Science.gov

Sample records for fibrin glue scaffold

  1. Evaluation of bone matrix gelatin/fibrin glue and chitosan/gelatin composite scaffolds for cartilage tissue engineering.

    PubMed

    Wang, Z H; Zhang, J; Zhang, Q; Gao, Y; Yan, J; Zhao, X Y; Yang, Y Y; Kong, D M; Zhao, J; Shi, Y X; Li, X L

    2016-01-01

    This study was designed to evaluate bone matrix gelatin (BMG)/fibrin glue and chitosan/gelatin composite scaffolds for cartilage tissue engineering. Chondrocytes were isolated from costal cartilage of Sprague-Dawley rats and seeded on BMG/fibrin glue or chitosan/gelatin composite scaffolds. After different in vitro culture durations, the scaffolds were subjected to hematoxylin and eosin, Masson's trichrome, and toluidine blue staining, anti-collagen II and anti-aggrecan immunohistochemistry, and scanning electronic microscopy (SEM) analysis. After 2 weeks of culture, chondrocytes were distributed evenly on the surfaces of both scaffolds. Cell numbers and the presence of extracellular matrix components were markedly increased after 8 weeks of culture, and to a greater extent on the chitosan/gelatin scaffold. The BMG/fibrin glue scaffold showed signs of degradation after 8 weeks. Immunofluorescence analysis confirmed higher levels of collagen II and aggrecan using the chitosan/gelatin scaffold. SEM revealed that the majority of cells on the surface of the BMG/fibrin glue scaffold demonstrated a round morphology, while those in the chitosan/gelatin group had a spindle-like shape, with pseudopodia. Chitosan/gelatin scaffolds appear to be superior to BMG/ fibrin glue constructs in supporting chondrocyte attachment, proliferation, and biosynthesis of cartilaginous matrix components. PMID:27525846

  2. Fibrin glue in ophthalmology

    PubMed Central

    Panda, Anita; Kumar, Sandeep; Kumar, Abhiyan; Bansal, Raseena; Bhartiya, Shibal

    2009-01-01

    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. PMID:19700876

  3. Autologous Fibrin Glue as an Encapsulating Scaffold for Delivery of Retinal Progenitor Cells

    PubMed Central

    Ahmed, Tamer A. E.; Ringuette, Randy; Wallace, Valerie A.; Griffith, May

    2015-01-01

    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 down-regulation of the progenitor marker SOX2 and enhanced the expression of the differentiation markers cone-rod homeobox 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. PMID:25692127

  4. Evaluation of an in vivo heterotopic model of osteogenic differentiation of equine bone marrow and muscle mesenchymal stem cells in fibrin glue scaffold.

    PubMed

    McDuffee, Laurie A; Esparza Gonzalez, Blanca P; Nino-Fong, Rodolfo; Aburto, Enrique

    2014-02-01

    Autologous mesenchymal stem cells (MSCs) have been used as a potential cell-based therapy in various animal and human diseases. Their differentiation capacity makes them useful as a novel strategy in the treatment of tissue injury in which the healing process is compromised or delayed. In horses, bone healing is slow, taking a minimum of 6-12 months. The osteogenic capacity of equine bone marrow and muscle MSCs mixed with fibrin glue or phosphate-buffered saline (PBS) as a scaffold is assessed. Bone production by the following groups was compared: Group 1, bone marrow (BM) MSCs in fibrin glue; Group 2, muscle (M) MSCs in fibrin glue; Group 3, BM MSCs in PBS; Group 4, M MSCs in PBS and as a control; Group 5, fibrin glue without cells. BM and M MSCs underwent osteogenic stimulation for 48 h prior to being injected intramuscularly into nude mice. After 4 weeks, the mice were killed and muscle samples were collected and evaluated for bone formation and mineralization by using radiology, histochemistry and immunohistochemistry. Positive bone formation and mineralization were confirmed in Group 1 in nude mice based on calcium deposition and the presence of osteocalcin and collagen type I; in addition, a radiopaque area was observed on radiographs. However, no evidence of mineralization or bone formation was observed in Groups 2-5. In this animal model, equine BM MSCs mixed with fibrin glue showed better osteogenic differentiation capacity compared with BM MSCs in PBS and M MSCs in either carrier. PMID:24258028

  5. [Fibrin glue and bone regeneration].

    PubMed

    Zilch, H; Wolff, R

    1987-01-01

    The osteoinductive property of fibrin glue with and without admixture of aprotinin was proven in animal model. Aprotinin as an inhibitor of the fibrinolysis is supposed to be an inhibitor of the osteogenesis, too. Three holes of 4 mm diameter and 2 mm depth were placed into the diaphysis of both femura in 12 adults dogs. The defects were filled with either pure fibrin glue or with glue containing aprotinin (3000 KIE), or with nothing (vacant). After 8 weeks the quantity of the new built woven-bone was examined by plane geometry and the "Bone Metabolising Unit (BMU)" (Frost) which are crossing the border of lamellar bone and new woven bone were counted out. There was seen no statistical significantly between the three groups neither in the quantity of new bone nor in the BMU. Therefore the fibrin glue has no osteoinductive property. PMID:2441537

  6. Fibrin glue is a candidate scaffold for long-term therapeutic protein expression in spontaneously differentiated adipocytes in vitro

    SciTech Connect

    Aoyagi, Yasuyuki; Kuroda, Masayuki; Asada, Sakiyo; Tanaka, Shigeaki; Konno, Shunichi; Tanio, Masami; Aso, Masayuki; Okamoto, Yoshitaka; Nakayama, Toshinori; Saito, Yasushi; Bujo, Hideaki

    2012-01-01

    Adipose tissue is expected to provide a source of cells for protein replacement therapies via auto-transplantation. However, the conditioning of the environment surrounding the transplanted adipocytes for their long-term survival and protein secretion properties has not been established. We have recently developed a preparation procedure for preadipocytes, ceiling culture-derived proliferative adipocytes (ccdPAs), as a therapeutic gene vehicle suitable for stable gene product secretion. We herein report the results of our evaluation of using fibrin glue as a scaffold for the transplanted ccdPAs for the expression of a transduced gene in a three-dimensional culture system. The ccdPAs secreted the functional protein translated from an exogenously transduced gene, as well as physiological adipocyte proteins, and the long viability of ccdPAs (up to 84 days) was dependent on the fibrinogen concentrations. The ccdPAs spontaneously accumulated lipid droplets, and their expression levels of the transduced exogenous gene with its product were maintained for at least 56 days. The fibrinogen concentration modified the adipogenic differentiation of ccdPAs and their exogenous gene expression levels, and the levels of exogenously transduced gene expression at the different fibrinogen concentrations were dependent on the extent of adipogenic differentiation in the gel. These results indicate that fibrin glue helps to maintain the high adipogenic potential of cultured adipocytes after passaging in a 3D culture system, and suggests that once they are successfully implanted at the transplantation site, the cells exhibit increased expression of the transduced gene with adipogenic differentiation.

  7. Comparative repair capacity of knee osteochondral defects using regenerated silk fiber scaffolds and fibrin glue with/without autologous chondrocytes during 36 weeks in rabbit model.

    PubMed

    Kazemnejad, Somaieh; Khanmohammadi, Manijeh; Mobini, Sahba; Taghizadeh-Jahed, Masoud; Khanjani, Sayeh; Arasteh, Shaghayegh; Golshahi, Hannaneh; Torkaman, Giti; Ravanbod, Roya; Heidari-Vala, Hamed; Moshiri, Ali; Tahmasebi, Mohammad-Naghi; Akhondi, Mohammad-Mehdi

    2016-06-01

    The reconstruction capability of osteochondral (OCD) defects using silk-based scaffolds has been demonstrated in a few studies. However, improvement in the mechanical properties of natural scaffolds is still challengeable. Here, we investigate the in vivo repair capacity of OCD defects using a novel Bombyx mori silk-based composite scaffold with great mechanical properties and porosity during 36 weeks. After evaluation of the in vivo biocompatibility and degradation rate of these scaffolds, we examined the effectiveness of these fabricated scaffolds accompanied with/without autologous chondrocytes in the repair of OCD lesions of rabbit knees after 12 and 36 weeks. Moreover, the efficiency of these scaffolds was compared with fibrin glue (FG) as a natural carrier of chondrocytes using parallel clinical, histopathological and mechanical examinations. The data on subcutaneous implantation in mice showed that the designed scaffolds have a suitable in vivo degradation rate and regenerative capacity. The repair ability of chondrocyte-seeded scaffolds was typically higher than the scaffolds alone. After 36 weeks of implantation, most parts of the defects reconstructed by chondrocytes-seeded silk scaffolds (SFC) were hyaline-like cartilage. However, spontaneous healing and filling with a scaffold alone did not eventuate in typical repair. We could not find significant differences between quantitative histopathological and mechanical data of SFC and FGC. The fabricated constructs consisting of regenerated silk fiber scaffolds and chondrocytes are safe and suitable for in vivo repair of OCD defects and promising for future clinical trial studies. PMID:26822846

  8. Fibrin Glue as a Drug Delivery System

    PubMed Central

    Spicer, Patrick P.; Mikos, Antonios G.

    2010-01-01

    Fibrin glue has been used surgically for decades for hemostasis as well as a sealant. It has also been researched as both a gel for cell delivery and a vehicle for drug delivery. The drug delivery applications for fibrin glue span tissue engineering to chemotherapy and involve several mechanisms for drug matrix interactions and control of release kinetics. Additionally, drugs or factors can be loaded in the gel via impregnation and tethering to the gel through covalent linkages or affinity based systems. This review highlights recent research of fibrin glue as a drug delivery vehicle. PMID:20637815

  9. Adhesive strength of autologous fibrin glue.

    PubMed

    Yoshida, H; Hirozane, K; Kamiya, A

    2000-03-01

    To establish an easy and rapid method for measuring the adhesive strength of fibrin glue and to clarify the factor(s) most affecting the strength, a study was made on the effect of the concentration of plasma components on the strength of cryoprecipitate (Cryo) prepared from a subject's own autologous plasma to be used as fibrin glue. The adhesive strength of the Cryo was measured with various supporting materials instead of animal skin using a tester of tension and compression. The results were as follows: (1) the strength of Cryo applied to ground flat glass (4 cm2) was significantly greater than that applied to clear glass, clear plastic, or smooth and flat wood chips; (2) the adhesive strength of Cryo depended on the concentration of thrombin with the optimal concentration being 50 units/ml; (3) the concentration of CaCl2 did not affect the adhesive strength of Cryo; (4) the adhesive reaction was dependent on the temperature and the adhesive strength more quickly reached a steady state at 37 degrees C than at lower temperature; (5) the adhesive strength was correlated well with the total concentration of fibrinogen and fibronectin. These results indicate that the adhesive strength of Cryo can be easily and quickly evaluated using a tester and ground glass with thrombin at 50 units/ml, and that the adhesive strength of Cryo can be predicted from the total concentration of fibrinogen and fibronectin. PMID:10726885

  10. [Treatment of pseudoarthrosis of the carpal scaphoid with fibrin glue].

    PubMed

    Carozzi, S

    1983-08-01

    The author think that "Fibrin Seal Glue" and mechanical syntesis is an opimal method for osteosintesis of the Carpal scaphoid. He speaks about 5 patients treated with optimal results in 50 days mean. PMID:6395974

  11. Effect of collagen sponge and fibrin glue on bone repair

    PubMed Central

    SANTOS, Thiago de Santana; ABUNA, Rodrigo Paolo Flores; de ALMEIDA, Adriana Luisa Gonçalves; BELOTI, Marcio Mateus; ROSA, Adalberto Luiz

    2015-01-01

    ABSTRACT The ability of hemostatic agents to promote bone repair has been investigated using in vitro and in vivo models but, up to now, the results are inconclusive. Objective In this context, the aim of this study was to compare the potential of bone repair of collagen sponge with fibrin glue in a rat calvarial defect model. Material and Methods Defects of 5 mm in diameter were created in rat calvariae and treated with either collagen sponge or fibrin glue; untreated defects were used as control. At 4 and 8 weeks, histological analysis and micro-CT-based histomorphometry were carried out and data were compared by two-way ANOVA followed by Student-Newman-Keuls test when appropriated (p≤0.05). Results Three-dimensional reconstructions showed increased bone formation in defects treated with either collagen sponge or fibrin glue compared with untreated defects, which was confirmed by the histological analysis. Morphometric parameters indicated the progression of bone formation from 4 to 8 weeks. Additionally, fibrin glue displayed slightly higher bone formation rate when compared with collagen sponge. Conclusion Our results have shown the benefits of using collagen sponge and fibrin glue to promote new bone formation in rat calvarial bone defects, the latter being discreetly more advantageous. PMID:26814464

  12. Successful management of congenital chyloperitoneum with fibrin glue.

    PubMed

    Antao, Brice; Croaker, David; Squire, Roly

    2003-11-01

    Chylous ascites in children has been treated in a variety of ways, including a low-fat diet, medium chain triglycerides, diuretics, total parental nutrition, surgical exploration, and internal peritoneo-venous shunting. The authors describe a child with persistent congenital chyloperitoneum treated successfully with the application of fibrin glue and recommend this as an effective alternative to traditional approaches. PMID:14614734

  13. Use of autologous fibrin glue for endoscopic treatment of esophageal lesions

    PubMed Central

    Lucas, Matthias; Seeber, Petra

    2015-01-01

    Background and study aims: Esophageal leaks are a potentially life-threatening condition. One treatment option is injection therapy with commercially available fibrin glue. We describe herein a method to close esophageal leaks by injecting autologous fibrin glue prepared exclusively with the patient's own blood. PMID:26528493

  14. Warning: fatal reaction to the use of fibrin glue in deep hepatic wounds. Case reports.

    PubMed

    Berguer, R; Staerkel, R L; Moore, E E; Moore, F A; Galloway, W B; Mockus, M B

    1991-03-01

    Two cases of severe hypotension following the use of fibrin glue for hemostasis in hepatic injuries are reported. A systemic reaction to bovine thrombin via large venous lacerations is suspected. A preliminary animal study supports this hypothesis. Caution is advised in the use of fibrin glue for hemostasis in deep hepatic wounds. PMID:2002531

  15. Sutureless colon anastomosis with fibrin glue in the rat.

    PubMed

    Haukipuro, K A; Hulkko, O A; Alavaikko, M J; Laitinen, S T

    1988-08-01

    The only technique available for creating an intestinal anastomosis without tissue strangulation is gluing. Theoretically, this could lead to a higher hydroxyproline content and greater mechanical strength than in a sutured anastomosis. To test the hypothesis, 83 rats underwent left colon resection and inverted primary anastomosis with either one layer of sutures (NG group) or fibrin glue (FG group). Seven-day FG anastomoses showed less adhesions (P = .02) but one subclinical leakage and a further radiologic one, compared with a greater amount of adhesions but no leakages in the NG group. The mean bursting pressures (mmHg) in the FG and NG groups, respectively, were 25 +/- 20 (SD) and 63 +/- 23 (N.S.) 30 minutes after surgery, 107 +/- 33 and 115 +/- 30 after one day, 81 +/- 31 and 133 +/- 26 (P less than .001) after four days, and 161 +/- 36 and 175 +/- 24 after seven days. The somewhat earlier rise in hydroxyproline content in the glued anastomoses did not lead to significant intergroup differences. The glued anastomoses were thus weak during the critical lag period of healing. Also, by preventing adhesion formation, the glue may reduce the extra blood supply from perianastomotic vessels. The outcomes might have differed more under demanding experimental or clinical situations. PMID:2456902

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

    PubMed Central

    Langer, Stefan; Schildhauer, Thomas A.; Dudda, Marcel; Sauber, Jeannine; Spindler, Nick

    2015-01-01

    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. PMID:26759762

  17. Hybrid composites of calcium phosphate granules, fibrin glue, and bone marrow for skeletal repair.

    PubMed

    Le Nihouannen, Damien; Goyenvalle, Eric; Aguado, Eric; Pilet, Paul; Bilban, Melitta; Daculsi, Guy; Layrolle, Pierre

    2007-05-01

    Synthetic bone substitutes, such as calcium phosphate ceramics, give good results in clinical applications. In order to adapt to surgical sites, bioceramics come in the form of blocks or granules, and are either dense or porous. Combining these bioceramics with fibrin glue provides a mouldable and self-hardening composite biomaterial with the biochemical properties of each component. Critical-sized defects in the femoral condyle of rabbits were filled with TricOs/fibrin glue/bone marrow hybrid/composite material. The TricOs granules (1-2 mm) were composed of hydroxyapatite and beta tricalcium phosphate (60/40 in weight). The fibrin glue was composed of fibrinogen, thrombin and other biological factors and mixed with MBCP granules either simultaneously or sequentially. Bone marrow was also added to the MBCP/fibrin composite prior to filling the defects. After 3, 6, 12, and 24 weeks of implantation, the newly-formed bone was analysed with histology, histomorphometry and mechanical tests. The newly-formed bone had grown centripetally. Simultaneous application of fibrin glue showed better results for mechanical properties than sequential application after 6 weeks. Around 40% of bone had formed after 24 weeks in the three groups. Although the addition of bone marrow did not improve bone formation, the MBCP/fibrin material could be used in clinical bone filling applications. PMID:17117470

  18. Clinical evaluations of autologous fibrin glue and polyglycolic acid sheets as oral surgical wound coverings after partial glossectomy.

    PubMed

    Kouketsu, Atsumu; Nogami, Shinnosuke; Fujiwara, Minami; Mori, Shiro; Yamauchi, Kensuke; Hashimoto, Wataru; Miyashita, Hitoshi; Kurihara, Jun; Kawai, Tadashi; Higuchi, Keisuke; Takahashi, Tetsu

    2016-08-01

    Polyglycolic acid (PGA) sheets and commercial fibrin glue are commonly used to cover open wound surfaces in oral surgery. Compared to commercial fibrin glue composed of pooled allogeneic blood, autologous fibrin glue is less expensive and poses lower risks of viral infection and allergic reaction. Here, we evaluated postoperative pain, scar contracture, ingestion, tongue dyskinesia, and postoperative bleeding in 24 patients who underwent partial glossectomy plus the application of a PGA sheet and an autologous fibrin glue covering (autologous group) versus 11 patients in whom a PGA sheet and commercial fibrin glue were used (allogeneic group). The evaluated clinical measures were nearly identical in both groups. Remarkable wound surface granulation was recognized in two cases in the autologous group. No complications were observed in either group, including viral infection or allergic reaction. Abnormal postoperative bleeding in the wound region was observed in one case in the allogeneic group. Coagulation and adhesion of the autologous fibrin glue were equivalent to those of conventional therapy with a PGA sheet and commercial fibrin glue. Thus, our results show that covering wounds with autologous fibrin glue and PGA sheets may help avoid the risks of viral infection and allergic reaction in partial glossectomy cases. PMID:27341770

  19. A new technique using fibrin glue in the management of auricular hematoma.

    PubMed

    Mohamad, Shwan H; Barnes, Martyn; Jones, Stephen; Mahendran, Suresh

    2014-11-01

    : This study aims to describe a new technique for the management of auricular hematoma using fibrin glue. Five difficult cases of auricular hematoma were managed using this technique, including 2 recurrent and 3 delayed presentations. After skin preparation and local anesthetic, an incision was made, the hematoma was evacuated, and the cavity was washed out with saline. Fibrin glue was applied liberally; a dental roll pressure dressing was applied and secured with a prolene bead suture. The patients were given a course of oral antibiotic and reviewed after 5 days for removal of the external dressing. They were later assessed to exclude re-accumulation of the hematoma. All patients had complete resolution of the hematoma without re-accumulation; they were satisfied with the cosmetic results and experienced no complications. This case series provides evidence that fibrin glue is effective in the management of auricular hematoma. Larger studies may provide further evidence of the effectiveness of this new technique. PMID:24699189

  20. Characterization of a fibrin glue-GDNF slow-release preparation.

    PubMed

    Cheng, H; Fraidakis, M; Blombäck, B; Lapchak, P; Hoffer, B; Olson, L

    1998-01-01

    One novel method to deliver trophic factor locally in the CNS is to mix it into fibrin glue. In the present studies, [125I]-labeled GDNF-containing fibrin glue balls were used to determine binding and spread of the trophic factor. First, the binding of different concentrations of [125I]-labeled GDNF in fibrin glue was determined in vitro. Within the six concentrations used (from 200 nM to 0.004 nM, 0 M as control), there was a strong linear correlation between the [125I]-GDNF concentration and the recovered radioactivity (r = 0.992). The mean bound radioactivity in 16 samples with 4 nM [125I]-GDNF was 71262 +/- 2710 CPM, and accounted for 89.8% of the mean initial count of free [125I]-GDNF (79369 +/- 3499 CPM). Second, [125I]-GDNF-containing glue balls were implanted into the anterior chamber of adult rats. The implanted fibrin glue balls decreased in size with time, but could still be identified on the irises 2 wk after implantation. Radioactivity was concentrated at the implantation sites in the early stages with a distribution in the surrounding iris tissue, which became separated into focal radioactive spots at the third week. Counts of radioactivity were significantly higher in the [125I]-GDNF glue ball-implanted irises than controls until 14 days after implantation. A study of the [125I] decay over time using least-squares linear regression demonstrated first-order kinetics (r = -0.98, p <0.02) with k = 0.0091 and T 1/2 = 76 h. Finally, [125I]-GDNF-containing glue balls were implanted in the spinal cord of adult rats. Radioactivity was concentrated at the implantation sites in the early stages and was later distributed more widely in the surrounding thoracic cord. The [125I]-GDNF-containing glue degraded over time and became a porous meshwork with decreasing radioactivity at the later time points. Radioactivity in the spinal cords subjected to implantation of [125I]-GDNF-containing glue balls was higher than in controls for 14 days. Study of the [125I] decay

  1. Hemostasis of solid viscus trauma by intraparenchymal injection of fibrin glue.

    PubMed

    Hauser, C J

    1989-03-01

    Fibrin glue (FG) is an effective hemostatic agent applied topically to the spleen. In this study, FG was found to be an effective hemostatic agent when applied topically in standardized wounds of the canine liver, spleen, and pancreas. It was markedly more effective, however, when injected intraparenchymally. In a case of severe blunt trauma in a patient with acute alcoholic hepatitis, intraparenchymal FG was lifesaving. Fibrin glue is a useful adjunct in the management of trauma to all the abdominal solid viscera. Intraparenchymal injection is the preferred mode of FG application. PMID:2465750

  2. Scaffold architecture and fibrin gels promote meniscal cell proliferation

    SciTech Connect

    Pawelec, K. M. E-mail: jw626@cam.ac.uk; Best, S. M.; Cameron, R. E.; Wardale, R. J. E-mail: jw626@cam.ac.uk

    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.

  3. Microporous Nanofibrous Fibrin-based Scaffolds for Bone Tissue Engineering

    PubMed Central

    Osathanon, Thanaphum; Linnes, Michael L.; Rajachar, Rupak M.; Ratner, Buddy D.; Somerman, Martha J.; Giachelli, Cecilia M.

    2008-01-01

    The fibrotic response of the body to synthetic polymers limits their success in tissue engineering and other applications. Though porous polymers have demonstrated improved healing, difficulty in controlling their pore sizes and pore interconnections has clouded the understanding of this phenomenon. In this study, a novel method to fabricate natural polymer/calcium phosphate composite scaffolds with tightly controllable pore size, pore interconnection, and calcium phosphate deposition was developed. Microporous, nanofibrous fibrin scaffolds were fabricated using sphere-templating methods. Composite scaffolds were created by solution deposition of calcium phosphate on fibrin surfaces or by direct incorporation of nanocrystalline hydroxyapatite (nHA). The SEM results showed that fibrin scaffolds exhibited a highly porous and interconnected structure. Osteoblast-like cells, obtained from murine calvaria, attached, spread and showed a polygonal morphology on the surface of the biomaterial. Multiple cell layers and fibrillar matrix deposition were observed. Moreover, cells seeded on mineralized fibrin scaffolds exhibited significantly higher alkaline phosphatase activity as well as osteoblast marker gene expression compared to fibrin scaffolds and nHA incorporated fibrin scaffolds (0.25 g and 0.5 g). All types of scaffolds were degraded both in vitro and in vivo. Furthermore, these scaffolds promoted bone formation in a mouse calvarial defect model and the bone formation was enhanced by addition of rhBMP-2. PMID:18640716

  4. Fibrin glue repair leads to enhanced axonal elongation during early peripheral nerve regeneration in an in vivo mouse model

    PubMed Central

    Koulaxouzidis, Georgios; Reim, Gernot; Witzel, Christian

    2015-01-01

    Microsurgical suturing is the gold standard of nerve coaptation. Although literature on the usefulness of fibrin glue as an alternative is becoming increasingly available, it remains contradictory. Furthermore, no data exist on how both repair methods might influence the morphological aspects (arborization; branching) of early peripheral nerve regeneration. We used the sciatic nerve transplantation model in thy-1 yellow fluorescent protein mice (YFP; n = 10). Pieces of nerve (1cm) were grafted from YFP-negative mice (n = 10) into those expressing YFP. We performed microsuture coaptations on one side and used fibrin glue for repair on the contralateral side. Seven days after grafting, the regeneration distance, the percentage of regenerating and arborizing axons, the number of branches per axon, the coaptation failure rate, the gap size at the repair site and the time needed for surgical repair were all investigated. Fibrin glue repair resulted in regenerating axons travelling further into the distal nerve. It also increased the percentage of arborizing axons. No coaptation failure was detected. Gap sizes were comparable in both groups. Fibrin glue significantly reduced surgical repair time. The increase in regeneration distance, even after the short period of time, is in line with the results of others that showed faster axonal regeneration after fibrin glue repair. The increase in arborizing axons could be another explanation for better functional and electrophysiological results after fibrin glue repair. Fibrin glue nerve coaptation seems to be a promising alternative to microsuture repair. PMID:26330844

  5. Hyaluronan and Fibrin Biomaterial as Scaffolds for Neuronal Differentiation of Adult Stem Cells Derived from Adipose Tissue and Skin

    PubMed Central

    Gardin, Chiara; Vindigni, Vincenzo; Bressan, Eriberto; Ferroni, Letizia; Nalesso, Elisa; Puppa, Alessandro Della; D’Avella, Domenico; Lops, Diego; Pinton, Paolo; Zavan, Barbara

    2011-01-01

    Recently, we have described a simple protocol to obtain an enriched culture of adult stem cells organized in neurospheres from two post-natal tissues: skin and adipose tissue. Due to their possible application in neuronal tissue regeneration, here we tested two kinds of scaffold well known in tissue engineering application: hyaluronan based membranes and fibrin-glue meshes. Neurospheres from skin and adipose tissue were seeded onto two scaffold types: hyaluronan based membrane and fibrin-glue meshes. Neurospheres were then induced to acquire a glial and neuronal-like phenotype. Gene expression, morphological feature and chromosomal imbalance (kariotype) were analyzed and compared. Adipose and skin derived neurospheres are able to grow well and to differentiate into glial/neuron cells without any chromosomal imbalance in both scaffolds. Adult cells are able to express typical cell surface markers such as S100; GFAP; nestin; βIII tubulin; CNPase. In summary, we have demonstrated that neurospheres isolated from skin and adipose tissues are able to differentiate in glial/neuron-like cells, without any chromosomal imbalance in two scaffold types, useful for tissue engineering application: hyaluronan based membrane and fibrin-glue meshes. PMID:22072917

  6. Comparison of fibrin glue and suture in the healing of teat incisions in lactating goats.

    PubMed

    Alan, M; Yener, Z; Tasal, I; Bakir, B

    2008-05-01

    The aims of this study were to investigate whether fibrin glue can be used to close experimentally induced incisions of the teat (mammary papillae) in lactating goats and to compare the healing of the glued with the sutured incisions. Four clinically healthy lactating dairy goats, namely 8 mammary papillae were used. After surgical preparation of the papillae, a 3.5 cm long incision of each papilla was made through skin, muscular layer and mucosa into the papillary sinus. The wounds in the right papillae in all goats were closed with U-shaped uninterrupted 00 chromic catgut sutures. The wounds in the left papillae in all goats were closed, using fibrin glue. One incision was seen to be dehisced and fistulous one day after in fibrin glued teats. The animals were slaughtered 8 days after surgical manipulation. The mammary papillae were removed and examined in the viewpoint on gross and microscopic findings. The healing of wounds was slower and feeble in glued mammary papillary incisions, however faster and stronger in sutured incisions on day 8 after operations. But, available outcomes like less tissue thickness and positive cosmetic results could be obtained byfibrin glue used on mammary papillary incisions, which are very important for teats to be milked by hand and milking machine. Results suggest that it is advisable to use only one or two simple interrupted sutures in teat incisions glued with fibrin to prevent the dehiscence but with a more reliable healing than the sutured incisions. PMID:18547021

  7. Fibrin glue from stored human plasma. An inexpensive and efficient method for local blood bank preparation.

    PubMed

    Spotnitz, W D; Mintz, P D; Avery, N; Bithell, T C; Kaul, S; Nolan, S P

    1987-08-01

    European surgeons have used fibrin glue extensively during thoracic, cardiovascular, and general surgical operations. Until now, however, it has been available only as a commercial preparation made from pooled human plasma, and it has not been approved by the U.S. Food and Drug Administration for use in the United States because of a high associated risk of hepatitis and acquired immune deficiency syndrome. Methods of obtaining fibrinogen, an essential component of fibrin glue, from cryoprecipitate or fresh frozen plasma have been published recently. However, the cryoprecipitate method results in relatively low concentrations of fibrinogen, which can reduce glue effectiveness. The fresh frozen plasma method is more expensive and does not meet the standards of the American Association of Blood Banks for the "closed" system required for safe handling and management of blood component products. Both the cryoprecipitate and the fresh frozen plasma methods result in waste of unstable clotting factors. These factors are necessary to replace human plasma clotting deficiencies but are not necessary for the production of fibrin glue. The authors have developed an efficient, high-concentration blood bank method for producing and maintaining a local supply of a safer and less expensive but equally effective material derived from stored human plasma. This material is produced using approved blood bank techniques for a "closed" system in blood component production, thus reducing the risks of contamination and infection, and its fibrinogen concentration is higher than that of standard cryoprecipitate. The cost of 1 unit of this fibrin glue is comparable to that for 1 unit of cryoprecipitate and less than that for 1 unit of fresh frozen plasma.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2440358

  8. Fibrin gel as alternative scaffold for respiratory tissue engineering.

    PubMed

    Cornelissen, Christian G; Dietrich, Maren; Krüger, Stefan; Spillner, Jan; Schmitz-Rode, Thomas; Jockenhoevel, Stefan

    2012-03-01

    Fibrin gel has proven a valuable scaffold for tissue engineering. Complex geometries can be produced by injection molding; it offers effective cell seeding and can be produced autologous. In order to evaluate its suitability for respiratory tissue engineering, we examined proliferation, functionality, and differentiation of respiratory epithelial cells on fibrin gel in comparison to culture on collagen-coated, microporous membranes. Respiratory epithelial cells formed a confluent layer by day 4, and proliferation showed no significant difference with respect to surface. Measurement of the transepithelial electrical resistance reflected the development of a confluent epithelial cell layer and the subsequent initiation of adequate ion-transfer processes. Appearance of ciliae could be detected at similar time points, and ciliary beating could be observed for cells on both surfaces. Histology and immunohistochemistry of cells grown on fibrin gel revealed the onset of adequate differentiation. As no significant differences in respiratory epithelial cells' proliferation, function, and differentiation could be observed between cells grown on fibrin gel compared to cells on a collagen-coated, microporous surface, we concluded that fibrin gel might prove a suitable scaffold for respiratory tissue engineering and merits further investigation to overcome the limitations associated with scaffolds currently in use. PMID:22009317

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

    PubMed Central

    Buen, Eliseo Portilla-de; Orozco-Mosqueda, Abel; Leal-Cortés, Caridad; Vázquez-Camacho, Gonzalo; Fuentes-Orozco, Clotilde; Alvarez-Villaseñor, Andrea Socorro; Macías-Amezcua, Michel Dassaejv; González-Ojeda, Alejandro

    2014-01-01

    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. PMID:24714834

  10. Fibrin glue-assisted for the treatment of corneal perforations using glycerin-cryopreserved corneal tissue

    PubMed Central

    Dong, Nuo; Li, Cheng; Chen, Wen-Sheng; Qin, Wen-Juan; Xue, Yu-Hua; Wu, Hu-Ping

    2014-01-01

    AIM To evaluate the outcomes and safety of lamellar keratoplasty (LK) assisted by fibrin glue in corneal perforations. METHODS Six eyes of 6 patients affected by different corneal pathologies (2 posttraumatic corneal scar and 3 bacterial keratitis) underwent LK procedures by using fibrin glue. The mean corneal perforation diameter was 1.35±0.64mm (range, 0.7-2.5mm), and the greatest diameter of the ulcerative stromal defect was 2.47±0.77mm in average (range, 1.5-3.5mm). The donor corneal lamella diameters were 0.20-mm larger and thicker than the recipient to restore a physiologic corneal thickness and shape: mean donor diameter was 8.34±0.28mm (range, 8.2-8.7mm) and mean thickness was 352±40.27mm (range, 220-400mm). Mean follow-up was 7.33±1.97 months (range, 6-11 months). Postoperatively, the graft status, graft clarity, anterior chamber response, the visual prognosis, intraocular pressures, and postoperative complications were recorded. RESULTS All the corneal perforations were successfully healed after the procedure. The best-corrected visual acuity (BCVA) ranged from 20/1 000 to 20/50 in their initial presentation, and from 20/100 to 20/20 in their last visit, showed increase in all the patients. No major complications such as graft dislocation and graft failure were noted. Neovascularization developed in the superficial stroma of donor graft in 1 case. High intraocular pressure developed on day 2 after surgery, while was remained in normal range after application of anti-glaucomatous eyedrops for 1 week in 1 case. CONCLUSION Fibrin glue-assisted sutureless LK is valuable for maintaining the ocular integrity in the treatment of corneal perforations. PMID:24634865

  11. Endoluminal embolization of bilateral atherosclerotic common iliac aneurysms with fibrin tissue glue (Beriplast)

    SciTech Connect

    Beese, Richard C.; Tomlinson, Mark A.; Buckenham, Timothy M.

    2000-05-15

    The standard surgical approach to nonleaking iliac aneurysms found at repair of a leaking abdominal aortic aneurysm is to minimize the operative risk by repairing the abdominal aorta only. This means that the bypassed iliac aneurysms may have to be repaired later. As this population of patients are usually elderly with coexisting medical problems, interventional radiology is being used to embolize these aneurysms, thus avoiding the morbidity and mortality associated with further general anesthesia and surgery. Various materials and stents have been reported to be effective in the treatment of iliac aneurysms. We report the successful use of endoluminal fibrin tissue glue (Beriplast) to treat two large iliac aneurysms in a patient who had had a previous abdominal aortic aneurysm repair. We discuss the technique involved and the reasons why we used tissue glue in this patient.

  12. Fixation of fractured inferior orbital wall using fibrin glue in inferior blowout fracture surgery.

    PubMed

    Jo, Eun Jun; Yang, Ho Jik; Kim, Jong Hwan

    2015-01-01

    The objectives of surgical treatment for orbital fracture are to return soft tissue to its original position as well as reduce and fix the bone fragments properly. Reduction of the orbital bone through a subciliary or conjunctival incision and reduction using a urinary balloon catheter were simultaneously performed on 53 patients between 2010 and 2013. Fibrin glue was used to attach the reduced bone fragments. These patients had less than 2 cm(2) of bone defect and showed diplopia, eye movement limitation, and enophthalmos. Diplopia, eye movement limitation, and enophthalmos were each reduced to 3/32, 2/25, and 2/48, respectively. There were no adverse effects, such as infection or hematoma, and because implants were not used, there was no possibility of its extrusion or foreign body reaction. The operation time decreased compared with when using an implant, and the bone fragments remained in a fixed position even after removing the urinary balloon catheter. Therefore, the use of fibrin glue proved to be effective in orbital floor fractures. PMID:25565237

  13. Scalded Skin of Rat Treated by Using Fibrin Glue Combined with Allogeneic Bone Marrow Mesenchymal Stem Cells

    PubMed Central

    Yang, Yadong; Li, Ying; Fang, Guojian; Zhang, Keji

    2014-01-01

    Background It is difficult to achieve satisfactory results with the traditional treatment of large-area skin defects and deep burns. Objective To test the treatment effect of an active dressing film made of a mixture of fibrin glue and bone marrow mesenchymal stem cells (BMSCs) for repairing burn wounds on the skin of rats. Methods Two scald wounds were made on the back of each rat. A total of 30 scald wounds were randomly divided into 3 groups, with 10 wounds in each group. In the experimental treatment group, the scald wounds were covered with the fibrin glue and BMSC mixture. The wounds of the experimental control group were covered with fibrin glue only. No intervention was administered to the blank control group. Thirty days after treatment, pathological sections were cut from the scalded local tissues of all rats from the 3 groups and observed with a microscope. Results The speed of scald wound healing in the experimental treatment group was faster than the other 2 groups. In the experimental treatment group, histopathological analysis revealed that the sebaceous glands showed obviously proliferous at the edge of the new tissue and gradually extended to the deep dermal layer of the new tissue. Conclusion BMSCs may have an active role in promoting skin tissue repair and generating skin appendages. Allogeneic BMSCs mixed with fibrin glue can contribute to the quick formation of a film-like gel over the scald wounds, which might be of significance for emergency treatment and skin-grafting operations. PMID:24966626

  14. Preservation of the cardiac function in infarcted rat hearts by the transplantation of adipose-derived stem cells with injectable fibrin scaffolds.

    PubMed

    Zhang, Xuelian; Wang, Haibin; Ma, Xiang; Adila, Azhati; Wang, Baozhu; Liu, Fen; Chen, Bangdang; Wang, Changyong; Ma, Yitong

    2010-12-01

    Cell-based therapy can improve cardiac function but is limited by the low cell retention and survival within ischemic tissues. Injectable cardiac tissue engineering aims to support cell-based therapies and enhance their efficacy for cardiac diseases. So far, no research has been devoted to studying the usefulness of the combination of fibrin glue (as scaffold) and adipose-derived stem cells (ADSCs) to treat myocardial infarction. In our study, the rat ADSCs were isolated from subcutaneous adipose tissues. The surface phenotype of these cells was analyzed by flow cytometry. The fibrin glue was then co-injected with ADSCs into the left ventricular wall of rat infarction models. The structure and functional consequences of transplantation were determined by detailed histological analysis and echocardiography. Most cultured ADSCs expressed CD105 and CD90, and were negative for CD34 and CD45. After injection, both the 24-h cell retention and four-week graft size were significantly higher and larger in the Fibrin + ADSCs group than those of the ADSCs group alone (P < 0.01). The heart function improved significantly in the Fibrin + ADSCs group compared with that of the ADSCs group four weeks after transplantation (P < 0.01). In addition, the arteriole densities within the infarcted area improved significantly in the Fibrin + ADSCs group compared with those in the ADSCs group four weeks after transplantation (P < 0.01). In conclusion, the ADSCs with the fibrin glue has the therapeutic potential to improve the function of infarcted hearts. The method of in situ injectable tissue engineering combining fibrin glue with ADSCs is promising clinically. PMID:21127347

  15. Successful Treatment of Congenital Chyloperitoneum with Platelet-Rich Fibrin Glue

    PubMed Central

    Joudi, Marjan; Alamdari, Daryoush Hamidi; Rahimi, Hamid-Reza

    2013-01-01

    Background Congenital chyloperitoneum is an uncommon clinical condition. A few cases of congenital chyloperitoneum in children have been described who were treated in a variety of methods. Case Presentation Congenital chyloperito was diagnosed in a 5-day-old baby boy with a significant abdominal distension. Due to the failed conservative managements by medium-chain triglycerides (MCT) enriched milk and partial parenteral nutrition (PPN), the authors tried platelet rich fibrin glue (PRFG) as an alternative choice which was applied through an already inserted intra-abdominal catheter. PRFG successfully stopped the lymph leakage from all over the small intestinal mesentery; thereby PRFG may be considered as an effective alternative treatment before surgical intervention. Conclusion Applying PRFG is an easy, safe, and effective alternative option that may be used to close the chylous ascites lymph leakage in children if conservative management with PPN fails. PMID:23795263

  16. Fibrin glue protection of primary anastomosis in the obstructed left colon. An experimental study on the rat.

    PubMed

    Hulkko, O A; Haukipuro, K A; Laitinen, S T

    1988-01-01

    A left-sided colon obstruction was produced with a polypropylene sling in 65 rats. Colon resection and primary anastomosis were performed three days later. The animals were then randomly allocated to the FG (fibrin glue) group receiving sealing of the anastomosis with 0.4 ml of fibrin glue (Beriplast R), or to the NG (non-glue) group. The anastomoses were assessed 30 min, two days and four days later. Adhesion formation was similar in both groups. The number of macroscopic or radiological leakages did not differ either. At 30 min the mean bursting pressure was 74.6 +/- 8.6 (SD) mmHg in the FG group and 58.3 +/- 21.6 mmHg in NG (non-glue) group (p less than 0.05, Mann-Whitney test). Later on the strength of the anastomoses was equal in both groups. We conclude that the initial sealing of weak points in the anastomoses was beneficial but the inherent strength per se could not be enhanced. PMID:2451367

  17. Medpor Implant Fixation Using Fibrin Glue in the Treatment of Medial Orbital Wall Fracture.

    PubMed

    Kang, Nakheon; Song, Seung Han; Kyung, Hyunwoo; Oh, Sang-Ha

    2015-06-01

    The optimal treatment modalities are determined based on the symptoms and degree of the bone defects in patients with medial orbital wall blowout fracture. Most of the patients in this series underwent implant surgery. However, there are many patients whose implants were not fixed during surgery. Therefore, some patients who had implant migration occurred had been reported. We have therefore used methods for applying fibrin glue (Tisseel, Baxter Healthcare, Norfolk, United Kingdom) for the fixation of implant. Between 2007 and 2013, a total of 168 patients underwent porous polyethylene orbital implant (Medpor) surgery with the application of Tisseel. All the patients underwent surgical treatments via a transcaruncular approach, for which the Medpor was used. Postoperative complications include 6 cases of the limitation of extraoccular movement, 10 cases of diplopia, and 7 cases of enophthalmos. However, there were no specific complications caused by Tisseel. All the patients were satisfied with the treatment outcomes. In this study, we report the usefulness of Tisseel in the fixation of the medial orbital wall fracture using the Medpor implant with a review of literatures. PMID:26080196

  18. Fibrin glue eliminates the need for packing after complex liver injuries.

    PubMed Central

    Feinstein, A. J.; Varela, J. E.; Cohn, S. M.; Compton, R. P.; McKenney, M. G.

    2001-01-01

    Hemostasis after traumatic liver injury can be extremely difficult to obtain, particularly in coagulopathic patients who have suffered extensive liver damage. We determined the ability of a fibrin glue preparation (FG) to terminate ongoing bleeding using a new, clinically relevant porcine model of complex hepatic injury. Anesthetized swine (n = 6, 18 to 19 kg) received an external blast to the right upper abdomen and were immediately anticoagulated with intravenous heparin (200 u/kg). Uncontrolled hemorrhage from blast continued from time of injury (t = 0 minutes) to t = 15 minutes. Lactated Ringer's solution was infused to keep mean arterial pressure (MAP) > 80 mm Hg until the end of experiment (t = 90 minutes). Animals underwent routine surgical techniques to control bleeding, and FG was employed in the event these measures failed. Estimated blood loss and fluid resuscitation volume were measured. Serial MAP, arterial base excess, and temperature were recorded. Animals were severely injured with significant blood loss prior to laparotomy (26 +/- 6 cc/kg) and during routine surgical efforts to arrest hemorrhage (11 +/- 2 cc/kg). Bleeding could not be controlled with standard techniques in any animal. FG rapidly controlled hemorrhage and eliminated the need for packing. Re-bleeding was noted in only one animal (portal vein injury). FG can control severe hepatic hemorrhage when surgical techniques fail. Further work in the clinical arena is warranted to determine the potential benefits of FG in arresting hemorrhage in hemodynamically unstable coagulopathic patients with complex hepatic injuries. PMID:11769337

  19. THE ROLE OF FIBRIN GLUE AND SUTURE ON THE FIXATION OF ULTRA FROZEN PRESERVED MENISCUS TRANSPLANTATION IN RABBITS

    PubMed Central

    Reckers, Leandro José; Fagundes, Djalma José; Pozo Raymundo, José Luiz; Granata Júnior, Geraldo Sérgio de Mello; Moreira, Márcia Bento; Paiva, Vanessa Carla; Negrini Fagundes, Anna Luiza; Cohen, Moises

    2015-01-01

    Objective: To evaluate the ability of fibrin adhesive in promoting the meniscus fixation within two, four and eight weeks compared to the conventional soft-tissue suture technique. Materials and Methods: 36 right medial menisci of rabbits preserved at negative 73° Celsius for 30 days were transplanted to animals of the same sample and fixed with soft-tissue suture or fibrin glue. After 2, 4 or 8 weeks, the appearance of the menisci and the quality of fixation were macroscopically checked and evaluated by a scoring system. The findings were subjected to the statistical study of variance analysis (p ≤ 0.05%). Results: The deep-frozen meniscus preservation maintained the integrity of the meniscus transplant, and, macroscopically, there was no significant reduction of the length of the meniscus in all post-transplant periods (p = 0.015). The menisci fixed with fibrin showed slight changes in color and surface roughness. There were no signs of rejection or infection in both groups. Suture fixation scoring was superior (p = 0.015) in all periods (80% of total fixation) as compared to the setting promoted by fibrin (20% of total fixation). Conclusion: The homologous transplantation of the meniscus of rabbits experienced various degrees of integration to the knee according to the fixation method; the surgical soft tissues suturing technique was shown to be superior in the evaluation of scores compared to the fixation with fibrin adhesive. PMID:27004186

  20. Fabrication of electrospun poly (lactide-co-glycolide)-fibrin multiscale scaffold for myocardial regeneration in vitro.

