine kidneys is a major challenge because the decontamination agent or irradiation needs to diffuse deep into the structure to eliminate all microbial contamination while minimizing damage to the structure and composition of the decellularized extracellular matrix. In this study, we compared four decontamination treatments that could be applicable to whole porcine kidneys: 70% ethanol, 0.2% peracetic acid in 1 M NaCl, 0.2% peracetic acid in 4% ethanol, and gamma (γ)-irradiation. Porcine kidneys were decellularized by perfusion of 0.5% (w/v) aqueous solution of sodium dodecyl sulfate and the four decontamination treatments were optimized using segments (n = 60) of renal tissue to ensure a consistent comparison. Although all four methods were successful in decontamination, γ-irradiation was very damaging to collagen fibers and glycosaminoglycans, leading to less proliferation of human renal cortical tubular epithelium cells within the porcine decellularized extracellular matrix. The effectiveness of the other three optimized solution treatments were then all confirmed using whole decellularized porcine kidneys (n = 3). An aqueous solution of 0.2% peracetic acid in 1 M NaCl was determined to be the best method for decontamination of porcine decellularized extracellular matrix. © The Author(s) 2015.

Umbilical cord stem cells released from alginate-fibrin microbeads inside macroporous and biofunctionalized calcium phosphate cement for bone regeneration

Science.gov (United States)

Chen, Wenchuan; Zhou, Hongzhi; Weir, Michael D.; Bao, Chongyun; Xu, Hockin H.K.

2012-01-01

The need for bone repair has increased as the population ages. The objectives of this study were to (1) develop a novel biofunctionalized and macroporous calcium phosphate cement (CPC) containing alginate-fibrin microbeads encapsulating human umbilical cord mesenchymal stem cells (hUCMSCs); and (2) investigate hUCMSC proliferation and osteogenic differentiation inside CPC for the first time. Macroporous CPC was developed using calcium phosphate powders, chitosan, and gas-foaming porogen. Five types of CPCs were fabricated: CPC control, CPC + 0.05% fibronectin (Fn), CPC + 0.1% Fn, CPC + 0.1% Arg-Gly-Asp (RGD), and CPC + 0.1% Fn + 0.1% RGD. Alginate-fibrin microbeads containing 106 hUCMSCs/mL were encapsulated in the CPC paste. After CPC had set, the degradable microbeads released hUCMSCs inside CPC. hUCMScs proliferated inside CPC, with cell density at 21 d being 4-fold that at 1 d. CPC + 0.1% RGD had the highest cell density, which was 4-fold that of CPC control. The released cells differentiated into the osteogenic lineage and synthesized bone minerals. hUCMSCs inside the CPC + 0.1% RGD construct had gene expressions of alkaline phosphatase (ALP), osteocalcin (OC) and collagen I, which were twice those of CPC control. Mineral synthesis by hUCMSCs inside the CPC + 0.1% RGD construct was 2-fold that in CPC control. RGD and Fn incorporation in CPC did not compromise the strength of CPC, which matched the reported strength of cancellous bone. In conclusion, degradable microbeads released the hUCMSCs which proliferated, differentiated and synthesized minerals inside the macroporous CPC for the first time. CPC with RGD greatly enhanced cell functions. The novel biofunctionalized and macroporous CPC-microbead-hUCMSC construct is promising for bone tissue engineering applications. PMID:22391411

Binding of matrix metalloproteinase inhibitors to extracellular matrix: 3D-QSAR analysis.

Science.gov (United States)

Zhang, Yufen; Lukacova, Viera; Bartus, Vladimir; Nie, Xiaoping; Sun, Guorong; Manivannan, Ethirajan; Ghorpade, Sandeep R; Jin, Xiaomin; Manyem, Shankar; Sibi, Mukund P; Cook, Gregory R; Balaz, Stefan

2008-10-01

Binding to the extracellular matrix, one of the most abundant human protein complexes, significantly affects drug disposition. Specifically, the interactions with extracellular matrix determine the free concentrations of small molecules acting in tissues, including signaling peptides, inhibitors of tissue remodeling enzymes such as matrix metalloproteinases, and other drug candidates. The nature of extracellular matrix binding was elucidated for 63 matrix metalloproteinase inhibitors, for which the association constants to an extracellular matrix mimic were reported here. The data did not correlate with lipophilicity as a common determinant of structure-nonspecific, orientation-averaged binding. A hypothetical structure of the binding site of the solidified extracellular matrix surrogate was analyzed using the Comparative Molecular Field Analysis, which needed to be applied in our multi-mode variant. This fact indicates that the compounds bind to extracellular matrix in multiple modes, which cannot be considered as completely orientation-averaged and exhibit structural dependence. The novel comparative molecular field analysis models, exhibiting satisfactory descriptive and predictive abilities, are suitable for prediction of the extracellular matrix binding for the untested chemicals, which are within applicability domains. The results contribute to a better prediction of the pharmacokinetic parameters such as the distribution volume and the tissue-blood partition coefficients, in addition to a more imminent benefit for the development of more effective matrix metalloproteinase inhibitors.

Effect of fibrin-binding synthetic oligopeptide on the healing of full-thickness skin wounds in streptozotocin-induced diabetic rats.

Science.gov (United States)

Chung, Jae-Eun; Kim, Yun-Jeong; Park, Yoon-Jeong; Koo, Ki-Tae; Seol, Yang-Jo; Lee, Yong-Moo; Rhyu, In-Chul; Ku, Young

2013-01-01

The aim of this study was to investigate whether topical application of fibrin-binding oligopeptides derived from FN promotes wound healing in streptozotocin (STZ)-induced diabetic rats. Oligopeptides including fibrin-binding sequences (FF3: CFDKYTGNTYRV, FF5 : CTSRNRCNDQ) of FN repeats were synthesized. Each peptide was loaded in 15 x 15 mm fibrous alginate dressings, and the release kinetics of the peptides was evaluated using trinitrobenzene sulfonic acid for 336 hours. Two full-thickness cutaneous wounds were prepared on the dorsal skin of each 75 diabetes induced rats. Each wound was divided into FF3-loaded alginate dressing group, FF5-loaded alginate dressing group, alginate dressing group and negative control group. Animals were sacrificed at day 0,3,7 and 14. The wound closure rate, inflammation degree, expression of TGF-β1 and hydroxyproline contents were evaluated. Both FF3 and FF5 peptides were released rapidly within the first 24 hours. FF3-loaded dressing treated wounds closed significantly faster than other wounds at day 3. And at day 14, FF3- & FF5- loaded dressing treated wounds demonstrated less inflammatory cells infiltration than alginate dressing treated and negative group wounds. TGF-β1 positive cells were more abundant in FF3-, FF5-treated alginate dressing treated wound at day 3 and 14. At last, the hyrdroxyproline contents in the FF3, FF5 group were higher at day 7 and day 14. Topical application of fibrin-binding domain synthetic oligopeptides from FN resulted in acceleration of full-thickness cutaneous wound healing in diabetic rats.

Laparoendoscopic single-site myomectomy and the use of fibrin sealant (Tisseel

Directory of Open Access Journals (Sweden)

Angelito Magno

2015-11-01

ensured after the suturing. A fibrin sealant, Tisseel (Baxter Healthcare Corp., Deerfield, IL, is applied over the suture site as an adjunct to hemostasis and also to prevent adhesion. The fundamental advantage of LESS is less incision, as a result, improves cosmesis. LESS myomectomy has many technical difficulties, including reduced visualization, loss of triangulation, and instrument interference. Thus, the type, location and numbers of the myomas are critical to succeed LESS myomectomy. The Food and Drug Administration has approved fibrin sealant in 1998 as an adjunct to hemostasis and sealing. Besides, certain studies have reported its anti-adhesion property. Upon mixing of the two components in the lumens of Tisseel, the combinations of thrombin and fibrinogen transformed into fibrin, forming a rubber-like tissue that adheres to the wound surface.

Mycolactone-Dependent Depletion of Endothelial Cell Thrombomodulin Is Strongly Associated with Fibrin Deposition in Buruli Ulcer Lesions.