    PubMed

    Sreerekha, Perumcherry Raman; Menon, Deepthy; Nair, Shantikumar V; Chennazhi, Krishna Prasad

    2013-04-01

    Myocardial tissue engineering is one of the most promising treatment strategies to restore heart function after a massive heart attack. The biomaterials, cells, and scaffold design play important roles in engineering of heart tissue. In this study, we have developed a fibrin-based multiscale electrospun composite scaffold for myocardial regeneration. Fibrin is the natural wound-healing matrix having angiogenic potential and comprehensively used for tissue engineering applications. It provides a natural environment for cell attachment, migration, and proliferation. Morphological, chemical, and mechanical characterization of the scaffolds was done by scanning electron microscopy, fibrin-specific phosphotungstic acid hematoxylin staining, and mechanical testing. The fiber diameters of fibrin nanofibers range from 50 to 300 nm and that of poly (lactide-co-glycolide) microfibers range from 2 to 4 μm, which mimics the structural hierarchy of native myocardial tissue. Our results indicate that this scaffold enhances the differentiation of mesenchymal stem cells into cardiomyocytes. The cardiac phenotype of the cells was confirmed by the presence of cardiac-specific proteins like α-sarcomeric actinin, troponin, tropomyosin, desmin, and atrial natriuretic peptide Estimation of D-Dimer in the culture supernatant for 2 weeks and analysis of scaffold for 3 weeks of in vitro culture of cardiomyocytes indicated the degradation of fibrin and presence of newly synthesized collagen respectively. Our results demonstrate the promising potential of this scaffold for myocardial tissue engineering applications. PMID:23083104

  1. Filling and shielding for postoperative gastric perforations of endoscopic submucosal dissection using polyglycolic acid sheets and fibrin glue

    PubMed Central

    Takimoto, Kengo; Hagiwara, Akeo

    2016-01-01

    Background and study aims: Many medical institutions in Japan perform endoscopic mucosal dissection (ESD) to treat early gastric cancer. Perforations can occur during ESD, and clipping has been reported as useful for treating small pinhole perforations. However, it is often difficult to close postoperative perforations because they usually have large diameters, and the muscle layer around the perforated region is often fragile, so additional open surgery is the only currently used method to treat large perforations and delayed perforations. Another method for large perforation is needed to treat perforations endoscopically. Ono et al. reported a case in which a postoperative perforation was closed using a polyglycolic acid (PGA) sheet and fibrin glue. In addition, it has been used by the authors’ group to repair duodenal injuries that occur during ESD. We report 3 cases in which PGA sheets and fibrin glue were successfully used to repair postoperative gastric perforations endoscopically. This method is simple, safe, and effective, and is a new way to treat large perforations and delayed perforations that occur following ESD. PMID:27556075

  2. Optimization and Use of 3D sintered porous material in medical field for mixing fibrin glue.

    NASA Astrophysics Data System (ADS)

    Delmotte, Y.; Laroumanie, H.; Brossard, G.

    2012-04-01

    In medical field, Mixing of two or more chemical components (liquids and/or gases) is extremely important as improper mixing can affect the physico-chemical properties of the final product. At Baxter Healthcare Corporation, we are using a sintered porous material (PM) as a micro-mixer in medical device for mixing Fibrinogen and Thrombin in order to obtain a homogeneous polymerized Fibrin glue clot used in surgery. First trials were carried out with an interconnected PM from Porvair® (made of PE - porosity: 40% - permeability: 18Darcy). The injection rate is very low, usually about 10mL/min (Re number about 50) which keeps fluids in a laminar flow. Such a low flow rate does not favour mixing of fluids having gradient of viscosity if a mixer is not used. Promising results that were obtained lead the team to understand this ability to mix fluids which will be presented in the poster. Topology of porous media (PM) which associates a solid phase with interconnected (or not) porous structure is known and used in many commodity products. Researches on PM usually focus on flows inside this structure. By opposition to transport and filtration capacity, as well as mechanic and thermic properties, mixing is rarely associated with PM. However over the past few years, we shown that some type of PM have a real capacity to mix certain fluids. Poster will also describe the problematic of mixing complex biological fluids as fibrinogen and Thrombin. They indeed present a large viscosity difference (ratio about 120) limiting the diffusion and the interaction between the two solutions. As those products are expensive, we used Water (1cPo) and Glycerol 87% (120cPo) which are matching the viscosities of Thrombin and Fibrinogen. A parametric investigation of the "porous micro-mixer" as well as a scale up investigation was carried out to examine the influence of both diffusion and advection to successful mix fluids of different viscosity. Experiments were implemented with Planar Laser

  3. Fibrin Gel as an Injectable Biodegradable Scaffold and Cell Carrier for Tissue Engineering

    PubMed Central

    Li, Yuting; Meng, Hao; Liu, Yuan

    2015-01-01

    Due to the increasing needs for organ transplantation and a universal shortage of donated tissues, tissue engineering emerges as a useful approach to engineer functional tissues. Although different synthetic materials have been used to fabricate tissue engineering scaffolds, they have many limitations such as the biocompatibility concerns, the inability to support cell attachment, and undesirable degradation rate. Fibrin gel, a biopolymeric material, provides numerous advantages over synthetic materials in functioning as a tissue engineering scaffold and a cell carrier. Fibrin gel exhibits excellent biocompatibility, promotes cell attachment, and can degrade in a controllable manner. Additionally, fibrin gel mimics the natural blood-clotting process and self-assembles into a polymer network. The ability for fibrin to cure in situ has been exploited to develop injectable scaffolds for the repair of damaged cardiac and cartilage tissues. Additionally, fibrin gel has been utilized as a cell carrier to protect cells from the forces during the application and cell delivery processes while enhancing the cell viability and tissue regeneration. Here, we review the recent advancement in developing fibrin-based biomaterials for the development of injectable tissue engineering scaffold and cell carriers. PMID:25853146

  4. Fibrin-Loaded Porous Poly(Ethylene Glycol) Hydrogels as Scaffold Materials for Vascularized Tissue Formation

    PubMed Central

    Jiang, Bin; Waller, Thomas M.; Larson, Jeffery C.; Appel, Alyssa A.

    2013-01-01

    Vascular network formation within biomaterial scaffolds is essential for the generation of properly functioning engineered tissues. In this study, a method is described for generating composite hydrogels in which porous poly(ethylene glycol) (PEG) hydrogels serve as scaffolds for mechanical and structural support, and fibrin is loaded within the pores to induce vascularized tissue formation. Porous PEG hydrogels were generated by a salt leaching technique with 100–150-μm pore size and thrombin (Tb) preloaded within the scaffold. Fibrinogen (Fg) was loaded into pores with varying concentrations and polymerized into fibrin due to the presence of Tb, with loading efficiencies ranging from 79.9% to 82.4%. Fibrin was distributed throughout the entire porous hydrogels, lasted for greater than 20 days, and increased hydrogel mechanical stiffness. A rodent subcutaneous implant model was used to evaluate the influence of fibrin loading on in vivo response. At weeks 1, 2, and 3, all hydrogels had significant tissue invasion, but no difference in the depth of invasion was found with the Fg concentration. Hydrogels with fibrin loading induced more vascularization, with a significantly higher vascular density at 20 mg/mL (week 1) and 40 mg/mL (weeks 2 and 3) Fg concentration compared to hydrogels without fibrin. In conclusion, we have developed a composite hydrogel that supports rapid vascularized tissue ingrowth, and thus holds great potential for tissue engineering applications. PMID:23003671

  5. Immobilization of alkaline phosphatase on microporous nanofibrous fibrin scaffolds for bone tissue engineering.

    PubMed

    Osathanon, Thanaphum; Giachelli, Cecilia M; Somerman, Martha J

    2009-09-01

    Alkaline phosphatase (ALP) promotes bone formation by degrading inorganic pyrophosphate (PP(i)), an inhibitor of hydroxyapatite formation, and generating inorganic phosphate (P(i)), an inducer of hydroxyapatite formation. P(i) is a crucial molecule in differentiation and mineralization of osteoblasts. In this study, a method to immobilize ALP on fibrin scaffolds with tightly controllable pore size and pore interconnection was developed, and the biological properties of these scaffolds were characterized both in vitro and in vivo. Microporous, nanofibrous fibrin scaffolds (FS) were fabricated using a sphere-templating method. ALP was covalently immobilized on the fibrin scaffolds using 1-ethyl-3-(dimethylaminopropyl)carbodiimide hydrochloride (EDC). Scanning electron microscopic observation (SEM) showed that mineral was deposited on immobilized alkaline phosphatase fibrin scaffolds (immobilized ALP/FS) when incubated in medium supplemented with beta-glycerophosphate, suggesting that the immobilized ALP was active. Primary calvarial cells attached, spread and formed multiple layers on the surface of the scaffolds. Mineral deposition was also observed when calvarial cells were seeded on immobilized ALP/FS. Furthermore, cells seeded on immobilized ALP/FS exhibited higher osteoblast marker gene expression compared to control FS. Upon implantation in mouse calvarial defects, both the immobilized ALP/FS and FS alone treated group had higher bone volume in the defect compared to the empty defect control. Furthermore, bone formation in the immobilized ALP/FS treated group was statistically significant compared to FS alone group. However, the response was not robust. PMID:19501906

  6. Haemostasis with fibrin glue injection into the pericardial space for right ventricular perforation caused by an iatrogenic procedural complication.

    PubMed

    Arai, Hirofumi; Miyamoto, Takamichi; Hara, Nobuhiro; Obayashi, Tohru

    2016-01-01

    An 89-year-old woman with severe aortic valve stenosis and bradycardia presented with circulatory shock due to cardiac tamponade. We performed pericardiocentesis, and then diagnosed right ventricular perforation by echocardiography with microcavitation contrast medium just before inserting a drainage tube. We then inserted the drainage tube in the appropriate position and withdrew blood-filled fluid. The patient was haemodynamically stabilised, but haemorrhage from the perforation site continued for a few days. We injected fibrin glue into the pericardial space through the drainage tube and achieved haemostasis. Thus, we avoided surgery to close the perforation in this high-risk patient. There was no recurrence of haemorrhage. She subsequently had elective aortic valve replacement at another hospital. No adhesions in the pericardial space were seen during surgery. PMID:27190133

  7. Free-electron laser effects on fibrin tissue glue: a preliminary study

    NASA Astrophysics Data System (ADS)

    Joos, Karen M.; Topadze, Katie; Shieh, Charles; Shen, Jin-Hui; Casagrande, Vivien A.

    2000-06-01

    One glaucoma challenge is the treatment of leaking trabeculectomy blebs. Simple methods such as patching, autologous blood injection, compression sutures or cyanoacrylate glue application often fail. Because the conjunctiva is thin and ischemic, it often can't be sutured together so major surgery is required to excise the thin tissue and advance healthy conjunctiva. We report the preliminary results of Tisseel and Tisseel treated with two wavelengths from Vanderbilt's free electron laser placed on leaking trabeculectomy bleb holes in Dutch belted rabbits. The holes were healed at one week in the sutured group and in the 7.7 micrometer FEL-treated Tisseel group. One hole was healed in the cyanoacrylate glue-treated group. Holes remained in the other treatment groups. Tisseel irradiated with 7.7 micrometer energy from the free electron laser may promote healing of trabeculectomy bleb holes.

  8. 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

    PubMed Central

    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

  9. Effect of fibrin glue and endothelial cell growth factor on the early healing response of the transplanted allogenic meniscus: a pilot study.

    PubMed

    Nabeshima, Y; Kurosaka, M; Yoshiya, S; Mizuno, K

    1995-01-01

    Twentyfour meniscal allotransplantations were conducted in 12 adult mongrel dogs. The medial meniscus was replaced using a deep-frozen meniscal allograft. The junction between the meniscus and capsule was treated in one of the three ways. In the control group, the meniscus was sutured only to the adjacent capsular tissue (group C). In the second group, fibrin glue was injected at the junction (group F), and in the third group, fibrin glue and endothelial cell growth factor (ECGF) were injected at the juncture between the transplanted meniscus and the adjacent capsule before the meniscus was sutured (group FE). Histological observation was performed to investigate the effect of fibrin glue and ECGF on the healing process of transplants at various intervals of 1, 4, 8 and 12 weeks. No immunological response was noted in any of the knees. The healing of the transplanted meniscus was first observed at the peripheral attachment. Also, the pannus-like tissue extended from the synovium to the surface of the meniscus. The healing rate in each group at 1 week and 12 weeks was 22% and 77% in group C, 52% and 80% in group F, and 64% and 80% in group FE, respectively. At 4 and 8 weeks, early cellular repopulation was found in group FE and the area which contained new cells was larger than the acellular central core at 8 weeks. However, there was no difference among the three groups at 12 weeks.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7773819

  10. Staple Line Coverage with a Polyglycolic Acid Patch and Fibrin Glue without Pleural Abrasion after Thoracoscopic Bullectomy for Primary Spontaneous Pneumothorax

    PubMed Central

    Hong, Ki Pyo; Kim, Do Kyun; Kang, Kyung Hoon

    2016-01-01

    Background This study was conducted to determine the efficacy of staple line coverage using a polyglycolic acid patch and fibrin glue without pleural abrasion to prevent recurrent postoperative pneumothorax. Methods A retrospective analysis was carried out of 116 operations performed between January 2011 and April 2013. During this period, staple lines were covered with a polyglycolic acid patch and fibrin glue in 58 cases (group A), while 58 cases underwent thoracoscopic bullectomy only (group B). Results The median follow-up period was 33 months (range, 22 to 55 months). The duration of chest tube drainage was shorter in group A (group A 2.7±1.2 day vs. group B 3.9±2.3 day, p=0.001). Prolonged postoperative air leakage occurred more frequently in group B than in group A (43% vs. 19%, p=0.005). The postoperative recurrence rate of pneumothorax was significantly lower in group A (8.6%) than in group B (24.1%) (p=0.043). The total cost of treatment during the follow-up period, including the cost for the treatment of postoperative recurrent pneumothorax, was not significantly different between the two groups (p=0.43). Conclusion Without pleural abrasion, staple line coverage with a medium-sized polyglycolic acid patch and fibrin glue after thoracoscopic bullectomy for primary spontaneous pneumothorax is a useful technique that can reduce the duration of postoperative pleural drainage and the postoperative recurrence rate of pneumothorax. PMID:27066431

  11. Optimization of acidic fibroblast growth factor (FGF-1) and its delivery through a modified degradable fibrin scaffold

    NASA Astrophysics Data System (ADS)

    Pandit, Abhay Smashikant

    The aim of this investigation was to develop a degradable fibrin wound dressing that can deliver an optimized dose of acidic fibroblast growth factor (FGF-1). This aim led to three distinct phases of study. In the first phase, a structurally modified fibrin degradable scaffold was developed and tested in a rabbit ear ulcer model. A significant increase in the angiogenic and fibroblastic response with a corresponding decrease in healing time was seen in the modified fibrin-treated ulcers as compared with untreated ulcers and ulcers treated with non-modified fibrin systems. In the second phase of the study, a biochemical factor, FGF-1, was added to this scaffold. An optimal dose of 8 mug of FGF-1 was determined to be required to initiate a desired wound-healing response in a rabbit ear ulcer model, based on an enhanced angiogenic and fibroblastic response and an increased epithelialization rate. The objective of the last phase was to investigate the efficacy of a modified scaffold as a vehicle for FGF-1. In vivo testing was conducted in a full-thickness defect model in a rabbit. Improvements were seen in the angiogenic and fibroblastic responses in the FGF-1/modified fibrin treatment group and, hence, FGF-1/modified fibrin was the preferred treatment. In conclusion, the modified fibrin/FGF-1 matrix served as a suitable vehicle for the growth factor, providing a desired healing response and a desirable release rate and, thus, was determined to be an effective scaffold.

  12. The Effect of Bone Marrow-Derived Mesenchymal Stem Cells and Their Conditioned Media Topically Delivered in Fibrin Glue on Chronic Wound Healing in Rats.

    PubMed

    Mehanna, Radwa A; Nabil, Iman; Attia, Noha; Bary, Amany A; Razek, Khalid A; Ahmed, Tamer A E; Elsayed, Fatma

    2015-01-01

    Bone marrow-derived mesenchymal stem cells (BM-MSCs) represent a modern approach for management of chronic skin injuries. In this work, we describe BM-MSCs application versus their conditioned media (CM) when delivered topically admixed with fibrin glue to enhance the healing of chronic excisional wounds in rats. Fifty-two adult male rats were classified into four groups after induction of large-sized full-thickness skin wound: control group (CG), fibrin only group (FG), fibrin + MSCs group (FG + SCs), and fibrin + CM group (FG + CM). Healing wounds were evaluated functionally and microscopically. Eight days after injury, number of CD68+ macrophages infiltrating granulation tissue was considerably higher in the latter two groups. Although--later--none of the groups depicted a substantially different healing rate, the quality of regenerated skin was significantly boosted by the application of either BM-MSCs or their CM both (1) structurally as demonstrated by the obviously increased mean area percent of collagen fibers in Masson's trichrome-stained skin biopsies and (2) functionally as supported by the interestingly improved epidermal barrier as well as dermal tensile strength. Thus, we conclude that topically applied BM-MSCs and their CM-via fibrin vehicle--could effectively improve the quality of healed skin in chronic excisional wounds in rats, albeit without true acceleration of wound closure. PMID:26236740

  13. The Effect of Bone Marrow-Derived Mesenchymal Stem Cells and Their Conditioned Media Topically Delivered in Fibrin Glue on Chronic Wound Healing in Rats

    PubMed Central

    Mehanna, Radwa A.; Nabil, Iman; Attia, Noha; Bary, Amany A.; Razek, Khalid A.; Ahmed, Tamer A. E.; Elsayed, Fatma

    2015-01-01

    Bone marrow-derived mesenchymal stem cells (BM-MSCs) represent a modern approach for management of chronic skin injuries. In this work, we describe BM-MSCs application versus their conditioned media (CM) when delivered topically admixed with fibrin glue to enhance the healing of chronic excisional wounds in rats. Fifty-two adult male rats were classified into four groups after induction of large-sized full-thickness skin wound: control group (CG), fibrin only group (FG), fibrin + MSCs group (FG + SCs), and fibrin + CM group (FG + CM). Healing wounds were evaluated functionally and microscopically. Eight days after injury, number of CD68+ macrophages infiltrating granulation tissue was considerably higher in the latter two groups. Although—later—none of the groups depicted a substantially different healing rate, the quality of regenerated skin was significantly boosted by the application of either BM-MSCs or their CM both (1) structurally as demonstrated by the obviously increased mean area percent of collagen fibers in Masson's trichrome-stained skin biopsies and (2) functionally as supported by the interestingly improved epidermal barrier as well as dermal tensile strength. Thus, we conclude that topically applied BM-MSCs and their CM—via fibrin vehicle—could effectively improve the quality of healed skin in chronic excisional wounds in rats, albeit without true acceleration of wound closure. PMID:26236740

  14. Preparation of 3D fibrin scaffolds for stem cell culture applications.

    PubMed

    Kolehmainen, Kathleen; Willerth, Stephanie M

    2012-01-01

    Stem cells are found in naturally occurring 3D microenvironments in vivo, which are often referred to as the stem cell niche. Culturing stem cells inside of 3D biomaterial scaffolds provides a way to accurately mimic these microenvironments, providing an advantage over traditional 2D culture methods using polystyrene as well as a method for engineering replacement tissues. While 2D tissue culture polystrene has been used for the majority of cell culture experiments, 3D biomaterial scaffolds can more closely replicate the microenvironments found in vivo by enabling more accurate establishment of cell polarity in the environment and possessing biochemical and mechanical properties similar to soft tissue. A variety of naturally derived and synthetic biomaterial scaffolds have been investigated as 3D environments for supporting stem cell growth. While synthetic scaffolds can be synthesized to have a greater range of mechanical and chemical properties and often have greater reproducibility, natural biomaterials are often composed of proteins and polysaccharides found in the extracelluar matrix and as a result contain binding sites for cell adhesion and readily support cell culture. Fibrin scaffolds, produced by polymerizing the protein fibrinogen obtained from plasma, have been widely investigated for a variety of tissue engineering applications both in vitro and in vivo. Such scaffolds can be modified using a variety of methods to incorporate controlled release systems for delivering therapeutic factors. Previous work has shown that such scaffolds can be used to successfully culture embryonic stem cells and this scaffold-based culture system can be used to screen the effects of various growth factors on the differentiation of the stem cells seeded inside. This protocol details the process of polymerizing fibrin scaffolds from fibrinogen solutions using the enzymatic activity of thrombin. The process takes 2 days to complete, including an overnight dialysis step for the

  15. Preparation of 3D Fibrin Scaffolds for Stem Cell Culture Applications

    PubMed Central

    Kolehmainen, Kathleen; Willerth, Stephanie M.

    2012-01-01

    Stem cells are found in naturally occurring 3D microenvironments in vivo, which are often referred to as the stem cell niche 1. Culturing stem cells inside of 3D biomaterial scaffolds provides a way to accurately mimic these microenvironments, providing an advantage over traditional 2D culture methods using polystyrene as well as a method for engineering replacement tissues 2. While 2D tissue culture polystrene has been used for the majority of cell culture experiments, 3D biomaterial scaffolds can more closely replicate the microenvironments found in vivo by enabling more accurate establishment of cell polarity in the environment and possessing biochemical and mechanical properties similar to soft tissue.3 A variety of naturally derived and synthetic biomaterial scaffolds have been investigated as 3D environments for supporting stem cell growth. While synthetic scaffolds can be synthesized to have a greater range of mechanical and chemical properties and often have greater reproducibility, natural biomaterials are often composed of proteins and polysaccharides found in the extracelluar matrix and as a result contain binding sites for cell adhesion and readily support cell culture. Fibrin scaffolds, produced by polymerizing the protein fibrinogen obtained from plasma, have been widely investigated for a variety of tissue engineering applications both in vitro and in vivo4. Such scaffolds can be modified using a variety of methods to incorporate controlled release systems for delivering therapeutic factors 5. Previous work has shown that such scaffolds can be used to successfully culture embryonic stem cells and this scaffold-based culture system can be used to screen the effects of various growth factors on the differentiation of the stem cells seeded inside 6,7. This protocol details the process of polymerizing fibrin scaffolds from fibrinogen solutions using the enzymatic activity of thrombin. The process takes 2 days to complete, including an overnight dialysis

  16. A new heterologous fibrin sealant as a scaffold to cartilage repair-Experimental study and preliminary results.

    PubMed

    de Barros, Caio Nunes; Miluzzi Yamada, Ana Lúcia; Junior, Rui Seabra F; Barraviera, Benedito; Hussni, Carlos Alberto; de Souza, Jaqueline Brandão; Watanabe, Marcos Jun; Rodrigues, Celso Antônio; Garcia Alves, Ana Liz

    2016-07-01

    Autologous fibrin gel is commonly used as a scaffold for filling defects in articular cartilage. This biomaterial can also be used as a sealant to control small hemorrhages and is especially helpful in situations where tissue reparation capacity is limited. In particular, fibrin can act as a scaffold for various cell types because it can accommodate cell migration, differentiation, and proliferation. Despite knowledge of the advantages of this biomaterial and mastery of the techniques required for its application, the durability of several types of sealant at the site of injury remains questionable. Due to the importance of such data for evaluating the quality and efficiency of fibrin gel formulations on its use as a scaffold, this study sought to analyze the heterologous fibrin sealant developed from the venom of Crotalus durissus terrificus using studies in ovine experimental models. The fibrin gel developed from the venom of this snake was shown to act as a safe, stable, and durable scaffold for up to seven days, without causing adverse side effects. Fibrin gel produced from the venom of the Crotalus durissus terrificus snake possesses many clinical and surgical uses. It presents the potential to be used as a biomaterial to help repair skin lesions or control bleeding, and it may also be used as a scaffold when applied together with various cell types. The intralesional use of the fibrin gel from the venom of this snake may improve surgical and clinical treatments in addition to being inexpensive and adequately consistent, durable, and stable. The new heterologous fibrin sealant is a scaffold candidate to cartilage repair in this study. PMID:26264444

  17. Mini-open transthoracic approach for resection of a calcified herniated thoracic disc and repair of the dural surface with fibrin glue: a case report.

    PubMed

    Yoshioka, Katsuhito; Murakami, Hideki; Demura, Satoru; Kato, Satoshi; Tsuchiya, Hiroyuki

    2015-08-01

    This study reports a case of severe anterior compression of the spinal cord by a calcified herniated thoracic disc at the T9/10 level in a 46-year-old woman. She underwent resection of the calcified herniated thoracic disc and the integrated dura, using a microscopically assisted mini-open transthoracic approach. The remaining dura mater was shaped and repaired by alternate overlapping without suture. The dural surface was reinforced with a combination of fibrin glue and a polyglycolic acid sheet. This novel procedure prevented postoperative cerebrospinal fluid leakage. The patient made an excellent recovery, without any complications. PMID:26321561

  18. Cardiac Extracellular Matrix-Fibrin Hybrid Scaffolds with Tunable Properties for Cardiovascular Tissue Engineering

    PubMed Central

    Williams, Corin; Budina, Erica; Stoppel, Whitney L.; Sullivan, Kelly E.; Emani, Sirisha; Emani, Sitaram M.; Black, Lauren D.

    2014-01-01

    Solubilized cardiac extracellular matrix (ECM) is being developed as an injectable therapeutic that offers promise for promoting cardiac repair. However, the ECM alone forms a hydrogel that is very soft compared to the native myocardium. As both the stiffness and composition of the ECM are important in regulating cell behavior and can have complex synergistic effects, we sought to develop an ECM-based scaffold with tunable biochemical and mechanical properties. We used solubilized rat cardiac ECM from two developmental stages (neonatal, adult) combined with fibrin hydrogels that were crosslinked with transglutaminase. We show that ECM was retained within the gels and Young’s modulus could be tuned to span the range of the developing and mature heart. C-kit+ cardiovascular progenitor cells from pediatric patients with congenital heart defects were seeded into the hybrid gels. Both the elastic modulus and composition of the scaffolds impacted the expression of endothelial and smooth muscle cell genes. Furthermore, we demonstrate that the hybrid gels are injectable, and thus have potential for minimally invasive therapies. ECM-fibrin hybrid scaffolds offer new opportunities for exploiting the effects of both composition and mechanical properties in directing cell behavior for tissue engineering. PMID:25463503

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

    SciTech Connect

    Puente, Pilar de la

    2013-02-01

    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.

  20. Treatment of life-threatening wounds with a combination of allogenic platelet-rich plasma, fibrin glue and collagen matrix, and a literature review

    PubMed Central

    ASADI, MEHDI; ALAMDARI, DARYOUSH HAMIDI; RAHIMI, HAMID REZA; ALIAKBARIAN, MOHSEN; JANGJOO, ALI; ABDOLLAHI, ABBAS; BAHAR, MOSTAFA MEHRABI; AZADMAND, ALI; FORGHANI, NASER; SADEGH, MOHAMMAD NORI; KHAYAMY, MOHAMMAD ESMAIL; SEIFALIAN, ALEXANDER

    2014-01-01

    Currently there is no ideal procedure for the treatment of recalcitrant ulcers that are unresponsive to the majority of common treatments. However, several novel approaches have been proposed, including bone marrow stem cells, platelets, fibrin glue and collagen matrix. For the first approach treatment of a chronic wound, a non-invasive method is highly desirable. The present study was undertaken with the aim of evaluating the effect of a combination of platelets, fibrin glue and collagen matrix (PFC) in one treatment. A total of ten patients with aggressive, refractory, life-threatening wounds were recruited for the study and their treatment effects were evaluated. Initially, the ulcers were extensively debrided, measured and photographed at weekly intervals. The PFC combination was applied topically to the wound every two days. Following treatment, the wound was completely closed in nine patients and was markedly reduced in the other patient. The mean 100% healing time for the nine patients was 11.3±5.22 weeks. There was no evidence of local or systemic complications or any abnormal tissue formation, keloid or hypertrophic scarring. Therefore, the results of the present study indicate that in the first approach, the combination of PFC components may be used safely in order to synergize the effect of chronic wound healing. PMID:25009595

  1. Novel magnetic fibrin hydrogel scaffolds containing thrombin and growth factors conjugated iron oxide nanoparticles for tissue engineering

    PubMed Central

    Ziv-Polat, Ofra; Skaat, Hadas; Shahar, Abraham; Margel, Shlomo

    2012-01-01

    Novel tissue-engineered magnetic fibrin hydrogel scaffolds were prepared by the interaction of thrombin-conjugated iron oxide magnetic nanoparticles with fibrinogen. In addition, stabilization of basal fibroblast growth factor (bFGF) was achieved by the covalent and physical conjugation of the growth factor to the magnetic nanoparticles. Adult nasal olfactory mucosa (NOM) cells were seeded in the transparent fibrin scaffolds in the absence or presence of the free or conjugated bFGF-iron oxide nanoparticles. The conjugated bFGF enhanced significantly the growth and differentiation of the NOM cells in the fibrin scaffolds, compared to the same or even five times higher concentration of the free bFGF. In the presence of the bFGF-conjugated magnetic nanoparticles, the cultured NOM cells proliferated and formed a three-dimensional interconnected network composed mainly of tapered bipolar cells. The magnetic properties of these matrices are due to the integration of the thrombin- and bFGF-conjugated magnetic nanoparticles within the scaffolds. The magnetic properties of these scaffolds may be used in future work for various applications, such as magnetic resonance visualization of the scaffolds after implantation and reloading the scaffolds via magnetic forces with bioactive agents, eg, growth factors bound to the iron oxide magnetic nanoparticles. PMID:22419873

  2. [BMP-2 gene carried by biodegradable scaffold and fibrinous gel for repairing segmental radial defect in rabbit].

    PubMed

    Li, Jianjun; Wang, Enbo; Sun, Hongbin; Han, Dong; Wang, Huan; Bai, Lunhao; Li, Lei; Liu, Xueyong; Xu, Xinxiang

    2007-04-01

    Adenovirus carrying BMP-2 gene, after being mixed with fibrinous gel, was siphoned off on biodegradable scaffolds (PLA/PCL). The composite was used to repair 1.5 cm long radius defect in rabbits. Four methods were in use in the experiments: Ad-BMP-2 plus fibrinous gel and PLA/PCL (Group A), reconstructed hBMP-2 plus fibrinous gel and PLA/PCL (Group B), Ad-Lacz plus fibrinous gel and PLA/PCL (Group C), and fibrinous gel and PLA/PCL (Group D). Results showed that the defects treated in Group A were repaired with much more new bone regenerated, bridged earlier and stronger than those in Group B 12 weeks after operation. The defects treated in the other two groups could not attain osseous tissue healing. BMP-2 gene carried by biodegradable scaffold and fibrinous gel is easy to conduct and has very strong osteoinduction ability. It is really a good method to repair segmental bone defects. PMID:17591257

  3. Bio-printing of collagen and VEGF-releasing fibrin gel scaffolds for neural stem cell culture.

    PubMed

    Lee, Yeong-Bae; Polio, Samuel; Lee, Wonhye; Dai, Guohao; Menon, Lata; Carroll, Rona S; Yoo, Seung-Schik

    2010-06-01

    Time-released delivery of soluble growth factors (GFs) in engineered hydrogel tissue constructs promotes the migration and proliferation of embedded cells, which is an important factor for designing scaffolds that ultimately aim for neural tissue regeneration. We report a tissue engineering technique to print murine neural stem cells (C17.2), collagen hydrogel, and GF (vascular endothelial growth factor: VEGF)-releasing fibrin gel to construct an artificial neural tissue. We examined the morphological changes of the printed C17.2 cells embedded in the collagen and its migration toward the fibrin gel. The cells showed high viability (92.89+/-2.32%) after printing, which was equivalent to that of manually-plated cells. C17.2 cells printed within 1mm from the border of VEGF-releasing fibrin gel showed GF-induced changes in their morphology. The cells printed in this range also migrated toward the fibrin gel, with the total migration distance of 102.4+/-76.1microm over 3days. The cells in the control samples (fibrin without the VEGF or VEGF printed directly in collagen) neither proliferated nor migrated. The results demonstrated that bio-printing of VEGF-containing fibrin gel supported sustained release of the GF in the collagen scaffold. The presented method can be gainfully used in the development of three-dimensional (3D) artificial tissue assays and neural tissue regeneration applications. PMID:20211178

  4. Recombinant human bone morphogenetic protein-2 suspended in fibrin glue enhances bone formation during distraction osteogenesis in rabbits

    PubMed Central

    Li, Yunfeng; Li, Rui; Hu, Jing; Song, Donghui; Jiang, Xiaowen

    2016-01-01

    Introduction Bone morphogenetic protein-2 (BMP-2) has high potential for bone formation, but its in vivo effects are unpredictable due to the short life time. This study was designed to evaluate the effects of recombinant human (rh) BMP-2 suspended in fibrin on bone formation during distraction osteogenesis (DO) in rabbits. Material and methods The in vitro release kinetics of rhBMP-2 suspended in fibrin was tested using an enzyme-linked immunosorbent assay. Unilateral tibial lengthening for 10 mm was achieved in 48 rabbits. At the completion of osteodistraction, vehicle, fibrin, rhBMP-2 or rhBMP-2 suspended in fibrin (rhBMP-2 + fibrin) was injected into the center of the lengthened gap, with 12 animals in each group. Eight weeks later, the distracted callus was examined by histology, micro-CT and biomechanical testing. Radiographs of the distracted tibiae were taken at both 4 and 8 weeks after drug treatment. Results It was found that fibrin prolonged the life span of rhBMP-2 in vitro with sustained release during 17 days. The rhBMP-2 + fibrin treated animals showed the best results in bone mineral density, bone volume fraction, cortical bone thickness by micro-CT evaluation and mechanical properties by the three-point bending test when compared to the other groups (p < 0.05). In histological images, rhBMP-2 + fibrin treatment showed increased callus formation and better gap bridging compared to the other groups. Conclusions The results of this study suggest that fibrin holds promise to be a good carrier of rhBMP-2, and rhBMP-2 suspended in fibrin showed a stronger promoting effect on bone formation during DO in rabbits. PMID:27279839

  5. The Effect of Sterilization Methods on the Structural and Chemical Properties of Fibrin Microthread Scaffolds.

    PubMed

    Grasman, Jonathan M; O'Brien, Megan P; Ackerman, Kevin; Gagnon, Keith A; Wong, Gregory M; Pins, George D

    2016-06-01

    A challenge for the design of scaffolds in tissue engineering is to determine a terminal sterilization method that will retain the structural and biochemical properties of the materials. Since commonly used heat and ionizing energy-based sterilization methods have been shown to alter the material properties of protein-based scaffolds, the effects of ethanol and ethylene oxide (EtO) sterilization on the cellular compatibility and the structural, chemical, and mechanical properties of uncrosslinked, UV crosslinked, or 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) crosslinked fibrin microthreads in neutral (EDCn) or acidic (EDCa) buffers are evaluated. EtO sterilization significantly reduces the tensile strength of uncrosslinked microthreads. Surface chemistry analyses show that EtO sterilization induces alkylation of EDCa microthreads leading to a significant reduction in myoblast attachment. The material properties of EDCn microthreads do not appear to be affected by the sterilization method. These results significantly enhance the understanding of how sterilization or crosslinking techniques affect the material properties of protein scaffolds. PMID:26847494

  6. Use of fibrin glue in preventing pseudorecurrence after laparoscopic total extraperitoneal repair of large indirect inguinal hernia

    PubMed Central

    Sürgit, Önder; Çavuşoğlu, Nadir Turgut; Ünal, Yılmaz; Koşar, Pınar Nergis; İçen, Duygu

    2016-01-01

    Purpose Seroma is among the most common complications of laparoscopic total extraperitoneal (TEP) for especially large indirect inguinal hernia, and may be regarded as a recurrence by some patients. A potential area localized behind the mesh and extending from the inguinal cord into the scrotum may be one of the major etiological factors of this complication. Our aim is to describe a novel technique in preventing pseudorecurrence by using fibrin sealant to close that potential dead space. Methods Forty male patients who underwent laparoscopic TEP for indirect inguinal hernia with at least 100-mL volume were included in this prospective clinical study. While fibrin sealant was used to close the potential dead space in the study group, nothing was used in the control group. The volume of postoperative fluid collection on ultrasound was compared between the groups. Results Patient characteristics and the volumes of hernia sac were similar between the 2 groups. The mean volume of postoperative fluid collection was found as 120.2 mL in the control group and 53.7 mL in the study group, indicating a statistical significance (P < 0.001). Conclusion Minimizing the potential dead space with a fibrin sealant can reduce the amount of postoperative fluid collection, namely the incidence of pseudorecurrence. PMID:27617253

  7. Treatment of non-healing sternum wound after open-heart surgery with allogenic platelet-rich plasma and fibrin glue-preliminary outcomes

    PubMed Central

    Tashnizi, Mohammad Abbasi; Alamdari, Daryoush Hamidi; Khayami, Mohammad Esmail; Rahimi, Hamid Reza; Moeinipour, Aliasghar; Amouzeshi, Ahmad; Seifalian, Alexander M.

    2013-01-01

    Introduction: Non-healing wound in the sternal region after coronary arteries bypass graft surgery is a serious complication. For healing a chronic wound, several novel approaches have been proposed recently such as using bone marrow stem cells, platelets and fibrin glue (PFG); but a non-invasive method is highly desirable in the first approach for treatment. The current study was undertaken to evaluate the effect of the combination of PFG in one treatment. Materials and Methods: We report on the treatment of six patients with life-threatening chronic sternum wounds, which caused septicemia with multi-drug resistant pathogens. The ulcers were extensively debrided initially and were measured and photographed at weekly intervals. The combination of PFG was applied topically on the wound after every 2 days. Results: The wounds were completely closed in five patients and significantly reduced in size in one. There was no evidence of local or systemic complications and any abnormal tissue formation, keloid or hypertrophic scarring. Conclusions: Our study suggests, in the first approach, PFG can be used safely in order to heal a non healing sternum wound following coronary artery bypass surgery. PMID:24459346

  8. Synthetic vs natural scaffolds for human limbal stem cells

    PubMed Central

    Tominac Trcin, Mirna; Dekaris, Iva; Mijović, Budimir; Bujić, Marina; Zdraveva, Emilija; Dolenec, Tamara; Pauk-Gulić, Maja; Primorac, Dragan; Crnjac, Josip; Špoljarić, Branimira; Mršić, Gordan; Kuna, Krunoslav; Špoljarić, Daniel; Popović, Maja

    2015-01-01

    Aim To investigate the impact of synthetic electrospun polyurethane (PU) and polycaprolactone (PCL) nanoscaffolds, before and after hydrolytic surface modification, on viability and differentiation of cultured human eye epithelial cells, in comparison with natural scaffolds: fibrin and human amniotic membrane. Methods Human placenta was taken at elective cesarean delivery. Fibrin scaffolds were prepared from commercial fibrin glue kits. Nanoscaffolds were fabricated by electrospinning. Limbal cells were isolated from surpluses of human cadaveric cornea and seeded on feeder 3T3 cells. The scaffolds used for viability testing and immunofluorescence analysis were amniotic membrane, fibrin, PU, and PCL nanoscaffolds, with or without prior NaOH treatment. Results Scanning electron microscope photographs of all tested scaffolds showed good colony spreading of seeded limbal cells. There was a significant difference in viability performance between cells with highest viability cultured on tissue culture plastic and cells cultured on all other scaffolds. On the other hand, electrospun PU, PCL, and electrospun PCL treated with NaOH had more than 80% of limbal cells positive for stem cell marker p63 compared to only 27%of p63 positive cells on fibrin. Conclusion Natural scaffolds, fibrin and amniotic membrane, showed better cell viability than electrospun scaffolds. On the contrary, high percentages of p63 positive cells obtained on these scaffolds still makes them good candidates for efficient delivery systems for therapeutic purposes. PMID:26088849

  9. Modified fibrin hydrogel matrices: both, 3D-scaffolds and local and controlled release systems to stimulate angiogenesis.

    PubMed

    Hall, Heike

    2007-01-01

    Sufficient blood perfusion is essential for all tissues to guarantee nutrient- and gas exchange. As many diseases are induced by the reduction of blood perfusion such that these tissues gradually loose their ability to function properly, therapeutic angiogenesis aims to increase blood flow in ischemic tissues by stimulating the patient's endogenous capacity to develop new blood vessels. These studies include application of angiogenesis stimulating (growth) factors and adhesion sequences as well as local gene therapy. One approach is to rationally design 3D-fibrin hydrogel matrices that provide specific adhesion sequences such as a receptor for alpha v beta 3-integrin expressed on angiogenic endothelial cells and that, in addition, are able to store and release angiogenic growth factors such as VEGF-A(165) and bFGF that target cell type-specific responses. Moreover, these matrices can be modified to release complexed plasmid DNA that transfect surrounding cells and improve angiogenesis. During wound healing, cells infiltrate into the scaffold and degrade it, thereby releasing entrapped growth factors or complexed plasmid DNA, and with the speed of tissue regeneration the scaffold is completely removed when tissue healing is achieved. The long-term aim is to develop biomimetic 3D-matrices for applications in a biomaterials context that can be applied directly at the site of injury by minimal invasive surgery. 3D-fibrin matrices constitute a scaffold and release system for single or combined therapeutic biomolecules and may therefore be able to contribute to the patients' endogenous healing response resulting in the functional recovery of a diseased tissue or organ. PMID:18220797

  10. Combined left hepatectomy with fenestration and using a harmonic scalpel, fibrin glue and closed suction drainage to prevent bile leakage and ascites in the management of symptomatic polycystic liver disease: a case report

    PubMed Central

    2009-01-01

    Introduction Surgical treatment is the usual therapy for patients with polycystic liver disease and with severe symptoms, yet the results of surgery are often disappointing and the optimal surgical approach is uncertain. Case presentation We present the case of a 41-year-old Greek woman who underwent combined left hepatectomy with fenestration for symptomatic polycystic liver disease using ultrasound scalpel, fibrin glue and closed suction drain to prevent bile leakage, haemorrhage and ascites. Liver resection using the ultrasound scissors allowed quick parenchyma dissection under haemostatic conditions with safe coagulation of small vessels and bile ducts. Moreover, the ultrasound scalpel was applied to the cyst cavities exposed on the peritoneum to ablate the fluid-producing epithelial cyst lining. We also covered the cut cystic cavities exposed to the peritoneum surface of the liver with fibrin glue. Instead of allowing the opened cysts to drain into the abdominal cavity, we used two wide bore closed suction fluted drains. We did not observe excessive fluid loss through the drainage after the second postoperative day. The drain tubes were removed on the third postoperative day. Conclusion In our patient, effective treatment of ascites and prevention of bile leakage and bleeding indicate that this new approach is promising and may become a useful surgical technique for polycystic liver disease.

  11. Enhanced Osteogenic and Vasculogenic Differentiation Potential of Human Adipose Stem Cells on Biphasic Calcium Phosphate Scaffolds in Fibrin Gels.