Directory of Open Access Journals (Sweden)

Joy Ogbechi

2015-07-01

Full Text Available A well-known histopathological feature of diseased skin in Buruli ulcer (BU is coagulative necrosis caused by the Mycobacterium ulcerans macrolide exotoxin mycolactone. Since the underlying mechanism is not known, we have investigated the effect of mycolactone on endothelial cells, focussing on the expression of surface anticoagulant molecules involved in the protein C anticoagulant pathway. Congenital deficiencies in this natural anticoagulant pathway are known to induce thrombotic complications such as purpura fulimans and spontaneous necrosis. Mycolactone profoundly decreased thrombomodulin (TM expression on the surface of human dermal microvascular endothelial cells (HDMVEC at doses as low as 2 ng/ml and as early as 8 hrs after exposure. TM activates protein C by altering thrombin's substrate specificity, and exposure of HDMVEC to mycolactone for 24 hours resulted in an almost complete loss of the cells' ability to produce activated protein C. Loss of TM was shown to be due to a previously described mechanism involving mycolactone-dependent blockade of Sec61 translocation that results in proteasome-dependent degradation of newly synthesised ER-transiting proteins. Indeed, depletion from cells determined by live-cell imaging of cells stably expressing a recombinant TM-GFP fusion protein occurred at the known turnover rate. In order to determine the relevance of these findings to BU disease, immunohistochemistry of punch biopsies from 40 BU lesions (31 ulcers, nine plaques was performed. TM abundance was profoundly reduced in the subcutis of 78% of biopsies. Furthermore, it was confirmed that fibrin deposition is a common feature of BU lesions, particularly in the necrotic areas. These findings indicate that there is decreased ability to control thrombin generation in BU skin. Mycolactone's effects on normal endothelial cell function, including its ability to activate the protein C anticoagulant pathway are strongly associated with this

Laparoscopic intraperitoneal mesh fixation with fibrin sealant (Tisseel®) vs. titanium tacks: a randomised controlled experimental study in pigs

DEFF Research Database (Denmark)

Eriksen, J.R.; Bech, Jakob Ilsted; Linnemann, D.

2008-01-01

feasible in a pig model. There is still no evidence that fibrin-sealing alone is appropriate for intraperitoneal mesh fixation in hernia repair, but the technique might become an alternative or supplement to mechanical mesh fixation. Until then, further experimental research in animal hernia models...

Management of radicular cysts using platelet-rich fibrin and bioactive glass: a report of two cases.

Science.gov (United States)

Zhao, Jiing-Huei; Tsai, Chung-Hung; Chang, Yu-Chao

2014-07-01

Platelet-rich fibrin (PRF) created by Choukroun's protocol concentrates most platelets and leukocytes from a blood harvest into a single autologous fibrin biomaterial. However, no current data is available concerning the use of PRF for the treatment of periapical lesions. Two cases of radicular cysts were reported using an interdisciplinary approach, including regular endodontic therapy followed by surgical management with PRF and bioactive glass. Two cases of radicular cysts presented as an incidental radiographic finding, appearing as an apical radiolucency with well-circumscribed sclerotic borders. After regular endodontic retreatment, cystic lining/granulation tissues were enucleated and the periradicular bony defect was grafted using PRF and bioactive glass. Then, PRF was applied to serve as a membrane over the grafted defects. Recall periapical radiographs of Case 1 and cone beam computer tomography of Case 2 showed satisfactory healing of the periapical pathosis. In Case 2, the bony defect appeared completely healed at 4 months surgical reentry and the new bone was clinically very dense and mature. The results of these case reports show that the combination of PRF and bioactive glass is an effective modality of regenerative treatment for radicular cysts. Copyright © 2012. Published by Elsevier B.V.

Management of radicular cysts using platelet-rich fibrin and bioactive glass: A report of two cases

Directory of Open Access Journals (Sweden)

Jiing-Huei Zhao

2014-07-01

Full Text Available Platelet-rich fibrin (PRF created by Choukroun’s protocol concentrates most platelets and leukocytes from a blood harvest into a single autologous fibrin biomaterial. However, no current data is available concerning the use of PRF for the treatment of periapical lesions. Two cases of radicular cysts were reported using an interdisciplinary approach, including regular endodontic therapy followed by surgical management with PRF and bioactive glass. Two cases of radicular cysts presented as an incidental radiographic finding, appearing as an apical radiolucency with well-circumscribed sclerotic borders. After regular endodontic retreatment, cystic lining/granulation tissues were enucleated and the periradicular bony defect was grafted using PRF and bioactive glass. Then, PRF was applied to serve as a membrane over the grafted defects. Recall periapical radiographs of Case 1 and cone beam computer tomography of Case 2 showed satisfactory healing of the periapical pathosis. In Case 2, the bony defect appeared completely healed at 4 months surgical reentry and the new bone was clinically very dense and mature. The results of these case reports show that the combination of PRF and bioactive glass is an effective modality of regenerative treatment for radicular cysts.

Sparse Matrix for ECG Identification with Two-Lead Features

Directory of Open Access Journals (Sweden)

Kuo-Kun Tseng

2015-01-01

Full Text Available Electrocardiograph (ECG human identification has the potential to improve biometric security. However, improvements in ECG identification and feature extraction are required. Previous work has focused on single lead ECG signals. Our work proposes a new algorithm for human identification by mapping two-lead ECG signals onto a two-dimensional matrix then employing a sparse matrix method to process the matrix. And that is the first application of sparse matrix techniques for ECG identification. Moreover, the results of our experiments demonstrate the benefits of our approach over existing methods.

Time-dependent changes in extra-domain A-fibronectin concentration and relative amounts of fibronectin-fibrin complexes in plasma of patients with peripheral arterial disease after endovascular revascularisation.

Science.gov (United States)

Pupek, Małgorzata; Krzyżanowska-Gołąb, Dorota; Kotschy, Daniel; Witkiewicz, Wojciech; Kwiatkowska, Wiesława; Kotschy, Maria; Kątnik-Prastowska, Iwona

2018-03-13

Fibronectin (FN) may be involved in time- and stage-dependent and inter-related controlled processes of inflammation, coagulation, and wound healing accompanying peripheral arterial disease (PAD). In the present study, FN and FN-containing extra-domain A (EDA-FN), macromolecular FN-fibrin complexes, and FN monomer were analysed in the plasma of 142 PAD patients, including 37 patients with restenosis, for 37 months after revascularisation. FN concentration increased significantly in the plasma of PAD patients within 7 to 12 months after revascularisation, whereas the high concentration of EDA-FN was maintained up to 24 months, significantly higher in the group 7 to 12 months after revascularisation with recurrence of stenosis and lower in the PAD groups 1 to 3 months and 4 to 6 months after revascularisation with comorbid diabetes and ulceration, respectively. The relative amounts of FN-fibrin complexes up to 1600 kDa and FN monomer were significantly higher, within intervals of 4 to 24 months and 4 to 6 months after revascularisation, respectively. Moreover, the relative amounts of 750 to 1600 kDa FN-fibrin complexes within 13 to 24 months after revascularisation were higher in comparison with those in the group without restenosis. In conclusion, high levels of EDA-FN and FN-fibrin complexes could have potential diagnostic value in the management of PAD patients after revascularisation, predicting restenosis risk. © 2018 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Expression of extracellular matrix components and related growth factors in human tendon and muscle after acute exercise

DEFF Research Database (Denmark)

Heinemeier, K M; Bjerrum, S S; Schjerling, P

2013-01-01

Acute kicking exercise induces collagen synthesis in both tendon and muscle in humans, but it is not known if this relates to increased collagen transcription and if other matrix genes are regulated. Young men performed 1 h of one-leg kicking at 67% of max workload. Biopsies were taken from...... the patellar tendon and vastus lateralis muscle of each leg at 2 (n = 10), 6 (n = 11), or 26 h (n = 10) after exercise. Levels of messenger ribonucleic acid mRNA for collagens, noncollagenous matrix proteins, and growth factors were measured with real-time reverse transcription polymerase chain reaction...

Differential Mueller matrix polarimetry technique for non-invasive measurement of glucose concentration on human fingertip.

Science.gov (United States)

Phan, Quoc-Hung; Lo, Yu-Lung

2017-06-26

A differential Mueller matrix polarimetry technique is proposed for obtaining non-invasive (NI) measurements of the glucose concentration on the human fingertip. The feasibility of the proposed method is demonstrated by detecting the optical rotation angle and depolarization index of tissue phantom samples containing de-ionized water (DI), glucose solutions with concentrations ranging from 0~500 mg/dL and 2% lipofundin. The results show that the extracted optical rotation angle increases linearly with an increasing glucose concentration, while the depolarization index decreases. The practical applicability of the proposed method is demonstrated by measuring the optical rotation angle and depolarization index properties of the human fingertips of healthy volunteers.

Senescent intervertebral disc cells exhibit perturbed matrix homeostasis phenotype.