    PubMed

    van Esterik, Fransisca A S; Zandieh-Doulabi, Behrouz; Kleverlaan, Cornelis J; Klein-Nulend, Jenneke

    2016-01-01

    For bone tissue engineering synthetic biphasic calcium phosphate (BCP) with a hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) ratio of 60/40 (BCP60/40) is successfully clinically applied, but the high percentage of HA may hamper efficient scaffold remodelling. Whether BCP with a lower HA/β-TCP ratio (BCP20/80) is more desirable is still unclear. Vascular development is needed before osteogenesis can occur. We aimed to test the osteogenic and/or vasculogenic differentiation potential as well as degradation of composites consisting of human adipose stem cells (ASCs) seeded on BCP60/40 or BCP20/80 incorporated in fibrin gels that trigger neovascularization for bone regeneration. ASC attachment to BCP60/40 and BCP20/80 within 30 min was similar (>93%). After 11 days of culture BCP20/80-based composites showed increased alkaline phosphatase activity and DMP1 gene expression, but not RUNX2 and osteonectin expression, compared to BCP60/40-based composites. BCP20/80-based composites also showed enhanced expression of the vasculogenic markers CD31 and VEGF189, but not VEGF165 and endothelin-1. Collagen-1 and collagen-3 expression was similar in both composites. Fibrin degradation was increased in BCP20/80-based composites at day 7. In conclusion, BCP20/80-based composites showed enhanced osteogenic and vasculogenic differentiation potential compared to BCP60/40-based composites in vitro, suggesting that BCP20/80-based composites might be more promising for in vivo bone augmentation than BCP60/40-based composites. PMID:27547223

  12. Enhanced Osteogenic and Vasculogenic Differentiation Potential of Human Adipose Stem Cells on Biphasic Calcium Phosphate Scaffolds in Fibrin Gels

    PubMed Central

    2016-01-01

    For bone tissue engineering synthetic biphasic calcium phosphate (BCP) with a hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) ratio of 60/40 (BCP60/40) is successfully clinically applied, but the high percentage of HA may hamper efficient scaffold remodelling. Whether BCP with a lower HA/β-TCP ratio (BCP20/80) is more desirable is still unclear. Vascular development is needed before osteogenesis can occur. We aimed to test the osteogenic and/or vasculogenic differentiation potential as well as degradation of composites consisting of human adipose stem cells (ASCs) seeded on BCP60/40 or BCP20/80 incorporated in fibrin gels that trigger neovascularization for bone regeneration. ASC attachment to BCP60/40 and BCP20/80 within 30 min was similar (>93%). After 11 days of culture BCP20/80-based composites showed increased alkaline phosphatase activity and DMP1 gene expression, but not RUNX2 and osteonectin expression, compared to BCP60/40-based composites. BCP20/80-based composites also showed enhanced expression of the vasculogenic markers CD31 and VEGF189, but not VEGF165 and endothelin-1. Collagen-1 and collagen-3 expression was similar in both composites. Fibrin degradation was increased in BCP20/80-based composites at day 7. In conclusion, BCP20/80-based composites showed enhanced osteogenic and vasculogenic differentiation potential compared to BCP60/40-based composites in vitro, suggesting that BCP20/80-based composites might be more promising for in vivo bone augmentation than BCP60/40-based composites. PMID:27547223

  13. Mesenchymal stromal cells integrate and form longitudinally-aligned layers when delivered to injured spinal cord via a novel fibrin scaffold

    PubMed Central

    Hyatt, Alex J.T.; Wang, Difei; van Oterendorp, Christian; Fawcett, James W.; Martin, Keith R.

    2014-01-01

    Mesenchymal stromal cells (MSCs) have been shown to promote healing and regeneration in a number of CNS injury models and therefore there is much interest in the clinical use of these cells. For spinal cord injuries, a standard delivery method for MSCs is intraspinal injection, but this can result in additional injury and provides little control over how the cells integrate into the tissue. The present study examines the use of a novel fibrin scaffold as a new method of delivering MSCs to injured spinal cord. Use of the fibrin scaffold resulted in the formation of longitudinally-aligned layers of MSCs growing over the spinal cord lesion site. Host neurites were able to migrate into this MSC architecture and grow longitudinally. The length of the MSC bridge corresponded to the length of the fibrin scaffold. MSCs that were delivered via intraspinal injection were mainly oriented perpendicular to the plane of the spinal cord and remained largely restricted to the lesion site. Host neurites within the injected MSC graft were also oriented perpendicular to the plane of the spinal cord. PMID:24680849

  14. What Is the Biological and Clinical Relevance of Fibrin?

    PubMed

    Litvinov, Rustem I; Weisel, John W

    2016-06-01

    As our knowledge of the structure and functions of fibrinogen and fibrin has increased tremendously, several key findings have given some people a superficial impression that the biological and clinical significance of these clotting proteins may be less than earlier thought. Most strikingly, studies of fibrinogen knockout mice demonstrated that many of these mice survive to weaning and beyond, suggesting that fibrin(ogen) may not be entirely necessary. Humans with afibrinogenemia also survive. Furthermore, in recent years, the major emphasis in the treatment of arterial thrombosis has been on inhibition of platelets, rather than fibrin. In contrast to the initially apparent conclusions from these results, it has become increasingly clear that fibrin is essential for hemostasis; is a key factor in thrombosis; and plays an important biological role in infection, inflammation, immunology, and wound healing. In addition, fibrinogen replacement therapy has become a preferred, major treatment for severe bleeding in trauma and surgery. Finally, fibrin is a unique biomaterial and is used as a sealant or glue, a matrix for cells, a scaffold for tissue engineering, and a carrier and/or a vector for targeted drug delivery. PMID:27056152

  15. Fibrinogen and fibrin based micro and nano scaffolds incorporated with drugs, proteins, cells and genes for therapeutic biomedical applications

    PubMed Central

    Rajangam, Thanavel; An, Seong Soo A

    2013-01-01

    Over the past two decades, many types of natural and synthetic polymer-based micro- and nanocarriers, with exciting properties and applications, have been developed for application in various types of tissue regeneration, including bone, cartilage, nerve, blood vessels, and skin. The development of suitable polymers scaffold designs to aid the repair of specific cell types have created diverse and important potentials in tissue restoration. Fibrinogen (Fbg)- and fibrin (Fbn)-based micro- and nanostructures can provide suitable natural matrix environments. Since these primary materials are abundantly available in blood as the main coagulation proteins, they can easily interact with damaged tissues and cells through native biochemical interactions. Fbg- and Fbn-based micro and nanostructures can also be consecutively furnished/or encapsulated and specifically delivered, with multiple growth factors, proteins, and stem cells, in structures designed to aid in specific phases of the tissue regeneration process. The present review has been carried out to demonstrate the progress made with micro and nanoscaffold applications and features a number of applications of Fbg- and Fbn-based carriers in the field of biomaterials, including the delivery of drugs, active biomolecules, cells, and genes, that have been effectively used in tissue engineering and regenerative medicine. PMID:24106425

  16. Mesenchymal stem cells engrafted in a fibrin scaffold stimulate Schwann cell reactivity and axonal regeneration following sciatic nerve tubulization.

    PubMed

    Cartarozzi, Luciana P; Spejo, Aline B; Ferreira, Rui S; Barraviera, Benedito; Duek, Eliana; Carvalho, Juliana L; Góes, Alfredo M; Oliveira, Alexandre L R

    2015-03-01

    The present study investigated the effectiveness of mesenchymal stem cells (MSCs) associated with a fibrin scaffold (FS) for the peripheral regenerative process after nerve tubulization. Adult female Lewis rats received a unilateral sciatic nerve transection followed by repair with a polycaprolactone (PCL)-based tubular prosthesis. Sixty days after injury, the regenerated nerves were studied by immunohistochemistry. Anti-p75NTR immunostaining was used to investigate the reactivity of the MSCs. Basal labeling, which was upregulated during the regenerative process, was detected in uninjured nerves and was significantly greater in the MSC-treated group. The presence of GFP-positive MSCs was detected in the nerves, indicating the long term survival of such cells. Moreover, there was co-localization between MSCs and BNDF immunoreactivity, showing a possible mechanism by which MSCs improve the reactivity of SCs. Myelinated axon counting and morphometric analyses showed that MSC engrafting led to a higher degree of fiber compaction combined with a trend of increased myelin sheath thickness, when compared with other groups. The functional result of MSC engrafting was that the animals showed higher motor function recovery at the seventh and eighth week after lesion. The findings herein show that MSC+FS therapy improves the nerve regeneration process by positively modulating the reactivity of SCs. PMID:25602253

  17. Glorious Glue

    ERIC Educational Resources Information Center

    Guhin, Paula

    2010-01-01

    There's something irresistible about squeezing out lines and shapes with a bottle of glue. It's fun, yes. But, even better: it's tactile. The glue dries slightly raised on the surface, lending itself to several exciting treatments. In this article, the author describes some activities that confirm how a simple art material like glue can be…

  18. Mussel Glue

    NASA Technical Reports Server (NTRS)

    1987-01-01

    A mytilus edilus, a common blue ocean mussel is attaching itself to the underside of a wet glass in a laboratory. It secretes a glue like substance in the form of multiple threads which attach to surfaces such as shells, rocks, piers and ships. This natural super glue hardens within minutes and tightly affixes to its selected platform even in the roughest seas. Its superior adhesive properties suggest many practical applications. One company, Bio-Polymers, Inc., has developed a synthetic mussel glue for the commercial market.

  19. The Effects of Constant Flow Bioreactor Cultivation and Keratinocyte Seeding Densities on Prevascularized Organotypic Skin Grafts Based on a Fibrin Scaffold

    PubMed Central

    Helmedag, Marius Julian; Weinandy, Stefan; Marquardt, Yvonne; Baron, Jens Malte; Pallua, Norbert; Suschek, Christoph V.

    2015-01-01

    Organotypic full-thickness skin grafts (OTSG) are already an important technology for treating various skin conditions and are well established for skin research and development. These obvious benefits are often impaired by the need of laborious production, their noncomplete autologous composition, and, most importantly, their lack of included vasculature. Therefore, our study focused on combining a prevascularized dermal layer with an epidermis to cultivate full-thickness skin grafts incorporating capillary-like networks. It has been shown that prevascularization accelerates ingrowth of tissue-engineered grafts, and it is a prerequisite to circumvent diffusion limits due to graft thickness. To obtain such a graft, we chose a dermal layer incorporating human umbilical vein endothelial cells (HuVEC) amid human dermal fibroblasts within a fibrin-based scaffold, seeded apically with human foreskin keratinocytes (hfKC). Our research investigated the used concept's feasibility, as well as the effect of hfKC addition on the development of a well-connected capillary-like network after approximately 21 days. In addition, we evaluated the utilization of a custom-made constant flow bioreactor for simplified cultivation of these grafts, therefore possibly easing graft production and presumably increasing their cost effectiveness. Skin grafts were assessed by conventional two-dimensional histology. In addition, software-assisted three-dimensional evaluation of the capillary-like structure networks was performed by two-photon laser scanning microscopy (TPLSM) and subsequent image processing was done with ImagePro® Analyzer 7.0 software, thereby evaluating its platform technology power in the field of prevascularized skin grafts. All samples showed a capillary-like structure network, but we could report a significant reduction of its total length after 14 days of tri-culture with 5×105/cm2 seeded hfKC, possibly indicating nutritional deficiencies for this particular high cell

  20. The effects of fibrin tissue adhesive on the middle ear.

    PubMed

    Katzke, D; Pusalkar, A; Steinbach, E

    1983-02-01

    This study investigated the effects of fibrin glue ('Tissucol', Immuno Pty. Ltd.) in the middle and inner ear. Small amounts of the adhesive were used in 36 operations performed on 18 rabbits. The light microscopic examination of these ears four, eight and 12 weeks after surgery showed that the adhesive was well tolerated and that it did not have any toxic effect on the middle ear or membranous labyrinth. The fibrin tissue adhesive can therefore safely be used to facilitate reconstructive middle-ear surgery and, with the aid of fascia, also for the closure of labyrinthine fistulae; or to achieve a definite seal of oval window niche after stapes surgery. PMID:6600776

  1. Enhanced Neurite Growth from Mammalian Neurons in Three-Dimensional Salmon Fibrin Gels

    PubMed Central

    Ju, Yo-El; Janmey, Paul A.; McCormick, Margaret; Sawyer, Evelyn S.; Flanagan, Lisa A.

    2007-01-01

    Three-dimensional fibrin matrices have been used as cellular substrates in vitro and as bridging materials for central nervous system repair. Cells can be embedded within fibrin gels since the polymerization process is non-toxic, making fibrin an attractive scaffold for transplanted cells. Most studies have utilized fibrin prepared from human or bovine blood proteins. However, fish fibrin may be well suited for neuronal growth since fish undergo remarkable central nervous system regeneration and molecules implicated in this process are present in fibrin. We assessed the growth of mammalian central nervous system neurons in bovine, human, and salmon fibrin and found that salmon fibrin gels encouraged the greatest degree of neurite (dendrite and axon) growth and were the most resistant to degradation by cellular proteases. The neurite growth-promoting effect was not due to the thrombin used to polymerize the gels or to any copurifying plasminogen. Co-purified fibronectin partially accounted for the effect on neurites, and blockade of fibrinogen/fibrin-binding integrins markedly decreased neurite growth. Anion exchange chromatography revealed different elution profiles for salmon and mammalian fibrinogens. These data demonstrate that salmon fibrin encourages the growth of neurites from mammalian neurons and suggest that salmon fibrin may be a beneficial scaffold for neuronal regrowth after CNS injury. PMID:17258313

  2. Characterization of Chondrocyte Scaffold Carriers for Cell-based Gene Therapy in Articular Cartilage Repair

    PubMed Central

    Shui, Wei; Yin, Liangjun; Luo, Jeffrey; Li, Ruidong; Zhang, Wenwen; Zhang, Jiye; Huang, Wei; Hu, Ning; Liang, Xi; Deng, Zhong-Liang; Hu, Zhenming; Shi, Lewis; Luu, Hue H.; Haydon, Rex C.; He, Tong-Chuan; Ho, Sherwin

    2014-01-01

    Articular cartilage lesions in the knee are common injuries. Chondrocyte transplant represents a promising therapeutic modality for articular cartilage injuries. Here, we characterize the viability and transgene expression of articular chondrocytes cultured in 3-D scaffolds provided by four types of carriers. Articular chondrocytes are isolated from rabbit knees and cultured in four types of scaffolds: type I collagen sponge, fibrin glue, hyaluronan, and Open-cell PolyLactic Acid (OPLA). The cultured cells are transduced with adenovirus expressing green fluorescence protein (AdGFP) and luciferase (AdGL3-Luc). The viability and gene expression in the chondrocytes are determined with fluorescence microscopy and luciferase assay. Cartilage matrix production is assessed by Alcian blue staining. Rabbit articular chondrocytes are effectively infected by AdGFP and exhibited sustained GFP expression. All tested scaffolds support the survival and gene expression of the infected chondrocytes. However, the highest transgene expression is observed in the OPLA carrier. At four weeks, Alcian blue-positive matrix materials are readily detected in OPLA cultures. Thus, our results indicate that, while all tested carriers can support the survival of chondrocytes, OPLA supports the highest transgene expression and is the most conductive scaffold for matrix production, suggesting that OPLA may be a suitable scaffold for cell-based gene therapy of articular cartilage repairs. PMID:23629940

  3. [Animal experiments on cementing small osteochondral fragments with fibrin glue].

    PubMed

    Zilch, H

    1980-01-01

    An experiment on revascularization of glued osteochondral fragments was carried out. A chiseled part of the medial femoral condyle of the knee joint of the rabbit was fixed on the right side with an acryl adhesive and on the left side with a new fibrinogen adhesive system (FAS), consisting of highly concentrated fibrinogen, thrombin, and factor XIII. The animals were sacrificed after three, six, ten, and twenty eight days. The FAS is changed into granulation tissue rich in vessels and, therefore, there is a quick revascularization of the fragments soon after three days. On the contrary the acryl adhesive is a foreign body and prevents ingrowth of capillaries during the time of investigation. Immobilization with plaster is necessary to prevent the fragment from gliding off. PMID:6972890

  4. TAPE: A Biodegradable Hemostatic Glue Inspired by a Ubiquitous Compound in Plants for Surgical Application.

    PubMed

    Kim, Keumyeon; Lee, Haeshin; Hong, Seonki

    2016-01-01

    This video describes the simplest protocol for preparing biodegradable surgical glue that has an effective hemostatic ability and greater water-resistant adhesion strength than commercial tissue adhesives. Medical adhesives have attracted great attention as potential alternative tools to sutures and staples due to their convenience in usage with minimal invasiveness. Although there are several protocols for developing tissue adhesives including those commercially available such as fibrin glues and cyanoacrylate-based materials, mostly they require a series of chemical syntheses of organic molecules, or complicated protein-purification methods, in the case of bio-driven materials (i.e., fibrin glue). Also, the development of surgical glues exhibiting high adhesive properties while maintaining biodegradability is still a challenge due to difficulties in achieving good performance in the wet environment of the body. We illustrate a new method to prepare a medical glue, known as TAPE, by the weight-based separation of a water-immiscible supramolecular aggregate formed after a physical mixing of a plant-derived, wet-resistant adhesive molecule, Tannic Acid (TA), and a well-known biopolymer, Poly(Ethylene) glycol (PEG). With our approach, TAPE shows high adhesion strength, which is 2.5-fold more than commercial fibrin glue in the presence of water. Furthermore, TAPE is biodegradable in physiological conditions and can be used as a potent hemostatic glue against tissue bleeding. We expect the widespread use of TAPE in a variety of medical settings and drug delivery applications, such as polymers for muco-adhesion, drug depots, and others. PMID:27341544

  5. Salmon fibrin treatment of spinal cord injury promotes functional recovery and density of serotonergic innervation.

    PubMed

    Sharp, Kelli G; Dickson, Amanda R; Marchenko, Steve A; Yee, Kelly M; Emery, Pauline N; Laidmåe, Ivo; Uibo, Raivo; Sawyer, Evelyn S; Steward, Oswald; Flanagan, Lisa A

    2012-05-01

    The neural degeneration caused by spinal cord injury leaves a cavity at the injury site that greatly inhibits repair. One approach to promoting repair is to fill the cavity with a scaffold to limit further damage and encourage regrowth. Injectable materials are advantageous scaffolds because they can be placed as a liquid in the lesion site then form a solid in vivo that precisely matches the contours of the lesion. Fibrin is one type of injectable scaffold, but risk of infection from blood borne pathogens has limited its use. We investigated the potential utility of salmon fibrin as an injectable scaffold to treat spinal cord injury since it lacks mammalian infectious agents and encourages greater neuronal extension in vitro than mammalian fibrin or Matrigel®, another injectable material. Female rats received a T9 dorsal hemisection injury and were treated with either salmon or human fibrin at the time of injury while a third group served as untreated controls. Locomotor function was assessed using the BBB scale, bladder function was analyzed by measuring residual urine, and sensory responses were tested by mechanical stimulation (von Frey hairs). Histological analyses quantified the glial scar, lesion volume, and serotonergic fiber density. Rats that received salmon fibrin exhibited significantly improved recovery of both locomotor and bladder function and a greater density of serotonergic innervation caudal to the lesion site without exacerbation of pain. Rats treated with salmon fibrin also exhibited less autophagia than those treated with human fibrin, potentially pointing to amelioration of sensory dysfunction. Glial scar formation and lesion size did not differ significantly among groups. The pattern and timing of salmon fibrin's effects suggest that it acts on neuronal populations but not by stimulating long tract regeneration. Salmon fibrin clearly has properties distinct from those of mammalian fibrin and is a beneficial injectable scaffold for treatment

  6. Glue Guns: Aiming for Safety

    ERIC Educational Resources Information Center

    Roy, Ken

    2010-01-01

    While glue guns are very useful, there are safety issues. Regardless of the temperature setting, glue guns can burn skin. The teacher should demonstrate and supervise the use of glue guns and have a plan should a student get burned. There should be an initial first aid protocol in place, followed by a visit to the school nurse. An accident report…

  7. Structural basis for the nonlinear mechanics of fibrin networks under compression.

    PubMed

    Kim, Oleg V; Litvinov, Rustem I; Weisel, John W; Alber, Mark S

    2014-08-01

    Fibrin is a protein polymer that forms a 3D filamentous network, a major structural component of protective physiological blood clots as well as life threatening pathological thrombi. It plays an important role in wound healing, tissue regeneration and is widely employed in surgery as a sealant and in tissue engineering as a scaffold. The goal of this study was to establish correlations between structural changes and mechanical responses of fibrin networks exposed to compressive loads. Rheological measurements revealed nonlinear changes of fibrin network viscoelastic properties under dynamic compression, resulting in network softening followed by its dramatic hardening. Repeated compression/decompression enhanced fibrin clot stiffening. Combining fibrin network rheology with simultaneous confocal microscopy provided direct evidence of structural modulations underlying nonlinear viscoelasticity of compressed fibrin networks. Fibrin clot softening in response to compression strongly correlated with fiber buckling and bending, while hardening was associated with fibrin network densification. Our results suggest a complex interplay of entropic and enthalpic mechanisms accompanying structural changes and accounting for the nonlinear mechanical response in fibrin networks undergoing compressive deformations. These findings provide new insight into the fibrin clot structural mechanics and can be useful for designing fibrin-based biomaterials with modulated viscoelastic properties. PMID:24840618

  8. Structural basis for the nonlinear mechanics of fibrin networks under compression

    PubMed Central

    Kim, Oleg V.; Litvinov, Rustem I.; Weisel, John W.; Alber, Mark S.

    2014-01-01

    Fibrin is a protein polymer that forms a 3D filamentous network, a major structural component of protective physiological blood clots as well as life threatening pathological thrombi. It plays an important role in wound healing, tissue regeneration and is widely employed in surgery as a sealant and in tissue engineering as a scaffold. The goal of this study was to establish correlations between structural changes and mechanical responses of fibrin networks exposed to compressive loads. Rheological measurements revealed nonlinear changes of fibrin network viscoelastic properties under dynamic compression, resulting in network softening followed by its dramatic hardening. Repeated compression/decompression enhanced fibrin clot stiffening. Combining fibrin network rheology with simultaneous confocal microscopy provided direct evidence of structural modulations underlying nonlinear viscoelasticity of compressed fibrin networks. Fibrin clot softening in response to compression strongly correlated with fiber buckling and bending, while hardening was associated with fibrin network densification. Our results suggest a complex interplay of entropic and enthalpic mechanisms accompanying structural changes and accounting for the nonlinear mechanical response in fibrin networks undergoing compressive deformations. These findings provide new insight into the fibrin clot structural mechanics and can be useful for designing fibrin-based biomaterials with modulated viscoelastic properties. PMID:24840618

  9. Characterisation of a novel light activated adhesive scaffold: Potential for device attachment.

    PubMed

    Ark, Morris; Boughton, Philip; Lauto, Antonio; Tran, Giang T; Chen, Yongjuan; Cosman, Peter H; Dunstan, Colin R

    2016-09-01

    .61±2.81kPa after 15min of light activation, this is comparable to the adhesion strength of fibrin glue on scaffolds. Cell attachment was seen to be similar to the controls, but cells appeared to have better cell survivability. In conclusion, the RBC-scaffolds show promise for use as a novel light activated attachment device with potential applications in attaching an anti-reflux valve in the lower oesophagus and also in wound healing applications for stomach ulcers. PMID:27281161

  10. Influence of Delivery Method on Neuroprotection by Bone Marrow Mononuclear Cell Therapy following Ventral Root Reimplantation with Fibrin Sealant

    PubMed Central

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

    2014-01-01

    The present work compared the local injection of mononuclear cells to the spinal cord lateral funiculus with the alternative approach of local delivery with fibrin sealant after ventral root avulsion (VRA) and reimplantation. For that, female adult Lewis rats were divided into the following groups: avulsion only, reimplantation with fibrin sealant; root repair with fibrin sealant associated with mononuclear cells; and repair with fibrin sealant and injected mononuclear cells. Cell therapy resulted in greater survival of spinal motoneurons up to four weeks post-surgery, especially when mononuclear cells were added to the fibrin glue. Injection of mononuclear cells to the lateral funiculus yield similar results to the reimplantation alone. Additionally, mononuclear cells added to the fibrin glue increased neurotrophic factor gene transcript levels in the spinal cord ventral horn. Regarding the motor recovery, evaluated by the functional peroneal index, as well as the paw print pressure, cell treated rats performed equally well as compared to reimplanted only animals, and significantly better than the avulsion only subjects. The results herein demonstrate that mononuclear cells therapy is neuroprotective by increasing levels of brain derived neurotrophic factor (BDNF) and glial derived neurotrophic factor (GDNF). Moreover, the use of fibrin sealant mononuclear cells delivery approach gave the best and more long lasting results. PMID:25157845

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

    PubMed Central

    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

  12. Aulogous fibrin sealant (Vivostat®) in the neurosurgical practice: Part II: Vertebro-spinal procedures

    PubMed Central

    Graziano, Francesca; Maugeri, Rosario; Basile, Luigi; Meccio, Favia; Iacopino, Domenico Gerardo

    2016-01-01

    Background: Epidural hematomas, cerebrospinal fluid fistula, and spinal infections are challenging postoperative complications following vertebro-spinal procedures. We report our preliminary results using autologous fibrin sealant as both fibrin glue and a hemostatic during these operations. Methods: Prospectively, between January 2013 and March 2015, 68 patients received an autologous fibrin sealant prepared with the Vivostat® system applied epidurally to provide hemostasis and to seal the dura. The surgical technique, time to bleeding control, and associated complications were recorded. Results: Spinal procedures were performed in 68 patients utilizing autologous fibrin glue/Vivostat® to provide rapid hemostasis and/or to seal the dura. Only 2 patients developed postoperative dural fistulas while none exhibited hemorrhages, allergic reactions, systemic complications, or infections. Conclusions: In this preliminary study, the application of autologous fibrin sealant with Vivostat® resulted in rapid hemostasis and/or acted as an effective dural sealant. Although this product appears to be safe and effective, further investigations are warranted. PMID:26904371

  13. A prospective, randomized, double-blind trial of the use of fibrin sealant for face lifts.

    PubMed

    Oliver, D W; Hamilton, S A; Figle, A A; Wood, S H; Lamberty, B G

    2001-12-01

    Fibrin sealant imitates the final phase of the blood coagulation process. Fibrinogen is converted into fibrin on a tissue surface by the action of thrombin, which is then cross-linked by factor XIIIa, creating a mechanically stable fibrin network. This fibrin network is thought to reduce the amount of postoperative bleeding by sealing capillary vessels and allowing raw operative surfaces to adhere. The authors conducted a prospective, double-blind, randomized, controlled trial on the use of fibrin sealant in 20 consecutive patients undergoing bilateral face lifts by the same surgeon. Each patient was randomized for the use of fibrin sealant on either the right or the left side with the contralateral side acting as the control. Total drainage was recorded on each side for 24 hours before drains were removed. The age range of the patients in the trial (all of whom were women) was 44 to 70 years (mean, 55). The side treated with fibrin glue had a median drainage of 10 ml and the control side 30 ml. The Wilcoxon signed rank test shows a significant difference in drainage between sides (p = 0.002). The reduction in postoperative drainage could also reduce pain and bruising, increasing patient satisfaction with this procedure. The need for drains may also be obviated. PMID:11743409

  14. The pilot study of fibrin with temporomandibular joint derived synovial stem cells in repairing TMJ disc perforation.

    PubMed

    Wu, Yang; Gong, Zhongcheng; Li, Jian; Meng, Qinggong; Fang, Wei; Long, Xing

    2014-01-01

    TMJ disc related diseases are difficult to be cured due to the poor repair ability of the disc. TMJ-SDSCs were ideal cell sources for cartilage tissue engineering which have been widely used in hyaline cartilage regeneration. Fibrin gel has been demonstrated as a potential scaffold for neocartilage formation. The aim of this study was to repair the TMJ disc perforation using fibrin/chitosan hybrid scaffold combined with TMJ-SDSCs. Rat TMJ-SDSCs were cultured on hybrid scaffold or pure chitosan scaffolds. The cell seeding efficiency, distribution, proliferation, and chondrogenic differentiation capacity were investigated. To evaluate the in vivo repair ability of cell/scaffold construct, rat TMJ disc explants were punched with a defect to mimic TMJ disc perforation. Cell seeded scaffolds were inserted into the defect of TMJ disc explants and then were implanted subcutaneously in nude mice for 4 weeks. Results demonstrated that fibrin may improve cell seeding, proliferation, and chondrogenic induction in vitro. The in vivo experiments showed more cartilage ECM deposition in fibrin/chitosan scaffold, which suggested an enhanced reparative ability. This pilot study demonstrated that the regenerative ability of TMJ-SDSCs seeded in fibrin/chitosan scaffold could be applied for repairing TMJ disc perforation. PMID:24822210

  15. The Pilot Study of Fibrin with Temporomandibular Joint Derived Synovial Stem Cells in Repairing TMJ Disc Perforation

    PubMed Central

    Gong, Zhongcheng; Li, Jian; Meng, Qinggong; Fang, Wei; Long, Xing

    2014-01-01

    TMJ disc related diseases are difficult to be cured due to the poor repair ability of the disc. TMJ-SDSCs were ideal cell sources for cartilage tissue engineering which have been widely used in hyaline cartilage regeneration. Fibrin gel has been demonstrated as a potential scaffold for neocartilage formation. The aim of this study was to repair the TMJ disc perforation using fibrin/chitosan hybrid scaffold combined with TMJ-SDSCs. Rat TMJ-SDSCs were cultured on hybrid scaffold or pure chitosan scaffolds. The cell seeding efficiency, distribution, proliferation, and chondrogenic differentiation capacity were investigated. To evaluate the in vivo repair ability of cell/scaffold construct, rat TMJ disc explants were punched with a defect to mimic TMJ disc perforation. Cell seeded scaffolds were inserted into the defect of TMJ disc explants and then were implanted subcutaneously in nude mice for 4 weeks. Results demonstrated that fibrin may improve cell seeding, proliferation, and chondrogenic induction in vitro. The in vivo experiments showed more cartilage ECM deposition in fibrin/chitosan scaffold, which suggested an enhanced reparative ability. This pilot study demonstrated that the regenerative ability of TMJ-SDSCs seeded in fibrin/chitosan scaffold could be applied for repairing TMJ disc perforation. PMID:24822210

  16. Glue Sniffers with Special Needs.

    ERIC Educational Resources Information Center

    O'Connor, Denis

    1987-01-01

    Glue sniffing and solvent misuse have seriously affected children and teenagers throughout the United Kingdom. This article discusses glue sniffing in terms of prevalence, association with disability, physical and psychological effects, signs and symptoms, counseling for sniffers, and successful interventions including an approach using videotape…

  17. Rapidly light-activated surgical protein glue inspired by mussel adhesion and insect structural crosslinking.

    PubMed

    Jeon, Eun Young; Hwang, Byeong Hee; Yang, Yun Jung; Kim, Bum Jin; Choi, Bong-Hyuk; Jung, Gyu Yong; Cha, Hyung Joon

    2015-10-01

    Currently approved surgical tissue glues do not satisfy the requirements for ideal bioadhesives due to limited adhesion in wet conditions and severe cytotoxicity. Herein, we report a new light-activated, mussel protein-based bioadhesive (LAMBA) inspired by mussel adhesion and insect dityrosine crosslinking chemistry. LAMBA exhibited substantially stronger bulk wet tissue adhesion than commercially available fibrin glue and good biocompatibility in both in vitro and in vivo studies. Besides, the easily tunable, light-activated crosslinking enabled an effective on-demand wound closure and facilitated wound healing. Based on these outstanding properties, LAMBA holds great potential as an ideal surgical tissue glue for diverse medical applications, including sutureless wound closures of skin and internal organs. PMID:26197411

  18. Fibrin-based biomaterials: Modulation of macroscopic properties through rational design at the molecular level

    PubMed Central

    Brown, Ashley C.; Barker, Thomas H.

    2013-01-01

    Fibrinogen is one of the primary components of the coagulation cascade and rapidly forms an insoluble matrix following tissue injury. In addition to its important role in hemostasis, fibrin acts as a scaffold for tissue repair and provides important cues for directing cell phenotype following injury. Because of these properties and the ease of polymerization of the material, fibrin has been widely utilized as a biomaterial for over a century. Modifying the macroscopic properties of fibrin, such as elasticity and porosity, has been somewhat elusive until recently, yet with a molecular-level rational design approach can now be somewhat easily modified through alterations of molecular interactions key to the protein’s polymerization process. This review outlines the biochemistry of fibrin and discusses methods for modification of molecular interactions and their application to fibrin based biomaterials. PMID:24056097

  19. 21 CFR 178.3120 - Animal glue.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Animal glue. 178.3120 Section 178.3120 Food and... and Production Aids § 178.3120 Animal glue. Animal glue may be safely used as a component of articles..., transporting, or holding food, subject to the provisions of this section. (a) Animal glue consists of...

  20. 21 CFR 178.3120 - Animal glue.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Animal glue. 178.3120 Section 178.3120 Food and... and Production Aids § 178.3120 Animal glue. Animal glue may be safely used as a component of articles..., transporting, or holding food, subject to the provisions of this section. (a) Animal glue consists of...

  1. 21 CFR 178.3120 - Animal glue.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Animal glue. 178.3120 Section 178.3120 Food and... Animal glue. Animal glue may be safely used as a component of articles intended for use in producing... the provisions of this section. (a) Animal glue consists of the proteinaceous extractives...

  2. 21 CFR 178.3120 - Animal glue.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Animal glue. 178.3120 Section 178.3120 Food and... and Production Aids § 178.3120 Animal glue. Animal glue may be safely used as a component of articles..., transporting, or holding food, subject to the provisions of this section. (a) Animal glue consists of...

  3. 21 CFR 178.3120 - Animal glue.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Animal glue. 178.3120 Section 178.3120 Food and... and Production Aids § 178.3120 Animal glue. Animal glue may be safely used as a component of articles..., transporting, or holding food, subject to the provisions of this section. (a) Animal glue consists of...

  4. The GlueX Detector

    SciTech Connect

    David Lawrence

    2009-12-01

    The GlueX detector is being built along with the new experimental Hall D at Jefferson lab as part of the 12~GeV upgrade project which received CD-3 approval in fall 2008. GlueX is a fixed target experiment built around a 2~Tesla superconducting solenoid having charged particle tracking and calorimetry with large acceptance. A high rate DAQ system consisting of pipeline electronics will allow the detector to operate at high luminosity ($10^{8}$ tagged $\\gamma$/sec on target). Details on the photon beam and GlueX detector are given including capabilities in resolutions and rates.

  5. Improved Growth Factor Directed Vascularization into Fibrin Constructs Through Inclusion of Additional Extracellular Molecules

    PubMed Central

    Smith, JD; Melhem, ME; Magge, KT; Waggoner, AS; Campbell, PG

    2009-01-01

    Using the chick chorioallantoic membrane assay (CAM) and a novel histological technique we investigated the ability of blood vessels to directly invade fibrin-based scaffolds. In our initial experiments utilizing vascular endothelial growth factor (VEGF165) we found no direct invasion. Instead, the fibrin was completely degraded and replaced with highly vascularized new tissue. Addition of fibroblast growth factor-2 (FGF-2), bone morphogenic protein-2 (BMP-2), or platelet-derived growth factor-BB (PDGF-BB) to the fibrin construct also did not result in construct vascularization. Because natural and regenerating tissues exhibit complex extracellular matrices (ECMs), we hypothesized that a more complex scaffold may improve blood vessel invasion. Addition of fibronectin, hyaluronic acid, and collagen type I within 20 mg/mL fibrin constructs resulted in no significant improvement. However, the same additive concentrations within 10 mg/mL fibrin constructs resulted in dramatic improvements, specifically with hyaluronic acid. Overall, we believe these results indicate the importance of structural and functional cues of not only in the initial scaffold but also as the construct is degraded and remodeled. Furthermore, the CAM assay may represent a useful model for understanding ECM interactions as well as for screening and designing tissue engineered scaffolds. PMID:17223139

  6. Traumatic dislocation of the incudostapedial joint repaired with fibrin tissue adhesive.

    PubMed

    Nikolaidis, Vasilios

    2011-03-01

    We present a case of traumatic dislocation of the incudostapedial joint (ISJ) and a simple method for controlled application of the glue using commercial fibrin tissue adhesive. A 26-year-old female presented to our ENT clinic for hearing impairment to her left ear 2 months after a head trauma due to a motorcycle accident. The audiogram revealed a 40- to 50-dB HL conductive hearing loss with a notch configuration in bone conduction curve on the left ear. Computed tomography of the left temporal bone revealed a longitudinal fracture line. An exploratory tympanotomy was performed under general anesthesia. The ISJ was found dislocated while the incus was trapped by the edges of the bony lateral attic wall fracture. A small bony edge that impeded incus movement was removed and a small amount of the glue was precisely applied to the lenticular process of the incus with an angled incision knife. The long process of the incus was firmly pressed over the stapes for 30 seconds with a 90° hook and 60 seconds after the application of the glue the ISJ was repaired. One year after our patient achieved full airbone gap (ABG) closure (ABG, ≤10 dB HL), while she demonstrated overclosure in frequencies 2 and 4 kHz. Fibrin tissue glue allowed safe, rapid, and accurate repair of the ISJ and resulted in an anatomically normal articulation as the mass and shape of the ossicles was preserved. Moreover, our patient achieved full ABG closure. PMID:21344438

  7. Transglutaminases: nature's biological glues.

    PubMed Central

    Griffin, Martin; Casadio, Rita; Bergamini, Carlo M

    2002-01-01

    Transglutaminases (Tgases) are a widely distributed group of enzymes that catalyse the post-translational modification of proteins by the formation of isopeptide bonds. This occurs either through protein cross-linking via epsilon-(gamma-glutamyl)lysine bonds or through incorporation of primary amines at selected peptide-bound glutamine residues. The cross-linked products, often of high molecular mass, are highly resistant to mechanical challenge and proteolytic degradation, and their accumulation is found in a number of tissues and processes where such properties are important, including skin, hair, blood clotting and wound healing. However, deregulation of enzyme activity generally associated with major disruptions in cellular homoeostatic mechanisms has resulted in these enzymes contributing to a number of human diseases, including chronic neurodegeneration, neoplastic diseases, autoimmune diseases, diseases involving progressive tissue fibrosis and diseases related to the epidermis of the skin. In the present review we detail the structural and regulatory features important in mammalian Tgases, with particular focus on the ubiquitous type 2 tissue enzyme. Physiological roles and substrates are discussed with a view to increasing and understanding the pathogenesis of the diseases associated with transglutaminases. Moreover the ability of these enzymes to modify proteins and act as biological glues has not gone unnoticed by the commercial sector. As a consequence, we have included some of the present and future biotechnological applications of this increasingly important group of enzymes. PMID:12366374

  8. Formation and stability of interpenetrating polymer network hydrogels consisting of fibrin and hyaluronic acid for tissue engineering.

    PubMed

    Lee, Fan; Kurisawa, Motoichi

    2013-02-01

    Fibrin gel is widely used as a tissue engineering scaffold. However, it has poor mechanical properties, which often result in rapid contraction and degradation of the scaffold. An interpenetrating polymer network (IPN) hydrogel composed of fibrin and hyaluronic acid-tyramine (HA-Tyr) was developed to improve the mechanical properties. The fibrin network was formed by cleaving fibrinogen with thrombin, producing fibrin monomers that rapidly polymerize. The HA network was formed through the coupling of tyramine moieties using horseradish peroxidase (HRP) and hydrogen peroxide (H₂O₂). The degree of crosslinking of the HA-Tyr network can be tuned by varying the H₂O₂ concentration, producing IPN hydrogels with different storage moduli (G'). While fibrin gels were completely degraded in the presence of plasmin and contracted when embedded with cells, the shape of the IPN hydrogels was maintained due to structural support by the HA-Tyr networks. Cell proliferation and capillary formation occurred in IPN hydrogels and were found to decrease with increasing G' of the hydrogels. The results suggest that fibrin-HA-Tyr IPN hydrogels are a potential alternative to fibrin gels as scaffolds for tissue engineering applications that require shape stability. PMID:22943886

  9. Biomechanical properties of Achilles tendon repair augmented with a bioadhesive-coated scaffold

    PubMed Central

    Brodie, Michael; Vollenweider, Laura; Murphy, John L; Xu, Fangmin; Lyman, Arinne; Lew, William D; Lee, Bruce P

    2011-01-01

    The Achilles tendon is the most frequently ruptured tendon. Both acute and chronic (neglected) tendon ruptures can dramatically affect a patient’s quality of life, and require a prolonged period of recovery before return to pre-injury activity levels. This paper describes the use of an adhesive-coated biologic scaffold to augment primary suture repair of transected Achilles tendons. The adhesive portion consisted of a synthetic mimic of mussel adhesive proteins that can adhere to various surfaces in a wet environment, including biologic tissues. When combined with biologic scaffolds such as bovine pericardium or porcine dermal tissues, these adhesive constructs demonstrated lap shear adhesive strengths significantly greater than that of fibrin glue, while reaching up to 60% of the strength of a cyanoacrylate-based adhesive. These adhesive constructs were wrapped around transected cadaveric porcine Achilles tendons repaired with a combination of parallel and three-loop suture patterns. Tensile mechanical testing of the augmented repairs exhibited significantly higher stiffness (22–34%), failure load (24–44%), and energy to failure (27–63%) when compared to control tendons with suture repair alone. Potential clinical implications of this novel adhesive biomaterial are discussed. PMID:21266745

  10. Enhanced Viability of Endothelial Colony Forming Cells in Fibrin Microbeads for Sensor Vascularization

    PubMed Central

    Gandhi, Jarel K.; Zivkovic, Lada; Fisher, John P.; Yoder, Mervin C.; Brey, Eric M.

    2015-01-01

    Enhanced vascularization at sensor interfaces can improve long-term function. Fibrin, a natural polymer, has shown promise as a biomaterial for sensor coating due to its ability to sustain endothelial cell growth and promote local vascularization. However, the culture of cells, particularly endothelial cells (EC), within 3D scaffolds for more than a few days is challenging due to rapid loss of EC viability. In this manuscript, a robust method for developing fibrin microbead scaffolds for long-term culture of encapsulated ECs is described. Fibrin microbeads are formed using sodium alginate as a structural template. The size, swelling and structural properties of the microbeads were varied with needle gauge and composition and concentration of the pre-gel solution. Endothelial colony-forming cells (ECFCs) were suspended in the fibrin beads and cultured within a perfusion bioreactor system. The perfusion bioreactor enhanced ECFCs viability and genome stability in fibrin beads relative to static culture. Perfusion bioreactors enable 3D culture of ECs within fibrin beads for potential application as a sensor coating. PMID:26393602

  11. Fibrin Networks Support Recurring Mechanical Loads by Adapting their Structure across Multiple Scales.

    PubMed

    Kurniawan, Nicholas A; Vos, Bart E; Biebricher, Andreas; Wuite, Gijs J L; Peterman, Erwin J G; Koenderink, Gijsje H

    2016-09-01

    Tissues and cells sustain recurring mechanical loads that span a wide range of loading amplitudes and timescales as a consequence of exposure to blood flow, muscle activity, and external impact. Both tissues and cells derive their mechanical strength from fibrous protein scaffolds, which typically have a complex hierarchical structure. In this study, we focus on a prototypical hierarchical biomaterial, fibrin, which is one of the most resilient naturally occurring biopolymers and forms the structural scaffold of blood clots. We show how fibrous networks composed of fibrin utilize irreversible changes in their hierarchical structure at different scales to maintain reversible stress stiffening up to large strains. To trace the origin of this paradoxical resilience, we systematically tuned the microstructural parameters of fibrin and used a combination of optical tweezers and fluorescence microscopy to measure the interactions of single fibrin fibers for the first time, to our knowledge. We demonstrate that fibrin networks adapt to moderate strains by remodeling at the network scale through the spontaneous formation of new bonds between fibers, whereas they adapt to high strains by plastic remodeling of the fibers themselves. This multiscale adaptation mechanism endows fibrin gels with the remarkable ability to sustain recurring loads due to shear flows and wound stretching. Our findings therefore reveal a microscopic mechanism by which tissues and cells can balance elastic nonlinearity and plasticity, and thus can provide microstructural insights into cell-driven remodeling of tissues. PMID:27602730

  12. Platelet Rich Fibrin in Periodontal Regeneration

    PubMed Central

    Arunachalam, Muthukumaraswamy; Pulikkotil, Shaju J.; Sonia, Nath

    2016-01-01

    Periodontitis is a chronic bacterial infection resulting in destruction of the supporting structures of the teeth. Regeneration of the lost tissues has faced difficulties primarily due to the lack of support during the intricate healing processes. A surgical additive which can ‘jump start’ the healing process to a more predictable regenerative process is always on the wish list of any periodontist. Platelet-rich fibrin (PRF) is a second generation platelet concentrate that has been considered to be an important, easy to obtain, predictable surgical additive for periodontal regeneration. This autologous scaffold provides the much needed bio-chemical mediators which has the potential for enhancing reconstruction of the periodontium. This review article tries to understand as to why PRF would be an important link to reach predictable periodontal regeneration. PMID:27386002

  13. The GlueX Experiment

    SciTech Connect

    Curtis A. Meyer

    2006-11-01

    The GlueX experiment at Jefferson Lab is part of the planned CEBAF 12GeV upgrade. The project received its Critical Decision 1 (CD1) in February of 2006, and CD2 is anticipated in 2007. The GlueX experiment will search for and study the spectrum of gluonic excitations of mesons in the 1.5 to 2.5GeV/c^2 mass region using an 8.5 to 9GeV beam of linearly polarized photons.

  14. Generation of a Fibrin Based Three-Layered Skin Substitute.

    PubMed

    Kober, Johanna; Gugerell, Alfred; Schmid, Melanie; Kamolz, Lars-Peter; Keck, Maike

    2015-01-01

    A variety of skin substitutes that restore epidermal and dermal structures are currently available on the market. However, the main focus in research and clinical application lies on dermal and epidermal substitutes whereas the development of a subcutaneous replacement (hypodermis) is often disregarded. In this study we used fibrin sealant as hydrogel scaffold to generate a three-layered skin substitute. For the hypodermal layer adipose-derived stem cells (ASCs) and mature adipocytes were embedded in the fibrin hydrogel and were combined with another fibrin clot with fibroblasts for the construction of the dermal layer. Keratinocytes were added on top of the two-layered construct to form the epidermal layer. The three-layered construct was cultivated for up to 3 weeks. Our results show that ASCs and fibroblasts were viable, proliferated normally, and showed physiological morphology in the skin substitute. ASCs were able to differentiate into mature adipocytes during the course of four weeks and showed morphological resemblance to native adipose tissue. On the surface keratinocytes formed an epithelial-like layer. For the first time we were able to generate a three-layered skin substitute based on a fibrin hydrogel not only serving as a dermal and epidermal substitute but also including the hypodermis. PMID:26236715

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

    PubMed

    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

    2014-01-01

    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. PMID:24830554

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

    PubMed Central

    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.

    2014-01-01

    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. PMID:24830554

  17. A new heterologous fibrin sealant as scaffold to recombinant human bone morphogenetic protein-2 (rhBMP-2) and natural latex proteins for the repair of tibial bone defects.

    PubMed

    Machado, Eduardo Gomes; Issa, João Paulo Mardegan; Figueiredo, Fellipe Augusto Tocchini de; Santos, Geovane Ribeiro Dos; Galdeano, Ewerton Alexandre; Alves, Mariana Carla; Chacon, Erivelto Luis; Ferreira Junior, Rui Seabra; Barraviera, Benedito; Cunha, Marcelo Rodrigues da

    2015-04-01

    Tissue engineering has special interest in bone tissue aiming at future medical applications Studies have focused on recombinant human bone morphogenetic protein-2 (rhBMP-2) and natural latex proteins due to the osteogenic properties of rhBMP-2 and the angiogenic characteristic of fraction 1 protein (P-1) extracted from the rubber tree Hevea brasiliensis. Furthermore, heterologous fibrin sealant (FS) has been shown as a promising alternative in regenerative therapies. The aim of this study was to evaluate these substances for the repair of bone defects in rats. A bone defect measuring 3mm in diameter was created in the proximal metaphysis of the left tibia of 60 rats and was implanted with rhBMP-2 or P-1 in combination with a new heterologous FS derived from snake venom. The animals were divided into six groups: control (unfilled bone defect), rhBMP-2 (defect filled with 5μg rhBMP-2), P-1 (defect filled with 5μg P-1), FS (defect filled with 8μg FS), FS/rhBMP-2 (defect filled with 8μg FS and 5μg rhBMP-2), FS/P-1 (defect filled with 8μg FS and 5μg P-1). The animals were sacrificed 2 and 6 weeks after surgery. The newly formed bone projected from the margins of the original bone and exhibited trabecular morphology and a disorganized arrangement of osteocyte lacunae. Immunohistochemical analysis showed intense expression of osteocalcin in all groups. Histometric analysis revealed a significant difference in all groups after 2 weeks (p<0.05), except for the rhBMP-2 and FS/rhBMP-2 groups (p>0.05). A statistically significant difference (p<0.05) was observed in all groups after 6 weeks in relation to the volume of newly formed bone in the surgical area. In conclusion, the new heterologous fibrin sealant was found to be biocompatible and the combination with rhBMP-2 showed the highest osteogenic and osteoconductive capacity for bone healing. These findings suggest a promising application of this combination in the regeneration surgery. PMID:25825118

  18. Glues Used in Airplane Parts

    NASA Technical Reports Server (NTRS)

    Allen, S W; Truax, T R

    1920-01-01

    This report was prepared for the National Advisory Committee for Aeronautics and presents the results of investigations conducted by the Forest Products Laboratory of the United States Forest Service on the manufacture, preparation, application, testing and physical properties of the different types of glues used in wood airplane parts.

  19. Fabrication and physical and biological properties of fibrin gel derived from human plasma

    NASA Astrophysics Data System (ADS)

    Zhao, Haiguang; Ma, Lie; Zhou, Jie; Mao, Zhengwei; Gao, Changyou; Shen, Jiacong

    2008-03-01

    The fast development of tissue engineering and regenerative medicine drives the old biomaterials, for example, fibrin glue, to find new applications in these areas. Aiming at developing a commercially available hydrogel for cell entrapment and delivery, in this study we optimized the fabrication and gelation conditions of fibrin gel. Fibrinogen was isolated from human plasma by a freeze-thaw circle. Gelation of the fibrinogen was accomplished by mixing with thrombin. Absorbance of the fibrinogen/thrombin mixture at 550 nm as a function of reaction time was monitored by UV-VIS spectroscopy. It was found that the clotting time is significantly influenced by the thrombin concentration and the temperature, while less influenced by the fibrinogen concentration. After freeze-drying, the fibrin gel was characterized by scanning electron microscopy (SEM), revealing fibrous microstructure. Thermal gravimetric analysis found that the degradation temperature of the crosslinked fibrin gel starts from 288 °C, which is about 30 °C higher than that of the fibrinogen. The hydrogel has an initial water-uptake ratio of ~50, decreased to 30-40 after incubation in water for 11 h depending on the thrombin concentration. The fibrin gels lost their weights in PBS very rapidly, while slowly in DMEM/fetal bovine serum and DMEM. In vitro cell culture found that human fibroblasts could normally proliferate in the fibrin gel with spreading morphology. In conclusion, the fibrin gel containing higher concentration of fibrinogen (20 mg ml-1) and thrombin (5 U ml-1) has suitable gelation time and handling properties, and thus is applicable as a delivery vehicle for cells such as fibroblasts.

  20. Characterisation of cell-substrate interactions between Schwann cells and three-dimensional fibrin hydrogels containing orientated nanofibre topographical cues.

    PubMed

    Hodde, Dorothee; Gerardo-Nava, José; Wöhlk, Vanessa; Weinandy, Stefan; Jockenhövel, Stefan; Kriebel, Andreas; Altinova, Haktan; Steinbusch, Harry W M; Möller, Martin; Weis, Joachim; Mey, Jörg; Brook, Gary A

    2016-02-01

    The generation of complex three-dimensional bioengineered scaffolds that are capable of mimicking the molecular and topographical cues of the extracellular matrix found in native tissues is a field of expanding research. The systematic development of such scaffolds requires the characterisation of cell behaviour in response to the individual components of the scaffold. In the present investigation, we studied cell-substrate interactions between purified populations of Schwann cells and three-dimensional fibrin hydrogel scaffolds, in the presence or absence of multiple layers of highly orientated electrospun polycaprolactone nanofibres. Embedded Schwann cells remained viable within the fibrin hydrogel for up to 7 days (the longest time studied); however, cell behaviour in the hydrogel was somewhat different to that observed on the two-dimensional fibrin substrate: Schwann cells failed to proliferate in the fibrin hydrogel, whereas cell numbers increased steadily on the two-dimensional fibrin substrate. Schwann cells within the fibrin hydrogel developed complex process branching patterns, but, when presented with orientated nanofibres, showed a strong tendency to redistribute themselves onto the nanofibres, where they extended long processes that followed the longitudinal orientation of the nanofibres. The process length along nanofibre-containing fibrin hydrogel reached near-maximal levels (for the present experimental conditions) as early as 1 day after culturing. The ability of this three-dimensional, extracellular matrix-mimicking scaffold to support Schwann cell survival and provide topographical cues for rapid process extension suggest that it may be an appropriate device design for the bridging of experimental lesions of the peripheral nervous system. PMID:26215203

  1. Novel Technique Using Polyester Fabric and Fibrin Sealant Patch for Acute Aortic Dissection.

    PubMed

    Ohira, Suguru; Fukumoto, Atsushi; Matsushiro, Takuya; Yaku, Hitoshi

    2016-08-01

    We describe a simple and effective technique for acute aortic dissection using a combination of polyester fabric and a fibrin sealant patch (FSP) to achieve effective reinforcement and haemostasis of the aortic stump. Firstly, the 0.61mm thick knitted polyester fabric sheet was cut to half of the size of the FSP. Next, fibrin glue was sprayed onto the collagen layer of the FSP. Subsequently, a fabric sheet was placed upon it, and the FSP was put together with the irrigated collagen layer, and then completely dried to bind the patch. As a result, the dry fibrinogen/thrombin layers, as an adhesive surface, faced outward. This patch was trimmed to a 10-15-mm-wide strip. The composite patch was inserted into the false lumen. The stump was gently pressed to fix the aortic intima and adventitia. There are several advantages: the combined patch can be prepared during systemic cooling, and therefore can minimise the circulatory arrest time; secondly, the false lumen is not directly exposed to fibrin glue and so the risk of embolism is extremely low; thirdly, the expected haemostatic effect is greater as FSP lines the exterior of the intima, achieving haemostasis for suture holes. PMID:27011040

  2. Polyphosphate enhances fibrin clot structure

    PubMed Central

    Smith, Stephanie A.

    2008-01-01

    Polyphosphate, a linear polymer of inorganic phosphate, is present in platelet dense granules and is secreted on platelet activation. We recently reported that polyphosphate is a potent hemostatic regulator, serving to activate the contact pathway of blood clotting and accelerate factor V activation. Because polyphosphate did not alter thrombin clotting times, it appeared to exert all its procoagulant actions upstream of thrombin. We now report that polyphosphate enhances fibrin clot structure in a calcium-dependent manner. Fibrin clots formed in the presence of polyphosphate had up to 3-fold higher turbidity, had higher mass-length ratios, and exhibited thicker fibers in scanning electron micrographs. The ability of polyphosphate to enhance fibrin clot turbidity was independent of factor XIIIa activity. When plasmin or a combination of plasminogen and tissue plasminogen activators were included in clotting reactions, fibrin clots formed in the presence of polyphosphate exhibited prolonged clot lysis times. Release of polyphosphate from activated platelets or infectious microorganisms may play an important role in modulating fibrin clot structure and increasing its resistance to fibrinolysis. Polyphosphate may also be useful in enhancing the structure of surgical fibrin sealants. PMID:18544683

  3. Effect of Age and Diabetes on the Response of Mesenchymal Progenitor Cells to Fibrin Matrices

    PubMed Central

    Stolzing, A.; Colley, H.; Scutt, A.

    2011-01-01

    Mesenchymal stem cells are showing increasing promise in applications such as tissue engineering and cell therapy. MSC are low in number in bone marrow, and therefore in vitro expansion is often necessary. In vivo, stem cells often reside within a niche acting to protect the cells. These niches are composed of niche cells, stem cells, and extracellular matrix. When blood vessels are damaged, a fibrin clot forms as part of the wound healing response. The clot constitutes a form of stem cell niche as it appears to maintain the stem cell phenotype while supporting MSC proliferation and differentiation during healing. This is particularly appropriate as fibrin is increasingly being suggested as a scaffold meaning that fibrin-based tissue engineering may to some extent recapitulate wound healing. Here, we describe how fibrin modulates the clonogenic capacity of MSC derived from young/old human donors and normal/diabetic rats. Fibrin was prepared using different concentrations to modulate the stiffness of the substrate. MSC were expanded on these scaffolds and analysed. MSC showed an increased self-renewal on soft surfaces. Old and diabetic cells lost the ability to react to these signals and can no longer adapt to the changed environment. PMID:22194749

  4. The α-Helix to β-Sheet Transition in Stretched and Compressed Hydrated Fibrin Clots

    PubMed Central

    Litvinov, Rustem I.; Faizullin, Dzhigangir A.; Zuev, Yuriy F.; Weisel, John W.

    2012-01-01

    Fibrin is a protein polymer that forms the viscoelastic scaffold of blood clots and thrombi. Despite the critical importance of fibrin deformability for outcomes of bleeding and thrombosis, the structural origins of the clot’s elasticity and plasticity remain largely unknown. However, there is substantial evidence that unfolding of fibrin is an important part of the mechanism. We used Fourier transform infrared spectroscopy to reveal force-induced changes in the secondary structure of hydrated fibrin clots made of human blood plasma in vitro. When extended or compressed, fibrin showed a shift of absorbance intensity mainly in the amide I band (1600–1700 cm−1) as well as in the amide II and III bands, indicating an increase of the β-sheets and a corresponding reduction of the α-helices. The structural conversions correlated directly with the strain or pressure and were partially reversible at the conditions applied. The additional absorbance observed at 1612–1624 cm−1 was characteristic of the nascent interchain β-sheets, consistent with protein aggregation and fiber bundling during clot deformation observed using scanning electron microscopy. We conclude that under extension and/or compression an α-helix to β-sheet conversion of the coiled-coils occurs in the fibrin clot as a part of forced protein unfolding. PMID:23009851

  5. The Use Fibrin Sealant after Spinal Intradural Tumor Surgery: Is It Necessary?

    PubMed Central

    Won, Young Il; Chung, Chun Kee; Jahng, Tae-Ahn; Park, Sung Bae

    2016-01-01

    Objective A fibrin sealant is commonly applied after closure of an incidental or intended durotomy to reduce the complications associated with the leakage of cerebrospinal fluid. Routine usage might not be essential after closure of an intended durotomy, which has clear cut-margins. We investigated the efficacy of fibrin sealants for primary intradural spinal cord tumor surgery. Methods A retrospective review was performed for 231 consecutive surgically treated patients with primary intradural spinal cord tumors without extradural extension. Fibrin sealants were not used for 47 patients (group I: age, 51.57±16.75 years) and were applied to 184 patients (group II: age, 48.8±14.7 years). The surgical procedures were identical except for the use of a fibrin sealant after closure of the durotomy. The primary outcome was the occurrence of complications (wound problems, hematoma collection, infection, and neurological deterioration). The covariates were age, sex, body mass index, operation time, pre-/postoperative ambulation, number of laminectomies, and type of tumor. Results Schwannoma was the most common pathology (n=134), followed by meningioma (n=35) and ependymoma (n=31). Complications occurred in 13 patients (3 in group I and 10 in group II, p=0.73). The postoperative ambulation status (p<0.01; odds ratio, 28.8; 95% confidence interval, 6.9-120.0) and operation time (p=0.04; cutoff, 229 minutes; sensitivity, 62%; specificity, 72%) were significant factors, whereas the use of a fibrin glue was not (p=0.47). Conclusion The use of a fibrin sealant might not be essential to reduce complications after surgery for primary spinal intradural tumor. PMID:27123027

  6. ERK Signals: Scaffolding Scaffolds?

    PubMed Central

    Casar, Berta; Crespo, Piero

    2016-01-01

    ERK1/2 MAP Kinases become activated in response to multiple intra- and extra-cellular stimuli through a signaling module composed of sequential tiers of cytoplasmic kinases. Scaffold proteins regulate ERK signals by connecting the different components of the module into a multi-enzymatic complex by which signal amplitude and duration are fine-tuned, and also provide signal fidelity by isolating this complex from external interferences. In addition, scaffold proteins play a central role as spatial regulators of ERKs signals. In this respect, depending on the subcellular localization from which the activating signals emanate, defined scaffolds specify which substrates are amenable to be phosphorylated. Recent evidence has unveiled direct interactions among different scaffold protein species. These scaffold-scaffold macro-complexes could constitute an additional level of regulation for ERK signals and may serve as nodes for the integration of incoming signals and the subsequent diversification of the outgoing signals with respect to substrate engagement. PMID:27303664

  7. Biomimetic interconnected porous keratin-fibrin-gelatin 3D sponge for tissue engineering application.

    PubMed

    Singaravelu, Sivakumar; Ramanathan, Giriprasath; Raja, M D; Nagiah, Naveen; Padmapriya, P; Kaveri, Krishnasamy; Sivagnanam, Uma Tiruchirapalli

    2016-05-01

    The medicated wound dressing material with highly interconnected pores, mimicking the function of the extracellular matrix was fabricated for the promotion of cell growth. In this study, keratin (K), fibrin (F) and gelatin (G) composite scaffold (KFG-SPG) was fabricated by freeze drying technique and the mupirocin (D) drug was successfully incorporated with KFG-SPG (KFG-SPG-D) intended for tissue engineering applications. The fabrication of scaffold was performed without the use of any strong chemical solvents, and the solid sponge scaffold was obtained with well interconnected pores. The porous morphology of the scaffold was confirmed by SEM analysis and exhibited competent mechanical properties. KFG-SPG and KFG-SPG-D possess high level of biocompatibility, cell proliferation and cell adhesion of NIH 3T3 fibroblast and human keratinocytes (HaCaT) cell lines thereby indicating the scaffolds potential as a suitable medicated dressing for wound healing. PMID:26875534

  8. The mechanics of fibrin networks and their alterations by platelets

    NASA Astrophysics Data System (ADS)

    Jawerth, Louise Marie

    Fibrin is a biopolymer that assembles into a network during blood coagulation to become the structural scaffold of a blood clot. The precise mechanics of this network are crucial for a blood clot to properly stem the flow of blood at the site of vascular injury while still remaining pliable enough to avoid dislocation. A hallmark of fibrin's mechanical response is strain-stiffening: at small strains, its response is low and linear; while at high strains, its stiffness increases non-linearly with increasing strain. The physical origins of strain-stiffening have been studied for other biopolymer systems but have remained elusive for biopolymer networks composed of stiff filaments, such as fibrin. To understand the origins of this intriguing behavior, we directly observe and quantify the motion of all of the fibers in the fibrin networks as they undergo shear in 3D using confocal microscopy. We show that the strain-stiffening response of a clot is a result of the full network deformation rather than an intrinsic strain-stiffening response of the individual fibers. We observe a distinct transition from a linear, low-strain regime, where all fibers avoid any internal stretching, to a non-linear, high-strain regime, where an increasing number of fibers become stretched. This transition is characterized by a high degree of non-affine motion. Moreover, we are able to precisely calculate the non-linear stress-strain response of the network by using the strains on each fiber measured directly with confocal microscopy and by assuming the fibers behave like linearly elastic beams. This result confirms that it is the network deformation that causes the strain-stiffening behavior of fibrin clots. These data are consistent with predictions for low-connectivity networks with soft, bending, or floppy modes. Moreover, we show that the addition of small contractile cells, platelets, increases the low-strain stiffness of the network while the high-strain stiffness is independent of

  9. Bioreactor Conditioning for Accelerated Remodeling of Fibrin-Based Tissue Engineered Heart Valves

    NASA Astrophysics Data System (ADS)

    Schmidt, Jillian Beth

    Fibrin is a promising scaffold material for tissue engineered heart valves, as it is completely biological, allows for engineered matrix alignment, and is able to be degraded and replaced with collagen by entrapped cells. However, the initial fibrin matrix is mechanically weak, and extensive in vitro culture is required to create valves with sufficient mechanical strength and stiffness for in vivo function. Culture in bioreactor systems, which provide cyclic stretching and enhance nutrient transport, has been shown to increase collagen production by cells entrapped in a fibrin scaffold, accelerating strengthening of the tissue and reducing the required culture time. In the present work, steps were taken to improve bioreactor culture conditions with the goal of accelerating collagen production in fibrin-based tissue engineered heart valves using two approaches: (i) optimizing the cyclic stretching protocol and (ii) developing a novel bioreactor system that permits transmural and lumenal flow of culture medium for improved nutrient transport. The results indicated that incrementally increasing strain amplitude cyclic stretching with small, frequent increments in strain amplitude was optimal for collagen production in our system. In addition, proof of concept studies were performed in the novel bioreactor system and increased cellularity and collagen deposition near the lumenal surface of the tissue were observed.

  10. Glue Film Thickness Measurements by Spectral Reflectance

    SciTech Connect

    B. R. Marshall

    2010-09-20

    Spectral reflectance was used to determine the thickness of thin glue layers in a study of the effect of the glue on radiance and reflectance measurements of shocked-tin substrates attached to lithium fluoride windows. Measurements based on profilometry of the components were found to be inaccurate due to flatness variations and deformation of the tin substrate under pressure during the gluing process. The accuracy of the spectral reflectance measurements were estimated to be ±0.5 μm, which was sufficient to demonstrate a convincing correlation between glue thickness and shock-generated light.

  11. Esthetics and super glue: a case report.

    PubMed

    Winkler, Sheldon; Wood, Robert; Facchiano, Anne M; Bergloff, Jonathan F

    2003-01-01

    This article describes how a man attempted to repair damage to his maxillary teeth with super glue. Such action is discouraged, however, because of possible adverse reactions in the hard and soft tissues. PMID:14719578

  12. Spiders Tune Glue Viscosity to Maximize Adhesion.

    PubMed

    Amarpuri, Gaurav; Zhang, Ci; Diaz, Candido; Opell, Brent D; Blackledge, Todd A; Dhinojwala, Ali

    2015-11-24

    Adhesion in humid conditions is a fundamental challenge to both natural and synthetic adhesives. Yet, glue from most spider species becomes stickier as humidity increases. We find the adhesion of spider glue, from five diverse spider species, maximizes at very different humidities that matches their foraging habitats. By using high-speed imaging and spreading power law, we find that the glue viscosity varies over 5 orders of magnitude with humidity for each species, yet the viscosity at maximal adhesion for each species is nearly identical, 10(5)-10(6) cP. Many natural systems take advantage of viscosity to improve functional response, but spider glue's humidity responsiveness is a novel adaptation that makes the glue stickiest in each species' preferred habitat. This tuning is achieved by a combination of proteins and hygroscopic organic salts that determines water uptake in the glue. We therefore anticipate that manipulation of polymer-salts interaction to control viscosity can provide a simple mechanism to design humidity responsive smart adhesives. PMID:26513350

  13. [Cementing of small osteochondral fragments in hand surgery using a fibrin glue--clinical experiences].

    PubMed

    Zilch, H; Talke, M

    1980-01-01

    A short historical review of the development of a new fibrinogen adhesive system, consisting of highly concentrated fibrinogen, thrombin, and factor XIII, is given. Small osteochondral fragments are well fixed with this system. This was demonstrated in five cases with good success, the fragments being early revascularized. Some of these patients have had severe damage to the finger joint surface. The problems of a prematured fibrinolysis were discussed. PMID:6972891

  14. Animal experiments on hemostasis with a collagen-fibrin tissue-adhesive sealant in the nephrostomy tract.

    PubMed

    Pfab, R; Ascherl, R; Erhardt, W; Geissdörfer, K; Stemberger, A; Blümel, G; Hartung, R

    1987-01-01

    After a median laparatomy, nephrostomy was performed on 22 porcine kidneys: puncture, dilatation and introduction of a 26-French operating sheath through the parenchyma into the renal pelvis. At the end of the operation, an 8-French nephrostomy catheter prepared with a collagen-fibrin tissue-adhesive sealant was introduced through the operating sheath and the sheath was afterwards extracted. The hemostasis in the nephrostomy tract was very good in all 22 cases. There were no complications such as wound infection or stone formation during a post-operative period of between one and 95 days. Experimental investigations showed severe bleeding in nontamponade of the nephrostomy tract, in tamponade with an 8-French nephrostomy catheter and in tamponade of the nephrostomy tract with the collagen fleece wrapped around an 8-French nephrostomy catheter but not coated with the fibrin glue. PMID:2441506

  15. Astrocytes: Everything but the glue

    PubMed Central

    Gonzalez-Perez, Oscar; Lopez-Virgen, Veronica; Quiñones-Hinojosa, Alfredo

    2015-01-01

    The current knowledge in neuroscience indicates that neural tissue has two major cell populations: neurons and glia (term derived from the Greek word for glue). Neuronal population is characterized by the capacity to produce action potentials, whereas glial cells are typically identified as the subordinate cell population of neurons. To date, this point of view has changed dramatically and growing evidence indicates that glial cells play a crucial role in normal mental functions and the pathogenesis of neurological diseases. Classically, glial cells include four major populations clearly discernible in the adult brain: astrocytes, oligodendrocytes, microglia cells and NG2 glia. Astrocytes, also referred as to astroglia, are by far the most abundant cell lineage in the adult brain. These cells are in close contact with several tissue components of the brain parenchyma including neurons, vasculature, extracellular matrix and other glial populations. Hence, the number and strategic position of astrocytes provide them with exceptional capacity for modulating multiple functions in the neural tissue. PMID:25938129

  16. Fibrin nanoconstructs: a novel processing method and their use as controlled delivery agents

    NASA Astrophysics Data System (ADS)

    Praveen, G.; Sreerekha, P. R.; Menon, Deepthy; Nair, Shantikumar V.; Prasad Chennazhi, Krishna

    2012-03-01

    Fibrin nanoconstructs (FNCs) were prepared through a modified water-in-oil emulsification-diffusion route without the use of any surfactants, resulting in a high yield synthesis of fibrin nanotubes (FNTs) and fibrin nanoparticles (FNPs). The fibrin nanoconstructs formed an aligned structure with self-assembled nanotubes with closed heads that eventually formed spherical nanoparticles of size ˜250 nm. The nanotubes were typically ˜700 nm long and 150-300 nm in diameter, with a wall thickness of ˜50 nm and pore diameter of about 150-250 nm. These constructs showed high stability against aggregation indicated by a zeta potential of -44 mV and an excellent temperature stability upto 200 °C. Furthermore, they were found to be enzymatically degradable, thereby precluding any long term toxicity effects. These unique fibrin nanostructures were analyzed for their ability to deliver tacrolimus, an immunosuppressive drug that is used widely to prevent the initial phase of tissue rejection during allogenic transplantation surgeries. Upon conjugation with tacrolimus, a drug encapsulation efficiency of 66% was achieved, with the in vitro release studies in PBS depicting a sustained and complete drug release over a period of one week at the physiological pH of 7.4. At a more acidic pH, the drug release was very slow, suggesting their potential for oral-intestinal drug administration as well. The in vivo drug absorption rates analyzed in Sprague Dawley rats further confirmed the sustained release pattern of tacrolimus for both oral and parenteral delivery routes. The novel fibrin nanoconstructs developed using a green chemistry approach thus proved to be excellent biodegradable nanocarriers for oral as well as parenteral administrations, with remarkable potential also for delivering specific growth factors in tissue engineering scaffolds.

  17. The origins of strain stiffening in fibrin networks

    NASA Astrophysics Data System (ADS)

    Jawerth, Louise; Muenster, Stefan; Weitz, David

    2012-02-01

    Fibrin networks form the structural scaffold of blood clots; their non-linear mechanical properties are crucial to stem the flow of blood at a site of vascular injury. A hallmark of these networks is strain stiffening: a stiffness that increases non-linearly as a network is strained. Deformations of the fibers and the network combine to control the mechanical properties of the bulk and must lead to the strain stiffening behavior of the networks; however, the details of this process are unknown. Here, we study fibrin networks undergoing shear on a confocal microscope and compare this to bulk rheological measurements. We track individual fiber branchpoints as function of system strain. We characterize the non-affinity of the motion and show that the low strain, linear regime corresponds to highly non-affine motion while the high strain, nonlinear regime corresponds to affine motion. Moreover, we show that the non-linear bulk response can be well approximated by considering the fibers to be linear elastic elements with soft compressive behavior and, therefore, is a result of the topology of the network itself rather than nonlinearity of its constituents.

  18. The GlueX DIRC project

    NASA Astrophysics Data System (ADS)

    Stevens, J.; Barbosa, F.; Bessuille, J.; Chudakov, E.; Dzhygadlo, R.; Fanelli, C.; Frye, J.; Hardin, J.; Kelsey, J.; Patsyuk, M.; Schwartz, C.; Schwiening, J.; Shepherd, M.; Whitlatch, T.; Williams, M.

    2016-07-01

    The GlueX experiment was designed to search for and study the pattern of gluonic excitations in the meson spectrum produced through photoproduction reactions at a new tagged photon beam facility in Hall D at Jefferson Laboratory. The particle identification capabilities of the GlueX experiment will be enhanced by constructing a DIRC (Detection of Internally Reflected Cherenkov light) detector, utilizing components of the decommissioned BaBar DIRC. The DIRC will allow systematic studies of kaon final states that are essential for inferring the quark flavor content of both hybrid and conventional mesons. The design for the GlueX DIRC is presented, including the new expansion volumes that are currently under development.

  19. The GlueX DIRC project

    DOE PAGESBeta

    Stevens, J.; Barbosa, F.; Bessuille, J.; Chudakov, E.; Dzhygadlo, R.; Fanelli, C.; Frye, J.; Hardin, J.; Kelsey, J.; Patsyuk, M.; et al

    2016-07-20

    Here, the GlueX experiment was designed to search for and study the pattern of gluonic excitations in the meson spectrum produced through photoproduction reactions at a new tagged photon beam facility in Hall D at Jefferson Laboratory. The particle identification capabilities of the GlueX experiment will be enhanced by constructing a DIRC (Detection of Internally Reflected Cherenkov light) detector, utilizing components of the decommissioned BaBar DIRC. The DIRC will allow systematic studies of kaon final states that are essential for inferring the quark flavor content of both hybrid and conventional mesons. In this contribution, the design for the GlueX DIRCmore » will be discussed including new expansion volumes, read out with MaPMTs, that are currently under development.« less

  20. Physics Prospects with GlueX

    SciTech Connect

    Alexander Somov

    2011-10-01

    The new experiment GlueX is being currently constructed at Jefferson Lab. The experiment was designed to search for hybrid mesons with exotic-quantum-numbers using a beam of linearly polarized photons incident on a liquid hydrogen target. We will discuss the discovery potential of the GlueX experiment and briefly overview its physics program. GlueX is a new experiment at Jefferson Lab. whose physics program is intended to improve our knowledge of strong interactions. The main goal of the experiment is to search for gluonic excitations in photoproduction. The experiment is expected to collect a data sample a few order of magnitudes larger than all existing photoproduction data. The physics topics of the experiment spans from light meson spectroscopy to Primakoff production of pseudoscalar mesons. The construction of the experiment has started in 2009 and the commissioning stage is expected to be finished in 2015.

  1. [Mycelial wastes of penicillin fermentation as glue components].

    PubMed

    Kadimaliev, D A; Revin, V V; Vatolin, A K; Groshev, V M; Bychkov, M V

    2002-01-01

    A new trend in the rational use of micelial wastes after antibiotics fermentation was elaborated. The modification of P. chrysogenum micelium by means of acid and alkaline solutions allows to use it as bone glue component. As a result physico-mechanical characteristics of the mixture increase, while the ratio cost-price decreases. The obtained glue composition can be used in the production of glue paper tape, for paper and wood glue. PMID:12728627

  2. Hybrid elastin-like recombinamer-fibrin gels: physical characterization and in vitro evaluation for cardiovascular tissue engineering applications.

    PubMed

    Gonzalez de Torre, Israel; Weber, Miriam; Quintanilla, Luis; Alonso, Matilde; Jockenhoevel, Stefan; Rodríguez Cabello, José Carlos; Mela, Petra

    2016-08-16

    In the field of tissue engineering, the properties of the scaffolds are of crucial importance for the success of the application. Hybrid materials combine the properties of the different components that constitute them. In this study hybrid gels of Elastin-Like Recombinamer (ELR) and fibrin were prepared with a range of polymer concentrations and ELR-to-fibrin ratios. The correlation between SEM micrographs, porosities, swelling ratios and rheological properties was discussed and a poroelastic mechanism was suggested to explain the mechanical behavior of the hybrid gels. Applicability as scaffold materials for cardiovascular tissue engineering was shown by the realization of cell-laden matrixes which supported the synthesis of collagens as revealed by immunohistochemical analysis. As a proof of concept, a tissue-engineered heart valve was fabricated by injection moulding and cultivated in a bioreactor for 3 weeks under dynamic conditions. Tissue analysis revealed the production of collagen I and III, fundamental proteins for cardiovascular constructs. PMID:27430365

  3. Role of EVICEL Fibrin Sealant to Assist Hemostasis in Cranial and Spinal Epidural Space: A Neurosurgical Clinical Study.

    PubMed

    Gazzeri, Roberto; Fiore, Claudio; Galarza, Marcelo

    2015-05-01

    A variety of techniques have been used to stop venous bleeding from the cranial and spinal epidural space. These generally consist of packing with oxidized regenerated cellulose, fibrillar collagen, and so forth, and in cranial surgery, tack-up sutures. Bipolar coagulation may also be used to control bleeding from spinal venous plexus, but it may bear the risk of healthy nervous tissue injury: dissipation of heat from the tips of the bipolar forceps may induce thermal injury to adjacent neural structures. Quick and safe hemostasis reduces the duration of surgery. Efficient control of bleeding is also a prerequisite for the realization of the planned therapeutic procedure, that is, the result of surgery, and can thereby reduce perioperative morbidity. Fibrin sealant is safely used to increase hemostasis and to treat cerebrospinal leakage. Between January 2014 and March 2015, the authors used injection of fibrin sealant (EVICEL®, Johnson & Johnson Wound Management, Somerville, NJ) into the cranial and spinal epidural space to assist in hemostasis in 97 patients. EVICEL injection was used in 81 cases of cranial surgery and 16 cases of spinal surgery. When the venous bleeding continued from the epidural space after packing with classical hemostatic agents, fibrin sealant was used to stop venous bleeding. When arterial bleeding was present, fibrin sealant was not used. In all cases, the results were judged to be excellent with stoppage of epidural bleeding, or good with mild persistent oozing. During the 10-minute observation period, no patients treated with EVICEL required additional hemostatic measures. No complications related to the fibrin glue were encountered. PMID:26055033

  4. Multiple-Step Injection Molding for Fibrin-Based Tissue-Engineered Heart Valves.

    PubMed

    Weber, Miriam; Gonzalez de Torre, Israel; Moreira, Ricardo; Frese, Julia; Oedekoven, Caroline; Alonso, Matilde; Rodriguez Cabello, Carlos J; Jockenhoevel, Stefan; Mela, Petra

    2015-08-01

    Heart valves are elaborate and highly heterogeneous structures of the circulatory system. Despite the well accepted relationship between the structural and mechanical anisotropy and the optimal function of the valves, most approaches to create tissue-engineered heart valves (TEHVs) do not try to mimic this complexity and rely on one homogenous combination of cells and materials for the whole construct. The aim of this study was to establish an easy and versatile method to introduce spatial diversity into a heart valve fibrin scaffold. We developed a multiple-step injection molding process that enables the fabrication of TEHVs with heterogeneous composition (cell/scaffold material) of wall and leaflets without the need of gluing or suturing components together, with the leaflets firmly connected to the wall. The integrity of the valves and their functionality was proved by either opening/closing cycles in a bioreactor (proof of principle without cells) or with continuous stimulation over 2 weeks. We demonstrated the potential of the method by the two-step molding of the wall and the leaflets containing different cell lines. Immunohistology after stimulation confirmed tissue formation and demonstrated the localization of the different cell types. Furthermore, we showed the proof of principle fabrication of valves using different materials for wall (fibrin) and leaflets (hybrid gel of fibrin/elastin-like recombinamer) and with layered leaflets. The method is easy to implement, does not require special facilities, and can be reproduced in any tissue-engineering lab. While it has been demonstrated here with fibrin, it can easily be extended to other hydrogels. PMID:25654448

  5. Multiple-Step Injection Molding for Fibrin-Based Tissue-Engineered Heart Valves

    PubMed Central

    Weber, Miriam; Gonzalez de Torre, Israel; Moreira, Ricardo; Frese, Julia; Oedekoven, Caroline; Alonso, Matilde; Rodriguez Cabello, Carlos J.

    2015-01-01

    Heart valves are elaborate and highly heterogeneous structures of the circulatory system. Despite the well accepted relationship between the structural and mechanical anisotropy and the optimal function of the valves, most approaches to create tissue-engineered heart valves (TEHVs) do not try to mimic this complexity and rely on one homogenous combination of cells and materials for the whole construct. The aim of this study was to establish an easy and versatile method to introduce spatial diversity into a heart valve fibrin scaffold. We developed a multiple-step injection molding process that enables the fabrication of TEHVs with heterogeneous composition (cell/scaffold material) of wall and leaflets without the need of gluing or suturing components together, with the leaflets firmly connected to the wall. The integrity of the valves and their functionality was proved by either opening/closing cycles in a bioreactor (proof of principle without cells) or with continuous stimulation over 2 weeks. We demonstrated the potential of the method by the two-step molding of the wall and the leaflets containing different cell lines. Immunohistology after stimulation confirmed tissue formation and demonstrated the localization of the different cell types. Furthermore, we showed the proof of principle fabrication of valves using different materials for wall (fibrin) and leaflets (hybrid gel of fibrin/elastin-like recombinamer) and with layered leaflets. The method is easy to implement, does not require special facilities, and can be reproduced in any tissue-engineering lab. While it has been demonstrated here with fibrin, it can easily be extended to other hydrogels. PMID:25654448

  6. Summary of Glue Tests 1993

    SciTech Connect

    Bell, D.; /Fermilab

    1993-01-07

    I have reported most of the results of my adhesive testing to members of the VLPC design team at one time or another, usually verbally, but I am wnnng this summary as an easy reference to the results I obtained. The adhesives I tested were for two primary purposes. The first was adhering optical fibers to Torlon 7130; the other was for securing an aluminum nitride substrate to the same material. I have not had access to a scanning electron microscope and someone with the knowledge to determine actual failure mechanisms, so the deductions I have made about why some adhesives have worked well at low temperatures for some purposes and not for other applications while a different material never worked and another always worked are partially speculation. They should be taken merely at face value with no particular results 'carved in stone' so to speak. The first aspect of my testing was adhesion of optical fiber to torlon. Knowing that this is a very important joint, I tested a variety of glues of two primary types: acrylic and W cure. W cure adhesives are known to possess reasonably good properties at low temperatures and are quite convenient to use as long as a W source is available. The W cure adhesives I tested were: Loctite Utak 376 and also 7EN484(?), Master Bond 1 Component W 15-7, and Norland optical adhesive 61. I found them quite easy to use, and they were packaged in a way in which they were not likely to cause a mess. Lab 6 e Perimenters generally used the Loctite 376 optical cure adhesive in their research into connecting scintillating fibers to the standard type. The acrylics I tested were Loctite Speed Bonder 324 and Permabond Quick Bond 610. These worked reasonably well, but they require a considerably longer set time than the W cure adhesives and are more complicated to use. (5 minutes set time or so for the acrylics versus about 30 seconds for the W. The Loctite must have the activator applied about 5 minutes prior to the adhesive application and the

  7. Human umbilical cord stem cell encapsulation in novel macroporous and injectable fibrin for muscle tissue engineering.

    PubMed

    Liu, Jun; Xu, Hockin H K; Zhou, Hongzhi; Weir, Michael D; Chen, Qianming; Trotman, Carroll Ann

    2013-01-01

    There has been little research on the seeding of human umbilical cord mesenchymal stem cells (hUCMSCs) in three-dimensional scaffolds for muscle tissue engineering. The objectives of this study were: (i) to seed hUCMSCs in a fibrin hydrogel containing fast-degradable microbeads (dMBs) to create macropores to enhance cell viability; and (ii) to investigate the encapsulated cell proliferation and myogenic differentiation for muscle tissue engineering. Mass fractions of 0-80% of dMBs were tested, and 35% of dMBs in fibrin was shown to avoid fibrin shrinkage while creating macropores and promoting cell viability. This construct was referred to as "dMB35". Fibrin without dMBs was termed "dMB0". Microbead degradation created macropores in fibrin and improved cell viability. The percentage of live cells in dMB35 reached 91% at 16 days, higher than the 81% in dMB0 (p<0.05). Live cell density in dMB35 was 1.6-fold that of dMB0 (p<0.05). The encapsulated hUCMSCs proliferated, increasing the cell density by 2.6 times in dMB35 from 1 to 16 days. MTT activity for dMB35 was substantially higher than that for dMB0 at 16 days (p<0.05). hUCMSCs in dMB35 had high gene expressions of myotube markers of myosin heavy chain 1 (MYH1) and alpha-actinin 3 (ACTN3). Elongated, multinucleated cells were formed with positive staining of myogenic specific proteins including myogenin, MYH, ACTN and actin alpha 1. Moreover, a significant increase in cell fusion was detected with myogenic induction. In conclusion, hUCMSCs were encapsulated in fibrin with degradable microbeads for the first time, achieving greatly enhanced cell viability and successful myogenic differentiation with formation of multinucleated myotubes. The injectable and macroporous fibrin-dMB-hUCMSC construct may be promising for muscle tissue engineering applications. PMID:22902812

  8. Sutureless cataract incision closure using laser-activated tissue glues

    NASA Astrophysics Data System (ADS)

    Eaton, Alexander M.; Bass, Lawrence S.; Libutti, Steven K.; Schubert, Herman D.; Treat, Michael R.

    1991-06-01

    With the advent of phacoemulsification and foldable intraocular lenses, there is renewed interest in sutureless cataract wound. We report the use of laser activated tissue glues for the closure of scleral tunnel cataract incisions. Two glue mixtures were tested in enucleated porcine eyes. Glue A was composed of hyaluronic acid, human albumin, and indocyanine green dye. Glue B contained hyaluronic acid, chondroitin sulfate, human albumin, and indocyanine green dye. A Spectra Physics diode laser (808 nm) with a power density of 7-1 1 watts/cm2 was used for glue activation. Wound bursting pressures, as determined by the presence of fluid at the wound margin, was significantly higher with both glue combinations than without the glue (PGlue A was 69.9 17.1 mm Hg, and for Glue B was 42.9 9.4 mm Hg. These results suggest that laser activated tissue glues may be an alternative to suture closure of scleral tunnel cataract incisions.

  9. Zinc modulates thrombin adsorption to fibrin

    SciTech Connect

    Hopmeier, P.; Halbmayer, M.; Fischer, M.; Marx, G. )

    1990-05-01

    Human thrombin with high affinity to Sepharose insolubilized fibrin monomers (high-affinity thrombin) was used to investigate the effect of Zn(II) on the thrombin adsorption to fibrin. Results showed that at Zn(II) concentrations exceeding 100 mumols/l, thrombin binding to fibrin was decreased concomitant with the Zn(II) concentration and time; at lower Zn(II) concentrations, thrombin adsorption was enhanced. Experimental results were identical by using 125I-labelled high-affinity alpha-thrombin or by measuring the thrombin activity either by chromogenic substrate or by a clotting time method. In contrast, Ca(II) alone (final conc. 3 mmol/l) or in combination with Zn(II) was not effective. However, at higher Ca(II) concentrations (7.5-15 mmol/l), thrombin adsorption was apparently decreased. Control experiments revealed that Zn(II) had no impact on the clottability of fibrinogen, and that the results of the experiments with Ca(II) were not altered by possible cross-linking of fibrin. We conclude that unlike Ca(II), Zn(II) is highly effective in modulating thrombin adsorption to fibrin.

  10. The glue ear 'epidemic': a historical perspective.

    PubMed

    Alderson, David

    2011-12-01

    This paper explores the historical context of the dramatic rise in surgery for glue ear in the mid-20th century, and questions the published assertion that this represented a manufactured 'epidemic'. In examining historical sources, the reader's theoretical viewpoint greatly influences their conclusions: the sustained rise in treatment for glue ear may be seen as the advance of science in a golden age or the resistance of insular professionals to reason in the light of new scientific study methods. Current views on the practice of medicine, consumerism, science and standardisation, rationing and the nature of 'truth' all affect the way that we see this period. Technological advances clearly allowed better diagnosis and more effective treatment, but these did not appear to drive an 'epidemic', rather they were developed to meet the pre-existing challenges of otological practice. The proposition that an 'epidemic' was created does not appear to have any solid grounding. Society's perception of what constitutes disease and what needs treatment may have evolved, but the prevalence of other important diseases changed dramatically over this time period, and a real change in the epidemiology of glue ear cannot be dismissed. In defining the case for and against surgical treatment, a solely positivist, quantitative worldview cannot give us a complete picture of benefit and risk to individuals, families and society at large. PMID:21653931

  11. Fibrin Architecture in Clots: A Quantitative Polarized Light Microscopy Analysis

    PubMed Central

    Whittaker, Peter; Przyklenk, Karin

    2009-01-01

    Fibrin plays a vital structural role in thrombus integrity. Thus, the ability to assess fibrin architecture has potential to provide insight into thrombosis and thrombolysis. Fibrin has an anisotropic molecular structure, which enables it to be seen with polarized light. Therefore, we aimed to determine if automated polarized light microscopy methods of quantifying two structural parameters; fibrin fiber bundle orientation and fibrin's optical retardation (OR: a measure of molecular anisotropy) could be used to assess thrombi. To compare fibrin fiber bundle orientation we analyzed picrosirius red-stained sections obtained from clots formed: (A) in vitro, (B) in injured and stenotic coronary arteries, and (C) in surgically created aortic aneurysms (n = 6 for each group). To assess potential changes in OR, we examined fibrin in picrosirius red-stained clots formed after ischemic preconditioning (10 minutes ischemia + 10 minutes reflow; a circumstance shown to enhance lysability) and in control clots (n = 8 each group). The degree of fibrin organization differed significantly according to the location of clot formation; fibrin was most aligned in the aneurysms and least aligned in vitro whereas fibrin in the coronary clots had an intermediate organization. The OR of fibrin in the clots formed after ischemic preconditioning was lower than that in controls (2.9 ± 0.5 nm versus 5.4 ± 1.0 nm, P < 0.05). The automated polarized light analysis methods not only enabled fibrin architecture to be assessed, but also revealed structural differences in clots formed under different circumstances. PMID:19054699

  12. Scaffolding and Metacognition

    ERIC Educational Resources Information Center

    Holton, Derek; Clarke, David

    2006-01-01

    This paper proposes an expanded conception of scaffolding with four key elements: (1) scaffolding agency--expert, reciprocal, and self-scaffolding; (2) scaffolding domain--conceptual and heuristic scaffolding; (3) the identification of self-scaffolding with metacognition; and (4) the identification of six zones of scaffolding activity; each zone…

  13. Dry-cured ham restructured with fibrin.

    PubMed

    Romero de Ávila, M D; Hoz, L; Ordóñez, J A; Cambero, M I

    2014-09-15

    The viability of a fibrinogen-thrombin system (FT) to bind fresh deboned hams for incorporation in the salting and ripening processes, to produce cured ham, was studied. The effects of the different processing variables (pH, NaCl concentration, temperature and gelation time) on FT, a meat emulsion mixed with FT, fresh pork portions and deboned hams restructured with FT were analyzed. The most stable and firmest fibrin gels were obtained after 6h of adding the FT, with less than 2% NaCl and pH 7-8.4. Scanning electron microscopy of the fibrin gel showed fibrillar structures with a high degree of cross-linking and a high density. Two structures were found in the binding area of restructured meat; one in the central part with similar characteristics to fibrin gels and, another in the area of contact between the meat surfaces, where a filamentous structure connected the fibrin gels with the muscle bundles. PMID:24767091

  14. Platelets and fibrin strands during clot retraction.

    PubMed

    Morgenstern, E; Korell, U; Richter, J

    1984-03-15

    The ultrastructure of platelet fibrin contacts (PFC) and the course of the strands was investigated in serial sections of retracted clots with the help of specimen tilting. We found after retraction in a test tube as well as under isometric conditions in the resonance thrombograph, after HARTERT, an uniform type of PFC. The side to side contact between platelet surface and fibrin strands displayed a 15 nm wide space which was bridged of 10 - 30 nm by filamentary structure. In each case the direction of the fibrin strands changed on contact with the platelet surface (bend). These bends recurred if the adhering strands ran over a longer distance on the platelet surface. The bends can be explained by non-directional movement of the platelets or of their pseudopodia. Microfilaments (actomyosin) which run straight in pseudopodia and often also twisted in the platelet body support this assumption. The described mechanism - contact of the thrombin activated platelets with fibrin strands and simultaneous nondirectional movement of the platelets which bind further sections of the adhering strands to their surface - would provide a more satisfactory explanation for the retraction of the clot to 1/10 of its original volume. PMID:6539004

  15. Characterization of the chemotactic and mitogenic response of SMCs to PDGF-BB and FGF-2 in fibrin hydrogels

    PubMed Central

    Ucuzian, Areck A.; Brewster, Luke P.; East, Andrea T.; Pang, Yongang; Gassman, Andrew A.; Greisler, Howard P.