Science.gov (United States)

Ngo, Kevin; Patil, Prashanti; McGowan, Sara J; Niedernhofer, Laura J; Robbins, Paul D; Kang, James; Sowa, Gwendolyn; Vo, Nam

2017-09-01

Aging greatly increases the risk for intervertebral disc degeneration (IDD) as a result of proteoglycan loss due to reduced synthesis and enhanced degradation of the disc matrix proteoglycan (PG). How disc matrix PG homeostasis becomes perturbed with age is not known. The goal of this study is to determine whether cellular senescence is a source of this perturbation. We demonstrated that disc cellular senescence is dramatically increased in the DNA repair-deficient Ercc1 -/Δ mouse model of human progeria. In these accelerated aging mice, increased disc cellular senescence is closely associated with the rapid loss of disc PG. We also directly examine PG homeostasis in oxidative damage-induced senescent human cells using an in vitro cell culture model system. Senescence of human disc cells treated with hydrogen peroxide was confirmed by growth arrest, senescence-associated β-galactosidase activity, γH2AX foci, and acquisition of senescence-associated secretory phenotype. Senescent human disc cells also exhibited perturbed matrix PG homeostasis as evidenced by their decreased capacity to synthesize new matrix PG and enhanced degradation of aggrecan, a major matrix PG. of the disc. Our in vivo and in vitro findings altogether suggest that disc cellular senescence is an important driver of PG matrix homeostatic perturbation and PG loss. Published by Elsevier B.V.

Matrix metalloproteinase sensing via porous silicon microcavity devices functionalized with human antibodies

Energy Technology Data Exchange (ETDEWEB)

Martin, Marta; Gergely, Csilla [GES-UMR 5650, CNRS, Universite Montpellier 2, Pl. Eugene Bataillon 34095, Montpellier Cedex 5 (France); Taleb Bendiab, Chakib; Massif, Laurent; Cuisinier, Frederic [EA4203, Faculte d' Odontologie, Universite Montpellier 1, Montpellier Cedex 5 (France); Palestino, Gabriela [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, Av. Salvador Nava 6, 78000 San Luis Potosi (Mexico); Agarwal, Vivechana [CIICAP, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Col Chamilpa, Cuernavaca, Mor. (Mexico)

2011-06-15

Porous silicon microcavity (PSiMc) structures were used as support material for specific sensing of matrix metalloproteinases (MMPs). For lower concentrations of MMP-8, the structures were tested with two types of functionalization methods. Silanization of the oxidized porous silicon structures, followed by glutaraldehyde chemistry was found to give very inconsistent results. The use of biotinilated bovine serum albumin linked to the naked PSiMc was found to be an alternative method to attach the anti MMP-8 human antibody, previously modified with streptavidin, which was further used to sense MMP-8 (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Food Matrix Effects of Polyphenol Bioaccessibility from Almond Skin during Simulated Human Digestion

Directory of Open Access Journals (Sweden)

Giuseppina Mandalari

2016-09-01

Full Text Available The goal of the present study was to quantify the rate and extent of polyphenols released in the gastrointestinal tract (GIT from natural (NS and blanched (BS almond skins. A dynamic gastric model of digestion which provides a realistic simulation of the human stomach was used. In order to establish the effect of a food matrix on polyphenols bioaccessibility, NS and BS were either digested in water (WT or incorporated into home-made biscuits (HB, crisp-bread (CB and full-fat milk (FM. Phenolic acids were the most bioaccessible class (68.5% release from NS and 64.7% from BS. WT increased the release of flavan-3-ols (p < 0.05 and flavonols (p < 0.05 from NS after gastric plus duodenal digestion, whereas CB and HB were better vehicles for BS. FM lowered the % recovery of polyphenols, the free total phenols and the antioxidant status in the digestion medium, indicating that phenolic compounds could bind protein present in the food matrix. The release of bioactives from almond skins could explain the beneficial effects associated with almond consumption.

Extracellular matrix of the human aortic media: an ultrastructural histochemical and immunohistochemical study of the adult aortic media

NARCIS (Netherlands)

Dingemans, K. P.; Teeling, P.; Lagendijk, J. H.; Becker, A. E.

2000-01-01

Aortic distensability is the key to normal aortic function and relates to the lamellar unit in the media. However, the organization of the extracellular matrix components in these lamellar units, which are largely responsible for the distensability, is insufficiently known, especially in the human.

Dynamic imaging in electrical impedance tomography of the human chest with online transition matrix identification.

Science.gov (United States)

Moura, Fernando Silva; Aya, Julio Cesar Ceballos; Fleury, Agenor Toledo; Amato, Marcelo Britto Passos; Lima, Raul Gonzalez

2010-02-01

One of the electrical impedance tomography objectives is to estimate the electrical resistivity distribution in a domain based only on electrical potential measurements at its boundary generated by an imposed electrical current distribution into the boundary. One of the methods used in dynamic estimation is the Kalman filter. In biomedical applications, the random walk model is frequently used as evolution model and, under this conditions, poor tracking ability of the extended Kalman filter (EKF) is achieved. An analytically developed evolution model is not feasible at this moment. The paper investigates the identification of the evolution model in parallel to the EKF and updating the evolution model with certain periodicity. The evolution model transition matrix is identified using the history of the estimated resistivity distribution obtained by a sensitivity matrix based algorithm and a Newton-Raphson algorithm. To numerically identify the linear evolution model, the Ibrahim time-domain method is used. The investigation is performed by numerical simulations of a domain with time-varying resistivity and by experimental data collected from the boundary of a human chest during normal breathing. The obtained dynamic resistivity values lie within the expected values for the tissues of a human chest. The EKF results suggest that the tracking ability is significantly improved with this approach.

Broccoli and watercress suppress matrix metalloproteinase-9 activity and invasiveness of human MDA-MB-231 breast cancer cells

International Nuclear Information System (INIS)

Rose, Peter; Huang, Qing; Ong, Choon Nam; Whiteman, Matt

2005-01-01

A high dietary intake of cruciferous vegetables has been associated with a reduction in numerous human pathologies particularly cancer. In the current study, we examined the inhibitory effects of broccoli (Brassica oleracea var. italica) and watercress (Rorripa nasturtium aquaticum) extracts on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced cancer cell invasion and matrix metalloproteinase-9 activity using human MDA-MB-231 breast cancer cells. Aberrant overexpression of matrix metalloproteinases, including metalloproteinase-9, is associated with increased invasive potential in cancer cell lines. Our results demonstrate that extracts of broccoli and Rorripa suppressed TPA-induced MMP-9 activity and invasiveness in a concentration dependant manner as determined by zymographic analysis. Furthermore, fractionation of individual extracts followed by liquid chromatography mass spectroscopy analysis (LC-MS) revealed that the inhibitory effects of each vegetable were associated with the presence of 4-methysulfinylbutyl (sulforaphane) and 7-methylsulphinylheptyl isothiocyanates. Taken together, our data indicate that isothiocyanates derived form broccoli and Rorripa inhibit metalloproteinase 9 activities and also suppress the invasive potential of human MDA-MB-231 breast cancer cells in vitro. The inhibitory effects observed in the current study may contribute to the suppression of carcinogenesis by diets high in cruciferous vegetables

An Evaluation of the Accuracy of the Subtraction Method Used for Determining Platelet Counts in Advanced Platelet-Rich Fibrin and Concentrated Growth Factor Preparations

Directory of Open Access Journals (Sweden)

Taisuke Watanabe

2017-01-01

Full Text Available Platelet concentrates should be quality-assured of purity and identity prior to clinical use. Unlike for the liquid form of platelet-rich plasma, platelet counts cannot be directly determined in solid fibrin clots and are instead calculated by subtracting the counts in other liquid or semi-clotted fractions from those in whole blood samples. Having long suspected the validity of this method, we herein examined the possible loss of platelets in the preparation process. Blood samples collected from healthy male donors were immediately centrifuged for advanced platelet-rich fibrin (A-PRF and concentrated growth factors (CGF according to recommended centrifugal protocols. Blood cells in liquid and semi-clotted fractions were directly counted. Platelets aggregated on clot surfaces were observed by scanning electron microscopy. A higher centrifugal force increased the numbers of platelets and platelet aggregates in the liquid red blood cell fraction and the semi-clotted red thrombus in the presence and absence of the anticoagulant, respectively. Nevertheless, the calculated platelet counts in A-PRF/CGF preparations were much higher than expected, rendering the currently accepted subtraction method inaccurate for determining platelet counts in fibrin clots. To ensure the quality of solid types of platelet concentrates chairside in a timely manner, a simple and accurate platelet-counting method should be developed immediately.