    2010-01-01

    The delivery of growth factors to cellularize biocompatible scaffolds like fibrin is a commonly used strategy in tissue engineering. We characterized SMC proliferation and chemotaxis in response to PDGF-BB and FGF-2, alone and in combination, in 2-D culture and in 3-D fibrin hydrogels. While both growth factors induced an equipotent mitogenic response in 2-D culture, only FGF-2 was significantly mitogenic for SMCs in 3-D culture. Only PDGF-BB was significantly chemotactic in a modified Boyden chamber assay. In a 3-D assay of matrix invasion, both growth factors induced an invasive response into the fibrin hydrogel in both proliferating and non-proliferating, mitomycin C (MMC) treated cells. The invasive response was less attenuated by the inhibition of proliferation in PDGF-BB stimulated cells compared with FGF-2 stimulated cells. We conclude that SMCs cultured in fibrin hydrogels have a more robust chemotactic response to PDGF-BB compared with FGF-2, and that the response to FGF-2 is more dependent on cell proliferation. Delivery of both growth factors together potentiates the chemotactic, but not mitogenic response to either growth factor alone. PMID:20730936

  16. Dendritic polymers: Universal glue for cells

    NASA Astrophysics Data System (ADS)

    Frey, Holger

    2012-05-01

    A dendritic polymer consisting of inversely oriented lipid head groups on a polyvalent polyglycerol scaffold makes an effective reversible biomembrane adhesive that may find use as a tissue sealant and a drug-delivery vehicle.

  17. Impact of EmbryoGlue as the embryo transfer medium.

    PubMed

    Hazlett, William David; Meyer, Liza R; Nasta, Tricia E; Mangan, Patricia A; Karande, Vishvanath C

    2008-07-01

    Routine use of EmbryoGlue did not significantly improve pregnancy or implantation rates in nonselected patients receiving either a day 3 or day 5 embryo transfer compared with standard culture media. Future prospective randomized studies need to be performed to determine whether EmbryoGlue is beneficial in a selected patient population. PMID:17765233

  18. Artificial Lymphatic Drainage Systems for Vascularized Microfluidic Scaffolds

    PubMed Central

    Wong, Keith H. K.; Truslow, James G.; Khankhel, Aimal H.; Chan, Kelvin L. S.; Tien, Joe

    2012-01-01

    The formation of a stably perfused microvasculature continues to be a major challenge in tissue engineering. Previous work has suggested the importance of a sufficiently large transmural pressure in maintaining vascular stability and perfusion. Here we show that a system of empty channels that provides a drainage function analogous to that of lymphatic microvasculature in vivo can stabilize vascular adhesion and maintain perfusion rate in dense, hydraulically resistive fibrin scaffolds in vitro. In the absence of drainage, endothelial delamination increased as scaffold density increased from 6 mg/mL to 30 mg/mL and scaffold hydraulic conductivity decreased by a factor of twenty. Single drainage channels exerted only localized vascular stabilization, the extent of which depended on the distance between vessel and drainage as well as scaffold density. Computational modeling of these experiments yielded an estimate of 0.40–1.36 cm H2O for the minimum transmural pressure required for vascular stability. We further designed and constructed fibrin patches (0.8 by 0.9 cm2) that were perfused by a parallel array of vessels and drained by an orthogonal array of drainage channels; only with the drainage did the vessels display long-term stability and perfusion. This work underscores the importance of drainage in vascularization, especially when a dense, hydraulically resistive scaffold is used. PMID:23281125

  19. GlueX: Meson Spectroscopy in Photoproduction

    SciTech Connect

    Salgado, Carlos; Smith, Elton S.

    2014-03-01

    The goal of the GlueX experiment \\cite{gluex} is to provide crucial data to help understand the soft gluonic fields responsible for binding quarks in hadrons. Hybrid mesons, and in particular exotic hybrid mesons, provide the ideal laboratory for testing QCD in the confinement regime since these mesons explicitly manifest the gluonic degrees of freedom. Photoproduction is expected to be effective in producing exotic hybrids but there is little data on the photoproduction of light mesons. GlueX will use the new 12-GeV electron beam at Jefferson Lab to produce a 9-GeV beam of linearly polarized photons using the technique of coherent bremsstrahlung. A solenoid-based hermetic detector is under construction, which will be used to collect data on meson production and decays. These data will also be used to study the spectrum of conventional mesons, including the poorly understood excited vector mesons. This talk will give an update on the experiment as well as describe theoretical developments \\cite{Dudek:2011bn} to help understand how these data can provide insights into the fundamental theory of strong interactions.

  20. Intervertebral Disk Tissue Engineering Using Biphasic Silk Composite Scaffolds

    PubMed Central

    Park, Sang-Hyug; Gil, Eun Seok; Cho, Hongsik; Mandal, Biman B.; Tien, Lee W.; Min, Byoung-Hyun

    2012-01-01

    Scaffolds composed of synthetic, natural, and hybrid materials have been investigated as options to restore intervertebral disk (IVD) tissue function. These systems fall short of the lamellar features of the native annulus fibrosus (AF) tissue or focus only on the nucleus pulposus (NP) tissue. However, successful regeneration of the entire IVD requires a combination approach to restore functions of both the AF and NP. To address this need, a biphasic biomaterial structure was generated by using silk protein for the AF and fibrin/hyaluronic acid (HA) gels for the NP. Two cell types, porcine AF cells and chondrocytes, were utilized. For the AF tissue, two types of scaffold morphologies, lamellar and porous, were studied with the porous system serving as a control. Toroidal scaffolds formed out of the lamellar, and porous silk materials were used to generate structures with an outer diameter of 8 mm, inner diameter of 3.5 mm, and a height of 3 mm (the interlamellar distance in the lamellar scaffold was 150–250 μm, and the average pore sizes in the porous scaffolds were 100–250 μm). The scaffolds were seeded with porcine AF cells to form AF tissue, whereas porcine chondrocytes were encapsulated in fibrin/HA hydrogels for the NP tissue and embedded in the center of the toroidal disk. Histology, biochemical assays, and gene expression indicated that the lamellar scaffolds supported AF-like tissue over 2 weeks. Porcine chondrocytes formed the NP phenotype within the hydrogel after 4 weeks of culture with the AF tissue that had been previously cultured for 2 weeks, for a total of 6 weeks of cultivation. This biphasic scaffold simulating in combination of both AF and NP tissues was effective in the formation of the total IVD in vitro. PMID:21919790

  1. Scaffolded biology.

    PubMed

    Minelli, Alessandro

    2016-09-01

    Descriptions and interpretations of the natural world are dominated by dichotomies such as organism vs. environment, nature vs. nurture, genetic vs. epigenetic, but in the last couple of decades strong dissatisfaction with those partitions has been repeatedly voiced and a number of alternative perspectives have been suggested, from perspectives such as Dawkins' extended phenotype, Turner's extended organism, Oyama's Developmental Systems Theory and Odling-Smee's niche construction theory. Last in time is the description of biological phenomena in terms of hybrids between an organism (scaffolded system) and a living or non-living scaffold, forming unit systems to study processes such as reproduction and development. As scaffold, eventually, we can define any resource used by the biological system, especially in development and reproduction, without incorporating it as happens in the case of resources fueling metabolism. Addressing biological systems as functionally scaffolded systems may help pointing to functional relationships that can impart temporal marking to the developmental process and thus explain its irreversibility; revisiting the boundary between development and metabolism and also regeneration phenomena, by suggesting a conceptual framework within which to investigate phenomena of regular hypermorphic regeneration such as characteristic of deer antlers; fixing a periodization of development in terms of the times at which a scaffolding relationship begins or is terminated; and promoting plant galls to legitimate study objects of developmental biology. PMID:27287514

  2. Toward an understanding of fibrin branching structure

    NASA Astrophysics Data System (ADS)

    Fogelson, Aaron L.; Keener, James P.

    2010-05-01

    The blood clotting enzyme thrombin converts fibrinogen molecules into fibrin monomers which polymerize to form a fibrous three-dimensional gel. The concentration of thrombin affects the architecture of the resulting gel, in particular, a higher concentration of thrombin produces a gel with more branch points per unit volume and with shorter fiber segments between branch points. We propose a mechanism by which fibrin branching can occur and show that this mechanism can lead to dependence of the gel’s structure (at the time of gelation) on the rate at which monomer is supplied. A higher rate of monomer supply leads to a gel with a higher branch concentration and with shorter fiber segments between branch points. The origin of this dependence is explained.

  3. THE CONVERSION OF FIBRINOGEN TO FIBRIN

    PubMed Central

    Shulman, Sidney; Katz, Sidney; Ferry, John D.

    1953-01-01

    1. Fibrin clots prepared in the absence of calcium can be dissolved in solutions of lithium chloride and bromide and sodium bromide and iodide, as well as of guanidine hydrochloride and urea. These salts do not denature fibrinogen under the same conditions of concentration, temperature, and time. Sedimentation experiments on the fibrin solutions show in each case a single sharp peak with a sedimentation constant close to that of fibrinogen. 2. At lower concentrations, these salts inhibit the clotting of fibrinogen by thrombin, but in the case of lithium bromide and sodium iodide, at least, allow an intermediate polymer to accumulate whose sedimentation constant is close to that of the polymer observed in systems inhibited by hexamethylene glycol or urea. PMID:13069679

  4. Electrospinning versus knitting: two scaffolds for tissue engineering of the aortic valve.

    PubMed

    van Lieshout, M I; Vaz, C M; Rutten, M C M; Peters, G W M; Baaijens, F P T

    2006-01-01

    Two types of scaffolds were developed for tissue engineering of the aortic valve; an electrospun valvular scaffold and a knitted valvular scaffold. These scaffolds were compared in a physiologic flow system and in a tissue-engineering process. In fibrin gel enclosed human myofibroblasts were seeded onto both types of scaffolds and cultured for 23 days under continuous medium perfusion. Tissue formation was evaluated by confocal laser scanning microscopy, histology and DNA quantification. Collagen formation was quantified by a hydroxyproline assay. When subjected to physiologic flow, the spun scaffold tore within 6 h, whereas the knitted scaffold remained intact. Cells proliferated well on both types of scaffolds, although the cellular penetration into the spun scaffold was poor. Collagen production, normalized to DNA content, was not significantly different for the two types of scaffolds, but seeding efficiency was higher for the spun scaffold, because it acted as a cell impermeable filter. The knitted tissue constructs showed complete cellular in-growth into the pores. An optimal scaffold seems to be a combination of the strength of the knitted structure and the cell-filtering ability of the spun structure. PMID:16411600

  5. Mechanisms of fibrin polymerization and clinical implications

    PubMed Central

    Litvinov, Rustem I.

    2013-01-01

    Research on all stages of fibrin polymerization, using a variety of approaches including naturally occurring and recombinant variants of fibrinogen, x-ray crystallography, electron and light microscopy, and other biophysical approaches, has revealed aspects of the molecular mechanisms involved. The ordered sequence of fibrinopeptide release is essential for the knob-hole interactions that initiate oligomer formation and the subsequent formation of 2-stranded protofibrils. Calcium ions bound both strongly and weakly to fibrin(ogen) have been localized, and some aspects of their roles are beginning to be discovered. Much less is known about the mechanisms of the lateral aggregation of protofibrils and the subsequent branching to yield a 3-dimensional network, although the αC region and B:b knob-hole binding seem to enhance lateral aggregation. Much information now exists about variations in clot structure and properties because of genetic and acquired molecular variants, environmental factors, effects of various intravascular and extravascular cells, hydrodynamic flow, and some functional consequences. The mechanical and chemical stability of clots and thrombi are affected by both the structure of the fibrin network and cross-linking by plasma transglutaminase. There are important clinical consequences to all of these new findings that are relevant for the pathogenesis of diseases, prophylaxis, diagnosis, and treatment. PMID:23305734

  6. 21 CFR 864.7300 - Fibrin monomer paracoagulation test.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... clotting within a blood vessel) or in the differential diagnosis between disseminated intravascular coagulation and primary fibrinolysis (dissolution of the fibrin in a blood clot). (b) Classification. Class...

  7. 21 CFR 864.7300 - Fibrin monomer paracoagulation test.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... clotting within a blood vessel) or in the differential diagnosis between disseminated intravascular coagulation and primary fibrinolysis (dissolution of the fibrin in a blood clot). (b) Classification. Class...

  8. 21 CFR 864.7300 - Fibrin monomer paracoagulation test.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... clotting within a blood vessel) or in the differential diagnosis between disseminated intravascular coagulation and primary fibrinolysis (dissolution of the fibrin in a blood clot). (b) Classification. Class...

  9. Encapsulation of cardiomyocytes in a fibrin hydrogel for cardiac tissue engineering.

    PubMed

    Yuan Ye, Kathy; Sullivan, Kelly Elizabeth; Black, Lauren Deems

    2011-01-01

    Culturing cells in a three dimensional hydrogel environment is an important technique for developing constructs for tissue engineering as well as studying cellular responses under various culture conditions in vitro. The three dimensional environment more closely mimics what the cells observe in vivo due to the application of mechanical and chemical stimuli in all dimensions (1). Three-dimensional hydrogels can either be made from synthetic polymers such as PEG-DA (2) and PLGA (3) or a number of naturally occurring proteins such as collagen (4), hyaluronic acid (5) or fibrin (6,7). Hydrogels created from fibrin, a naturally occurring blood clotting protein, can polymerize to form a mesh that is part of the body's natural wound healing processes (8). Fibrin is cell-degradable and potentially autologous (9), making it an ideal temporary scaffold for tissue engineering. Here we describe in detail the isolation of neonatal cardiomyocytes from three day old rat pups and the preparation of the cells for encapsulation in fibrin hydrogel constructs for tissue engineering. Neonatal myocytes are a common cell source used for in vitro studies in cardiac tissue formation and engineering (4). Fibrin gel is created by mixing fibrinogen with the enzyme thrombin. Thrombin cleaves fibrinopeptides FpA and FpB from fibrinogen, revealing binding sites that interact with other monomers (10). These interactions cause the monomers to self-assemble into fibers that form the hydrogel mesh. Because the timing of this enzymatic reaction can be adjusted by altering the ratio of thrombin to fibrinogen, or the ratio of calcium to thrombin, one can injection mold constructs with a number of different geometries (11,12). Further we can generate alignment of the resulting tissue by how we constrain the gel during culture (13). After culturing the engineered cardiac tissue constructs for two weeks under static conditions, the cardiac cells have begun to remodel the construct and can generate a

  10. Treatment of osteochondral defects in the rabbit's knee joint by implantation of allogeneic mesenchymal stem cells in fibrin clots.

    PubMed

    Berninger, Markus T; Wexel, Gabriele; Rummeny, Ernst J; Imhoff, Andreas B; Anton, Martina; Henning, Tobias D; Vogt, Stephan

    2013-01-01

    bone (11). The sandwich-technique combines bone grafting with current approaches in Tissue Engineering (5,6). This combination seems to be able to overcome the limitations seen in osteochondral grafts alone. After autologous bone grafting to the subchondral defect area, a membrane seeded with autologous chondrocytes is sutured above and facilitates to match the topology of the graft with the injured site. Of course, the previous bone reconstruction needs additional surgical time and often even an additional surgery. Moreover, to date, long-term data is missing (12). Tissue Engineering without additional bone grafting aims to restore the complex structure and properties of native articular cartilage by chondrogenic and osteogenic potential of the transplanted cells. However, again, it is usually only the cartilage tissue that is more or less regenerated. Additional osteochondral damage needs a specific further treatment. In order to achieve a regeneration of the multilayered structure of osteochondral defects, three-dimensional tissue engineered products seeded with autologous/allogeneic cells might provide a good regeneration capacity (11). Beside autologous chondrocytes, mesenchymal stem cells (MSC) seem to be an attractive alternative for the development of a full-thickness cartilage tissue. In numerous preclinical in vitro and in vivo studies, mesenchymal stem cells have displayed excellent tissue regeneration potential (13,14). The important advantage of mesenchymal stem cells especially for the treatment of osteochondral defects is that they have the capacity to differentiate in osteocytes as well as chondrocytes. Therefore, they potentially allow a multilayered regeneration of the defect. In recent years, several scaffolds with osteochondral regenerative potential have therefore been developed and evaluated with promising preliminary results (1,15-18). Furthermore, fibrin glue as a cell carrier became one of the preferred techniques in experimental cartilage

  11. Clinical effect of tetracycline demineralization and fibrin-fibronectin sealing system application on healing response following flap debridement surgery.

    PubMed

    Trombelli, L; Scabbia, A; Scapoli, C; Calura, G

    1996-07-01

    The aim of this controlled clinical trial was to assess the effect on healing following tetracycline (TTC) conditioning and fibrin-fibronectin sealing system (FFSS) application in association with flap debridement surgery (FDS) in 11 patients under treatment for moderate to severe periodontitis. Selection criteria included the presence of two bilateral, homologous, non-molar, interproximal sites with probing depth > or = 5 mm. The areas bilateral to the trial sites were matched for number and type of the teeth, and similar periodontal involvement. After initial therapy, a split-mouth design was used in which one area was treated by flap debridement surgery alone (control), and the contralateral area was treated following surgery with a 4-minute burnishing application of 100 mg/ml TTC solution and FFSS (test). Fibrin glue was applied with a syringe on the demineralized root surfaces and surrounding bone margins. Healing by primary intention was encouraged by flap repositioning with interrupted sutures left in place for 14 days. A monthly maintenance recall program was followed. Patients were clinically evaluated at baseline and 6 months and the following measurements were taken: gingival index, plaque control record, clinical attachment level, probing depth, recession, bleeding on probing. Statistical evaluation indicated that both approaches resulted in significant probing depth reduction and clinical attachment gain. However, the differences in healing between the test and control groups were not clinically nor statistically significant. These results suggest there is no additional benefit with TTC demineralization and topical FFSS application in conjunction with flap debridement surgery. PMID:8832480

  12. The use of fibrin and gelatin fixation to repair a kinked internal carotid artery in carotid endarterectomy

    PubMed Central

    Kubota, Hisashi; Sanada, Yasuhiro; Tanikawa, Rokuya; Kato, Amami

    2016-01-01

    Background: The kinking of the internal carotid artery (ICA) after final closure in carotid endarterectomy (CEA) is thought to be uncommon. When it occurs, it is mandatory to reconstruct ICA to preserve normal blood flow. We herein present a case in which a fixation technique was applied to repair an ICA that became kinked during CEA. Case Description: A 68-year-old man presented with cerebral infarction due to an artery-to-artery embolism from the right cervical ICA stenosis. CEA was performed 12 days after admission. After final closure, a distal portion of ICA was found to have been kinked following plaque resection in CEA procedure. Fixation with fibrin glue and gelatin was used to reinforce the arterial wall and repair the kink. Postoperative magnetic resonance angiography demonstrated the release of the kink in ICA. Conclusion: Fixation with fibrin and gelatin is a salvage armamentarium that can be considered in CEA for the repair of kinked or tortuous ICA. PMID:27308092

  13. The adhesive skin exudate of Notaden bennetti frogs (Anura: Limnodynastidae) has similarities to the prey capture glue of Euperipatoides sp. velvet worms (Onychophora: Peripatopsidae).

    PubMed

    Graham, Lloyd D; Glattauer, Veronica; Li, Dongmei; Tyler, Michael J; Ramshaw, John A M

    2013-08-01

    The dorsal adhesive secretion of the frog Notaden bennetti and the prey-capture "slime" ejected by Euperipatoides sp. velvet worms look and handle similarly. Both consist largely of protein (55-60% of dry weight), which provides the structural scaffold. The major protein of the onychophoran glue (Er_P1 for Euperipatoides rowelli) and the dominant frog glue protein (Nb-1R) are both very large (260-500 kDa), and both give oddly "turbulent" electrophoresis bands. Both major proteins, which are rich in Gly (16-17 mol%) and Pro (7-12 mol%) and contain 4-hydroxyproline (Hyp, 4 mol%), have the composition of intrinsically unstructured proteins. Their propensities for elastomeric or amyloid structures are discussed in light of Er_P1's large content of intrinsically disordered long tandem repeats. The low carbohydrate content of both glues is consistent with conventional protein glycosylation, which in the N. bennetti adhesive was explored by 2D PAGE. The N-linked sugars of Nb-1R appear to prevent inappropriate self-aggregation. Some peptide sequences from Nb-1R are presented. Overall, there are enough similarities between the frog and the velvet worm glues to suspect that they employ related mechanisms for setting and adhesion. A common paradigm is proposed for amphibian and onychophoran adhesives, which, if correct, points to convergent evolution. PMID:23665109

  14. UNDERSIDE FROM SOUTH BANKS; NOTICE NEW GLUE LAM CROSSBEAMS SISTERED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    UNDERSIDE FROM SOUTH BANKS; NOTICE NEW GLUE LAM CROSSBEAMS SISTERED TO OLDER BEAMS, NEW STRINGERS AND COMPONENTS MAKE UP A NEARLY NEW SUPPORT SYSTEM - Short Bridge, Spanning South Santiam River at High Deck Road, Cascadia, Linn County, OR

  15. The GlueX Project at Jefferson Lab

    SciTech Connect

    Papandreou, Zisis

    2009-01-01

    One of the main scientific questions that remains unanswered in subatomic physics is the nature and behaviour of the "Glue" which holds the quarks together. The puzzling feature of this construction is that quarks are never found free, but only in triplets or pairs, a phenomenon known as "confinement". Since gluons carry colour charge, they can form chromoelectric flux tubes, which may result in unusual objects, such as glue-balls or hybrid combinations of gluons and quarks. In certain models, the later can be produced with quantum numbers not allowed in the simple quark picture. An international experiment (GlueX) at Jefferson Lab, Virginia, is being designed to search for such exotic hybrid mesons and thus elucidate the phenomenon of confinement. GlueX is considered a 'discovery' experiment; its salient features, the planned methodology of partial- wave analysis, and the R&D progress of its detector subsystems will be

  16. Constitution and in vivo test of micro-porous tubular scaffold for esophageal tissue engineering.

    PubMed

    Hou, Lei; Jin, Jiachang; Lv, Jingjing; Chen, Ling; Zhu, Yabin; Liu, Xingyu

    2015-11-01

    Current clinical techniques in treating long-gap esophageal defects often lead to complications and high morbidity. Aiming at long-gap synthetic esophageal substitute, we had synthesized a biodegradable copolymer, poly(L-lactide-co-caprolactone) (PLLC), with low glass transition temperature. In this work, we developed a tubular PLLC porous scaffold using a self-designed tubular mold and thermal induced phase separation (TIPS) method. In order to enhance the interaction between tissue and scaffold, fibrin, a natural fibrous protein derived from blood fibrinogen, was coated on the scaffold circumferential surface. The fibrin density was measured to be 1.23 ± 0.04 mg/cm(2). Primary epithelial cell culture demonstrated the improved in vitro biocompatibility. In animal study with partial scaffold implantation, in situ mucosa regeneration was observed along the degradation of the scaffold. These indicate that fibrin incorporated PLLC scaffold can greatly improve epithelial regeneration in esophagus repair, therefore serve as a good candidate for long-term evaluation of post-implantation at excision site. PMID:26208515

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

    SciTech Connect

    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.

  18. 21 CFR 864.7300 - Fibrin monomer paracoagulation test.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 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 monomer paracoagulation test....

  19. 21 CFR 864.7300 - Fibrin monomer paracoagulation test.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 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 monomer paracoagulation test....

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

    PubMed Central

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

    2015-01-01

    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. PMID:26635081

  1. [Strategies to choose scaffold materials for tissue engineering].

    PubMed

    Gao, Qingdong; Zhu, Xulong; Xiang, Junxi; Lü, Yi; Li, Jianhui

    2016-02-01

    mixed with sustained-release nano-microsphere containing growth factors. What's more, the stent internal surface coated with glue/collagen matrix mixing layer containing bFGF and EGF so could supplying the early release of the two cytokines. Finally, combining the poly(L-lactic acid)/poly(ε-caprolactone) biliary stent with the induced cells was the last step for preparing tissue-engineered bile duct. This literature reviewed a variety of the existing tissue engineering scaffold materials and briefly introduced the impact factors on the characteristics of tissue engineering scaffold materials such as preparation procedure, surface modification of scaffold, and so on. We explored the choosing strategy of desired tissue engineering scaffold materials. PMID:27382767

  2. The GlueX Start Counter

    NASA Astrophysics Data System (ADS)

    Pooser, Eric; GlueX Collaboration

    2013-10-01

    The GlueX experiment will be one of the largest photo-production facilities in the world and is currently under construction. This experiment will use the coherent bremsstrahlung technique to produce a 9 GeV linearly polarized photon beam incident on a liquid H2 target. A Start Counter detector has been designed to identify the accelerator electron beam buckets, approximately 2 ns apart, and to provide accurate timing information. It is now under construction at Florida International University (FIU). This detector is designed to operate at photon intensities of up to 108 γ /s in the coherent peak. It consists of an array of 30 individual scintillators with ``pointed'' ends that bend toward the beam at the downstream end. SiPM detectors, which comprise the readout system, are placed as close as possible at the end of each scintillator. The EJ-200 scintillator is best suited for the timing studies with a fast decay time of 2.0 ns. The physical properties of the scintillators, configured to the desired geometry, have been studied extensively at FIU. Geant4 simulations are currently underway to replicate and to understand our experimental results. The results of these timing studies and simulations are discussed.

  3. The GlueX Start Counter

    NASA Astrophysics Data System (ADS)

    Pooser, Eric; GlueX Collaboration

    2015-03-01

    The GlueX experiment will study meson photoproduction with unprecedented precision. This experiment will use the coherent bremsstrahlung technique to produce a 9 GeV linearly polarized photon beam incident on a liquid H2 target. A Start Counter detector has been fabricated to identify the accelerator electron beam buckets, approximately 2 ns apart, and to provide accurate timing information which is used in the level-1 trigger of the experiment. This detector is designed to operate at photon intensities of up to 108 γ / s in the coherent peak and provide a timing resolution < 350 ps so as to provide successful identification of the electron beam buckets to within 99 % accuracy. Furthermore, the Start Counter detector will provide excellent solid angle coverage, ~ 90 % of 4 π hermeticity , and a high degree of segmentation for background rejection. It consists of a cylindrical array of 30 scintillators with pointed ends that bend towards the beam at the downstream end. Silicon PhotoMultiplier (SiPM) detectors have been selected as the readout system. The physical properties of the Start Counter have been studied extensively. The results of theses studies are discussed. This material is based upon work supported by the U.S. Department of Energy, Office of Science, and Office of Nuclear Physics under Contracts DE-AC05-06OR23177 & DE-FG02-99ER41065.

  4. The GlueX Start Counter

    NASA Astrophysics Data System (ADS)

    Pooser, Eric; GlueX Collaboration

    2015-04-01

    The GlueX experiment will study meson photoproduction with unprecedented precision. This experiment will use the coherent bremsstrahlung technique to produce a 9 GeV linearly polarized photon beam incident on a liquid H2 target. A Start Counter detector has been fabricated to identify the accelerator electron beam buckets, approximately 2 ns apart, and to provide accurate timing information which is used in the level-1 trigger of the experiment. This detector is designed to operate at photon intensities of up to 108 γ / s in the coherent peak and provide a timing resolution < 350ps so as to provide successful identification of the electron beam buckets to within 99 % accuracy. Furthermore, the Start Counter detector will provide excellent solid angle coverage, ~ 90 % of 4 π hermeticity , and a high degree of segmentation for background rejection. It consists of a cylindrical array of 30 scintillators with pointed ends that bend towards the beam at the downstream end. Silicon PhotoMultiplier (SiPM) detectors have been selected as the readout system. The physical properties of the Start Counter have been studied extensively. The results of theses studies are discussed. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Contracts DE-AC05-06OR23177 & DE-FG02-99ER41065.

  5. The GlueX Start Counter

    NASA Astrophysics Data System (ADS)

    Pooser, Eric; GlueX Collaboration

    2014-09-01

    The GlueX experiment will study meson photoproduction with unprecedented precision. This experiment will use the coherent bremsstrahlung technique to produce a 9 GeV linearly polarized photon beam incident on a liquid H2 target. A Start Counter detector has been fabricated to identify the accelerator electron beam buckets, approximately 2 ns apart, and to provide accurate timing information which is used in the level-1 trigger of the experiment. This detector is designed to operate at photon intensities of up to 108 γ / s in the coherent peak and provide a timing resolution <350 ps so as to provide successful identification of the electron beam buckets to within 99% accuracy. Furthermore, the Start Counter detector will provide excellent solid angle coverage, ~90% of 4π hermeticity, and a high degree of segmentation for background rejection. It consists of a cylindrical array of 30 scintillators with pointed ends that bend towards the beam at the downstream end. Silicon PhotoMultiplier (SiPM) detectors have been selected as the readout system. The physical properties of the scintillators, have been studied extensively at FIU. The results of these studies are discussed.

  6. The GlueX Start Counter

    NASA Astrophysics Data System (ADS)

    Llodra, Anthony; Pooser, Eric; GlueX Collaboration

    2015-04-01

    The GlueX experiment, which is online as of October of 2014, will study meson photo production with unprecedented precision. This experiment will use the coherent bremsstrahlung technique to produce a 9 GeV linearly polarized photon beam incident on a liquid H2 target kept at a few degrees Kelvin. A Start Counter detector has been fabricated to identify the accelerator electron beam buckets, approximately 2 nanoseconds apart, and to provide accurate timing information. This detector is designed to operate at photon intensities of up to 108 γ/s in the coherent peak and provide a timing resolution of less than 350 picoseconds so as to provide successful identification of the electron beam buckets. It consists of a cylindrical array of 30 scintillators with pointed ends that bend towards the beam at the downstream end. The EJ-200 scintillator is best suited for the Start Counter due to its fast decay time on the order of 2 nanoseconds and long attenuation length. Silicon Photo Multiplier (SiPM) detectors have been selected as the readout system and are to be placed as close as possible, less than 300 micron, to the upstream end of each scintillator. The methods/details of the assembly and the optimization of the surface quality of scintillator paddles are discussed. This work was supported in part by DoE Contracts DE-FG02-99ER41065 and DE-AC05-06OR23177.

  7. Tissue-Engineered Fibrin-Based Heart Valve with Bio-Inspired Textile Reinforcement.

    PubMed

    Moreira, Ricardo; Neusser, Christine; Kruse, Magnus; Mulderrig, Shane; Wolf, Frederic; Spillner, Jan; Schmitz-Rode, Thomas; Jockenhoevel, Stefan; Mela, Petra

    2016-08-01

    The mechanical properties of tissue-engineered heart valves still need to be improved to enable their implantation in the systemic circulation. The aim of this study is to develop a tissue-engineered valve for the aortic position - the BioTexValve - by exploiting a bio-inspired composite textile scaffold to confer native-like mechanical strength and anisotropy to the leaflets. This is achieved by multifilament fibers arranged similarly to the collagen bundles in the native aortic leaflet, fixed by a thin electrospun layer directly deposited on the pattern. The textile-based leaflets are positioned into a 3D mould where the components to form a fibrin gel containing human vascular smooth muscle cells are introduced. Upon fibrin polymerization, a complete valve is obtained. After 21 d of maturation by static and dynamic stimulation in a custom-made bioreactor, the valve shows excellent functionality under aortic pressure and flow conditions, as demonstrated by hydrodynamic tests performed according to ISO standards in a mock circulation system. The leaflets possess remarkable burst strength (1086 mmHg) while remaining pliable; pronounced extracellular matrix production is revealed by immunohistochemistry and biochemical assay. This study demonstrates the potential of bio-inspired textile-reinforcement for the fabrication of functional tissue-engineered heart valves for the aortic position. PMID:27377438

  8. The Fibrin Matrix Regulates Angiogenic Responses within the Hemostatic Microenvironment through Biochemical Control

    PubMed Central

    Hadjipanayi, Ektoras; Kuhn, Peer-Hendrik; Kuekrek, Haydar; Mirzoyan, Lilit; Hummel, Anja; Kirchhoff, Katharina; Salgin, Burak; Isenburg, Sarah; Dornseifer, Ulf; Ninkovic, Milomir; Machens, Hans-Günther; Schilling, Arndt F.

    2015-01-01

    Conceptually, premature initiation of post-wound angiogenesis could interfere with hemostasis, as it relies on fibrinolysis. The mechanisms facilitating orchestration of these events remain poorly understood, however, likely due to limitations in discerning the individual contribution of cells and extracellular matrix. Here, we designed an in vitro Hemostatic-Components-Model (HCM) to investigate the role of the fibrin matrix as protein factor-carrier, independent of its cell-scaffold function. After characterizing the proteomic profile of HCM-harvested matrix releasates, we demonstrate that the key pro-/anti-angiogenic factors, VEGF and PF4, are differentially bound by the matrix. Changing matrix fibrin mass consequently alters the balance of releasate factor concentrations, with differential effects on basic endothelial cell (EC) behaviors. While increasing mass, and releasate VEGF levels, promoted EC chemotactic migration, it progressively inhibited tube formation, a response that was dependent on PF4. These results indicate that the clot’s matrix component initially serves as biochemical anti-angiogenic barrier, suggesting that post-hemostatic angiogenesis follows fibrinolysis-mediated angiogenic disinhibition. Beyond their significance towards understanding the spatiotemporal regulation of wound healing, our findings could inform the study of other pathophysiological processes in which coagulation and angiogenesis are prominent features, such as cardiovascular and malignant disease. PMID:26317771

  9. Short Stimulation of Electro-Responsive PAA/Fibrin Hydrogel Induces Collagen Production

    PubMed Central

    Rahimi, Nastaran; Swennen, Geertje; Verbruggen, Sanne; Scibiorek, Martyna; Molin, Daniel G.

    2014-01-01

    Acrylic acid/fibrin hydrogel can mechanically stimulate cells when an external electrical field is applied, enabling them to migrate and align throughout the depth of the gel. The ability of electro-responsive polyacrylic acid (PAA)/fibrin hydrogel to promote collagen production and remodeling has been investigated by three-dimensional (3D) culturing and conditioning of smooth muscle cells (SMCs). SMCs-seeded hydrogels were subjected to an alternating electrical field (0.06 V/mm) for 2 h for one, two, or three times per week during 4 weeks of culturing. Fluorescent images of collagen structure and accumulation, assessed by CNA-35 probe, showed increased collagen content (>100-fold at 1× stimulation/week) in the center of the hydrogels after 4 weeks of culture. The increase in collagen production correlated with increasing extracellular matrix gene expression and resulted in significantly improved mechanical properties of the stimulated hydrogels. Matrix metalloproteinase (MMP)-2 activity was also significantly enhanced by stimulation, which probably has a role in the reorganization of the collagen. Short stimulation (2 h) induced a favorable response in the cells and enhanced tissue formation and integrity of the scaffold by inducing collagen production. The presented set up could be used for conditioning and improving the functionality of current tissue-engineered vascular grafts. PMID:24341313

  10. Concentration of Fibrin and Presence of Plasminogen Affect Proliferation, Fibrinolytic Activity, and Morphology of Human Fibroblasts and Keratinocytes in 3D Fibrin Constructs

    PubMed Central

    Reinertsen, Erik; Skinner, Michael; Wu, Benjamin

    2014-01-01

    Fibrin is a hemostatic protein found in the clotting cascade. It is used in the operating room to stop bleeding and deliver cells and growth factors to heal wounds. However, formulations of clinically approved fibrin are optimized for hemostasis, and the extent to which biochemical and physical cues in fibrin mediate skin cell behavior is not fully understood nor utilized in the design of biomaterials. To determine if the concentration of fibrinogen and the presence of plasminogen affect cell behavior relevant to wound healing, we fabricated three-dimensional fibrin constructs made from 5, 10, or 20 mg/mL of clinical fibrin or plasminogen-depleted (PD) fibrin. We cultured dermal fibroblasts or epidermal keratinocytes in these constructs. Fibroblasts proliferated similarly in both types of fibrin, but keratinocytes proliferated more in low concentrations of clinical fibrin and less in PD fibrin. Clinical fibrin constructs with fibroblasts were less stiff and degraded faster than PD fibrin constructs with fibroblasts. Similarly, keratinocytes degraded clinical fibrin, but not PD fibrin. Fibroblast spreading varied with fibrin concentration in both types of fibrin. In conclusion, the concentration of fibrinogen and the presence of plasminogen affect fibroblast and keratinocyte proliferation, morphology, and fibrin degradation. Creating materials with heterogeneous regions of fibrin formulations and concentrations could be a novel strategy for controlling the phenotype of encapsulated fibroblasts and keratinocytes, and the subsequent biomechanical properties of the construct. However, other well-investigated aspects of wound healing remain to be utilized in the design of fibrin biomaterials, such as autocrine and paracrine signaling between fibroblasts, keratinocytes, and immune cells. PMID:24738616

  11. New techniques in the treatment of common perianal diseases: stapled hemorrhoidopexy, botulinum toxin, and fibrin sealant.

    PubMed

    Singer, Marc; Cintron, Jose

    2006-08-01

    There have been several recent advances in the treatment of common perianal diseases. Stapled hemorrhoidopexy is a procedure of hemorrhoidal fixation, combining the benefits of rubber band ligation into an operative technique. The treatment of anal fissure has typically relied upon internal sphincterotomy; however, it carries a risk of incontinence. The injection of botulinum toxin represents a new form of sphincter relaxation, without division of any sphincter muscle; morbidity is minimal and results are promising. For the treatment of fistula in a fistulotomy remains the gold standard, however, it carries significant risk of incontinence. Use of fibrin sealant to treat fistulae has been met with variable success. It offers sealing of the tract, and then provides scaffolding for native tissue ingrowth. PMID:16905418

  12. Measurement of Fibrin Fiber Strength using AFM

    NASA Astrophysics Data System (ADS)

    Jawerth, Louise; Falvo, Mchael; Canning, Anthony; Matthews, Garrett; Superfine, Richard; Guthold, Martin

    2003-11-01

    Blood clots usually form in the event of injury or damage to blood vessels to prevent the loss of blood. Moreover, as we age, blood clots often form in undesired locations, i.e. in blood vessels around the heart or brain, or in uninjured vessels resulting in heart attacks or strokes. Fibrin fibers, the skeleton of a blood clot, essentially perform the mechanical task of creating a blockage that stems blood flow. Thus, a better understanding of the mechanical properties of these fibers, such as the tensile strength and Young's modulus, will enhance our understanding of blood clots. For quantitative stress and strain measurements, we need to image the deformation of the fiber and measure the applied force simultaneously. For this reason, we are combining fluorescent microscopy with atomic force microscopy. Fibrin fibers were fluorescently labeled with streptavidin-coated quantum dots and deposited on a functionalized glass substrate, imaged and manipulated under buffer. We will describe our progress in obtaining quantitative lateral force measurements under buffer simultaneous with strain measurements from optical microscope images.

  13. Kinetics of ligation of fibrin oligomers.

    PubMed

    Nelb, G W; Kamykowski, G W; Ferry, J D

    1980-07-10

    Human fibrinogen was treated with thrombin in the presence of fibrinoligase and calcium ion at pH 8.5, ionic strength 0.45, and the ensuring polymerization was interrupted at various time intervals (t) both before and after the clotting time (tc) by solubilization with a solution of sodium dodecyl sulfate and urea. Aliquots of the solubilized protein were subjected to gel electrophoresis on polyacrylamide gels after disulfide reduction by dithiothreitol and on agarose gels without reduction. The degree of gamma-gamma ligation was determined from the former and the size distribution of ligated oligomers, for degree of polymerization x from 1 to 10, from the latter. The degree of gamma-gamma ligation was calculated independently from the size distribution with the assumption that every junction between two fibrin monomers remaining intact after solubilization is ligated, and this agreed well with the direct determination. The size distribution at t/tc = 1.3 to 1.6 differed somewhat from that calculated by the classical theory of linear polycondensation on the assumption that all reactive sites react with equal probability and rate. Analysis of the difference suggests that ligation of a fibrin digomer is not a random process; the probability of ligation of a given junction between two monomers increases with the oligomer length. The number-average degree of polymerization, xn, of ligated oligomers increases approximately linearly with time up to a value of 1.6. PMID:7391026

  14. Adhesive Performance of Biomimetic Adhesive-Coated Biologic Scaffolds

    PubMed Central

    Murphy, John L.; Vollenweider, Laura; Xu, Fangmin; Lee, Bruce P.

    2010-01-01

    Surgical repair of a discontinuity in traumatized or degenerated soft tissues is traditionally accomplished using sutures. A current trend is to reinforce this primary repair with surgical grafts, meshes, or patches secured with perforating mechanical devices (i.e., sutures, staples, or tacks). These fixation methods frequently lead to chronic pain and mesh detachment. We developed a series of biodegradable adhesive polymers that are synthetic mimics of mussel adhesive proteins (MAPs), composed of 3,4-dihydroxyphenylalanine (DOPA)-derivatives, polyethylene glycol (PEG), and polycaprolactone (PCL). These polymers can be cast into films, and their mechanical properties, extent of swelling, and degradation rate can be tailored through the composition of the polymers as well as blending with additives. When coated onto a biologic mesh used for hernia repair, these adhesive constructs demonstrated adhesive strengths significantly higher than fibrin glue. With further development, a pre-coated bioadhesive mesh may represent a new surgical option for soft tissue repair. PMID:20919699

  15. Fibrin-mediated lentivirus gene transfer: implications for lentivirus microarrays

    PubMed Central

    Raut, Shruti; Lei, Pedro; Padmashali, Roshan; Andreadis, Stelios T.

    2010-01-01

    We employed fibrin hydrogel as bioactive matrix for lentivirus mediated gene transfer. Fibrin-mediated gene transfer was highly efficient and exhibited strong dependence on fibrinogen concentration. Efficient gene transfer was achieved with fibrinogen concentration between 3.75 – 7.5 mg/mL. Lower fibrinogen concentrations resulted in diffusion of virus out of the gel while higher concentrations led to ineffective fibrin degradation by target cells. Addition of fibrinolytic inhibitors decreased gene transfer in a dose-dependent manner suggesting that fibrin degradation by target cells may be necessary for successful gene delivery. Under these conditions transduction may be limited only to cells interacting with the matrix thereby providing a method for spatially localized gene delivery. Indeed, when lentivirus-containing fibrin microgels were spotted in an array format gene transfer was confined to virus-containing fibrin spots with minimal cross-contamination between neighboring sites. Collectively, our data suggest that fibrin may provide an effective matrix for spatially-localized gene delivery with potential applications in high-throughput lentiviral microarrays and in regenerative medicine. PMID:20153386

  16. Growth factor-rich plasma increases tendon cell proliferation and matrix synthesis on a synthetic scaffold: an in vitro study.