Structure and function of ameloblastin as an extracellular matrix protein: adhesion, calcium binding, and CD63 interaction in human and mouse.

Science.gov (United States)

Zhang, Xu; Diekwisch, Thomas G H; Luan, Xianghong

2011-12-01

The functional significance of extracellular matrix proteins in the life of vertebrates is underscored by a high level of sequence variability in tandem with a substantial degree of conservation in terms of cell-cell and cell-matrix adhesion interactions. Many extracellular matrix proteins feature multiple adhesion domains for successful attachment to substrates, such as integrin, CD63, and heparin. Here we have used homology and ab initio modeling algorithms to compare mouse ameloblastin (mAMBN) and human ameloblastin (hABMN) isoforms and to analyze their potential for cell adhesion and interaction with other matrix molecules as well as calcium binding. Sequence comparison between mAMBN and hAMBN revealed a 26-amino-acid deletion in mAMBN, corresponding to a helix-loop-helix frameshift. The human AMBN domain (174Q-201G), homologous to the mAMBN 157E-178I helix-loop-helix region, formed a helix-loop motif with an extended loop, suggesting a higher degree of flexibility of hAMBN compared with mAMBN, as confirmed by molecular dynamics simulation. Heparin-binding domains, CD63-interaction domains, and calcium-binding sites in both hAMBN and mAMBN support the concept of AMBN as an extracellular matrix protein. The high level of conservation between AMBN functional domains related to adhesion and differentiation was remarkable when compared with only 61% amino acid sequence homology. © 2011 Eur J Oral Sci.

Detection of HOCl-mediated protein oxidation products in the extracellular matrix of human atherosclerotic plaques

DEFF Research Database (Denmark)

Woods, Alan A; Linton, Stuart M; Davies, Michael Jonathan

2003-01-01

Oxidation is believed to play a role in atherosclerosis. Oxidized lipids, sterols and proteins have been detected in early, intermediate and advanced human lesions at elevated levels. The spectrum of oxidized side-chain products detected on proteins from homogenates of advanced human lesions has...... been interpreted in terms of the occurrence of two oxidative mechanisms, one involving oxygen-derived radicals catalysed by trace transition metal ions, and a second involving chlorinating species (HOCl or Cl2), generated by the haem enzyme myeloperoxidase (MPO). As MPO is released extracellularly...... for 83-96% of the total oxidized protein side-chain products detected in these plaques. Oxidation of matrix components extracted from healthy artery tissue, and model proteins, with reagent HOCl is shown to give rise to a similar pattern of products to those detected in advanced human lesions...

Fibre-Matrix Interaction in Soft Tissue

International Nuclear Information System (INIS)

Guo, Zaoyang

2010-01-01

Although the mechanical behaviour of soft tissue has been extensively studied, the interaction between the collagen fibres and the ground matrix has not been well understood and is therefore ignored by most constitutive models of soft tissue. In this paper, the human annulus fibrosus is used as an example and the potential fibre-matrix interaction is identified by careful investigation of the experimental results of biaxial and uniaxial testing of the human annulus fibrosus. First, the uniaxial testing result of the HAF along the axial direction is analysed and it is shown that the mechanical behaviour of the ground matrix can be well simulated by the incompressible neo-Hookean model when the collagen fibres are all under contraction. If the collagen fibres are stretched, the response of the ground matrix can still be described by the incompressible neo-Hookean model, but the effective stiffness of the matrix depends on the fibre stretch ratio. This stiffness can be more than 10 times larger than the one obtained with collagen fibres under contraction. This phenomenon can only be explained by the fibre-matrix interaction. Furthermore, we find that the physical interpretation of this interaction includes the inhomogeneity of the soft tissue and the fibre orientation dispersion. The dependence of the tangent stiffness of the matrix on the first invariant of the deformation tensor can also be explained by the fibre orientation dispersion. The significant effect of the fibre-matrix interaction strain energy on mechanical behaviour of the soft tissue is also illustrated by comparing some simulation results.

Injectable scaffold materials differ in their cell instructive effects on primary human myoblasts

DEFF Research Database (Denmark)

Hejbøl, Eva Kildall; Sellathurai, Jeeva; Nair, Prabha Damodaran

2017-01-01

Scaffolds are materials used for delivery of cells for regeneration of tissues. They support three-dimensional organization and improve cell survival. For the repair of small skeletal muscles, injections of small volumes of cells are attractive, and injectable scaffolds for delivery of cells offer...... a minimally invasive technique. In this study, we examined in vitro the cell instructive effects of three types of injectable scaffolds, fibrin, alginate, and poly(lactic-co-glycolic acid)-based microparticles on primary human myoblasts. The myoblast morphology and progression in the myogenic program differed......, depending on the type of scaffold material. In alginate gel, the cells obtained a round morphology, they ceased to proliferate, and entered quiescence. In the fibrin gels, differentiation was promoted, and myotubes were observed within a few days in culture, while poly(lactic-co-glycolic acid...

Superoxide produced in the matrix of mitochondria enhances methylmercury toxicity in human neuroblastoma cells

Energy Technology Data Exchange (ETDEWEB)

Mailloux, Ryan J.; Yumvihoze, Emmanuel; Chan, Hing Man, E-mail: laurie.chan@uottawa.ca

2015-12-15

The mechanism of intracellular metabolism of methylmercury (MeHg) is not fully known. It has been shown that superoxide (O{sub 2}·{sup −}), the proximal reactive oxygen species (ROS) generated by mitochondria, is responsible for MeHg demethylation. Here, we investigated the impact of different mitochondrial respiratory inhibitors, namely rotenone and antimycin A, on the O{sub 2}·{sup −} mediated degradation of MeHg in human neuroblastoma cells SH-K-SN. We also utilized paraquat (PQ) which generates O{sub 2}·{sup −} in the mitochondrial matrix. We found that the cleavage of the carbon-metal bond in MeHg was highly dependent on the topology of O{sub 2}·{sup −} production by mitochondria. Both rotenone and PQ, which increase O{sub 2}·{sup −} in the mitochondrial matrix at a dose-dependent manner, enhanced the conversion of MeHg to inorganic mercury (iHg). Surprisingly, antimycin A, which prompts emission of O{sub 2}·{sup −} into the intermembrane space, did not have the same effect even though antimycin A induced a dose dependent increase in O{sub 2}·{sup −} emission. Rotenone and PQ also enhanced the toxicity of sub-toxic doses (0.1 μM) MeHg which correlated with the accumulation of iHg in mitochondria and depletion of mitochondrial protein thiols. Taken together, our results demonstrate that MeHg degradation is mediated by mitochondrial O{sub 2}·{sup −}, specifically within the matrix of mitochondria when O{sub 2}·{sup −} is in adequate supply. Our results also show that O{sub 2}·{sup −} amplifies MeHg toxicity specifically through its conversion to iHg and subsequent interaction with protein cysteine thiols (R-SH). The implications of our findings in mercury neurotoxicity are discussed herein. - Highlights: • Superoxide produced in the matrix of mitochondria degrades MeHg. • Superoxide produced in intermembrane space does not degrade MeHg. • Matrix-generated superoxide enhances Hg toxicity by converting MeHg to iHg.

Topical photodynamic therapy following excisional wounding of human skin increases production of transforming growth factor-β3 and matrix metalloproteinases 1 and 9, with associated improvement in dermal matrix organization.

Science.gov (United States)

Mills, S J; Farrar, M D; Ashcroft, G S; Griffiths, C E M; Hardman, M J; Rhodes, L E

2014-07-01

Animal studies report photodynamic therapy (PDT) to improve healing of excisional wounds; the mechanism is uncertain and equivalent human studies are lacking. To explore the impact of methyl aminolaevulinate (MAL)-PDT on clinical and microscopic parameters of human cutaneous excisional wound healing, examining potential modulation through production of transforming growth factor (TGF)-β isoforms. In 27 healthy older men (60-77 years), a 4-mm punch biopsy wound was created in skin of the upper inner arm and treated with MAL-PDT three times over 5 days. An identical control wound to the contralateral arm was untreated and both wounds left to heal by secondary intention. Wounds were re-excised during the inflammatory phase (7 days, n = 10), matrix remodelling (3 weeks, n = 8) and cosmetic outcome/dermal structure (9 months, n = 9). Production of TGF-β1, TGF-β3 and matrix metalloproteinases (MMPs) was assessed by immunohistochemistry alongside microscopic measurement of wound size/area and clinical assessment of wound appearance. MAL-PDT delayed re-epithelialization at 7 days, associated with increased inflammation. However, 3 weeks postwounding, treated wounds were smaller with higher production of MMP-1 (P = 0·01), MMP-9 (P = 0·04) and TGF-β3 (P = 0·03). TGF-β1 was lower than control at 7 days and higher at 3 weeks (both P = 0·03). At 9 months, MAL-PDT-treated wounds showed greater, more ordered deposition of collagen I, collagen III and elastin (all P < 0·05). MAL-PDT increases MMP-1, MMP-9 and TGF-β3 production during matrix remodelling, ultimately producing scars with improved dermal matrix architecture. © 2014 British Association of Dermatologists.

The Exopolysaccharide Matrix

Science.gov (United States)

Koo, H.; Falsetta, M.L.; Klein, M.I.

2013-01-01

Many infectious diseases in humans are caused or exacerbated by biofilms. Dental caries is a prime example of a biofilm-dependent disease, resulting from interactions of microorganisms, host factors, and diet (sugars), which modulate the dynamic formation of biofilms on tooth surfaces. All biofilms have a microbial-derived extracellular matrix as an essential constituent. The exopolysaccharides formed through interactions between sucrose- (and starch-) and Streptococcus mutans-derived exoenzymes present in the pellicle and on microbial surfaces (including non-mutans) provide binding sites for cariogenic and other organisms. The polymers formed in situ enmesh the microorganisms while forming a matrix facilitating the assembly of three-dimensional (3D) multicellular structures that encompass a series of microenvironments and are firmly attached to teeth. The metabolic activity of microbes embedded in this exopolysaccharide-rich and diffusion-limiting matrix leads to acidification of the milieu and, eventually, acid-dissolution of enamel. Here, we discuss recent advances concerning spatio-temporal development of the exopolysaccharide matrix and its essential role in the pathogenesis of dental caries. We focus on how the matrix serves as a 3D scaffold for biofilm assembly while creating spatial heterogeneities and low-pH microenvironments/niches. Further understanding on how the matrix modulates microbial activity and virulence expression could lead to new approaches to control cariogenic biofilms. PMID:24045647

Sildenafil attenuates pulmonary inflammation and fibrin deposition, mortality and right ventricular hypertrophy in neonatal hyperoxic lung injury

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Boersma Hester

2009-04-01

Full Text Available Abstract Background Phosphodiesterase-5 inhibition with sildenafil has been used to treat severe pulmonary hypertension and bronchopulmonary dysplasia (BPD, a chronic lung disease in very preterm infants who were mechanically ventilated for respiratory distress syndrome. Methods Sildenafil treatment was investigated in 2 models of experimental BPD: a lethal neonatal model, in which rat pups were continuously exposed to hyperoxia and treated daily with sildenafil (50–150 mg/kg body weight/day; injected subcutaneously and a neonatal lung injury-recovery model in which rat pups were exposed to hyperoxia for 9 days, followed by 9 days of recovery in room air and started sildenafil treatment on day 6 of hyperoxia exposure. Parameters investigated include survival, histopathology, fibrin deposition, alveolar vascular leakage, right ventricular hypertrophy, and differential mRNA expression in lung and heart tissue. Results Prophylactic treatment with an optimal dose of sildenafil (2 × 50 mg/kg/day significantly increased lung cGMP levels, prolonged median survival, reduced fibrin deposition, total protein content in bronchoalveolar lavage fluid, inflammation and septum thickness. Treatment with sildenafil partially corrected the differential mRNA expression of amphiregulin, plasminogen activator inhibitor-1, fibroblast growth factor receptor-4 and vascular endothelial growth factor receptor-2 in the lung and of brain and c-type natriuretic peptides and the natriuretic peptide receptors NPR-A, -B, and -C in the right ventricle. In the lethal and injury-recovery model we demonstrated improved alveolarization and angiogenesis by attenuating mean linear intercept and arteriolar wall thickness and increasing pulmonary blood vessel density, and right ventricular hypertrophy (RVH. Conclusion Sildenafil treatment, started simultaneously with exposure to hyperoxia after birth, prolongs survival, increases pulmonary cGMP levels, reduces the pulmonary

Human lung fibroblast-derived matrix facilitates vascular morphogenesis in 3D environment and enhances skin wound healing.

Science.gov (United States)

Du, Ping; Suhaeri, Muhammad; Ha, Sang Su; Oh, Seung Ja; Kim, Sang-Heon; Park, Kwideok

2017-05-01

Extracellular matrix (ECM) is crucial to many aspects of vascular morphogenesis and maintenance of vasculature function. Currently the recapitulation of angiogenic ECM microenvironment is still challenging, due mainly to its diverse components and complex organization. Here we investigate the angiogenic potential of human lung fibroblast-derived matrix (hFDM) in creating a three-dimensional (3D) vascular construct. hFDM was obtained via decellularization of in vitro cultured human lung fibroblasts and analyzed via immunofluorescence staining and ELISA, which detect multiple ECM macromolecules and angiogenic growth factors (GFs). Human umbilical vein endothelial cells (HUVECs) morphology was more elongated and better proliferative on hFDM than on gelatin-coated substrate. To prepare 3D construct, hFDM is collected, quantitatively analyzed, and incorporated in collagen hydrogel (Col) with HUVECs. Capillary-like structure (CLS) formation at 7day was significantly better with the groups containing higher doses of hFDM compared to the Col group (control). Moreover, the group (Col/hFDM/GFs) with both hFDM and angiogenic GFs (VEGF, bFGF, SDF-1) showed the synergistic activity on CLS formation and found much larger capillary lumen diameters with time. Further analysis of hFDM via angiogenesis antibody array kit reveals abundant biochemical cues, such as angiogenesis-related cytokines, GFs, and proteolytic enzymes. Significantly up-regulated expression of VE-cadherin and ECM-specific integrin subunits was also noticed in Col/hFDM/GFs. In addition, transplantation of Col/hFMD/GFs with HUVECs in skin wound model presents more effective re-epithelialization, many regenerated hair follicles, better transplanted cells viability, and advanced neovascularization. We believe that current system is a very promising platform for 3D vasculature construction in vitro and for cell delivery toward therapeutic applications in vivo. Functional 3D vasculature construction in vitro is still

The significance of fibrin binding by plasminogen activator inhibitor 1 for the mechanism of tissue-type plasminogen activator-mediated fibrinolysis

NARCIS (Netherlands)

Stringer, H. A.; Pannekoek, H.

1995-01-01

The specific, reversible interaction between plasminogen activator inhibitor 1 (PAI-1) and intact fibrin polymers was studied using both purified components and isolated activated platelets as a source of PAI-1. A key reagent in these experiments is a PAI-1 mutant, having its P1 reactive center

Host-Parasite Interaction: Parasite-Derived and -Induced Proteases That Degrade Human Extracellular Matrix

Directory of Open Access Journals (Sweden)

Carolina Piña-Vázquez

2012-01-01

Full Text Available Parasitic protozoa are among the most important pathogens worldwide. Diseases such as malaria, leishmaniasis, amoebiasis, giardiasis, trichomoniasis, and trypanosomiasis affect millions of people. Humans are constantly threatened by infections caused by these pathogens. Parasites engage a plethora of surface and secreted molecules to attach to and enter mammalian cells. The secretion of lytic enzymes by parasites into host organs mediates critical interactions because of the invasion and destruction of interstitial tissues, enabling parasite migration to other sites within the hosts. Extracellular matrix is a complex, cross-linked structure that holds cells together in an organized assembly and that forms the basement membrane lining (basal lamina. The extracellular matrix represents a major barrier to parasites. Therefore, the evolution of mechanisms for connective-tissue degradation may be of great importance for parasite survival. Recent advances have been achieved in our understanding of the biochemistry and molecular biology of proteases from parasitic protozoa. The focus of this paper is to discuss the role of protozoan parasitic proteases in the degradation of host ECM proteins and the participation of these molecules as virulence factors. We divide the paper into two sections, extracellular and intracellular protozoa.