    PubMed

    Visser, Lance C; Arnoczky, Steven P; Caballero, Oscar; Kern, Andreas; Ratcliffe, Anthony; Gardner, Keri L

    2010-03-01

    Numerous scaffolds have been proposed for use in connective tissue engineering. Although these scaffolds direct cell migration and attachment, many are biologically inert and thus lack the physiological stimulus to attract cells and induce mitogenesis and matrix synthesis. In the current study, a bioactive scaffold was created by combining a synthetic scaffold with growth factor-rich plasma (GFRP), an autologous concentration of growth factors derived from a platelet-rich plasma preparation. In vitro tendon cell proliferation and matrix synthesis on autologous GFRP-enriched scaffolds, autologous serum-enriched scaffolds, and scaffolds alone were compared. The GFRP preparation was found to have a 4.7-fold greater concentration of a sentinel growth factor (transforming growth factor-beta1) compared with serum. When combined with media containing calcium, the GFRP produced a thin fibrin matrix over and within the GFRP-enriched scaffolds. Cell proliferation assays demonstrated that GFRP-enriched scaffolds significantly enhanced cell proliferation over autologous serum and control groups at both 48 and 72 h. Analysis of the scaffolds at 14, 21, and 28 days revealed that GFRP-enriched scaffolds significantly increased the deposition of a collagen-rich extracellular matrix when compared with the other groups. These results indicate that GFRP can be used to enhance in vitro cellular population and matrix deposition of tissue-engineered scaffolds. PMID:19839921

  17. Interactions between ultrasound stimulated microbubbles and fibrin clots

    NASA Astrophysics Data System (ADS)

    Acconcia, Christopher; Leung, Ben Y. C.; Hynynen, Kullervo; Goertz, David E.

    2013-07-01

    While it is well established that ultrasound stimulated microbubbles (USMBs) can potentiate blood clot lysis, the mechanisms are not well understood. Here we examine the interaction between USMBs and fibrin clots, which are comprised of fibrin networks that maintain the mechanical integrity of blood clots. High speed camera observations demonstrated that USMBs can penetrate fibrin clots. Two-photon microscopy revealed that penetrating bubbles can leave behind patent "tunnels" along their paths and that fluid can be transported into the clots. Finally, it is observed that primary radiation forces associated with USMBs can induce local deformation and macroscopic translation of clot boundaries.

  18. Spider Glue Proteins Have Distinct Architectures Compared with Traditional Spidroin Family Members*

    PubMed Central

    Vasanthavada, Keshav; Hu, Xiaoyi; Tuton-Blasingame, Tiffany; Hsia, Yang; Sampath, Sujatha; Pacheco, Ryan; Freeark, Jordan; Falick, Arnold M.; Tang, Simon; Fong, Justine; Kohler, Kristin; La Mattina-Hawkins, Coby; Vierra, Craig

    2012-01-01

    Adhesive spider glues are required to perform a variety of tasks, including web construction, prey capture, and locomotion. To date, little is known regarding the molecular and structural features of spider glue proteins, in particular bioadhesives that interconnect dragline or scaffolding silks during three-dimensional web construction. Here we use biochemical and structural approaches to identify and characterize two aggregate gland specific gene products, AgSF1 and AgSF2, and demonstrate that these proteins co-localize to the connection joints of both webs and wrapping silks spun from the black widow spider, Latrodectus hesperus. Protein architectures are markedly divergent between AgSF1 and AgSF2, as well as traditional spider silk fibroin family members, suggesting connection joints consist of a complex proteinaceous network. AgSF2 represents a nonglycosylated 40-kDa protein that has novel internal amino acid block repeats with the consensus sequence NVNVN embedded in a glycine-rich matrix. Analysis of the amino acid sequence of AgSF1 reveals pentameric QPGSG iterations that are similar to conserved modular elements within mammalian elastin, a rubber-like elastomeric protein that interfaces with collagen. Wet-spinning methodology using purified recombinant proteins show AgSF1 has the potential to self-assemble into fibers. X-ray fiber diffraction studies performed on these synthetic fibers reveal the presence of noncrystalline domains that resemble classical rubber networks. Collectively, these data support that the aggregate gland serves to extrude a protein mixture that contains substances that allow for the self-assembly of fiber-like structures that interface with dragline silks to mediate prey capture. PMID:22927444

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

    PubMed Central

    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

  20. Three Dimensional Collagen Scaffold Promotes Intrinsic Vascularisation for Tissue Engineering Applications

    PubMed Central

    Chan, Elsa C.; Kuo, Shyh-Ming; Kong, Anne M.; Morrison, Wayne A.; Dusting, Gregory J.; Mitchell, Geraldine M.

    2016-01-01

    Here, we describe a porous 3-dimensional collagen scaffold material that supports capillary formation in vitro, and promotes vascularization when implanted in vivo. Collagen scaffolds were synthesized from type I bovine collagen and have a uniform pore size of 80 μm. In vitro, scaffolds seeded with primary human microvascular endothelial cells suspended in human fibrin gel formed CD31 positive capillary-like structures with clear lumens. In vivo, after subcutaneous implantation in mice, cell-free collagen scaffolds were vascularized by host neovessels, whilst a gradual degradation of the scaffold material occurred over 8 weeks. Collagen scaffolds, impregnated with human fibrinogen gel, were implanted subcutaneously inside a chamber enclosing the femoral vessels in rats. Angiogenic sprouts from the femoral vessels invaded throughout the scaffolds and these degraded completely after 4 weeks. Vascular volume of the resulting constructs was greater than the vascular volume of constructs from chambers implanted with fibrinogen gel alone (42.7±5.0 μL in collagen scaffold vs 22.5±2.3 μL in fibrinogen gel alone; p<0.05, n = 7). In the same model, collagen scaffolds seeded with human adipose-derived stem cells (ASCs) produced greater increases in vascular volume than did cell-free collagen scaffolds (42.9±4.0 μL in collagen scaffold with human ASCs vs 25.7±1.9 μL in collagen scaffold alone; p<0.05, n = 4). In summary, these collagen scaffolds are biocompatible and could be used to grow more robust vascularized tissue engineering grafts with improved the survival of implanted cells. Such scaffolds could also be used as an assay model for studies on angiogenesis, 3-dimensional cell culture, and delivery of growth factors and cells in vivo. PMID:26900837

  1. Closing microvascular lesions with fibrin sealant-attached muscle pads.

    PubMed

    Fehm, Nando Percy; Vatankhah, Bijan; Dittmar, Michael S; Tevetoglu, Yesim; Retzl, Gerald; Horn, Markus

    2005-01-01

    Fibrin sealants are used in a variety of surgical procedures, mainly for purposes of hemostasis and assisted wound healing. The combined use of fibrin sealant and autologous muscle pads for hemostasis was not reported previously. Arterial incisions in the common carotid artery in rats were closed by the combined application of fibrin sealant and an autologous muscle pad. Postsurgical vessel patency and degree of stenosis were evaluated by color duplex sonography, computed tomography angiography, and postmortem histology. The combined application of muscle pad and fibrin sealant and achievement of hemostasis was feasible in all animals. Seventy-eight percent of animals showed no or only slight postsurgical vessel stenosis. Our method is simple and quick to perform, showing a high potential for hemostasis in microvascular lesions. Therefore, it might be used in future experimental studies for conservation of vessel patency after arterial catheterization and in experimental or clinical vascular surgery. PMID:16184526

  2. Fibrin sealant use in pilonidal sinus: Systematic review

    PubMed Central

    Kayaalp, Cuneyt; Ertugrul, Ismail; Tolan, Kerem; Sumer, Fatih

    2016-01-01

    AIM: To review the current data about the success rates of fibrin sealant use in pilonidal disease. METHODS: Fibrin sealant can be used for different purposes in pilonidal sinus treatment, such as filling in the sinus tracts, covering the open wound after excision and lay-open treatment, or obliterating the subcutaneous dead space before skin closure. We searched Pubmed, Google-Scholar, Ebsco-Host, clinicaltrials, and Cochrane databases and found nine studies eligible for analysis; these studies included a total of 217 patients (84% male, mean age 24.2 ± 7.8). RESULTS: In cases where fibrin sealant was used to obliterate the subcutaneous dead space, there was no reduction in wound complication rates (9.8% vs 14.6%, P = 0.48). In cases where sealant was used to cover the laid-open area, the wound healing time and patient comfort were reported better than in previous studies (mean 17 d, 88% satisfaction). When fibrin sealant was used to fill the sinus tracts, the recurrence rate was around 20%, despite the highly selected grouping of patients. CONCLUSION: Consequently, using fibrin sealant to decrease the risk of seroma formation was determined to be an ineffective course of action. It was not advisable to fill the sinus tracts with fibrin sealant because it was not superior to other cost-effective and minimally invasive treatments. New comparative studies can be conducted to confirm the results of sealant use in covering the laid-open area. PMID:27022454

  3. Alterations in Fibrin Structure in Patients with Liver Diseases.

    PubMed

    Lisman, Ton; Ariëns, Robert A S

    2016-06-01

    The hemostatic balance in patients with liver diseases is relatively well preserved due to concomitant alterations in pro- and antihemostatic pathways. Thrombin generation studies support the notion of hemostatic competence in liver diseases, but in such tests alterations in fibrinogen level and function are not taken into account. We have recently studied structural and functional properties of the fibrin clot in patients with liver diseases. Although we have confirmed previous findings that hypersialylation of the fibrinogen molecule in patients with liver diseases contributes to a defective fibrinogen-to-fibrin conversion, we have found that once the clot has been formed, it has a thrombogenic nature as assessed by permeability assays. These thrombogenic properties of the fibrin clot in cirrhosis relate to incompletely characterized intrinsic changes in the fibrinogen molecule, which may include oxidation and hypersialylation. In addition, in patients with nonalcoholic fatty liver disease thrombogenic properties of the fibrin clot are not only due to liver disease but also to obesity and the metabolic syndrome. During liver transplantation, the clot normalizes and becomes increasingly permeable, and the functional properties of the fibrin clot are markedly normalized by fibrinogen concentrate, when added to plasma samples in vitro. These new insights in the functional properties of the fibrin clot in patients with liver diseases facilitate a more rational approach to treatment and prevention of both bleeding and thrombotic complications. PMID:27071046

  4. Multivalent Viral Capsids with Internal Cargo for Fibrin Imaging

    PubMed Central

    Obermeyer, Allie C.; Capehart, Stacy L.; Jarman, John B.; Francis, Matthew B.

    2014-01-01

    Thrombosis is the cause of many cardiovascular syndromes and is a significant contributor to life-threatening diseases, such as myocardial infarction and stroke. Thrombus targeted imaging agents have the capability to provide molecular information about pathological clots, potentially improving detection, risk stratification, and therapy of thrombosis-related diseases. Nanocarriers are a promising platform for the development of molecular imaging agents as they can be modified to have external targeting ligands and internal functional cargo. In this work, we report the synthesis and use of chemically functionalized bacteriophage MS2 capsids as biomolecule-based nanoparticles for fibrin imaging. The capsids were modified using an oxidative coupling reaction, conjugating ∼90 copies of a fibrin targeting peptide to the exterior of each protein shell. The ability of the multivalent, targeted capsids to bind fibrin was first demonstrated by determining the impact on thrombin-mediated clot formation. The modified capsids out-performed the free peptides and were shown to inhibit clot formation at effective concentrations over ten-fold lower than the monomeric peptide alone. The installation of near-infrared fluorophores on the interior surface of the capsids enabled optical detection of binding to fibrin clots. The targeted capsids bound to fibrin, exhibiting higher signal-to-background than control, non-targeted MS2-based nanoagents. The in vitro assessment of the capsids suggests that fibrin-targeted MS2 capsids could be used as delivery agents to thrombi for diagnostic or therapeutic applications. PMID:24960118

  5. Platelet-derived microparticles associate with fibrin during thrombosis.

    PubMed

    Siljander, P; Carpen, O; Lassila, R

    1996-06-01

    Platelet-derived microparticles (MP) are reported to express both pro- and anticoagulant activities. Nevertheless, their functional significance has remained unresolved. The present study monitored the generation and fate of MP in an experimental model of thrombosis with costimulation of platelets by collagen and thrombin. When minimally anticoagulated (0.5 micromol/L PPACK) blood was perfused over immobilized fibrillar type I collagen in a flow chamber at a low shear rate (300 s(-1)), endogenous thrombin was generated, as evidenced by thrombin-antithrombin III complex. In contrast to full anticoagulation 150 micromol/L PPACK) and the absence of collagen, large platelet aggregates and fibrin ensued during perfusions over collagen in the presence of thrombin. In these thrombi, MP, defined as GPIIbIIIa- and P-selectin-positive vesicles (<1 micron), were found to align fibrin in immunofluorescence and scanning immunoelectron microscopy. Moreover, in sections of embolectomized thromboemboli from patients GPIIbIIIa- and P-selectin-positive material compatible with MP was detected in a fibrin strand-like pattern. In vitro binding studies showed that MP bound to fibrin and acted there as procoagulants. In summary, we show that MP generated during thrombus formation associate with local fibrin. This adhesive function fibrin could imply a sustained modulatory role for MP in evolving thrombi. PMID:8639834

  6. Fibrin Sealants in Dura Sealing: A Systematic Literature Review

    PubMed Central

    2016-01-01

    Background 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. Methods 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. Results 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%, p<0.001); however, post-operative cerebrospinal fluid leakage occurred in more fibrin sealant than control patients (6.7% versus 2.0%, p>0.05). 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

  7. Gravity: The Glue of the Universe. History and Activities.

    ERIC Educational Resources Information Center

    Gilbert, Harry; Smith, Diana Gilbert

    This book presents a story of the history of gravity, the glue of the universe, and is based on two premises: (1) an understanding of mathematics is not required to grasp the concepts and implications of relativity; and (2) relativity has altered forever the perceptions of gravity, space, time, and how the universe works. A narrative text section…

  8. Relevance of matter and glue dynamics for baryon number fluctuations

    NASA Astrophysics Data System (ADS)

    Fu, Wei-jie; Pawlowski, Jan M.

    2015-12-01

    We investigate the impact of the matter and glue dynamics on baryon number fluctuations and the kurtosis of baryon number distribution. This is done within the framework of QCD-improved low-energy effective models. In particular, we include the momentum scale dependence of the quark-meson scattering and the nontrivial dispersions of both quarks and mesons. On the gluonic side, we take into account the backreaction of the matter sector on the glue dynamics. It is shown that the above fluctuations lead to a more rapid change of the baryon number fluctuations as well as the kurtosis of with the chiral crossover. We also study the signatures of quark confinement in low-energy QCD. It is shown that, contrary to the common picture, the effective thermal distribution in the presence of confining glue backgrounds does not tend towards the colorless baryonic one. Instead, the dominance of colorless hadronic states is obtained in a subtle interplay of quark and glue contributions to the canonical potential.

  9. A CCR2 macrophage endocytic pathway mediates extravascular fibrin clearance in vivo

    PubMed Central

    Motley, Michael P.; Madsen, Daniel H.; Jürgensen, Henrik J.; Spencer, David E.; Szabo, Roman; Holmbeck, Kenn; Flick, Matthew J.; Lawrence, Daniel A.; Castellino, Francis J.; Weigert, Roberto

    2016-01-01

    Extravascular fibrin deposition accompanies many human diseases and causes chronic inflammation and organ damage, unless removed in a timely manner. Here, we used intravital microscopy to investigate how fibrin is removed from extravascular space. Fibrin placed into the dermis of mice underwent 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(ogen) receptors, αMβ2 and ICAM-1, the myeloid cell integrin-binding site on fibrin or the endocytic collagen receptor, the mannose receptor. The study identifies a novel fibrin endocytic pathway engaged in extravascular fibrin clearance and shows that interstitial fibrin and collagen are cleared by different subsets of macrophages employing distinct molecular pathways. PMID:26647393

  10. A CCR2 macrophage endocytic pathway mediates extravascular fibrin clearance in vivo.

    PubMed

    Motley, Michael P; Madsen, Daniel H; Jürgensen, Henrik J; Spencer, David E; Szabo, Roman; Holmbeck, Kenn; Flick, Matthew J; Lawrence, Daniel A; Castellino, Francis J; Weigert, Roberto; Bugge, Thomas H

    2016-03-01

    Extravascular fibrin deposition accompanies many human diseases and causes chronic inflammation and organ damage, unless removed in a timely manner. Here, we used intravital microscopy to investigate how fibrin is removed from extravascular space. Fibrin placed into the dermis of mice underwent 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(ogen) receptors, αMβ2 and ICAM-1, the myeloid cell integrin-binding site on fibrin or the endocytic collagen receptor, the mannose receptor. The study identifies a novel fibrin endocytic pathway engaged in extravascular fibrin clearance and shows that interstitial fibrin and collagen are cleared by different subsets of macrophages employing distinct molecular pathways. PMID:26647393

  11. Scaffolder - software for manual genome scaffolding

    PubMed Central

    2012-01-01

    Background The assembly of next-generation short-read sequencing data can result in a fragmented non-contiguous set of genomic sequences. Therefore a common step in a genome project is to join neighbouring sequence regions together and fill gaps. This scaffolding step is non-trivial and requires manually editing large blocks of nucleotide sequence. Joining these sequences together also hides the source of each region in the final genome sequence. Taken together these considerations may make reproducing or editing an existing genome scaffold difficult. Methods The software outlined here, “Scaffolder,” is implemented in the Ruby programming language and can be installed via the RubyGems software management system. Genome scaffolds are defined using YAML - a data format which is both human and machine-readable. Command line binaries and extensive documentation are available. Results This software allows a genome build to be defined in terms of the constituent sequences using a relatively simple syntax. This syntax further allows unknown regions to be specified and additional sequence to be used to fill known gaps in the scaffold. Defining the genome construction in a file makes the scaffolding process reproducible and easier to edit compared with large FASTA nucleotide sequences. Conclusions Scaffolder is easy-to-use genome scaffolding software which promotes reproducibility and continuous development in a genome project. Scaffolder can be found at http://next.gs. PMID:22640820

  12. Foam-like compression behavior of fibrin networks.

    PubMed

    Kim, Oleg V; Liang, Xiaojun; Litvinov, Rustem I; Weisel, John W; Alber, Mark S; Purohit, Prashant K

    2016-02-01

    The rheological properties of fibrin networks have been of long-standing interest. As such there is a wealth of studies of their shear and tensile responses, but their compressive behavior remains unexplored. Here, by characterization of the network structure with synchronous measurement of the fibrin storage and loss moduli at increasing degrees of compression, we show that the compressive behavior of fibrin networks is similar to that of cellular solids. A nonlinear stress-strain response of fibrin consists of three regimes: (1) an initial linear regime, in which most fibers are straight, (2) a plateau regime, in which more and more fibers buckle and collapse, and (3) a markedly nonlinear regime, in which network densification occurs by bending of buckled fibers and inter-fiber contacts. Importantly, the spatially non-uniform network deformation included formation of a moving "compression front" along the axis of strain, which segregated the fibrin network into compartments with different fiber densities and structure. The Young's modulus of the linear phase depends quadratically on the fibrin volume fraction while that in the densified phase depends cubically on it. The viscoelastic plateau regime corresponds to a mixture of these two phases in which the fractions of the two phases change during compression. We model this regime using a continuum theory of phase transitions and analytically predict the storage and loss moduli which are in good agreement with the experimental data. Our work shows that fibrin networks are a member of a broad class of natural cellular materials which includes cancellous bone, wood and cork. PMID:25982442

  13. Nano-thrombelastography of fibrin during blood plasma clotting.

    PubMed

    Feller, Tímea; Kellermayer, Miklós S Z; Kiss, Balázs

    2014-06-01

    Hemostasis is a complex process that relies on the sensitive balance between the formation and breakdown of the thrombus, a three-dimensional polymer network of the fibrous protein fibrin. Neither the details of the fibrinogen-fibrin transition, nor the exact mechanisms of fibrin degradation are fully understood at the molecular level. In the present work we investigated the nanoscale-changes in the viscoelasticity of the 3D-fibrin network during fibrinogenesis and streptokinase (STK)-induced fibrinolysis by using a novel application of force spectroscopy, named nano-thrombelastography. In this method the changes in the bending of an oscillating atomic-force-microscope (AFM) cantilever in human blood-plasma droplet were followed as a function of time. Whereas the global features of the time-dependent change in cantilever deflection corresponded well to a macroscopic thrombelastogram, the underlying force spectra revealed large, sample-dependent oscillations in the range of 3-50nN and allowed the separation of elastic and viscous components of fibrin behavior. Upon STK treatment the nano-thrombelastogram signal decayed gradually. The decay was driven by a decrease in thrombus elasticity, whereas thrombus viscosity decayed with a time delay. In scanning AFM images mature fibrin appeared as 17-nm-high and 12-196-nm-wide filaments. STK-treatment resulted in the decrease of filament height and the appearance of a surface roughness with 23.7nm discrete steps that corresponds well to the length of a fibrinogen monomer. Thus, the initial decay of thrombus elasticity during fibrinolysis may be caused by the axial rupture of fibrin fibers. PMID:24736106

  14. Platelet rich fibrin in jaw defects

    NASA Astrophysics Data System (ADS)

    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.

  15. In Vitro Evaluation of Scaffolds for the Delivery of Mesenchymal Stem Cells to Wounds

    PubMed Central

    Wahl, Elizabeth A.; Fierro, Fernando A.; Peavy, Thomas R.; Hopfner, Ursula; Dye, Julian F.; Machens, Hans-Günther; Egaña, José T.; Schenck, Thilo L.

    2015-01-01

    Mesenchymal stem cells (MSCs) have been shown to improve tissue regeneration in several preclinical and clinical trials. These cells have been used in combination with three-dimensional scaffolds as a promising approach in the field of regenerative medicine. We compare the behavior of human adipose-derived MSCs (AdMSCs) on four different biomaterials that are awaiting or have already received FDA approval to determine a suitable regenerative scaffold for delivering these cells to dermal wounds and increasing healing potential. AdMSCs were isolated, characterized, and seeded onto scaffolds based on chitosan, fibrin, bovine collagen, and decellularized porcine dermis. In vitro results demonstrated that the scaffolds strongly influence key parameters, such as seeding efficiency, cellular distribution, attachment, survival, metabolic activity, and paracrine release. Chick chorioallantoic membrane assays revealed that the scaffold composition similarly influences the angiogenic potential of AdMSCs in vivo. The wound healing potential of scaffolds increases by means of a synergistic relationship between AdMSCs and biomaterial resulting in the release of proangiogenic and cytokine factors, which is currently lacking when a scaffold alone is utilized. Furthermore, the methods used herein can be utilized to test other scaffold materials to increase their wound healing potential with AdMSCs. PMID:26504774

  16. Platelet-rich fibrin-mediated revitalization of immature necrotic tooth.

    PubMed

    Mishra, Navin; Narang, Isha; Mittal, Neelam

    2013-07-01

    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. PMID:24124320

  17. Platelet-rich fibrin-mediated revitalization of immature necrotic tooth

    PubMed Central

    Mishra, Navin; Narang, Isha; Mittal, Neelam

    2013-01-01

    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. PMID:24124320

  18. Fibrin(ogen)olytic activity of bumblebee venom serine protease

    SciTech Connect

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

    2011-09-01

    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.

  19. Phase-separated chitosan–fibrin microbeads for cell delivery

    PubMed Central

    Chen, Zhewei; Wang, Limin; Stegemann, Jan P.

    2011-01-01

    Matrix-enhanced delivery of cells is a promising approach to improving current cell therapies. Our objective was to create cell-laden composite microbeads that combine the attractive features of the natural polymers chitosan and fibrin. Liquid polydimethylsiloxane was used to emulsify a chitosan–fibrinogen solution containing suspended human fibroblast cells, followed by initiation of thrombin-mediated polymerization of fibrin and thermal/pH-mediated gelation of chitosan. Chitosan/fibrin weight percent (wt%) ratios of 100/0, 75/25, 50/50 and 25/75 were investigated. Microbead diameters ranged from 275 ± 99 μm to 38 ± 10 μm using impeller speeds from 600 to 1400 rpm. Fibroblasts remained viable on day 1 post-fabrication in all matrices, but cell viability was markedly higher in high-fibrin microbeads by day 8 post-fabrication. Cell spreading and interaction with the extracellular matrix was also markedly increased in high-fibrin matrices. Such composite microbeads containing viable entrapped cells have potential for minimally invasive delivery of cells for a variety of tissue repair applications. PMID:21736519

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

    PubMed Central

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

    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 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. PMID:27143826

  1. [Nerve anastomoses. Sutures or fibrinogenic glue? Preliminary results].

    PubMed

    Boedts, D; Bouckaert, J I

    1984-01-01

    A comparative animal experiment was set up between two nerve anastomosis techniques, one by sealing nerve ends with a fibrinogen-thrombine glue and the other by classical perineural suturing. It was concluded that glueing nerve ends, from the surgical-technical point of view is a better method than suturing. It is an easy, time-sparing method which allows excellent coaptation of the severed nerves with minimal iatrogenic trauma. On the long run however some questions remain. There is the problem of induced fibrosis by using high doses of aprotinine and factor XIII at the site of the nerve junctions and on the other hand the influence of fibrinolysis in traumatized tissues, with early decrease of tensile strength at the junctions before nerve healing. So glued nerve ends should be completely free of tension, protected against secondary shearing forces, and also immobilization of the region is required. PMID:6385609

  2. The Forward Calorimeter of the GlueX Experiment

    NASA Astrophysics Data System (ADS)

    Bennett, Daniel; GlueX Collaboration

    2013-10-01

    The Forward Calorimeter (FCAL) of the GlueX experiment is a lead glass electromagnetic calorimeter currently being built in Hall D of Jefferson Lab. The GlueX experiment is a photoproduction experiment that will utilize coherent bremsstrahlung radiation to map out the light meson spectrum, including a search for hybrid mesons with exotic quantum numbers (JPC). The FCAL will detect photons between 1° and 10 .8° downstream from the target. The calorimeter is built out of 2800 elements, each of which consists of a lead glass block, an FEU 84-3 PMT, and a custom Cockcroft-Walton electronic base. In the Fall of 2011, a 25 element prototype detector was installed in Hall B of Jefferson Lab to measure the energy and timing resolution of the calorimeter using electrons between 100 and 250 MeV. The design and construction of FCAL and the results from the prototype test will be discussed.

  3. Glue, steam and Clarivein--Best practice techniques and evidence.

    PubMed

    Whiteley, Mark S

    2015-11-01

    In July 2013, the National Institute of Health and Clinical Excellence (NICE) recommended "endothermal" ablation (meaning endovenous thermal ablation) is the first line treatment for truncal venous reflux in varicose veins. The initial endovenous thermoablation devices were radiofrequency ablation and endovenous laser ablation. More recently, Glue (cyanoacrylate), endovenous steam and Clarivein (mechanochemical ablation or MOCA) have entered the market as new endovenous techniques for the treatment of varicose veins. Glue and Clarivein do not require tumescent anaesthesia and do not use heat and therefore termed non-tumescent non-thermal (NTNT). Steam both requires tumescence and is also a thermal technique (TT). This article reviews the current position of these 3 new technologies in the treatment of varicose veins. PMID:26556699

  4. [Adjusting gingival tissues morphology after dental implantation with fibrin use].

    PubMed

    Maĭborodin, I V; Kolesnikov, I S; Sheplev, B V; Ragimova, T M; Kovyntsev, A N; Kovyntsev, D N; Shevela, A I

    2009-01-01

    In gingival tissues of 62 patients after dental implantation of traditional type and with the use of thrombocyte rich fibrin preparation (TRFP) microcirculation and leucocytal infiltration were studied. It was disclosed that in all terms after titanium screw dental implant setting lymphostasis and leucocytal infiltration were seen as signs of active inflammatory process in gingival tissues. 3 months later after implants setting with the use of TRFP the lymphatic vessels status was normalized, the degree of leucocytal infiltration was reduced; when implantation was made without use of fibrin technologies in gingival tissues more leucocytes were found and lymphatic bed components were remained dilated. Besides fibrin preparation use in the process of dental implantation promoted quicker and stronger implant fixation, but granulomatous inflammatory process could develop and amount of eosinophils in gingival tissues could also increased. PMID:19365340

  5. Fibrin self-assembly is adapted to oxidation.

    PubMed

    Rosenfeld, Mark A; Bychkova, Anna V; Shchegolikhin, Alexander N; Leonova, Vera B; Kostanova, Elizaveta A; Biryukova, Marina I; Sultimova, Natalia B; Konstantinova, Marina L

    2016-06-01

    Fibrinogen is extremely susceptible to attack by reactive oxygen species (ROS). Having been suffered an oxidative modification, the fibrinogen molecules, now with altered spatial structure and function of fibrin network, affect hemostasis differently. However, the potential effects of the oxidative stress on the early stages of the fibrin self-assembly process remain unexplored. To clarify the damaging influence of ROS on the knob 'A': hole 'a' and the D:D interactions, the both are operating on the early stages of the fibrin polymerization, we have used a novel approach based on exploration of FXIIIa-mediated self-assembly of the cross-linked fibrin oligomers dissolved in the moderately concentrated urea solutions. The oligomers were composed of monomeric desA fibrin molecules created by cleaving the fibrinopeptides A off the fibrinogen molecules with a thrombin-like enzyme, reptilase. According to the UV-absorbance and fluorescence measurements data, the employed low ozone/fibrinogen ratios have induced only a slight fibrinogen oxidative modification that was accompanied by modest chemical transformations of the aromatic amino acid residues of the protein. Else, a slight consumption of the accessible tyrosine residues has been observed due to intermolecular dityrosine cross-links formation. The set of experimental data gathered with the aid of electrophoresis, elastic light scattering and analytical centrifugation has clearly witnessed that the oxidation can serve as an effective promoter for the observed enhanced self-assembly of the covalently cross-linked oligomers. At urea concentration of 1.20M, the pristine and oxidized fibrin oligomers were found to comprise a heterogeneous set of the double-stranded protofibrils that are cross-linked only by γ-γ dimers and the fibers consisting on average of four strands that are additionally linked by α polymers. The amounts of the oxidized protofibrils and the fibers accumulated in the system were higher than those

  6. Arthroscopic repair of acetabular chondral delamination with fibrin adhesive.

    PubMed

    Tzaveas, Alexandros P; Villar, Richard N

    2010-01-01

    Acetabular chondral delamination is a frequent finding at hip arthroscopy. The cartilage is macroscopically normal but disrupted from the subchondral bone. Excision of chondral flaps is the usual procedure for this type of lesion. However, we report 19 consecutive patients in whom the delaminated chondral flap was re-attached to the underlying subchondral bone with fibrin adhesive. We used the modified Harris hip score for assessment of pain and function. Improvement in pain and function was found to be statistically significant six months and one year after surgery. No local or general complications were noted. Three patients underwent further surgery for unrelated reasons. In each, the area of fibrin repair appeared intact and secure. Our results suggest that fibrin is a safe agent to use for acetabular chondral delamination. PMID:20235074

  7. Search for Gluonic Excitations in Hadrons with GlueX

    SciTech Connect

    Igor Senderovich

    2011-12-01

    The GlueX experiment will employ a linearly polarized 9 GeV tagged photon beam incident on a liquid hydrogen target to search for exotic states in the light meson spectrum. Optimized for this purpose, the detector has a highly uniform acceptance over nearly 4p solid angle, with high efficiency for both neutral and charged final state particles. An overview of the physics motivation and detector design will be given.

  8. Superselective Embolization in Posttraumatic Priapism with Glubran 2 Acrylic Glue

    SciTech Connect

    Gandini, Roberto; Spinelli, Alessio; Konda, Daniel Reale, Carlo Andrea; Fabiano, Sebastiano; Pipitone, Vincenzo; Simonetti, Giovanni

    2004-09-15

    Two patients with posttraumatic priapism underwent transcatheter embolization using microcoils, resulting in temporary penile detumescence and an apparent resolution of the artero-venous fistula. In both cases, priapism recurred 24 hours after the procedure and was successfully treated through selective transcatheter embolization of the nidus using acrylic glue (Glubran 2). The patients showed complete recovery of sexual activity within 30 days from the procedure and persistent exclusion of the artero-venous fistula after a 12-month follow-up.

  9. Fibrin activates GPVI in human and mouse platelets.

    PubMed

    Alshehri, Osama M; Hughes, Craig E; Montague, Samantha; Watson, Stephanie K; Frampton, Jon; Bender, Markus; Watson, Steve P

    2015-09-24

    The glycoprotein VI (GPVI)-Fc receptor γ (FcRγ) chain is the major platelet signaling receptor for collagen. Paradoxically, in a FeCl3 injury model, occlusion, but not initiation of thrombus formation, is delayed in GPVI-deficient and GPVI-depleted mice. In this study, we demonstrate that GPVI is a receptor for fibrin and speculate that this contributes to development of an occlusive thrombus. We observed a marked increase in tyrosine phosphorylation, including the FcRγ chain and Syk, in human and mouse platelets induced by thrombin in the presence of fibrinogen and the αIIbβ3 blocker eptifibatide. This was not seen in platelets stimulated by a protease activated receptor (PAR)-4 peptide, which is unable to generate fibrin from fibrinogen. The pattern of tyrosine phosphorylation was similar to that induced by activation of GPVI. Consistent with this, thrombin did not induce tyrosine phosphorylation of Syk and the FcRγ chain in GPVI-deficient mouse platelets. Mouse platelets underwent full spreading on fibrin but not fibrinogen, which was blocked in the presence of a Src kinase inhibitor or in the absence of GPVI. Spreading on fibrin was associated with phosphatidylserine exposure (procoagulant activity), and this too was blocked in GPVI-deficient platelets. The ectodomain of GPVI was shown to bind to immobilized monomeric and polymerized fibrin. A marked increase in embolization was seen following FeCl3 injury in GPVI-deficient mice, likely contributing to the delay in occlusion in this model. These results demonstrate that GPVI is a receptor for fibrin and provide evidence that this interaction contributes to thrombus growth and stability. PMID:26282541

  10. Fibrin activates GPVI in human and mouse platelets

    PubMed Central

    Alshehri, Osama M.; Montague, Samantha; Watson, Stephanie K.; Frampton, Jon; Bender, Markus; Watson, Steve P.

    2015-01-01

    The glycoprotein VI (GPVI)-Fc receptor γ (FcRγ) chain is the major platelet signaling receptor for collagen. Paradoxically, in a FeCl3 injury model, occlusion, but not initiation of thrombus formation, is delayed in GPVI-deficient and GPVI-depleted mice. In this study, we demonstrate that GPVI is a receptor for fibrin and speculate that this contributes to development of an occlusive thrombus. We observed a marked increase in tyrosine phosphorylation, including the FcRγ chain and Syk, in human and mouse platelets induced by thrombin in the presence of fibrinogen and the αIIbβ3 blocker eptifibatide. This was not seen in platelets stimulated by a protease activated receptor (PAR)-4 peptide, which is unable to generate fibrin from fibrinogen. The pattern of tyrosine phosphorylation was similar to that induced by activation of GPVI. Consistent with this, thrombin did not induce tyrosine phosphorylation of Syk and the FcRγ chain in GPVI-deficient mouse platelets. Mouse platelets underwent full spreading on fibrin but not fibrinogen, which was blocked in the presence of a Src kinase inhibitor or in the absence of GPVI. Spreading on fibrin was associated with phosphatidylserine exposure (procoagulant activity), and this too was blocked in GPVI-deficient platelets. The ectodomain of GPVI was shown to bind to immobilized monomeric and polymerized fibrin. A marked increase in embolization was seen following FeCl3 injury in GPVI-deficient mice, likely contributing to the delay in occlusion in this model. These results demonstrate that GPVI is a receptor for fibrin and provide evidence that this interaction contributes to thrombus growth and stability. PMID:26282541

  11. Charged Particle Tracking for the GlueX Detector

    NASA Astrophysics Data System (ADS)

    Taylor, Simon; GlueX Collaboration

    2011-04-01

    The GlueX experiment is a new experiment under construction at the Thomas Jefferson National Accelerator Facility designed to study gluonic degrees of freedom via the production of ``hybrid'' mesons with exotic quantum numbers. At full luminosity, the trigger rate is expected to be on the order of 150 kHz and the data rate to tape is expected to be on the order of 300 MB/s. In order to reduce the reconstruction time, the current GlueX analysis framework is multi-threaded such that multiple events can be analyzed in parallel on multi-core machines. The tracking code presents the largest bottleneck in the event reconstruction. By taking advantage of Single-Instruction, Multiple-Data (SIMD) instructions in the three-vector and matrix operations needed in the tracking code, the reconstruction can be sped up considerably. The current status of the tracking reconstruction for GlueX will be presented. This work was supported by the US Department of Energy contract DE-AC05-06OR23177, under which Jefferson Science Associates, LLC operates Thomas Jefferson National Accelerator Facility.

  12. Profile of solvent abusers (glue sniffers) in East Malaysia.

    PubMed

    Zabedah, M Y; Razak, M; Zakiah, I; Zuraidah, A B

    2001-12-01

    Solvent abuse is deliberate sniffing of an organic solvent for the intention of altering the physiological state of the individual. It is also commonly known as glue sniffing because glue is the most commonly abused substance. This form of substance abuse is widespread throughout the world and usually popular among secondary school children and young adults because of its easy availability and it is cheaper compared with most drugs of abuse. In Malaysia this problem has been recognized especially among the children in East Malaysia. In this study, 37 children and young adults from or around Kota Kinabalu, Sabah were referred to Bukit Padang Psychiatric Hospital by the Anti-drug Task force for suspected solvent abuse. These children were interviewed using questionaire and examined physically. Blood and urine were analysed for toluene and hippuric acid. 27 of the children, age ranging between 8 and 20 years, willingly admitted to sniffing glue for a period between a few months to 2 years. Most of them were children of Fillipino illegal immigrants in Kota Kinabalu. Biochemical parameters were found to be normal. Two of them were pale with low hemoglobin and 7 had eosinophilia. Haematuria and proteinuria were found in 21 children (78%). 16 blood samples with toluene levels ranging from 0.3 to 41 microg/ml and 10 urine samples have elevated urinary hippuric acid levels ranging from 1.2 to 7.4 mg/ml. Strong positive correlation was noted between mean blood toluene levels and duration of abuse. PMID:12166590

  13. Revascularization Induced Maturogenesis of Non-Vital Immature Permanent Tooth Using Platelet-Rich-Fibrin: A Case Report.

    PubMed

    Nagaveni, N B; Pathak, Sidhant; Poornima, P; Joshi, Jooie S

    2016-01-01

    The aim of this report is to describe a novel method of revascularization therapy done in a non-vital, immature permanent tooth using Platelet-rich fibrin (PRF),in a recently developed scaffold material to overcome limitations associated with the traditional method of revascularization using natural blood clot. PRF prepared from autologous blood was placed in the root canal and patient was followed up regularly at one, three, six, nine and 12 months for detailed clinical and radiographic evaluation. At 12 months, radiographic examination revealed root elongation, root end closure, continued thickening of the root dentinal walls, obliteration of root canal space, and normal periradicular anatomy. However, more long term prospective trials and histological studies are highly needed before to testify PRF a panacea for the regenerative endodontic therapy in children. PMID:26696103

  14. Macroporous Three Dimensional PDMS Scaffolds for Extrahepatic Islet Transplantation

    PubMed Central

    Pedraza, Eileen; Brady, Ann-Christina; Fraker, Christopher A.; Molano, R. Damaris; Sukert, Steven; Berman, Dora M.; Kenyon, Norma S.; Pileggi, Antonello; Ricordi, Camillo; Stabler, Cherie L.

    2015-01-01

    Clinical islet transplantation has demonstrated success in treating type 1 diabetes. A current limitation is the intrahepatic portal vein transplant site, which is prone to mechanical stress and inflammation. Transplantation of pancreatic islets into alternative sites is preferable, but challenging, as it may require a three-dimensional vehicle to confer mechanical protection and to confine islets to a well-defined, retrievable space where islet neovascularization can occur. We have fabricated biostable, macroporous scaffolds from poly(dimethylsiloxane) (PDMS) and investigated islet retention and distribution, metabolic function, and glucose-dependent insulin secretion within these materials. Islets from multiple sources, including rodents, non-human primates, and humans, were tested in vitro. We observed high islet retention and distribution within PDMS scaffolds, with retention of small islets (< 100 µm) improved through the post-loading addition of fibrin gel. Islets loaded within PDMS scaffolds exhibited viability and function comparable to standard culture conditions when incubated under normal oxygen tensions, but displayed improved viability compared to standard two-dimensional culture controls under low oxygen tensions. In vivo efficacy of scaffolds to support islet grafts was evaluated after transplantation in the omental pouch of chemically-induced diabetic syngeneic rats, which promptly achieved normoglycemia. Collectively, these results are promising in that they indicate the potential for transplanting islets into a clinically relevant, extrahepatic site that provides spatial distribution of islets, as well as intra-device vascularization. PMID:23031502

  15. Optimization of a biomimetic poly-(lactic acid) ligament scaffold

    NASA Astrophysics Data System (ADS)

    Uehlin, Andrew F.

    The anterior cruciate ligament (ACL) is the most commonly injured ligament of the knee, often requiring orthopedic reconstruction using autograft or allograph tissue, both with significant disadvantages. As a result, tissue engineering an ACL replacement graft has been heavily investigated. The present study attempts to replicate the morphology and mechanical properties of the ACL using a nanomatrix composite of highly-aligned poly(lactic acid) (PLA) fibers with various surface and biochemical modifications. Additionally, this study attempts to recreate the natural mineralization gradient found at the ACL enthesis onto the scaffold, capable of inducing a favorable cellular response in vitro. Unidirectional electrospinning was used to create nanofibers of PLA, followed by an induced degradation of the nanofibers via 0.25M NaOH hydrolysis. The effects of the unidirectional electrospinning as well as the effects of NaOH hydrolysis on fiber alignment, fiber diameter, surface morphology, crystallinity, in vitro swelling, immobilization of fibrin, and mechanical properties were investigated, resulting in a modified morphology correlating to the microstructure of native ligament tissue with similar mechanical properties. Furthering the development of the PLA nanomatrix composite, a bioinkjet printer was used to immobilize nanoparticulate hydroxyapatite (HANP) on the surface of the scaffold. A series of 300pL droplets of HANP bioink were printed over a gradient pattern mimetic of (and spatially corresponding to) the mineralization gradient found over the microanatomy at the ACL enthesis. Proliferation and differentiation response of human mesenchymal stem cells (hMSCs) in vitro was assessed on a variety of conditions and combinations of the PLA nanofiber scaffold surface modifications (inclusive and exclusive of HANP, fibrin, and various time dependent NaOH treatments). It was found that a combinatory effect of the HANP gradient with fibrin on 20 minute NaOH treated PLA

  16. Tissue engineering and regeneration using biodegradable scaffolds.

    PubMed

    Zhang, X; Zhang, Y

    2015-12-01

    A number of people across the world suffer from various diseases or genetic defects and many of these patients die because of the lack of the availability of ideal tissue substitute and/or treatment. An important aspect of the disease is its association with the loss of tissue function. Many end-stage diseases and/or complete organ failure often require total or partial organ transplantation to restore functionality. However, such transplantation surgeries are not always successful because of the organ/ tissue rejection and also the scarcity of donors. Regenerative medicine and tissue engineering aim to improve or repair the function of a dysfunctional tissue or organ. In spite of the many advances in tissue engineering methods, the field of regenerative medicine still awaits acceptable designs of bioscaffolds that are clinically tenable. Design of scaffolds and the nature of biomaterial used to make the scaffolds dictate cell behavior and function. Several approaches are currently being tried to optimize the design and improve the quality of the biomaterials. Innervation, vascularization and proper cell differentiation that are influenced by the biomaterials, are few challenges that need to be optimized along with the choice of stem cells that can be employed. Extracellular matrix scaffolds have proven to be a better choice for cartilage and bone repair while the fibrin, polyglycolate and polylactate etc are still being developed. Future research and technological innovations are still needed for a better choice of biomaterials that can support the tissue regeneration without causing any immune or inflammatory response from the host and which last for longer periods. PMID:25634586

  17. Comparative evaluation of the biological properties of fibrin for bone regeneration

    PubMed Central

    Oh, Joung-Hwan; Kim, Hye-Jin; Kim, Tae-Il; Woo, Kyung Mi

    2014-01-01

    Fibrin is a natural provisional matrix found in wound healing, while type I collagen is a major organic component of bone matrix. Despite the frequent use of fibrin and type I collagen in bone regenerative approaches, their comparative efficacies have not yet been evaluated. In the present study, we compared the effects of fibrin and collagen on the proliferation and differentiation of osteoblasts and protein adsorption. Compared to collagen, fibrin adsorbed approximately 6.7 times more serum fibronectin. Moreover, fibrin allowed the proliferation of larger MC3T3-E1 pre-osteoblasts, especially at a low cell density. Fibrin promoted osteoblast differentiation at higher levels than collagen, as confirmed by Runx2 expression and transcriptional activity, alkaline phosphatase activity, and calcium deposition. The results of the present study suggest that fibrin is superior to collagen in the support of bone regeneration. [BMB Reports 2014; 47(2): 110-114] PMID:24257120

  18. Potential of nanocrystalline cellulose-fibrin nanocomposites for artificial vascular graft applications.

    PubMed

    Brown, Elvie E; Hu, Dehong; Abu Lail, Nehal; Zhang, Xiao

    2013-04-01

    The potential of synthesizing new nanocomposites from nanocrystalline cellulose (NCC) and fibrin for small-diameter replacement vascular graft (SDRVG) application was demonstrated. Periodate oxidation of NCC can augment reactive carbonyl groups on NCC and facilitate its cross-linking with fibrin. NCC-fibrin nanocomposites were synthesized, composed of homogeneously dispersed oxidized NCC (ONCC) in a fibrin matrix, with fibrin providing elasticity and ONCC providing strength. The maximum strength and elongation of the nanocomposites were determined by Atomic Force Microscopy (AFM) and compared with a native blood vessel. The manipulation of degree of oxidation of NCC and the NCC-to-fibrin ratio resulted in the variation of strength and elongation of the nanocomposites, indicating that the nanocomposites can be tailored to conform to the diverse mechanical properties of native blood vessels. A mechanistic understanding of the molecular interactions of ONCC and fibrin was illustrated. This study established fundamental information to utilizing NCC for SDRVG applications. PMID:23421631

  19. Fiber optic immunosensor for cross-linked fibrin concentration

    NASA Astrophysics Data System (ADS)

    Moskowitz, Samuel E.