Random matrix analysis of human EEG data

Czech Academy of Sciences Publication Activity Database

Šeba, Petr

2003-01-01

Roč. 91, - (2003), s. 198104-1 - 198104-4 ISSN 0031-9007 R&D Projects: GA ČR GA202/02/0088 Institutional research plan: CEZ:AV0Z1010914 Keywords : random matrix theory * EEG signal Subject RIV: BE - Theoretical Physics Impact factor: 7.035, year: 2003

Modeling of Fibrin Gels Based on Confocal Microscopy and Light-Scattering Data

Science.gov (United States)

Magatti, Davide; Molteni, Matteo; Cardinali, Barbara; Rocco, Mattia; Ferri, Fabio

2013-01-01

Fibrin gels are biological networks that play a fundamental role in blood coagulation and other patho/physiological processes, such as thrombosis and cancer. Electron and confocal microscopies show a collection of fibers that are relatively monodisperse in diameter, not uniformly distributed, and connected at nodal points with a branching order of ∼3–4. Although in the confocal images the hydrated fibers appear to be quite straight (mass fractal dimension Dm = 1), for the overall system 1fibrin gels and can be sketched as an assembly of densely packed fractal blobs, i.e., regions of size ξ, where the fiber concentration is higher than average. The blobs are placed at a distance ξ0 between their centers of mass so that they are overlapped by a factor η = ξ/ξ0 and have Dm ∼1.2–1.6. The in silico gels’ structure is quantitatively analyzed by its 3D spatial correlation function g3D(r) and corresponding power spectrum I(q) = FFT3D[g3D(r)], from which ρ, d, Dm, η, and ξ0 can be extracted. In particular, ξ0 provides an excellent estimate of the gel mesh size. The in silico gels’ I(q) compares quite well with real gels’ elastic light-scattering measurements. We then derived an analytical form factor for accurately fitting the scattering data, which allowed us to directly recover the gels’ structural parameters. PMID:23473498

Evaluation of dermal-epidermal skin equivalents ('composite-skin') of human keratinocytes in a collagen-glycosaminoglycan matrix(Integra artificial skin).

Science.gov (United States)

Kremer, M; Lang, E; Berger, A C

2000-09-01

Integra artificial skin (Integra LifeSciences Corp., Plainsboro, NJ, USA) is a dermal template consisting of bovine collagen, chondroitin-6-sulphate and a silastic membrane manufactured as Integra. This product has gained widespread use in the clinical treatment of third degree burn wounds and full thickness skin defects of different aetiologies. The product was designed to significantly reduce the time needed to achieve final wound closure in the treatment of major burn wounds, to optimise the sparse autologous donor skin resources and to improve the durable mechanical quality of the skin substitute. The clinical procedure requires two stages. The first step creates a self neodermis, the second creates a self epidermis on the neodermis. However, it is desirable to cover major burn wounds early in a single step by a skin substitute consisting of a dermal equivalent seeded in vitro with autologous keratinocytes ('composite-skin') out of which a full thickness skin develops in vivo.The goal of this experimental study was to develop a method to integrate human keratinocytes in homogeneous distribution and depth into Integra Artificial Skin. The seeded cell-matrix composites were grafted onto athymic mice in order to evaluate their potential to reconstitute a human epidermis in vivo. We were able to demonstrate that the inoculated human keratinocytes reproducibly displayed a homogeneous pattern of distribution, adherence, proliferation and confluence. The cell-matrix composites grafted in this model exhibited good wound adherence, complete healing, minor wound contraction and had the potential to reconstitute an elastic, functional and durable human skin. Histologically we were able to show that the inoculated human keratinocytes in vivo colonised the matrix in a histomorphologically characteristic epidermal pattern (keratomorula, keratinocyte bubbling) and developed a persisting, stratified, keratinising epidermis which immunohistologically proved to be of human

Buddleja officinalis inhibits high glucose-induced matrix metalloproteinase activity in human umbilical vein endothelial cells.

Science.gov (United States)

Lee, Yun Jung; Kang, Dae Gill; Kim, Jin Sook; Lee, Ho Sub

2008-12-01

The aim of the present investigation was to investigate whether an aqueous extract of Buddleja officinalis (ABO), a traditional Korean herbal medicine, suppresses the endothelial extracellular matrix degradation under high glucose condition. The incubation with high concentration of glucose (25 mM) increased significantly matrix metalloproteinase (MMP)-2/-9 expressions and activities in primary cultured human umbilical vein endothelial cells (HUVEC). Pretreatment with ABO decreased high glucose-induced increase of MMP-2/-9 activities in a dose-dependent manner. Real time qRT-PCR revealed that high glucose-induced MMP-2/-9 mRNA expression levels were attenuated by pretreatment with ABO. High glucose-induced MCP-1 and IL-8 mRNA expression levels also decreased by ABO. ABO decreased high glucose-induced hydrogen peroxide production, oxidative stress marker. These results provide new insights into the pathophysiological mechanisms for anti-inflammatory properties of ABO in vascular diseases associated with diabetes mellitus. (c) 2008 John Wiley & Sons, Ltd.

Engineered matrix coatings to modulate the adhesion of CD133+ human hematopoietic progenitor cells.

Science.gov (United States)

Franke, Katja; Pompe, Tilo; Bornhäuser, Martin; Werner, Carsten

2007-02-01

Interactions of hematopoietic progenitor cells (HPC) with their local microenvironments in the bone marrow are thought to control homing, differentiation, and self-renewal of the cells. To dissect the role of extracellular matrix (ECM) components of the niche microenvironment, a set of well-defined ECM coatings including fibronectin, heparin, heparan sulphate, hyaluronic acid, tropocollagen I, and co-fibrils of collagen I with heparin or hyaluronic acid was prepared and analysed with respect to the attachment of human CD133+ HPC in vitro. The extension of the adhesion areas of individual cells as well as the fraction of adherent cells were assessed by reflection interference contrast microscopy (RICM). Intense cell-matrix interactions were found on surfaces coated with fibronectin, heparin, heparan sulphate, and on the collagen I based co-fibrils. Insignificant adhesion was found for tropocollagen I and hyaluronic acid. The strongest adhesion of HPC was observed on fibronectin with contact areas of about 7 microm(2). Interaction of HPC with coatings consisting of heparin, heparan sulphate, and co-fibrils result in small circular shaped contact zones of 3 microm(2) pointing to another, less efficient, adhesion mechanism. Analysing the specificity of cell-matrix interaction by antibody blocking experiments suggests an integrin(alpha(5)beta(1))-specific adhesion on fibronectin, while adhesion on heparin was shown to be mediated by selectins (CD62L). Taken together, our data provide a basis for the design of advanced culture carriers supporting site-specific proliferation or differentiation of HPC.

Autologous plasma rich in growth factors in the prevention of severe bleeding after teeth extractions in patients with bleeding disorders: a controlled comparison with fibrin glue

Science.gov (United States)

Cocero, Nadia; Pucci, Fabrizio; Messina, Maria; Pollio, Berardino; Mozzati, Marco; Bergamasco, Laura

2015-01-01

Background Dental extractions in haemophiliacs may cause secondary bleeding, requiring repeated surgical and haematological interventions. As a local haemostatic, fibrin glue has recognised efficacy but, as a plasma-derived product, it carries the risk of viral infections. We, therefore, compared fibrin glue with an autologous haemostatic, plasma rich in growth factors (PRGF), in a controlled trial. Material and methods One hundred and twenty patients with different blood disorders were randomised into two cohorts to undergo dental extraction procedures without hospitalisation. Prior to the extractions, patients underwent systemic haematological treatment. Complications were defined as secondary bleeding after the 7-day follow-up period or protracting after the repair procedure. Results There were 106 extractions (7 retained 3rd molars) in the group managed with fibrin glue: secondary bleeding affected 3/60 patients (5%) on the third day after extraction and necessitated additional surgery and systemic treatment (in one case the procedure had to be repeated on the 7th day). In the PRGF arm there were 98 extractions (23 retained 3rd molars): secondary bleeding affected two patients (3.3%) on the first day after extraction and was arrested with surgery without systemic treatment. Four out of the five secondary bleeds occurred in patients with haemophilia A. Concomitant diabetes or liver disease significantly increased the bleeding risk. Discussion The bleeding rates in the study and control arm prove that PRGF works as well as fibrin glue as a local haemostatic. Further assets are that PRGF has autologous origin, does not require additional systemic treatment in post-extraction repair surgery, is associated with an earlier onset of neo-angiogenesis and, overall, can reduce patients’ distress and costs to the health system. PMID:25369587

Treatment of endo-periodontal lesion using leukocyte-platelet-rich fibrin. A case report.

Science.gov (United States)

Betancourt, Pablo; Elgueta, Ricardo; Fuentes, Ramon

2017-12-30

The main objective of this paper was to report the clinical effectiveness of leukocyte- platelet- rich fibrin (L-PRF) in the treatment of a combined endo-periodontal lesion of an upper first premolar. The tooth had a profound abfraction on the vestibular aspect and presented no mobility but revealed a deep pocket measuring of 11 mm on the mesial vestibular aspect and 14 mm on the mesial palatine aspect. The three dimensional image analysis showed total bone loss in the mesial aspect and an extensively bone loss of the vestibular aspect of the vestibular root. Endodontic treatment was performed and periodontal access surgery (surgical periodontal therapy) was done with the application of autologous L-PRF. Three month and 6 months after surgery, the cone beam computed tomography (CBCT) exams showed no bone regeneration in any aspect of the tooth. However, periodontal examination showed a significative improvement in the deepness of surcus. The mesial vestibular aspect had a deep pocket of 3 mm and 5 mm on the mesial palatine aspect showing a reduction in deepness of 8 mm and 9 mm, respectively. The actual treatment for teeth with bad prognosis is the extraction and replacement with implants. Even though implants are capable of restore function and aesthetic, the abuse of this approach have led to the loss of teeth that could be successfully treated with a less invasive technique. The prognosis of teeth with endoperiodontal lesion is poor but could be enhanced with regenerative therapies. Until now there are no clinical trials and just four case report about the treatment of these teeth with platelet rich fibrin.

Omentin-1 prevents cartilage matrix destruction by regulating matrix metalloproteinases.

Science.gov (United States)

Li, Zhigang; Liu, Baoyi; Zhao, Dewei; Wang, BenJie; Liu, Yupeng; Zhang, Yao; Li, Borui; Tian, Fengde

2017-08-01

Matrix metalloproteinases (MMPs) play a crucial role in the degradation of the extracellular matrix and pathological progression of osteoarthritis (OA). Omentin-1 is a newly identified anti-inflammatory adipokine. Little information regarding the protective effects of omentin-1 in OA has been reported before. In the current study, our results indicated that omentin-1 suppressed expression of MMP-1, MMP-3, and MMP-13 induced by the proinflammatory cytokine interleukin-1β (IL-1β) at both the mRNA and protein levels in human chondrocytes. Importantly, administration of omentin-1 abolished IL-1β-induced degradation of type II collagen (Col II) and aggrecan, the two major extracellular matrix components in articular cartilage, in a dose-dependent manner. Mechanistically, omentin-1 ameliorated the expression of interferon regulatory factor 1 (IRF-1) by blocking the JAK-2/STAT3 pathway. Our results indicate that omentin-1 may have a potential chondroprotective therapeutic capacity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Effects of gastric bypass followed by a randomized study of physical training on markers of coagulation activation, fibrin clot properties, and fibrinolysis

DEFF Research Database (Denmark)

Stolberg, Charlotte Røn; Mundbjerg, Lene Hymøller; Funch-Jensen, Peter

2018-01-01

disease risk markers within coagulation activation, fibrin clot properties, and fibrinolysis. Setting: Bariatric center, Hospital of Southwest Jutland, Denmark. Methods: Sixty obese patients underwent RYGB and 6 months after RYGB were randomized to 26 weeks of physical training or a control group...

Platelet rich fibrin and alloplast in the treatment of intrabony defect

Directory of Open Access Journals (Sweden)

Saurav Panda

2014-01-01

Full Text Available Periodontal regeneration is defined as the reproduction or reconstitution of a lost or injured part to restore the architecture and function of the periodontium. The ultimate goal of periodontal therapy is to regenerate the lost periodontal tissues caused by periodontitis. The most positive outcome of periodontal regenerative procedures in intra bony defect has been achieved with bone grafts. For complete regeneration, delivery of growth factors in a local environment holds a great deal in adjunct to bone grafts. Platelet rich fibrin (PRF is considered as second generation platelet concentrate, consisting of viable platelets, releasing various growth factors. Hence, this case report aims to investigate the clinical and radiological (bone fill effectiveness of autologous PRF along with the use of alloplastic bone mineral in the treatment of intra bony defects.

Release of tensile strain on engineered human tendon tissue disturbs cell adhesions, changes matrix architecture, and induces an inflammatory phenotype

DEFF Research Database (Denmark)

Bayer, Monika L; Schjerling, Peter; Herchenhan, Andreas

2014-01-01

Mechanical loading of tendon cells results in an upregulation of mechanotransduction signaling pathways, cell-matrix adhesion and collagen synthesis, but whether unloading removes these responses is unclear. We investigated the response to tension release, with regard to matrix proteins, pro......-inflammatory mediators and tendon phenotypic specific molecules, in an in vitro model where tendon-like tissue was engineered from human tendon cells. Tissue sampling was performed 1, 2, 4 and 6 days after surgical de-tensioning of the tendon construct. When tensile stimulus was removed, integrin type collagen receptors...... were upregulated. Stimulation with the cytokine TGF-β1 had distinct effects on some tendon-related genes in both tensioned and de-tensioned tissue. These findings indicate an important role of mechanical loading for cellular and matrix responses in tendon, including that loss of tension leads...

Human Adipose Tissue Derived Extracellular Matrix and Methylcellulose Hydrogels Augments and Regenerates the Paralyzed Vocal Fold.

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Kim, Dong Wook; Kim, Eun Ji; Kim, Eun Na; Sung, Myung Whun; Kwon, Tack-Kyun; Cho, Yong Woo; Kwon, Seong Keun

2016-01-01

Vocal fold paralysis results from various etiologies and can induce voice changes, swallowing complications, and issues with aspiration. Vocal fold paralysis is typically managed using injection laryngoplasty with fat or synthetic polymers. Injection with autologous fat has shown excellent biocompatibility. However, it has several disadvantages such as unpredictable resorption rate, morbidities associated with liposuction procedure which has to be done in operating room under general anesthesia. Human adipose-derived extracellular matrix (ECM) grafts have been reported to form new adipose tissue and have greater biostability than autologous fat graft. Here, we present an injectable hydrogel that is constructed from adipose tissue derived soluble extracellular matrix (sECM) and methylcellulose (MC) for use in vocal fold augmentation. Human sECM derived from adipose tissue was extracted using two major steps-ECM was isolated from human adipose tissue and was subsequently solubilized. Injectable sECM/MC hydrogels were prepared by blending of sECM and MC. Sustained vocal fold augmentation and symmetric vocal fold vibration were accomplished by the sECM/MC hydrogel in paralyzed vocal fold which were confirmed by laryngoscope, histology and a high-speed imaging system. There were increased number of collagen fibers and fatty granules at the injection site without significant inflammation or fibrosis. Overall, these results indicate that the sECM/MC hydrogel can enhance vocal function in paralyzed vocal folds without early resorption and has potential as a promising material for injection laryngoplasty for stable vocal fold augmentation which can overcome the shortcomings of autologous fat such as unpredictable duration and morbidity associated with the fat harvest.

Management of a complicated pulmonary fistula caused by lung cancer using a fibrin glue-soaked polyglycolic acid sheet covered with an intercostal muscle flap.

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Maniwa, Tomohiro; Kaneda, Hiroyuki; Saito, Yukihito

2009-06-01

Pulmonary fistulas caused by tumours are very fragile and difficult to suture directly. It is impossible to close pulmonary fistulas with tissue sealants when massive air leakage occurs in the low pressure of the respiratory tract. A 73-year-old man with a pneumothorax caused by lung cancer had suffered a persistent massive air leakage for more than one month. We used a fibrin glue-soaked polyglycolic acid (PGA) sheet for sealing the complicated fistula. In addition, the visceral pleura of the fistula was wrapped with the pedicle of an intercostal muscle (ICM) flap to prevent massive air leakage. The pneumothorax did not reappear after surgery. Thus, a fibrin glue-soaked PGA sheet covered with an ICM flap was effective for sealing an intractable air-leaking fistula caused by lung cancer.

Oxygen tension is a determinant of the matrix-forming phenotype of cultured human meniscal fibrochondrocytes.