    2000-08-01

    Working with calcium ions in the blood, platelets produce thromboplastin which transforms prothrombin into thrombin. Removing peptides, thrombin changes fibrinogen into fibrin. Cross-linked insoluble fibrin polymers are solubilized by enzyme plasmin found in blood plasma. Resulting D-dimers are elevated in patients with intravascular coagulation, deep venous thrombosis, pulmonary embolism, myocardial infarction, multiple trauma, cancer, impaired renal and liver functions, and sepsis. Consisting principally of a NIR 780 nm GaAlAs laser diode and a 800 nm avalanche photodiode (APD), the fiber-optic immunosensor can determined D-dimer concentration to levels <0.1 ng/ml. A capture monoclonal antibody to the antigen soluble cross-linked fibrin is employed. Immobilized at the tip of an optical fiber by avidin-biotin, the captured antigen is detected by a second antibody which is labeled with NN 382 fluorescent dye. An evanescent wave traveling on an excitation optical fiber excites the antibody-antigen fluorophore complex. Concentration of cross-linked fibrin is directly proportional to the APD measured intensity of fluorescence. NIR fluorescence has advantages of low background interference, short fluorescence lifetime, and large difference between excitation and emission peaks. Competitive ELISA test for D-dimer concentration requires trained personnel performing a time consuming operation.

  20. Investigating the interaction between acoustically stimulated microbubbles and fibrin clots

    NASA Astrophysics Data System (ADS)

    Acconcia, Christopher; Leung, Ben; Hynynen, Kullervo; Goertz, David

    2012-11-01

    While it is well established that ultrasound stimulated microbubbles can potentiate thrombolysis, the mechanisms of action are poorly understood. The objective of this work was to gain a more fundamental understanding of how acoustically stimulated microbubbles interact with and potentially degrade fibrin clots. Owing to their optical transparency, the use of fibrin clots allowed to optically observe microbubbles interacting with the clot boundary and any resultant disruption of the fluorescently tagged fibrin network. It was found that microbubbles could readily penetrate into fibrin clots with velocities up to 0.2 m/s and to depths related to the number of pulses applied. At lower pressures (0.2-0.55 MPa), microbubbles as small as 3μm were observed to penetrate, whereas higher pressures (>0.9 MPa) caused the penetration of larger microbubbles (10-30μm), formed by coalescence prior to entry. In some cases, patent 'tunnels' remained along the path taken by penetrating microbubbles. Tunnel diameters ranged between 9-35μm depending largely on pressure and pulse duration. Two-photon microscopy indicated either patent tunnels or paths of disrupted fibers consistent with collapsed tunnel. Fluid flow within the clot was observed to accompany penetrating microbubbles, which may have implications for lytic enzyme penetration.

  1. Oriented fibrin gels formed by polymerization in strong magnetic fields

    NASA Astrophysics Data System (ADS)

    Torbet, J.

    1981-01-01

    Fibrinogen is a soluble plasma protein which, after cleavage by the specific proteolytic enzyme thrombin, polymerizes to form the filamentous fibrin network during blood clotting (see refs 1 and 2 for reviews). Fibrinogen has a molecular weight of 340,000 and is composed of two identical halves, each containing three peptide chains designated Aα, Bβ and γ. Fibrin monomers are produced by thrombin which releases the small negatively charged fibrinopeptides A and B. The overall shape of the fibrinogen molecule has not been unequivocally established1,2. The trinodular, elongated (~450 Å long) structure proposed by Hall and Slayter3 is the most widely accepted model and it has obtained additional support from recent work4-6. Fibrin monomers are also about 450 Å long7 and in fibres they probably have a half-staggered arrangement along the axis7,8. The fibres are an assembly of protofibrils whose structure and packing are not reliably known. We report here that highly oriented fibrin gels are formed when polymerization takes place slowly in a strong magnetic field. It is shown that the protofibrils pack into a three-dimensional crystalline lattice. We introduce magnetically induced birefringence as a potential tool for studying polymerization and briefly speculate on the applications of strong magnetic fields.

  2. Cutaneous collagenous vasculopathy associated with intravascular occlusive fibrin thrombi.

    PubMed

    Salama, Samih; Chorneyko, Kathy; Belovic, Brian

    2014-04-01

    Cutaneous collagenous vasculopathy (CCV) is a rare cutaneous microangiopathy that clinically resembles generalized essential telangiectasia with only 12 cases reported to date. The perivascular fibrosis is thought to be due to production of abnormal collagen by veil cells in the outer vessel walls as a result of unknown factors. This report is of an 84-year-old male with progressive telangiectasia. Biopsies showed characteristic features of CCV. In addition, there were multiple intravascular fibrin thrombi, some organizing and associated with endothelial cell hyperplasia with recanalization reminiscent of glomeruloid bodies and simulating reactive angioendotheliomatosis (RAE). Histochemically and ultrastructurally fibrin was noted within the vessel walls integrating into the fibrous tissue around the vessels; however, the patient had no evidence of coagulation disorder, cryoglobulinemia or cold agglutinemia. Immunofluorescence showed fibrinogen within the vessel walls but no immunoglobulins or C3. As well, there were minimal inflammatory cells. This suggests pauci-inflammatory injury to the endothelial cells by unknown angiogenic factors causing local intravascular fibrin thrombi with fibrin leaking and incorporating into the vessel walls, eventually leading to reparative perivascular fibrosis. This case suggests that some cases of CCV are related to a primary local intravascular occlusive thrombotic microangiopathy. However, the primary triggering factor causing the endothelial cell damage has yet to be elucidated. PMID:24350781

  3. Fibrin polymerization as a phase transition wave: A mathematical model

    NASA Astrophysics Data System (ADS)

    Lobanov, A. I.

    2016-06-01

    A mathematical model of fibrin polymerization is described. The problem of the propagation of phase transition wave is reduced to a nonlinear Stefan problem. A one-dimensional discontinuity fitting difference scheme is described, and the results of one-dimensional computations are presented.

  4. The use of platelet-rich fibrin combined with periodontal ligament and jaw bone mesenchymal stem cell sheets for periodontal tissue engineering

    PubMed Central

    Wang, Zhong-Shan; Feng, Zhi-Hong; Wu, Guo-Feng; Bai, Shi-Zhu; Dong, Yan; Chen, Fa-Ming; Zhao, Yi-Min

    2016-01-01

    Periodontal regeneration involves the restoration of at least three unique tissues: cementum, periodontal ligament tissue (PDL) and alveolar bone tissue. Here, we first isolated human PDL stem cells (PDLSCs) and jaw bone mesenchymal stem cells (JBMSCs). These cells were then induced to form cell sheets using an ascorbic acid-rich approach, and the cell sheet properties, including morphology, thickness and gene expression profile, were compared. Platelet-rich fibrin (PRF) derived from human venous blood was then fabricated into bioabsorbable fibrin scaffolds containing various growth factors. Finally, the in vivo potential of a cell-material construct based on PDLSC sheets, PRF scaffolds and JBMSC sheets to form periodontal tissue was assessed in a nude mouse model. In this model, PDLSC sheet/PRF/JBMSC sheet composites were placed in a simulated periodontal space comprising human treated dentin matrix (TDM) and hydroxyapatite (HA)/tricalcium phosphate (TCP) frameworks. Eight weeks after implantation, the PDLSC sheets tended to develop into PDL-like tissues, while the JBMSC sheets tended to produce predominantly bone-like tissues. In addition, the PDLSC sheet/PRF/JBMSC sheet composites generated periodontal tissue-like structures containing PDL- and bone-like tissues. Further improvements in this cell transplantation design may have the potential to provide an effective approach for future periodontal tissue regeneration. PMID:27324079

  5. The use of platelet-rich fibrin combined with periodontal ligament and jaw bone mesenchymal stem cell sheets for periodontal tissue engineering.

    PubMed

    Wang, Zhong-Shan; Feng, Zhi-Hong; Wu, Guo-Feng; Bai, Shi-Zhu; Dong, Yan; Chen, Fa-Ming; Zhao, Yi-Min

    2016-01-01

    Periodontal regeneration involves the restoration of at least three unique tissues: cementum, periodontal ligament tissue (PDL) and alveolar bone tissue. Here, we first isolated human PDL stem cells (PDLSCs) and jaw bone mesenchymal stem cells (JBMSCs). These cells were then induced to form cell sheets using an ascorbic acid-rich approach, and the cell sheet properties, including morphology, thickness and gene expression profile, were compared. Platelet-rich fibrin (PRF) derived from human venous blood was then fabricated into bioabsorbable fibrin scaffolds containing various growth factors. Finally, the in vivo potential of a cell-material construct based on PDLSC sheets, PRF scaffolds and JBMSC sheets to form periodontal tissue was assessed in a nude mouse model. In this model, PDLSC sheet/PRF/JBMSC sheet composites were placed in a simulated periodontal space comprising human treated dentin matrix (TDM) and hydroxyapatite (HA)/tricalcium phosphate (TCP) frameworks. Eight weeks after implantation, the PDLSC sheets tended to develop into PDL-like tissues, while the JBMSC sheets tended to produce predominantly bone-like tissues. In addition, the PDLSC sheet/PRF/JBMSC sheet composites generated periodontal tissue-like structures containing PDL- and bone-like tissues. Further improvements in this cell transplantation design may have the potential to provide an effective approach for future periodontal tissue regeneration. PMID:27324079

  6. Increased Plasminogen Activator (Urokinase) in Tissue Culture After Fibrin Deposition

    PubMed Central

    Bernik, Maria B.

    1973-01-01

    Lysis of fibrin in tissue culture has been shown to be due to plasminogen activator identified immunologically as urokinase. The present study examines fibrinolytic events in culture, particularly mechanisms leading to increased urokinase levels and accelerated fibrinolysis. Deposition of fibrin on cells in culture was followed by a two- to six-fold increase in urokinase in the supernates and rapid disappearance of the fibrin. Investigation of factors that might be responsible for these events (including fibrin, fibrinogen, vasoactive stimuli, and the enzymes thrombin and plasmin) indicated that the enhanced urokinase yields were mediated through plasmin and thrombin. Study of the possible modes of action of thrombin and plasmin indicated that these enzymes are capable of acting on the cells themselves as well as on cell-produced material. The effect on cells was manifested by mitotic activity or, occasionally, cell injury and death. Although these effects influenced urokinase levels, enhanced yields were explained best by the action of enzymes on cellproduced material. Studies with plasmin and thrombin, and also trypsin, indicated that proteolytic enzymes may act in various ways—affect the stability of urokinase, interfere with inhibition of urokinase by naturally occurring inhibitor(s), and induce urokinase activity from inactive material. Plasma and thrombin appeared to act primarily through the latter mechanism. Inactive material, which gave rise to urokinase upon exposure to proteolytic enzymes and which may represent urokinase precursor, was found in cultures of kidney, lung, spleen, and thyroid. Urokinase in such inactive state appears to be readily accessible to activation by enzymes, particularly plasmin and thrombin, thus facilitating removal of fibrin and possibly also providing pathways to excessive fibrinolysis. PMID:4266421

  7. [Bone tissue engineering scaffolds].

    PubMed

    Fang, Liru; Weng, Wenjian; Shen, Ge; Han, Gaorong; Santos, J D; Du, Peiyi

    2003-03-01

    Bone tissue engineering may provide an alternative to the repairs to skeletal defects resulting from disease, trauma or surgery. Scaffold has played an important role in bone tissue engineering, which functions as the architecture for bone in growth. In this paper, the authors gave a brief introduction about the requirement of bone tissue engineering scaffold, the key of the design of scaffolds and the current research on this subject. PMID:12744187

  8. Self-Assembling Peptide-Polymer Hydrogels Designed From the Coiled Coil Region of Fibrin

    PubMed Central

    Jing, Peng; Rudra, Jai S.; Herr, Andrew B.; Collier, Joel H.

    2010-01-01

    Biomaterials constructed from self-assembling peptides, peptide derivatives, and peptide-polymer conjugates are receiving increasing attention as defined matrices for tissue engineering, controlled therapeutic release, and in vitro cell expansion, but many are constructed from peptide structures not typically found in the human extracellular matrix. Here we report a self-assembling biomaterial constructed from a designed peptide inspired by the coiled coil domain of human fibrin, the major protein constituent of blood clots and the provisional scaffold of wound healing. Targeted substitutions were made in the residues forming the interface between coiled coil strands for a 37-amino acid peptide from human fibrinogen to stabilize the coiled coil peptide bundle, while the solvent-exposed residues were left unchanged to provide a surface similar to that of the native protein. This peptide, which self-assembled into coiled coil dimers and tetramers, was then used to produce triblock peptide-PEG-peptide bioconjugates that self-assembled into viscoelastic hydrogel biomaterials. PMID:18712921

  9. First results from the GlueX experiment

    NASA Astrophysics Data System (ADS)

    Al Ghoul, H.; Anassontzis, E. G.; Barbosa, F.; Barnes, A.; Beattie, T. D.; Bennett, D. W.; Berdnikov, V. V.; Black, T.; Boeglin, W.; Brooks, W. K.; Cannon, B.; Chernyshov, O.; Chudakov, E.; Crede, V.; Dalton, M. M.; Deur, A.; Dobbs, S.; Dolgolenko, A.; Dugger, M.; Egiyan, H.; Eugenio, P.; Foda, A. M.; Frye, J.; Furletov, S.; Gan, L.; Gasparian, A.; Gerasimov, A.; Gevorgyan, N.; Goryachev, V. S.; Guegan, B.; Guo, L.; Hakobyan, H.; Hakobyan, H.; Hardin, J.; Huber, G. M.; Ireland, D.; Ito, M. M.; Jarvis, N. S.; Jones, R. T.; Kakoyan, V.; Kamel, M.; Klein, F. J.; Kourkoumeli, C.; Kuleshov, S.; Lara, M.; Larin, I.; Lawrence, D.; Leckey, J.; Levine, W. I.; Livingston, K.; Lolos, G. J.; Mack, D.; Mattione, P. T.; Matveev, V.; McCaughan, M.; McGinley, W.; McIntyre, J.; Mendez, R.; Meyer, C. A.; Miskimen, R.; Mitchell, R. E.; Mokaya, F.; Moriya, K.; Nigmatkulov, G.; Ochoa, N.; Ostrovidov, A. I.; Papandreou, Z.; Pedroni, R.; Pennington, M.; Pentchev, L.; Ponosov, A.; Pooser, E.; Pratt, B.; Qiang, Y.; Reinhold, J.; Ritchie, B. G.; Robison, L.; Romanov, D.; Salgado, C.; Schumacher, R. A.; Semenov, A. Yu.; Semenova, I. A.; Senderovich, I.; Seth, K. K.; Shepherd, M. R.; Smith, E. S.; Sober, D. I.; Somov, A.; Somov, S.; Soto, O.; Sparks, N.; Staib, M. J.; Stevens, J. R.; Subedi, A.; Tarasov, V.; Taylor, S.; Tolstukhin, I.; Tomaradze, A.; Toro, A.; Tsaris, A.; Vasileiadis, G.; Vega, I.; Voulgaris, G.; Walford, N. K.; Whitlatch, T.; Williams, M.; Wolin, E.; Xiao, T.; Zarling, J.; Zihlmann, B.

    2016-05-01

    The GlueX experiment at Jefferson Lab ran with its first commissioning beam in late 2014 and the spring of 2015. Data were collected on both plastic and liquid hydrogen targets, and much of the detector has been commissioned. All of the detector systems are now performing at or near design specifications and events are being fully reconstructed, including exclusive production of π0, η and ω mesons. Linearly-polarized photons were successfully produced through coherent bremsstrahlung and polarization transfer to the ρ has been observed.

  10. Silicon photomultiplier characterization for the GlueX barrel calorimeter

    SciTech Connect

    F. Barbosa, J.E. McKisson, J. McKisson, Y. Qiang, E. Smith, C. Zorn

    2012-12-01

    GlueX is a new detector being constructed at Jefferson Laboratory to study gluonic excitations and confinement via the detection of exotic meson states. The hermetic detector includes a barrel calorimeter where the photodetectors must operate in a high magnetic field exceeding 0.5 T. After extensive tests with a variety of sensors, the chosen photodetector will be a custom silicon photomultiplier (SiPM) array manufactured by Hamamatsu Corporation. This paper will focus on the characterization of the first 80 production samples of these SiPMs, including dark rate, photodetection efficiency (PDE), crosstalk, response uniformity and radiation tolerance.

  11. Polyions act as an electrostatic glue for mesoscopic particle aggregates

    NASA Astrophysics Data System (ADS)

    Bordi, F.; Cametti, C.; Sennato, S.

    2005-06-01

    Although complexation of charged particles induced by polyions of opposite charge is a well-known phenomenon, the possibility of obtaining equilibrium clusters stuck together by flexible polyions, which act as an electrostatic glue, is not completely recognized. In this Letter, we call attention towards the behavior of polyions in attaching together charged particles, by means of controlled electrostatic interactions. As an example, we present some features of equilibrium clusters composed of cationic liposomes built up by DOTAP and glued up by an anionic polyion, polyacrylate sodium salt. We discuss briefly some applications in nanostructure science and biotechnology.

  12. Transcatheter glue arterial embolization of a mass in the hind limb of a dog

    PubMed Central

    de La Villeon, Guillaume; Louvet, Arnaud; Behr, Luc; Borenstein, Nicolas

    2011-01-01

    This article reports the use of transarterial glue embolization in the treatment of a soft-tissue mass in the hind limb of a dog that was referred for a > 15-cm diameter soft tissue mass in the caudal thigh. Clinical improvement showed that the percutaneous therapeutic cyanoacrylate glue embolization procedure was technically feasible and useful. PMID:21629422

  13. Spiritual and Religious Supports Part 8: Church G.L.U.E.

    ERIC Educational Resources Information Center

    Newman, Barbara J.

    2009-01-01

    CLC Network is an organization that partners with churches, schools, and families to help promote and build inclusive and interdependent communities for those with disabilities. This article describes CLC Network's most recent tool--a book entitled the G.L.U.E. Training Manual. G.L.U.E. is an adhesive process to allow each individual to be firmly…

  14. GLUE!: An Architecture for the Integration of External Tools in Virtual Learning Environments

    ERIC Educational Resources Information Center

    Alario-Hoyos, Carlos; Bote-Lorenzo, Miguel L.; Gomez-Sanchez, Eduardo; Asensio-Perez, Juan I.; Vega-Gorgojo, Guillermo; Ruiz-Calleja, Adolfo

    2013-01-01

    The integration of external tools in Virtual Learning Environments (VLEs) aims at enriching the learning activities that educational practitioners may design and enact. This paper presents GLUE!, an architecture that enables the lightweight integration of multiple existing external tools in multiple existing VLEs. GLUE! fosters this integration by…

  15. Elastic Behavior and Platelet Retraction in Low- and High-Density Fibrin Gels

    PubMed Central

    Wufsus, Adam R.; Rana, Kuldeepsinh; Brown, Andrea; Dorgan, John R.; Liberatore, Matthew W.; Neeves, Keith B.

    2015-01-01

    Fibrin is a biopolymer that gives thrombi the mechanical strength to withstand the forces imparted on them by blood flow. Importantly, fibrin is highly extensible, but strain hardens at low deformation rates. The density of fibrin in clots, especially arterial clots, is higher than that in gels made at plasma concentrations of fibrinogen (3–10 mg/mL), where most rheology studies have been conducted. Our objective in this study was to measure and characterize the elastic regimes of low (3–10 mg/mL) and high (30–100 mg/mL) density fibrin gels using shear and extensional rheology. Confocal microscopy of the gels shows that fiber density increases with fibrinogen concentration. At low strains, fibrin gels act as thermal networks independent of fibrinogen concentration. Within the low-strain regime, one can predict the mesh size of fibrin gels by the elastic modulus using semiflexible polymer theory. Significantly, this provides a link between gel mechanics and interstitial fluid flow. At moderate strains, we find that low-density fibrin gels act as nonaffine mechanical networks and transition to affine mechanical networks with increasing strains within the moderate regime, whereas high-density fibrin gels only act as affine mechanical networks. At high strains, the backbone of individual fibrin fibers stretches for all fibrin gels. Platelets can retract low-density gels by >80% of their initial volumes, but retraction is attenuated in high-density fibrin gels and with decreasing platelet density. Taken together, these results show that the nature of fibrin deformation is a strong function of fibrin fiber density, which has ramifications for the growth, embolization, and lysis of thrombi. PMID:25564864

  16. Elastic behavior and platelet retraction in low- and high-density fibrin gels.

    PubMed

    Wufsus, Adam R; Rana, Kuldeepsinh; Brown, Andrea; Dorgan, John R; Liberatore, Matthew W; Neeves, Keith B

    2015-01-01

    Fibrin is a biopolymer that gives thrombi the mechanical strength to withstand the forces imparted on them by blood flow. Importantly, fibrin is highly extensible, but strain hardens at low deformation rates. The density of fibrin in clots, especially arterial clots, is higher than that in gels made at plasma concentrations of fibrinogen (3-10 mg/mL), where most rheology studies have been conducted. Our objective in this study was to measure and characterize the elastic regimes of low (3-10 mg/mL) and high (30-100 mg/mL) density fibrin gels using shear and extensional rheology. Confocal microscopy of the gels shows that fiber density increases with fibrinogen concentration. At low strains, fibrin gels act as thermal networks independent of fibrinogen concentration. Within the low-strain regime, one can predict the mesh size of fibrin gels by the elastic modulus using semiflexible polymer theory. Significantly, this provides a link between gel mechanics and interstitial fluid flow. At moderate strains, we find that low-density fibrin gels act as nonaffine mechanical networks and transition to affine mechanical networks with increasing strains within the moderate regime, whereas high-density fibrin gels only act as affine mechanical networks. At high strains, the backbone of individual fibrin fibers stretches for all fibrin gels. Platelets can retract low-density gels by >80% of their initial volumes, but retraction is attenuated in high-density fibrin gels and with decreasing platelet density. Taken together, these results show that the nature of fibrin deformation is a strong function of fibrin fiber density, which has ramifications for the growth, embolization, and lysis of thrombi. PMID:25564864

  17. Hierarchical scaffolding with Bambus.

    PubMed

    Pop, Mihai; Kosack, Daniel S; Salzberg, Steven L

    2004-01-01

    The output of a genome assembler generally comprises a collection of contiguous DNA sequences (contigs) whose relative placement along the genome is not defined. A procedure called scaffolding is commonly used to order and orient these contigs using paired read information. This ordering of contigs is an essential step when finishing and analyzing the data from a whole-genome shotgun project. Most recent assemblers include a scaffolding module; however, users have little control over the scaffolding algorithm or the information produced. We thus developed a general-purpose scaffolder, called Bambus, which affords users significant flexibility in controlling the scaffolding parameters. Bambus was used recently to scaffold the low-coverage draft dog genome data. Most significantly, Bambus enables the use of linking data other than that inferred from mate-pair information. For example, the sequence of a completed genome can be used to guide the scaffolding of a related organism. We present several applications of Bambus: support for finishing, comparative genomics, analysis of the haplotype structure of genomes, and scaffolding of a mammalian genome at low coverage. Bambus is available as an open-source package from our Web site. PMID:14707177

  18. Beam Test Results of the GlueX Forward Calorimeter

    NASA Astrophysics Data System (ADS)

    Bauer, Kevin; Moriya, Kei; Shepherd, Matthew

    2013-04-01

    GlueX is an experiment to begin running in the near future at Jefferson Lab. Our research group is responsible for the forward calorimeter (FCAL) that is designed to measure the energy of photons produced from the decays of mesons. Recently, we conducted a beam test at Jefferson Lab using a prototype of the FCAL. Its goal was to experimentally verify the energy resolution of the FCAL as a function of beam energy. The prototype was tested with recoil electrons ranging in energy from 113MeV to 277MeV. We obtained the resolution by comparing the reconstructed energy to the known energy. In addition, we corrected our measured resolution for multiple scattering and energy loss based on a GEANT4 simulation of the prototype. Another important goal of the beam test was to measure the timing resolution of the channels on our flash analog to digital converters (fADCs). For GlueX, we need to require the timing resolution to be much less than the bunch spacing (2ns). The results of our studies indicate that the energy resolution of the FCAL is consistent with our predictions. We also found the timing resolution as a function of signal size and the results agreed with a similar study. For signals of about at least 75mV, the timing resolution achieved was significantly lower than 2ns.

  19. Potential of nanocrystalline cellulose-fibrin nanocomposites for artificial vascular graft applications

    SciTech Connect

    Brown, Elvie; Hu, Dehong; Abu-Lail, Nehal; Zhang, Xiao

    2013-02-19

    Nanocrystalline cellulose, a new bio-nanomaterial is utilized as a reinforcing material for biocompatible fibrin matrix to form into a nanocomposite for small-diameter replacement vascular graft application (SDRVG). The periodate oxidation of NCC, which provided it with a reactive carbonyl group, allowed molecular interaction between NCC and fibrin. Such interaction resulted into an effective mechanical reinforcement indicated by the improvement of max. force, elongation at break and modulus when oxidized NCC (ONCC) was incorporated into fibrin. The nanocomposite’s mechanical properties can be manipulated to conform to the native blood vessel by varying the ONCC to fibrin ratio and/or by controlling the degree of oxidation of NCC. Using atomic force microscopy had provided fundamental information on the effects of molecular interactions to the nanolevel mechanical properties of NCC/fibrin nanocomposites. This fundamental information established the positive feasibility and commenced continuing investigation for the practical SDRVG application of NCC/fibrin nanocomposite.

  20. Interaction of Fibrin with the VLDL Receptor: Further Characterization and Localization of the Fibrin-Binding Site

    PubMed Central

    Yakovlev, Sergiy; Medved, Leonid

    2016-01-01

    Our recent study revealed that fibrin interacts with the VLDL receptor (VLDLR) on endothelial cells through its βN-domains and this interaction promotes transendothelial migration of leukocytes and thereby inflammation. The major aims of the present study were to further characterize this interaction and localize fibrin-binding site in the VLDL receptor. To localize the fibrin-binding site, we expressed a soluble extracellular portion of this receptor, sVLDLRHT, its N- and C-terminal regions, VLDLR(1–8)HT and des(1–8)VLDLRHT, respectively, and a number of VLDLR fragments containing various combinations of CR-domains, and confirmed their proper folding by fluorescence spectroscopy. Interaction of these fragments with the (β15–66)2 fragment corresponding to a pair of VLDLR-binding βN-domains of fibrin was tested by different methods. Our experiments performed by ELISA and surface plasmon resonance revealed that the VLDLR(1–8)HT fragment containing eight CR-domain of VLDLR and its sub-fragments, VLDLR(1–4)HT and VLDLR(2–4)HT, interact with (β15–66)2 with practically the same affinity as sVLDLRHT while the affinity of VLDLR(2–3)HT was about 2-fold lower. In contrast, des(1–8)VLDLRHT exhibited no binding. Complex formation in solution between the fibrin-binding fragments of VLDLR and (β15–66)2 was detected by fluorescence spectroscopy. In addition, formation of a complex between VLDLR(2–4)HT and (β15–66)2 in solution was confirmed by size-exclusion chromatography. Thus, the results obtained indicate that minimal fibrin-binding structures are located within the second and third CR-domains of the VLDL receptor and the presence of the fourth CR-domain is required for the high affinity binding. They also indicate that tryptophan residues of CR-domains are involved in this binding. PMID:26153297

  1. Obstructive fibrinous tracheal pseudomembrane: a rare condition in postextubation stridor.

    PubMed

    Nakwan, Narongwit

    2014-07-01

    Obstructive fibrinous tracheal pseudomembrane (OFTP) is an airway complication that occurs after endotracheal intubation. It originates from superficial mucosal abrasion and desquamation of necrotic tracheal epithelium at the site of cuff pressure. This condition is a rare cause of postextubation stridor. We present a case of postextubation stridor secondary to OFTP, resulting in clinical features of upper airway obstruction > 8 h after extubation. The case features complete obstruction at the tip of the endotracheal tube from OFTP. PMID:24170917

  2. Altered plasma fibrin clot properties in essential thrombocythemia.

    PubMed

    Małecki, Rafał; Gacka, Małgorzata; Kuliszkiewicz-Janus, Małgorzata; Jakobsche-Policht, Urszula; Kwiatkowski, Jacek; Adamiec, Rajmund; Undas, Anetta

    2016-03-01

    Patients with increased thromboembolic risk tend to form denser fibrin clots which are relatively resistant to lysis. We sought to investigate whether essential thrombocythemia (ET) is associated with altered fibrin clot properties in plasma. Ex vivo plasma fibrin clot permeability coefficient (Ks), turbidimetry and clot lysis time (CLT) were measured in 43 consecutive patients with ET (platelet count from 245 to 991 × 10(3)/µL) and 50 control subjects matched for age, sex and comorbidities. Fibrinolysis proteins and inhibitors together with platelet activation markers were determined. Reduced Ks (-38%, p < 0.0001) and prolonged CLT (+34%, p < 0.0001) were observed in ET. The differences remained significant after adjustment for fibrinogen and platelet count. ET was associated with a slightly shorter lag phase (-5%, p = 0.01) and higher maximum absorbency of the turbidimetric curve (+6%, p < 0.001). The ET patients had higher plasma P-selectin by 193% (p < 0.00001) and platelet factor 4 (PF4) by 173% (p < 0.00001), with higher P-selectin observed in 19 (44%) patients with JAK-2 gene V617F mutation. Higher t-PA (+20%, p < 0.001), 23% higher plasminogen activator inhibitor-1, PAI-1 (+23%, p < 0.01) and unaltered thrombin-activatable fibrinolysis inhibitor, plasminogen and α2-antiplasmin activity were found in the ET group. Ks inversely correlated with fibrinogen, PF4 and C-reactive protein. CLT positively correlated only with PAI-1. Patients with ET display prothrombotic plasma fibrin clot phenotype including impaired fibrinolysis, which represents a new prothrombotic mechanism in this disease. PMID:25989112

  3. Dialysis catheter fibrin sheath stripping: a useful technique after failed catheter exchange.

    PubMed

    Mohamad Ali, Af; Uhwut, E; Liew, Sk

    2012-01-01

    Fibrin sheath formation around long-term haemodialysis catheter is a common cause of failed dialysis access. Treatment options include pharmacological and mechanical methods. This paper reports a case of failed dialysis access due to fibrin sheath encasement. Pharmacologic thrombolysis, mechanical disruption using guide wire and catheter exchange had failed to address the issue. Eventually, fibrin sheath stripping using the loop snare technique was able to successfully restore the catheter function. PMID:22970064

  4. Study the bonding mechanism of binders on hydroxyapatite surface and mechanical properties for 3DP fabrication bone scaffolds.

    PubMed

    Wei, Qinghua; Wang, Yanen; Li, Xinpei; Yang, Mingming; Chai, Weihong; Wang, Kai; zhang, Yingfeng

    2016-04-01

    In 3DP fabricating artificial bone scaffolds process, the interaction mechanism between binder and bioceramics power determines the microstructure and macro mechanical properties of Hydroxyapatite (HA) bone scaffold. In this study, we applied Molecular Dynamics (MD) methods to investigating the bonding mechanism and essence of binders on the HA crystallographic planes for 3DP fabrication bone scaffolds. The cohesive energy densities of binders and the binding energies, PCFs g(r), mechanical properties of binder/HA interaction models were analyzed through the MD simulation. Additionally, we prepared the HA bone scaffold specimens with different glues by 3DP additive manufacturing, and tested their mechanical properties by the electronic universal testing machine. The simulation results revealed that the relationship of the binding energies between binders and HA surface is consistent with the cohesive energy densities of binders, which is PAM/HA>PVA/HA>PVP/HA. The PCFs g(r) indicated that their interfacial interactions mainly attribute to the ionic bonds and hydrogen bonds which formed between the polar atoms, functional groups in binder polymer and the Ca, -OH in HA. The results of mechanical experiments verified the relationship of Young׳s modulus for three interaction models in simulation, which is PVA/HA>PAM/HA>PVP/HA. But the trend of compressive strength is PAM/HA>PVA/HA>PVP/HA, this is consistent with the binding energies of simulation. Therefore, the Young׳s modulus of bone scaffolds are limited by the Young׳s modulus of binders, and the compressive strength is mainly decided by the viscosity of binder. Finally, the major reasons for differences in mechanical properties between simulation and experiment were found, the space among HA pellets and the incomplete infiltration of glue were the main reasons influencing the mechanical properties of 3DP fabrication HA bone scaffolds. These results provide useful information in choosing binder for 3DP fabrication

  5. Human Adipose Stromal Vascular Cell Delivery in a Fibrin Spray

    PubMed Central

    Zimmerlin, Ludovic; Rubin, J. Peter; Pfeifer, Melanie E.; Moore, L.R.; Donnenberg, Vera S.; Donnenberg, Albert D.

    2014-01-01

    Background Adipose tissue represents a practical source of autologous mesenchymal stromal cells (MSC) and vascular-endothelial progenitor cells, available for regenerative therapy without in vitro expansion. One of the problems confronting the therapeutic application of such cells is how to immobilize them at the wound site. Here, we evaluated in vitro the growth and differentiation of human adipose stromal vascular fraction (SVF) cells after delivery using a fibrin spray system. Methods SVF cells were harvested from four human adult patients undergoing elective abdominoplasty using the LipiVage™ system. After collagenase digestion, mesenchymal and endothelial progenitor cells (pericytes, supra-adventitial stromal cells, endothelial progenitors) were quantified by flow cytometry before culture. SVF cells were applied to culture vessels using the Tisseel™ fibrin spray system. SVF cell growth and differentiation was documented by immunofluorescence staining and photomicrography. Results SVF cells remained viable following application and were expanded up to three weeks, when they reached confluence and adipogenic differentiation. Under angiogenic conditions, SVF cells formed endothelial (vWF+, CD31+ and CD34+) tubules surrounded by CD146+ and α-SMA+ perivascular/stromal cells. Discussion Human adipose tissue is a rich source of autologous stem cells, which are readily available for regenerative applications such as wound healing, without in vitro expansion. Our results indicate that mesenchymal and endothelial progenitor cells, prepared in a closed system from unpassaged lipoaspirate samples, retain their growth and differentiation capacity when applied and immobilized on a substrate using a clinically approved fibrin sealant spray system. PMID:23260090

  6. Physical Determinants of Fibrinolysis in Single Fibrin Fibers

    PubMed Central

    Bucay, Igal; O’Brien, E. Tim; Wulfe, Steven D.; Superfine, Richard; Wolberg, Alisa S.; Falvo, Michael R.; Hudson, Nathan E.

    2015-01-01

    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. PMID:25714359

  7. 21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... dissolution of the fibrin in a blood clot) and in monitoring therapy for disseminated intravascular coagulation (nonlocalized clotting in the blood vessels). (b) Classification. Class II (performance standards)....

  8. 21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... dissolution of the fibrin in a blood clot) and in monitoring therapy for disseminated intravascular coagulation (nonlocalized clotting in the blood vessels). (b) Classification. Class II (performance standards)....

  9. 21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... dissolution of the fibrin in a blood clot) and in monitoring therapy for disseminated intravascular coagulation (nonlocalized clotting in the blood vessels). (b) Classification. Class II (performance standards)....

  10. Comparison of the fibrin-binding activities in the N- and C-termini of fibronectin.

    PubMed Central

    Rostagno, A A; Schwarzbauer, J E; Gold, L I

    1999-01-01

    Fibronectin (Fn) binds to fibrin in clots by covalent and non-covalent interactions. The N- and C-termini of Fn each contain one non-covalent fibrin-binding site, which are composed of type 1 (F1) structural repeats. We have previously localized the N-terminal site to the fourth and fifth F1 repeats (4F1.5F1). In the current studies, using proteolytic and recombinant proteins representing both the N- and C-terminal fibrin-binding regions, we localized and characterized the C-terminal fibrin-binding site, compared the relative fibrin-binding activities of both sites and determined the contribution of each site to the fibrin-binding activity of intact Fn. By fibrin-affinity chromatography, a protein composed of the 10F1 repeat through to the C-terminus of Fn (10F1-COOH), expressed in COS-1 cells, and 10F1-12F1, produced in Saccharomyces cerevisiae, displayed fibrin-binding activity. However, since 10F1 and 10F1.11F1 were not active, the presence of 12F1 is required for fibrin binding. A proteolytic fragment of 14.4 kDa, beginning 14 residues N-terminal to 10F1, was isolated from the fibrin-affinity matrix. Radio-iodinated 14.4 kDa fibrin-binding peptide/protein (FBP) demonstrated a dose-dependent and saturable binding to fibrin-coated wells that was both competitively inhibited and reversed by unlabelled 14.4 kDa FBP. Comparison of the fibrin-binding affinities of proteolytic FBPs from the N-terminus (25.9 kDa FBP), the C-terminus (14.4 kDa) and intact Fn by ELISA yielded estimated Kd values of 216, 18 and 2.1 nM, respectively. The higher fibrin-binding affinity of the N-terminus was substantiated by the ability of both a recombinant 4F1.5F1 and a monoclonal antibody (mAb) to this site to maximally inhibit biotinylated Fn binding to fibrin by 80%, and by blocking the 90% inhibitory activity of a polyclonal anti-Fn, by absorption with the 25.9 kDa FBP. We propose that whereas the N-terminal site appears to contribute to most of the binding activity of native Fn to

  11. Optical imaging of fibrin deposition to elucidate participation of mast cells in foreign body responses

    PubMed Central

    Weng, Hong; Tang, Ewin N.; Baker, David W.; Tang, Liping

    2014-01-01

    Mast cell activation has been shown to be an initiator and a key determinant of foreign body reactions. However, there is no non-invasive method that can quantify the degree of implant-associated mast cell activation. Taking advantage of the fact that fibrin deposition is a hallmark of mast cell activation around biomaterial implants, a near infrared probe was fabricated to have high affinity to fibrin. Subsequent in vitro testing confirmed that this probe has high affinity to fibrin. Using a subcutaneous particle implantation model, we found significant accumulation of fibrin-affinity probes at the implant sites as early as 15 min following particle implantation. The accumulation of fibrin-affinity probes at the implantation sites could also be substantially reduced if anti-coagulant – heparin was administered at the implant sites. Further studies have shown that subcutaneous administration of mast cell activator – compound 48/80 – prompted the accumulation of fibrin-affinity probes. However, implant-associated fibrin-affinity probe accumulation was substantially reduced in mice with mast cell deficiency. The results show that our fibrin-affinity probes may serve as a powerful tool to monitor and measure the extent of biomaterial-mediated fibrin deposition and mast cell activation in vivo. PMID:24342726

  12. The potential applications of fibrin-coated electrospun polylactide nanofibers in skin tissue engineering.

    PubMed

    Bacakova, Marketa; Musilkova, Jana; Riedel, Tomas; Stranska, Denisa; Brynda, Eduard; Zaloudkova, Margit; Bacakova, Lucie

    2016-01-01

    Fibrin plays an important role during wound healing and skin regeneration. It is often applied in clinical practice for treatment of skin injuries or as a component of skin substitutes. We prepared electrospun nanofibrous membranes made from poly(l-lactide) modified with a thin fibrin nanocoating. Fibrin surrounded the individual fibers in the membrane and also formed a thin fibrous mesh on several places on the membrane surface. The cell-free fibrin nanocoating remained stable in the cell culture medium for 14 days and did not change its morphology. On membranes populated with human dermal fibroblasts, the rate of fibrin degradation correlated with the degree of cell proliferation. The cell spreading, mitochondrial activity, and cell population density were significantly higher on membranes coated with fibrin than on nonmodified membranes, and this cell performance was further improved by the addition of ascorbic acid in the cell culture medium. Similarly, fibrin stimulated the expression and synthesis of collagen I in human dermal fibroblasts, and this effect was further enhanced by ascorbic acid. The expression of beta1-integrins was also improved by fibrin, and on pure polylactide membranes, it was slightly enhanced by ascorbic acid. In addition, ascorbic acid promoted deposition of collagen I in the form of a fibrous extracellular matrix. Thus, the combination of nanofibrous membranes with a fibrin nanocoating and ascorbic acid seems to be particularly advantageous for skin tissue engineering. PMID:26955273

  13. Immunohistological assessment of fibrin deposition and thrombus formation in canine mammary neoplasia.

    PubMed

    Golombiewski, A; Gutberlet, K; Rudolph, R

    1997-08-01

    A commercially available monoclonal antibody against human fibrin was used to detect fibrin in canine formalin-fixed, paraffin wax-embedded tissue by applying a slightly modified alkaline phosphatase anti-alkaline phosphatase (APAAP) technique. Twenty-eight mammary tumours from six bitches were examined for the presence of fibrin. Thrombi and extravascular fibrin deposits were detected in 15 tumours (12 complex adenocarcinomas, one adenocarcinoma, two solid carcinomas), and a single thrombus was detected in one adenoma; 12 tumours (three adenomas, one complex adenoma, four complex adenocarcinomas and four adenocarcinomas) did not show any staining reaction. PMID:9352443

  14. The potential applications of fibrin-coated electrospun polylactide nanofibers in skin tissue engineering

    PubMed Central

    Bacakova, Marketa; Musilkova, Jana; Riedel, Tomas; Stranska, Denisa; Brynda, Eduard; Zaloudkova, Margit; Bacakova, Lucie

    2016-01-01

    Fibrin plays an important role during wound healing and skin regeneration. It is often applied in clinical practice for treatment of skin injuries or as a component of skin substitutes. We prepared electrospun nanofibrous membranes made from poly(l-lactide) modified with a thin fibrin nanocoating. Fibrin surrounded the individual fibers in the membrane and also formed a thin fibrous mesh on several places on the membrane surface. The cell-free fibrin nanocoating remained stable in the cell culture medium for 14 days and did not change its morphology. On membranes populated with human dermal fibroblasts, the rate of fibrin degradation correlated with the degree of cell proliferation. The cell spreading, mitochondrial activity, and cell population density were significantly higher on membranes coated with fibrin than on nonmodified membranes, and this cell performance was further improved by the addition of ascorbic acid in the cell culture medium. Similarly, fibrin stimulated the expression and synthesis of collagen I in human dermal fibroblasts, and this effect was further enhanced by ascorbic acid. The expression of beta1-integrins was also improved by fibrin, and on pure polylactide membranes, it was slightly enhanced by ascorbic acid. In addition, ascorbic acid promoted deposition of collagen I in the form of a fibrous extracellular matrix. Thus, the combination of nanofibrous membranes with a fibrin nanocoating and ascorbic acid seems to be particularly advantageous for skin tissue engineering. PMID:26955273

  15. The conversion of fibrinogen to fibrin. XIII. Dissolution of fibrin and inhibition of clotting by various neutral salts.