Directory of Open Access Journals (Sweden)

Adetola B Adesida

Full Text Available BACKGROUND: Meniscal cartilage displays a poor repair capacity, especially when injury is located in the avascular region of the tissue. Cell-based tissue engineering strategies to generate functional meniscus substitutes is a promising approach to treat meniscus injuries. Meniscus fibrochondrocytes (MFC can be used in this approach. However, MFC are unable to retain their phenotype when expanded in culture. In this study, we explored the effect of oxygen tension on MFC expansion and on their matrix-forming phenotype. METHODOLOGY/PRINCIPAL FINDINGS: MFC were isolated from human menisci followed by basic fibroblast growth factor (FGF-2 mediated cell expansion in monolayer culture under normoxia (21%O(2 or hypoxia (3%O(2. Normoxia and hypoxia expanded MFC were seeded on to a collagen scaffold. The MFC seeded scaffolds (constructs were cultured in a serum free chondrogenic medium for 3 weeks under normoxia and hypoxia. Constructs containing normoxia-expanded MFC were subsequently cultured under normoxia while those formed from hypoxia-expanded MFC were subsequently cultured under hypoxia. After 3 weeks of in vitro culture, the constructs were assessed biochemically, histologically and for gene expression via real-time reverse transcription-PCR assays. The results showed that constructs under normoxia produced a matrix with enhanced mRNA ratio (3.5-fold higher; p<0.001 of collagen type II to I. This was confirmed by enhanced deposition of collagen II using immuno-histochemistry. Furthermore, the constructs under hypoxia produced a matrix with higher mRNA ratio of aggrecan to versican (3.5-fold, p<0.05. However, both constructs had the same capacity to produce a glycosaminoglycan (GAG -specific extracellular matrix. CONCLUSIONS: Our data provide evidence that oxygen tension is a key player in determining the matrix phenotype of cultured MFC. These findings suggest that the use of normal and low oxygen tension during MFC expansion and subsequent neo

Bulk metallic glass matrix composite for good biocompatibility

International Nuclear Information System (INIS)

Hadjoub, F; Metiri, W; Doghmane, A; Hadjoub, Z

2012-01-01

Reinforcement volume fraction effects on acoustical parameters of Zr 41.2 Ti 13.8 Cu 12.5 Ni 10 Be 22.5 matrix composites reinforced by Mg, Ag and Cd metals have been studied via a simulation program based on acoustic microscopy technique. Moreover, acoustical parameters of human bone were compared to those of BMGs in both monolithic and reinforced case. It was found that elastic behavior of BMGs matrix composites in high reinforcement volume fraction is similar of that of human bone. This behavior leads to high biocompatibility and good transfer of stress between composite material and human system.

Effect of Human Serum and 2 Different Types of Platelet Concentrates on Human Meniscus Cell Migration, Proliferation, and Matrix Formation.

Science.gov (United States)

Freymann, Undine; Metzlaff, Sebastian; Krüger, Jan-Philipp; Hirsh, Glen; Endres, Michaela; Petersen, Wolf; Kaps, Christian

2016-06-01

To evaluate the effect of 10% human serum (HS), 5% platelet-rich plasma (PRP), and 5% autologous conditioned plasma (ACP) on migration, proliferation, and extracellular matrix (ECM) synthesis of human meniscus cells. Cell migration and proliferation on stimulation with HS, PRP, and ACP were assessed by chemotaxis assays and measurement of genomic DNA content. Meniscus cells were cultivated in pellets stimulated with 10% HS, 5% PRP, or 5% ACP. Meniscal ECM formation was evaluated by histochemical staining of collagen type I, type II, and proteoglycans and by analysis of fibrochondrocyte marker gene expression. Human meniscus cells were significantly attracted by all 3 blood-derived products (10% HS and 5% ACP: P = .0001, 5% PRP: P = .0002). Cell proliferation at day 9 was significantly increased on stimulation with 10% HS (P = .0001) and 5% PRP (P = .0002) compared with 5% ACP and controls. Meniscus cell pellet cultures showed the formation of a well-structured meniscal ECM with deposition of collagen type I, type II, and proteoglycans on stimulation with 10% HS, whereas 5% PRP or 5% ACP resulted in the formation of an inhomogeneous and more fibrous ECM. Stimulation with 10% HS and 5% ACP showed a significant induction of fibrochondrocyte marker genes such as aggrecan (HS: P = .0002, ACP: P = .0147), cartilage oligomeric matrix protein (HS: P = .0002, ACP: P = .0005), and biglycan (HS: P = .0002, ACP: P = .0003), whereas PRP showed no inducing effect. Among all tested blood-derived products, only stimulation with HS showed the formation of a meniscal ECM as well as positive cell proliferating and migrating effects in vitro. Regarding a potential biological repair of nonvascular meniscus lesions, our results may point toward the use of HS as a beneficial augment in regenerative meniscus repair approaches. Our findings may suggest that HS might be a beneficial augment for meniscus repair. Copyright © 2016 Arthroscopy Association of North America. Published

Effects of an injectable platelet-rich fibrin on osteoblast behavior and bone tissue formation in comparison to platelet-rich plasma.

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Wang, Xuzhu; Zhang, Yufeng; Choukroun, Joseph; Ghanaati, Shahram; Miron, Richard J

2018-01-01

Platelet-rich plasma (PRP) has been utilized for many years as a regenerative agent capable of inducing vascularization of various tissues using blood-derived growth factors. Despite this, drawbacks mostly related to the additional use of anti-coagulants found in PRP have been shown to inhibit the wound healing process. For these reasons, a novel platelet concentrate has recently been developed with no additives by utilizing lower centrifugation speeds. The purpose of this study was therefore to investigate osteoblast behavior of this novel therapy (injectable-platelet-rich fibrin; i-PRF, 100% natural with no additives) when compared to traditional PRP. Human primary osteoblasts were cultured with either i-PRF or PRP and compared to control tissue culture plastic. A live/dead assay, migration assay as well as a cell adhesion/proliferation assay were investigated. Furthermore, osteoblast differentiation was assessed by alkaline phosphatase (ALP), alizarin red and osteocalcin staining, as well as real-time PCR for genes encoding Runx2, ALP, collagen1 and osteocalcin. The results showed that all cells had high survival rates throughout the entire study period irrespective of culture-conditions. While PRP induced a significant 2-fold increase in osteoblast migration, i-PRF demonstrated a 3-fold increase in migration when compared to control tissue-culture plastic and PRP. While no differences were observed for cell attachment, i-PRF induced a significantly higher proliferation rate at three and five days when compared to PRP. Furthermore, i-PRF induced significantly greater ALP staining at 7 days and alizarin red staining at 14 days. A significant increase in mRNA levels of ALP, Runx2 and osteocalcin, as well as immunofluorescent staining of osteocalcin was also observed in the i-PRF group when compared to PRP. In conclusion, the results from the present study favored the use of the naturally-formulated i-PRF when compared to traditional PRP with anti

Ultrasound-responsive gene-activated matrices for osteogenic gene therapy using matrix-assisted sonoporation.

Science.gov (United States)

Nomikou, N; Feichtinger, G A; Saha, S; Nuernberger, S; Heimel, P; Redl, H; McHale, A P

2018-01-01

Gene-activated matrix (GAM)-based therapeutics for tissue regeneration are limited by efficacy, the lack of spatiotemporal control and availability of target cells, all of which impact negatively on their translation to the clinic. Here, an advanced ultrasound-responsive GAM is described containing target cells that facilitates matrix-assisted sonoporation (MAS) to induce osteogenic differentiation. Ultrasound-responsive GAMs consisting of fibrin/collagen hybrid-matrices containing microbubbles, bone morphogenetic protein BMP2/7 coexpression plasmids together with C2C12 cells were treated with ultrasound either in vitro or following parenteral intramuscular implantation in vivo. Using direct measurement for alkaline phosphatase activity, von Kossa staining and immunohistochemical analysis for osteocalcin expression, MAS-stimulated osteogenic differentiation was confirmed in the GAMs in vitro 7 days after treatment with ultrasound. At day 30 post-treatment with ultrasound, ectopic osteogenic differentiation was confirmed in vivo using X-ray microcomputed tomography and histological analysis. Osteogenic differentiation was indicated by the presence of ectopic bone structures in all animals treated with MAS. In addition, bone volumes in this group were statistically greater than those in the control groups. This novel approach of incorporating a MAS capability into GAMs could be exploited to facilitate ex vivo gene transfer with subsequent surgical implantation or alternatively provide a minimally invasive means of stimulating in situ transgene delivery for osteoinductive gene-based therapies. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

The role of the lysyl binding site of tissue-type plasminogen activator in the interaction with a forming fibrin clot

NARCIS (Netherlands)

Bakker, A.H.F.; Weening-Verhoeff, E.J.D.; Verheijen, J.H.

1995-01-01

To describe the role of the lysyl binding site in the interaction of tissue-type plasminogen activator (t-PA, FGK1K2P) with a forming fibrin clot, we performed binding experiments with domain deletion mutants GK1K2P, K2P, and the corresponding point mutants lacking the lysyl binding site in the

Two-way regulation between cells and aligned collagen fibrils: local 3D matrix formation and accelerated neural differentiation of human decidua parietalis placental stem cells.