    PubMed

    SHULMAN, S; KATZ, S; FERRY, J D

    1953-07-01

    1. Fibrin clots prepared in the absence of calcium can be dissolved in solutions of lithium chloride and bromide and sodium bromide and iodide, as well as of guanidine hydrochloride and urea. These salts do not denature fibrinogen under the same conditions of concentration, temperature, and time. Sedimentation experiments on the fibrin solutions show in each case a single sharp peak with a sedimentation constant close to that of fibrinogen. 2. At lower concentrations, these salts inhibit the clotting of fibrinogen by thrombin, but in the case of lithium bromide and sodium iodide, at least, allow an intermediate polymer to accumulate whose sedimentation constant is close to that of the polymer observed in systems inhibited by hexamethylene glycol or urea. PMID:13069679

  16. Chondrogenic Regeneration Using Bone Marrow Clots and a Porous Polycaprolactone-Hydroxyapatite Scaffold by Three-Dimensional Printing

    PubMed Central

    Yao, Qingqiang; Wei, Bo; Liu, Nancy; Li, Chenshuang; Guo, Yang; Shamie, Arya Nick; Chen, James; Tang, Cheng; Jin, Chengzhe; Xu, Yan

    2015-01-01

    Scaffolds play an important role in directing three-dimensional (3D) cartilage regeneration. Our recent study reported the potential advantages of bone marrow clots (MC) in promoting extracellular matrix (ECM) scaffold chondrogenic regeneration. The aim of this study is to build a new scaffold for MC, with improved characteristics in mechanics, shaping, and biodegradability, compared to our previous study. To address this issue, this study prepared a 3D porous polycaprolactone (PCL)-hydroxyapatite (HA) scaffold combined with MC (Group A), while the control group (Group B) utilized a bone marrow stem cell seeded PCL-HA scaffold. The results of in vitro cultures and in vivo implantation demonstrated that although an initial obstruction of nutrient exchange caused by large amounts of fibrin and erythrocytes led to a decrease in the ratio of live cells in Group A, these scaffolds also showed significant improvements in cell adhesion, proliferation, and chondrogenic differentiation with porous recanalization in the later culture, compared to Group B. After 4 weeks of in vivo implantation, Group A scaffolds have a superior performance in DNA content, Sox9 and RunX2 expression, cartilage lacuna-like cell and ECM accumulation, when compared to Group B. Furthermore, Group A scaffold size and mechanics were stable during in vitro and in vivo experiments, unlike the scaffolds in our previous study. Our results suggest that the combination with MC proved to be a highly efficient, reliable, and simple new method that improves the biological performance of 3D PCL-HA scaffold. The MC-PCL-HA scaffold is a candidate for future cartilage regeneration studies. PMID:25530453

  17. Chondrogenic regeneration using bone marrow clots and a porous polycaprolactone-hydroxyapatite scaffold by three-dimensional printing.

    PubMed

    Yao, Qingqiang; Wei, Bo; Liu, Nancy; Li, Chenshuang; Guo, Yang; Shamie, Arya Nick; Chen, James; Tang, Cheng; Jin, Chengzhe; Xu, Yan; Bian, Xiuwu; Zhang, Xinli; Wang, Liming

    2015-04-01

    Scaffolds play an important role in directing three-dimensional (3D) cartilage regeneration. Our recent study reported the potential advantages of bone marrow clots (MC) in promoting extracellular matrix (ECM) scaffold chondrogenic regeneration. The aim of this study is to build a new scaffold for MC, with improved characteristics in mechanics, shaping, and biodegradability, compared to our previous study. To address this issue, this study prepared a 3D porous polycaprolactone (PCL)-hydroxyapatite (HA) scaffold combined with MC (Group A), while the control group (Group B) utilized a bone marrow stem cell seeded PCL-HA scaffold. The results of in vitro cultures and in vivo implantation demonstrated that although an initial obstruction of nutrient exchange caused by large amounts of fibrin and erythrocytes led to a decrease in the ratio of live cells in Group A, these scaffolds also showed significant improvements in cell adhesion, proliferation, and chondrogenic differentiation with porous recanalization in the later culture, compared to Group B. After 4 weeks of in vivo implantation, Group A scaffolds have a superior performance in DNA content, Sox9 and RunX2 expression, cartilage lacuna-like cell and ECM accumulation, when compared to Group B. Furthermore, Group A scaffold size and mechanics were stable during in vitro and in vivo experiments, unlike the scaffolds in our previous study. Our results suggest that the combination with MC proved to be a highly efficient, reliable, and simple new method that improves the biological performance of 3D PCL-HA scaffold. The MC-PCL-HA scaffold is a candidate for future cartilage regeneration studies. PMID:25530453

  18. Fibrin gel-immobilized primary osteoblasts in calcium phosphate bone cement: in vivo evaluation with regard to application as injectable biological bone substitute.

    PubMed

    Kneser, U; Voogd, A; Ohnolz, J; Buettner, O; Stangenberg, L; Zhang, Y H; Stark, G B; Schaefer, D J

    2005-01-01

    Osteogenic injectable bone substitutes may be useful for many applications. We developed a novel injectable bone substitute based on osteoblast-fibrin glue suspension and calcium phosphate bone cement (BC). Human osteoblasts were isolated from trabecular bone samples and cultured under standard conditions. Osteoblasts were suspended in fibrinogen solution (FS). BC was cured with thrombin solution. 8 x 4 mm injectable bone discs were prepared using silicon molds and a custom-made applicator device. Discs containing BC, BC/FS, or BC/FS/osteoblasts were implanted subcutaneously into athymic nude mice. After 3, 9 and 24 weeks, specimens were explanted and subjected to morphologic and biomechanical evaluation. In vitro fibrin gel-embedded osteoblasts displayed a differentiated phenotype as evidenced by alkaline phosphatase, collagen type 1 and von Kossa stains. A proportion of osteoblasts appeared morphologically intact over a 3-day in vitro period following application into the BC. BC/FS and BC/FS/osteoblast discs were sparsely infiltrated with vascularized connective tissue. There was no bone formation in implants from all groups. However, positive von Kossa staining only in BC/FS/osteoblast groups suggests engraftment of at least some of the transplanted cells. Biomechanical evaluation demonstrated initial stability of the composites. Young's modulus and maximal load did not differ significantly in the BC/FS and BC/FS/osteoblast groups. The practicability of osteoblast-containing injectable bone could be demonstrated. The dense microstructure and the suboptimal initial vascularization of the composites may explain the lack of bone formation. Modifications with regard to enhanced osteoblast survival are mandatory for a possible application as injectable osteogenic bone replacement system. PMID:16046862

  19. Relative Gain Monitoring of the GlueX Calorimeters

    SciTech Connect

    Anassontzis, Efstratios G.; Kourkoumelis, C.; Vasileiadis, G.; Voulgaris, G.; Kappos, E.; Beattie, T.; Krueger, S.; Lolos, G. J.; Papandreou, Z.; Semenov, A. Yu.; Frye, John M.; Leckey, John P.; Shepherd, Matt; Bogart, T.; Smith, Elton S.

    2014-02-01

    The relative gain of the photodetectors for the GlueX Barrel and Forward calorimeters will be monitored using modular LED driver systems. The BCAL system consists of a global controller that feeds power, bias voltage and trigger signals to 96 local controllers situated at the ends of the 48 BCAL modules, which drive 40 LEDs associated with the 40 light guides at the end of each module. The FCAL system consists also of a global controller, a local controller for each acrylic quadrant covering the face of the FCAL, and ten 4-LED pulser boards per local controller connected in a star configuration along the edges of the acrylic panes. The respective systems are currently being installed on the detectors and their tested performance is presented herein.

  20. Bioorthogonal Click Chemistry-Based Synthetic Cell Glue.

    PubMed

    Koo, Heebeom; Choi, Myunghwan; Kim, Eunha; Hahn, Sei Kwang; Weissleder, Ralph; Yun, Seok Hyun

    2015-12-22

    Artificial methods of cell adhesion can be effective in building functional cell complexes in vitro, but methods for in vivo use are currently lacking. Here, a chemical cell glue based on bioorthogonal click chemistry with high stability and robustness is introduced. Tetrazine (Tz) and trans-cyclooctene (TCO) conjugated to the cell surface form covalent bonds between cells within 10 min in aqueous conditions. Glued, homogeneous, or heterogeneous cell pairs remain viable and stably attached in a microfluidic flow channel at a shear stress of 20 dyn cm(-2) . Upon intravenous injection of assembled Jurkat T cells into live mice, fluorescence microscopy shows the trafficking of cell pairs in circulation and their infiltration into lung tissues. These results demonstrate the promising potential of chemically glued cell pairs for various applications ranging from delivering therapeutic cells to studying cell-cell interactions in vivo. PMID:26768353

  1. Quark and Glue Components of the Proton Spin from Lattice Calculation

    NASA Astrophysics Data System (ADS)

    Liu, Keh-Fei

    2016-02-01

    The status of lattice calculations of the quark spin, the quark orbital angular momentum, the glue angular momentum and glue spin in the nucleon is summarized. The quark spin calculation is recently carried out from the anomalous Ward identity with chiral fermions and is found to be small mainly due to the large negative anomaly term which is believed to be the source of the ‘proton spin crisis’. We also present the first calculation of the glue spin at finite nucleon momenta.

  2. Exact approaches for scaffolding

    PubMed Central

    2015-01-01

    This paper presents new structural and algorithmic results around the scaffolding problem, which occurs prominently in next generation sequencing. The problem can be formalized as an optimization problem on a special graph, the "scaffold graph". We prove that the problem is polynomial if this graph is a tree by providing a dynamic programming algorithm for this case. This algorithm serves as a basis to deduce an exact algorithm for general graphs using a tree decomposition of the input. We explore other structural parameters, proving a linear-size problem kernel with respect to the size of a feedback-edge set on a restricted version of Scaffolding. Finally, we examine some parameters of scaffold graphs, which are based on real-world genomes, revealing that the feedback edge set is significantly smaller than the input size. PMID:26451725

  3. Increased fibrin formation and impaired fibrinolytic capacity in severe chronic kidney disease.

    PubMed

    Mörtberg, Josefin; Blombäck, Margareta; Wallén, Åkan; He, Shu; Jacobson, Stefan H; Spaak, Jonas

    2016-06-01

    Chronic kidney disease (CKD) is associated with a concurrent increased risk of thrombosis and bleeding. We aimed to investigate whether CKD is associated with increased fibrin formation, impaired fibrin degradation, or both. Twenty-one patients with CKD stage 4 (CKD 4), 15 haemodialysis patients, and 13 controls (C) without kidney disease were studied. We used a global assay to determine fibrin formation and degradation in plasma. Fibrin turbidity was measured over time to obtain a value of the coagulation activation profile (Cp) and the fibrinolysis activation profile (Fp), and the amount of fibrin formed, termed fibrin optical density sum (fibrin OD-sum). We used scanning electron microscopy (SEM) to visualize the fibrin network. Plasminogen activator inhibitor type-1 antigen, thrombin-activatable fibrinolysis inhibitor activity, fibrinogen, von Willebrand factor, antithrombin, albumin, and C-reactive protein were measured in plasma. Fibrin OD-sum was significantly elevated in haemodialysis patients [312 a.u.; 278-435 (median; interquartile range); P < 0.0013] and in CKD 4 (293 a.u.; 169-434; P = 0.0119) compared with controls (115 a.u.; 82-234). SEM showed a tight fibrin network in haemodialysis and CKD 4 patients. Fp was lower in the haemodialysis group than in controls (P = 0.030). Plasminogen activator inhibitor type-1 was lower in haemodialysis patients (P = 0.034). Thrombin-activatable fibrinolysis inhibitor activity, Cp, antithrombin, and C-reactive protein did not differ between groups. Fibrinogen was significantly elevated and albumin decreased in both haemodialysis and CKD 4 patients compared with controls. Von Willebrand factor was elevated in haemodialysis patients compared with controls (P = 0.010). The prothrombotic state in severe CKD is characterized by impaired fibrinolysis in association with increased fibrin formation despite normal levels of endogenous fibrinolysis inhibitors. PMID:26650459

  4. Acoustic droplet–hydrogel composites for spatial and temporal control of growth factor delivery and scaffold stiffness

    PubMed Central

    Fabiilli, Mario L.; Wilson, Christopher G.; Padilla, Frédéric; Martín-Saavedra, Francisco M.; Fowlkes, J. Brian; Franceschi, Renny T.

    2013-01-01

    Wound healing is regulated by temporally and spatially restricted patterns of growth factor signaling, but there are few delivery vehicles capable of the “on-demand” release necessary for recapitulating these patterns. Recently we described a perfluorocarbon double emulsion that selectively releases a protein payload upon exposure to ultrasound through a process known as acoustic droplet vaporization (ADV). In this study, we describe a delivery system composed of fibrin hydrogels doped with growth factor-loaded double emulsion for applications in tissue regeneration. Release of immunoreactive basic fibroblast growth factor (bFGF) from the composites increased up to 5-fold following ADV and delayed release was achieved by delaying exposure to ultrasound. Releasates of ultrasound-treated materials significantly increased the proliferation of endothelial cells compared to sham controls, indicating that the released bFGF was bioactive. ADV also triggered changes in the ultrastructure and mechanical properties of the fibrin as bubble formation and consolidation of the fibrin in ultrasound-treated composites were accompanied by up to a 22-fold increase in shear stiffness. ADV did not reduce the viability of cells suspended in composite scaffolds. These results demonstrate that an acoustic droplet–hydrogel composite could have broad utility in promoting wound healing through on-demand control of growth factor release and/or scaffold architecture. PMID:23535233

  5. Viscoelastic, physical, and bio-degradable properties of dermal scaffolds and related cell behaviour.

    PubMed

    Sharma, Vaibhav; Patel, Nimesha; Kohli, Nupur; Ravindran, Nivedita; Hook, Lilian; Mason, Chris; García-Gareta, Elena

    2016-01-01

    Dermal scaffolds promote healing of debilitating skin injuries caused by burns and chronic skin conditions. Currently available products present disadvantages and therefore, there is still a clinical need for developing new dermal substitutes. This study aimed at comparing the viscoelastic, physical and bio-degradable properties of two dermal scaffolds, the collagen-based and clinically well established Integra(®) and a novel fibrin-based dermal scaffold developed at our laboratory called Smart Matrix(®), to further evaluate our previous published findings that suggested a higher influx of cells, reduced wound contraction and less scarring for Smart Matrix(®) when used in vivo. Rheological results showed that Integra(®) (G'  =  313.74 kPa) is mechanically stronger than Smart Matrix(®) (G'  =  8.26 kPa), due to the presence of the silicone backing layer in Integra(®). Micro-pores were observed on both dermal scaffolds, although nano-pores as well as densely packed nano-fibres were only observed for Smart Matrix(®). Average surface roughness was higher for Smart Matrix(®) (Sa  =  114.776 nm) than for Integra(®) (Sa  =  75.565 nm). Both scaffolds possess a highly porous structure (80-90%) and display a range of pore micro-sizes that represent the actual in vivo scenario. In vitro proteolytic bio-degradation suggested that Smart Matrix(®) would degrade faster upon implantation in vivo than Integra(®). For both scaffolds, the enzymatic digestion occurs via bulk degradation. These observed differences could affect cell behaviour on both scaffolds. Our results suggest that fine-tuning of scaffolds' viscoelastic, physical and bio-degradable properties can maximise cell behaviour in terms of attachment, proliferation and infiltration, which are essential for tissue repair. PMID:27586397

  6. Scaffolds in Tendon Tissue Engineering

    PubMed Central

    Longo, Umile Giuseppe; Lamberti, Alfredo; Petrillo, Stefano; Maffulli, Nicola; Denaro, Vincenzo

    2012-01-01

    Tissue engineering techniques using novel scaffold materials offer potential alternatives for managing tendon disorders. Tissue engineering strategies to improve tendon repair healing include the use of scaffolds, growth factors, cell seeding, or a combination of these approaches. Scaffolds have been the most common strategy investigated to date. Available scaffolds for tendon repair include both biological scaffolds, obtained from mammalian tissues, and synthetic scaffolds, manufactured from chemical compounds. Preliminary studies support the idea that scaffolds can provide an alternative for tendon augmentation with an enormous therapeutic potential. However, available data are lacking to allow definitive conclusion on the use of scaffolds for tendon augmentation. We review the current basic science and clinical understanding in the field of scaffolds and tissue engineering for tendon repair. PMID:22190961

  7. Magnetic resonance profiling studies of the drying of film-forming aqueous dispersions and glue layers.

    PubMed

    Bennett, G; Gorce, J-P; Keddie, J L; McDonald, P J; Berglind, H

    2003-01-01

    We report magnetic resonance profiling experiments to monitor (i) the drying of alkyd emulsion layers, (ii) the cure of wood glue layers and (iii) water transport through glue lines. The alkyd drying is a two stage process. We report new results which support previous evidence that the alkyd drops do not coalesce until the water fraction is below circa 0.02. The profiles recorded from glue layers suggest that MR is a sensitive probe of the curing process and barrier properties of the glue. The measurements were made using GARField (stray field, STRAFI like) magnetic resonance profiling and an improved GARField magnet design characterized by two values of the gradient-to-field strength ratio at two locations offering the same field strength is also reported. PMID:12850713

  8. Event based uncertainty assessment in urban drainage modelling, applying the GLUE methodology

    NASA Astrophysics Data System (ADS)

    Thorndahl, S.; Beven, K. J.; Jensen, J. B.; Schaarup-Jensen, K.

    2008-08-01

    SummaryIn the present paper an uncertainty analysis on an application of the commercial urban drainage model MOUSE is conducted. Applying the Generalized Likelihood Uncertainty Estimation (GLUE) methodology the model is conditioned on observation time series from two flow gauges as well as the occurrence of combined sewer overflow. The GLUE methodology is used to test different conceptual setups in order to determine if one model setup gives a better goodness of fit conditional on the observations than the other. Moreover, different methodological investigations of GLUE are conducted in order to test if the uncertainty analysis is unambiguous. It is shown that the GLUE methodology is very applicable in uncertainty analysis of this application of an urban drainage model, although it was shown to be quite difficult to get good fits of the whole time series.

  9. Nonlinear temperature dependence of glue-induced birefringence in polarization maintaining FBG sensors

    NASA Astrophysics Data System (ADS)

    Hopf, Barbara; Koch, Alexander W.; Roths, Johannes

    2016-05-01

    Glue-induced stresses decrease the accuracy of surface-mounted fiber Bragg gratings (FBG). Significant temperature dependent glue-induced birefringence was verified when a thermally cured epoxy-based bonding technique had been used. Determining the peak separation of two azimuthally aligned FBGs in PM fibers combined with a polarization resolved measurement set-up in a temperature range between -30°C and 150°C revealed high glue-induced stresses at low temperatures. Peak separations of about 60 pm and a nonlinear temperature dependence of the glue-induced birefringence due to stress relaxation processes and a visco-elastic behavior of the used adhesive have been shown.

  10. 21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Fibrinogen/fibrin degradation products assay. 864.7320 Section 864.7320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7320 Fibrinogen/fibrin degradation...

  11. 21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Fibrinogen/fibrin degradation products assay. 864.7320 Section 864.7320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7320 Fibrinogen/fibrin degradation...

  12. Modification of fibrin network ultrastructure by Fab fragments specific for different domain of fibrinogen.

    PubMed

    Cierniewski, C S; Janiak, A; Wyroba, E

    1986-01-01

    Kinetics of inhibition of fibrin monomer polymerization produced by Fab fragments prepared from immunochemically purified monospecific antibodies to the surface epitopes of different domains of fibrinogen molecule has been correlated with electron microscopic observations of resulting specimens. Fab fragments prepared from anti FgD antisera were the most efficient inhibitors of thrombin-catalysed conversion of fibrinogen to fibrin; polymerization of fibrin monomers as detected spectrophotometrically was abolished at 2:1 molar ratio of anti FgD Fab fragments to fibra monomer. These Fab fragments acting as a steric hindrance of polymerization sites inhibited the first stage of fibrin monomer aggregation. Interaction of Fab fragments derived from antibodies specific for alpha 239-476 with corresponding segment of fibrinogen molecule resulted in a weak inhibition of fibrin monomer polymerization. However, fibrin obtained in the presence of these Fab fragments was significantly modified and showed no periodicity. This observation may suggest that anti alpha 239-476 Fab impaired the course of the second stage of fibrin monomer polymerization, i.e. lateral association of fibrin fibrils. PMID:2433859

  13. Simultaneous measurement of thrombin generation and fibrin formation in whole blood under flow conditions.

    PubMed

    Kelchtermans, Hilde; Pelkmans, Leonie; Bouwhuis, Anne; Schurgers, Evelien; Lindhout, Theo; Huskens, Dana; Miszta, Adam; Hemker, H Coenraad; Lancé, Marcus D; de Laat, Bas

    2016-07-01

    Assays based on the formation of thrombin and fibrin are frequently used, and results are considered exchangeable in research/clinical settings. However, thrombin generation and fibrin formation do not always go hand in hand and flow profoundly influences thrombus formation. We describe the technical/clinical evaluation of an assay to simultaneously measure thrombin generation and fibrin formation under conditions of flow. Introduction of a fluorometer into a 'cone and base principle'-based rheometer allowed the measurement of thrombin generation (using a thrombin-sensitive substrate) and fibrin formation (changes in viscosity), while applying a linear shear flow. Increasing shear rates inversely related with thrombin generation and fibrin formation. Increasing fibrinogen concentrations in defibrinated plasma resulted in increased thrombin generation and fibrin formation. In pre-operative samples of 70 patients undergoing cardiothoracic surgery, fibrin formation and thrombin generation parameters correlated with fibrinogen content, rotational thromboelastometry (ROTEM) and whole blood Calibrated Automated Thrombinography (CAT) parameters, respectively. Upon dividing patients into two groups based on the median clot strength, a significant difference in perioperative/total blood loss was established. In conclusion, we clinically evaluated a method capable of simultaneously measuring thrombin generation and fibrin formation in plasma/whole blood under continuous flow, rendering our method one step closer to physiology. Importantly, our test proved to be indicative for the amount of blood loss during/after cardiothoracic surgery. PMID:27074907

  14. Role of fibrinopeptide B release: comparison of fibrins produced by thrombin and Ancrod.

    PubMed

    Shen, L L; Hermans, J; McDonagh, J; McDonagh, R P

    1977-06-01

    The gelation time, opacity, light scattering, and elastic moduli of human fibrin gels clotted in the presence of thrombin, Ancrod, and Reptilase have been compared. At low ionic strength lateral association to thick fibers is observed in all cases. At all ionic strengths thrombin fibrin forms thicker fibers than does Ancrod fibrin. We have demonstrated that an increase in the extent of lateral association is linked to an increase in its velocity and to a decrease in the gelation time. One may consider the removal of fibrinopeptide B to act as a switch: after it is removed fibrin assembles rapidly to thick fibers and gelation is fast; but when this peptide is still attached, there is a slow assembly of thin fibers, and gelation, especially of dilute fibrin, is delayed. We believe that this delay is critical for the complete digestion by plasmin of fibrin formed during in vivo defibrination with Ancrod and of fibrin produced by very small amounts of thrombin (which would still contain fibrinopeptide B), and that slow release of fibrinopeptide B is part of a control mechanism for the regulation of fibrin formation and the prevention of intravascular coagulation. PMID:879301

  15. Aprotinin extends mechanical integrity time of cell-seeded fibrin sutures.

    PubMed

    Coffin, Spencer T; Gaudette, Glenn R

    2016-09-01

    Cell therapy has the potential to treat different pathologies, including myocardial infarctions (heart attacks), although cell engraftment remains elusive with most delivery methods. Biological sutures composed of fibrin have been shown to effectively deliver human mesenchymal stem cell (MSC) to infarcted hearts. However, human MSCs rapidly degrade fibrin making cell seeding and delivery time sensitive. To delay the degradation process, we propose using Aprotinin, a proteolytic enzyme inhibitor that has been shown to slow fibrinolysis. Human MSCs seeded on fibrin sutures and incubated with Aprotinin demonstrated similar cell viability, examined using a LIVE/DEAD stain, to controls. No differences in proliferation, as determined by Ki-67 presence, were observed. Human MSCs incubated in Aprotinin differentiated into adipocytes, osteocytes, and chondrocytes, confirming multipotency. The number of cells adhered to fibrin sutures increased through Aprotinin supplementation at 2, 3, and 5 day time points. Uniaxial tensile testing was used to examine the effect of Aprotinin on suture integrity. Sutures exposed to Aprotinin had higher ultimate tensile strength and modulus when compared to sutures exposed to standard growth media. Fibrin sutures incubated in Aprotinin had larger diameters and less fibrin degradation products compared to the controls, confirming decreased fibrinolysis. These data suggest that Aprotinin can reduce degradation of fibrin sutures without significant effects on MSC function, providing a novel method for extending the implantation window and increasing the number of cells delivered via fibrin sutures. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2271-2279, 2016. PMID:27101153

  16. Influence of a constant magnetic field on the fibrinogen-fibrin system. [in blood coagulation process

    NASA Technical Reports Server (NTRS)

    Matskevichene, V. B.; Platonova, A. T.

    1974-01-01

    The effect of a constant magnetic field with a strength of 2500 oersteds on the fibrinogen-fibrin system was studied in the organism of healthy rabbits with exposure times of 1 and 5 hours. The results obtained indicate disruptions in the stage of conversion of fibrinogen to fibrin and an increase in the amount of fibrinogen.

  17. Protein unfolding accounts for the unusual mechanical behavior of fibrin networks

    PubMed Central

    Purohit, Prashant K.; Litvinov, Rustem I.; Brown, Andre E. X.; Discher, Dennis E.; Weisel, John W.

    2011-01-01

    We describe the mechanical behavior of isotropic fibrin networks at the macroscopic scale in terms of the nanoscale force response of fibrin molecules that are its basic building blocks. We show that the remarkable extensibility and compressibility of fibrin networks have their origins in the unfolding of fibrin molecules. The force-stretch behavior of a single fibrin fiber is described using a two-state model in which the fiber has a linear force-stretch relation in the folded phase and behaves like a worm-like-chain in the unfolded phase. The nanoscale force-stretch response is connected to the macro-scale stress-stretch response by means of the eight-chain model. This model is able to capture the macroscopic response of a fibrin network in uniaxial tension and appears remarkably simple given the molecular complexity. We use the eight-chain model to explain why fibrin networks have negative compressibility and Poisson’s ratio greater than one due to unfolding of fibrin molecules. PMID:21342665

  18. Optimizing a spontaneously contracting heart tissue patch with rat neonatal cardiac cells on fibrin gel

    PubMed Central

    Tao, Ze-Wei; Mohamed, Mohamed; Hogan, Matthew; Gutierrez, Laura; Birla, Ravi K.

    2014-01-01

    Engineered cardiac tissues have been constructed with primary or stem cell-derived cardiac cells on natural or synthetic scaffolds. They represent a tremendous potential for treatment of injured areas through addition of tensional support and delivery of sufficient cells. In this study 1 to 6 million (M) neonatal cardiac cells were seeded on fibrin gels to fabricate cardiac tissue patches, and the effects of culture time and cell density on spontaneous contraction rates, twitch forces and paced response frequencies were measured. Electrocardiograms and signal volume index of connexin 43 were also analyzed. Patches of 1–6M cell densities exhibited maximal contraction rates between 305–410 bpm within the first 4 days after plating; low cell densities (1–3M) patches sustained rhythmic contraction longer than high cell densities (4–6M). Patches with 1–6 M cell densities generated contractile forces in the range 2.245–14.065 mN/mm3 on days 4–6. Upon patch formation, a paced response frequency of approximately 6 Hz was obtained, and decreased to approximately 3 Hz after 6 days of culture. High cell density patches contained a thicker real cardiac tissue layer which generated higher R wave amplitudes; however, low density patches had a greater signal volume index of connexin 43. In addition, all patches manifested endothelial cell growth and robust nuclear division. The present study demonstrates that the proper time for in vivo implantation of this cardiac construct is just at patch formation and patches with 3–4M cell densities are the best candidates. PMID:24771636

  19. Double Coaxial Microcatheter Technique for Glue Embolization of Renal Arteriovenous Malformations

    SciTech Connect

    Uchikawa, Yoko; Mori, Kensaku; Shiigai, Masanari; Konishi, Takahiro; Hoshiai, Sodai; Ishigro, Toshitaka Hiyama, Takashi; Nakai, Yasunobu; Minami, Manabu

    2015-10-15

    PurposeTo demonstrate the technical benefit of the double coaxial microcatheter technique for embolization of renal arteriovenous malformations (AVMs) with n-butyl cyanoacrylate and iodized oil (glue).Materials and MethodsSix consecutive patients (1 man and 5 women; mean age 61 years; range 44–77 years) with renal AVMs were included. Five patients had hematuria, and one had a risk of heart failure due to a large intrarenal arteriovenous shunt. All patients underwent transarterial embolization using glue and the double coaxial microcatheter technique with outer 2.6F and inner 1.9F microcatheters. After glue injection, the inner microcatheter was retracted, while the outer microcatheter was retained. We assessed the complications and clinical outcomes of this technique.ResultsTechnical success was achieved in all patients. In 9 sessions, 34 feeding arteries were embolized with glue using the double coaxial microcatheter technique, 1 was embolized with glue using a single microcatheter, and 2 were embolized with coils. The double coaxial microcatheter technique was useful for selecting small tortuous feeding arteries, preventing glue reflux to the proximal arteries, and approaching multiple feeding arteries without complete retraction of the microcatheters. As a minor complication, glue migrated into the venous system in four patients without any sequelae. In all patients, favorable clinical outcomes, including hematuria cessation in five patients and improvement of the large intrarenal arteriovenous shunt in one patient, were obtained without deterioration of renal function.ConclusionGlue embolization with the double coaxial microcatheter technique was useful for treating renal AVMs with multiple tortuous feeding arteries.

  20. The presence of γ’ chain impairs fibrin polymerization

    PubMed Central

    Gersh, Kathryn C.; Nagaswami, Chandrasekaran; Weisel, John W.; Lord, Susan T.

    2009-01-01

    Introduction A fraction of fibrinogen molecules contain an alternatively spliced variant chain called γ’. Plasma levels of this variant have been associated with both myocardial infarction and venous thrombosis. Because clot structure has been associated with cardiovascular risk, we examined the effect of γ’ chain on clot structure. Materials and Methods We expressed three fibrinogen variants in Chinese hamster ovary (CHO) cells: γ/γ homodimer, γ/γ’ heterodimer, and γ’/γ’ homodimer. We observed thrombin-catalyzed fibrinopeptide release by HPLC, fibrin polymerization by turbidity, and clot structure by scanning electron microscopy. We characterized post-translational modifications by mass spectrometry. Results Fibrinopeptide A was released at the same rate for all three fibrinogens, while fibrinopeptide B was released faster from the γ’/γ’ homodimer. The rise in turbidity was slower and final absorbance was lower during polymerization of γ’-containing fibrinogens than for γ/γ fibrinogen. Micrographs showed that γ’/γ’ fibrin clots are composed of very thin fibers, while the diameter of γ/γ’ fibers is similar to γ/γ fibers. Further, the fiber networks formed from γ’-containing samples were non-uniform. Mass spectrometry showed heterogeneous addition of N-glycans and tyrosine sulfation in the γ’ chain. Conclusions The presence of γ’ chains slows lateral aggregation and alters fibrin structure. We suggest these changes are likely due to charge-charge repulsion, such that polymerization of the γ’/γ’ homodimer is more impaired than the heterodimer since these repulsions are partially offset by incorporation of γ chains in the γ/γ’ heterodimer. PMID:19138790

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

    NASA Astrophysics Data System (ADS)

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

    2012-11-01

    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 there is turnover of fibrin in an uncrosslinked clot. A peptide representing the knobs involved in fibrin polymerization can compete for the holes and dissolve a preformed fibrin clot, or increase the fraction of soluble oligomers, with striking rearrangements in clot structure. These results imply that in vivo clots or thrombi are more dynamic structures than previously believed that may be remodeled as a result of local environmental conditions, may account for some embolization, and suggest a target for therapeutic intervention.

  2. Transurethral Use of Evicel® Fibrin Sealant

    PubMed Central

    Masel, Jonathan L.

    2015-01-01

    Transurethral resection of bladder tumor remains the most common procedure for the diagnosis, management, and treatment of bladder cancer. Deep resection of the detrusor muscle for the correct staging of bladder cancer can increase the risk of hemorrhage that can be difficult to control with standard transurethral surgical maneuvers. Evicel® Fibrin Sealant was applied transurethrally to manage difficult hemorrhage following transurethral resection of bladder tumor in two surgically complex bladder cancer patients. Our early experience suggests Evicel® can be an effective tool in managing difficult to control hemorrhage associated with TURBT. Further clinical investigation is to be encouraged. PMID:26793564

  3. Fibrinous anterior uveitis following laser in situ keratomileusis.

    PubMed

    Parmar, Pragya; Salman, Amjad; Rajmohan, M; Jesudasan, Nelson C A

    2009-01-01

    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. PMID:19574707

  4. Platelet-rich fibrin application in dentistry: a literature review

    PubMed Central

    Borie, Eduardo; Oliví, Daniel García; Orsi, Iara Augusta; Garlet, Katia; Weber, Benjamín; Beltrán, Víctor; Fuentes, Ramón

    2015-01-01

    The development of bioactive surgical additives to regulate the inflammation and increase the speed of healing process is one of the great challenges in clinical research. In this sense, platelet rich fibrin (PRF) appears as a natural and satisfactory alternative with favorable results and low risks. The following review attempts to summarize the relevant literature regarding the technique of using PRF, focusing on its preparation, advantages, and disadvantages of using it in clinical applications. PRF alone or in combination with other biomaterials seems to have several advantages and indications both for medicine and dentistry, due it is a minimally invasive technique with low risks and satisfactory clinical results. PMID:26221349

  5. Evidence from Multiple Species that Spider Silk Glue Component ASG2 is a Spidroin.

    PubMed

    Collin, Matthew A; Clarke, Thomas H; Ayoub, Nadia A; Hayashi, Cheryl Y

    2016-01-01

    Spiders in the superfamily Araneoidea produce viscous glue from aggregate silk glands. Aggregate glue coats prey-capture threads and hampers the escape of prey from webs, thereby increasing the foraging success of spiders. cDNAs for Aggregate Spider Glue 1 (ASG1) and 2 (ASG2) have been previously described from the golden orb-weaver, Nephila clavipes, and Western black widow, Latrodectus hesperus. To further investigate aggregate glues, we assembled ASG1 and ASG2 from genomic target capture libraries constructed from three species of cob-web weavers and three species of orb-web weavers, all araneoids. We show that ASG1 is unlikely to be a glue, but rather is part of a widespread arthropod gene family, the peritrophic matrix proteins. For ASG2, we demonstrate its remarkable architectural and sequence similarities to spider silk fibroins, indicating that ASG2 is a member of the spidroin gene family. Thus, spidroins have diversified into glues in addition to task-specific, high performance fibers. PMID:26875681

  6. Dynamics of spider glue adhesion: effect of surface energy and contact area

    NASA Astrophysics Data System (ADS)

    Amarpuri, Gaurav; Chen, Yizhou; Blackledge, Todd; Dhinojwala, Ali

    Spider glue is a unique biological adhesive which is humidity responsive such that the adhesion continues to increase upto 100% relative humidity (RH) for some species. This is unlike synthetic adhesives that significantly drop in adhesion with an increase in humidity. However, most of adhesion data reported in literature have used clean hydrophilic glass substrate, unlike the hydrophobic, and charged insect cuticle surface that adheres to spider glue in nature. Previously, we have reported that the spider glue viscosity changes over five orders of magnitude with humidity. Here, we vary the surface energy and surface charge of the substrate to test the change in Larnioides cornutus spider glue adhesion with humidity. We find that an increase in both surface energy and surface charge density increases the droplet spreading and there exists an optimum droplet contact area where adhesion is maximized. Moreover, spider glue droplets act as reusable adhesive for low energy hydrophobic surface at the optimum humidity. These results explain why certain prey are caught more efficiently by spiders in their habitat. The mechanism by which spider species tune its glue adhesion for local prey capture can inspire new generation smart adhesives.

  7. Evidence from Multiple Species that Spider Silk Glue Component ASG2 is a Spidroin

    PubMed Central

    Collin, Matthew A.; Clarke, Thomas H.; Ayoub, Nadia A.; Hayashi, Cheryl Y.

    2016-01-01

    Spiders in the superfamily Araneoidea produce viscous glue from aggregate silk glands. Aggregate glue coats prey-capture threads and hampers the escape of prey from webs, thereby increasing the foraging success of spiders. cDNAs for Aggregate Spider Glue 1 (ASG1) and 2 (ASG2) have been previously described from the golden orb-weaver, Nephila clavipes, and Western black widow, Latrodectus hesperus. To further investigate aggregate glues, we assembled ASG1 and ASG2 from genomic target capture libraries constructed from three species of cob-web weavers and three species of orb-web weavers, all araneoids. We show that ASG1 is unlikely to be a glue, but rather is part of a widespread arthropod gene family, the peritrophic matrix proteins. For ASG2, we demonstrate its remarkable architectural and sequence similarities to spider silk fibroins, indicating that ASG2 is a member of the spidroin gene family. Thus, spidroins have diversified into glues in addition to task-specific, high performance fibers. PMID:26875681

  8. Systems level approach reveals the correlation of endoderm differentiation of mouse embryonic stem cells with specific microstructural cues of fibrin gels

    PubMed Central

    Task, Keith; D'Amore, Antonio; Singh, Satish; Candiello, Joe; Jaramillo, Maria; Wagner, William R.; Kumta, Prashant; Banerjee, Ipsita

    2014-01-01

    Stem cells receive numerous cues from their associated substrate that help to govern their behaviour. However, identification of influential substrate characteristics poses difficulties because of their complex nature. In this study, we developed an integrated experimental and systems level modelling approach to investigate and identify specific substrate features influencing differentiation of mouse embryonic stem cells (mESCs) on a model fibrous substrate, fibrin. We synthesized a range of fibrin gels by varying fibrinogen and thrombin concentrations, which led to a range of substrate stiffness and microstructure. mESCs were cultured on each of these gels, and characterization of the differentiated cells revealed a strong influence of substrate modulation on gene expression patterning. To identify specific substrate features influencing differentiation, the substrate microstructure was quantified by image analysis and correlated with stem cell gene expression patterns using a statistical model. Significant correlations were observed between differentiation and microstructure features, specifically fibre alignment. Furthermore, this relationship occurred in a lineage-specific manner towards endoderm. This systems level approach allows for identification of specific substrate features from a complex material which are influential to cellular behaviour. Such analysis may be effective in guiding the design of scaffolds with specific properties for tissue engineering applications. PMID:24718448

  9. Implantable arterial grafts from human fibroblasts and fibrin using a multi-graft pulsed flow-stretch bioreactor with noninvasive strength monitoring

    PubMed Central

    Syedain, Zeeshan H.; Meier, Lee A.; Bjork, Jason W.; Lee, Ann; Tranquillo, Robert T.

    2011-01-01

    Tissue-engineered arteries based on entrapment of human dermal fibroblasts in fibrin gel yield completely biological vascular grafts that possess circumferential alignment characteristic of native arteries and essential to their mechanical properties. A bioreactor was developed to condition six grafts in the same culture medium while being subjected to similar cyclic distension and transmural flow resulting from pulsed flow distributed among the graft lumens via a manifold. The lumenal pressure and circumferential stretch were noninvasively monitored and used to calculate stiffness in the range of 80-120 mmHg and then to successfully predict graft burst strength. The length of the graft was incrementally shortened during bioreactor culture to maintain circumferential alignment and achieve mechanical anisotropy comparable to native arteries. After 7-9 weeks of bioreactor culture, the fibrin-based grafts were extensively remodeled by the fibroblasts into circumferentially-aligned tubes of collagen and other extracellular matrix with burst pressures in the range of 1400-1600 mmHg and compliance comparable to native arteries. The tissue suture retention force was also suitable for implantation in the rat model and, with poly(lactic acid) sewing rings entrapped at both ends of the graft, also in the ovine model. The strength achieved with a biological scaffold in such a short duration is unprecedented for an engineered artery. PMID:20934214

  10. Effects of a fibrin-fibronectin sealing system on proliferation and type I collagen synthesis of human PDL fibroblasts in vitro.

    PubMed

    Fabris, G; Trombelli, L; Schincaglia, G P; Cavallini, R; Calura, G; del Senno, L

    1998-01-01

    Fibrin glue (FG) is an agent widely used in many surgical disciplines for achieving hemostasis and tissue adhesion. The aim of this investigation was to determine the effectiveness of a highly concentrated FG (Tissucol) on the growth and phenotypic expression of human periodontal ligament (PDL) fibroblasts. PDL fibroblast strains were established from cells scraped from PDL, and cultured in the presence and absence of FG for 48 and 72 h. Cell proliferation was studied by counting cells and mitoses, and by immunocytochemical detection of the proliferation-associated Ki-67 nuclear antigen. Type-I collagen production was assessed by radioimmunological assay of the procollagen C-terminal peptide. Results showed that FG treatment was compatible with PDL fibroblast growth and type-I collagen synthesis, although a reduced trend in cell proliferation and collagen production was found in FG-supplemented cultures compared to control cultures. We conclude that FG may represent a suitable substrate for supporting PDL fibroblast growth and function. PMID:9477014

  11. Fibrin solubilizing properties of certain anionic and cationic detergents.

    PubMed

    Chakrabarty, S

    1989-08-15

    The fibrinolytic (fibrin dissolving) properties of several anionic, cationic, nonionic and zwitterionic detergents were assessed in an in vitro fibrin agarose assay. Of the 4 anionic detergents tested, only sodium dodecyl sulfate (SDS) was found to be fibrinolytic. SDS was fibrinolytic either in the absence or presence of factor XIII. Four other cationic detergents were found to possess similar fibrinolytic properties. These cationic detergents were cetyltrimethylammonium bromide (CTAB), mix alkyltrimethyl ammonium bromide (MTAB), hexadecyltrimethylammonium bromide (HTAB) and cetylpyridium chloride (CPC). The nonionic (digitonin, triton X-100/tween 20) and zeitterionic (CHAPS, zeittergent 3-08) detergents were not fibrinolytic. Detergents mediated fibrinolysis, unlike that of tissue type plasminogen activator and urokinase, was independent of the presence of plasminogen. Non-detergents such as polyethylene glycol and highly charged compounds such as poly-1-lysine and poly-1-glutamic acid were not fibrinolytic. Fibrinolytic activity was observed for SDS and the cationic detergents at concentrations ranging from 0.1-10 percent. The effects of these fibrinolytic detergents (SDS, CTAB, MTAB, HTAB and CPC) on clot formation and on pre-formed clots were then assessed, using freshly drawn human venous blood. Incorporation of these detergents into blood inhibited the formation of clots in a concentration dependent manner. The detergents were also able to dissolve pre-formed clots in a similar fashion. SDS was found to be most potent in these properties. PMID:2510356

  12. Soft fibrin gels promote selection and growth of tumorigenic cells

    NASA Astrophysics Data System (ADS)

    Liu, Jing; Tan, Youhua; Zhang, Huafeng; Zhang, Yi; Xu, Pingwei; Chen, Junwei; Poh, Yeh-Chuin; Tang, Ke; Wang, Ning; Huang, Bo

    2012-08-01

    The identification of stem-cell-like cancer cells through conventional methods that depend on stem cell markers is often unreliable. We developed a mechanical method for selecting tumorigenic cells by culturing single cancer cells in fibrin matrices of ~100 Pa in stiffness. When cultured within these gels, primary human cancer cells or single cancer cells from mouse or human cancer cell lines grew within a few days into individual round colonies that resembled embryonic stem cell colonies. Subcutaneous or intravenous injection of 10 or 100 fibrin-cultured cells in syngeneic or severe combined immunodeficiency mice led to the formation of solid tumours at the site of injection or at the distant lung organ much more efficiently than control cancer cells selected using conventional surface marker methods or cultured on conventional rigid dishes or on soft gels. Remarkably, as few as ten such cells were able to survive and form tumours in the lungs of wild-type non-syngeneic mice.

  13. Migration of keratinocytes through tunnels of digested fibrin

    NASA Astrophysics Data System (ADS)

    Ronfard, Vincent; Barrandon, Yann

    2001-04-01

    We report here a hitherto undescribed form of cell migration. When a suspension of human keratinocytes is plated on a fibrin matrix, single cells invade the matrix and progress through it as rounded cells by dissolving the fibrin and thereby creating tunnels. These tunnels are cylindrical or helical, the latter being the result of constant change in the path of cellular advance around the helical axis. Helical tunnel formation is strongly promoted by epidermal growth factor. The rate of migration of the cell through the track of a helical tunnel (up to 2.1 mm per day) is about 7-fold greater than through a cylindrical tunnel. Pericellular fibrinolysis leading to tunnel formation depends on the presence of plasminogen in the medium and its conversion to plasmin by a cellular activator. Formation of tunnels requires that plasminogen activator be localized on the advancing surface of the keratinocyte; we propose that the tunnel is cylindrical when the site of release of plasmin is located at a fixed point on the cell surface and helical when the site of release precesses.

  14. Biomimetic Scaffolds for Osteogenesis

    PubMed Central

    Yuan, Nance; Rezzadeh, Kameron S.; Lee, Justine C.

    2015-01-01

    Skeletal regenerative medicine emerged as a field of investigation to address large osseous deficiencies secondary to congenital, traumatic, and post-oncologic conditions. Although autologous bone grafts have been the gold standard for reconstruction of skeletal defects, donor site morbidity remains a significant limitation. To address these limitations, contemporary bone tissue engineering research aims to target delivery of osteogenic cells and growth factors in a defined three dimensional space using scaffolding material. Using bone as a template, biomimetic strategies in scaffold engineering unite organic and inorganic components in an optimal configuration to both support osteoinduction as well as osteoconduction. This article reviews the various structural and functional considerations behind the development of effective biomimetic scaffolds for osteogenesis and highlights strategies for enhancing osteogenesis. PMID:26413557

  15. Use of Autologous Human mesenchymal Stromal Cell/Fibrin Clot Constructs in Upper Limb Non-Unions: Long-Term Assessment

    PubMed Central

    Bottai, Vanna; Ghilardi, Marco; D'Alessandro, Delfo; Danti, Serena; Dell'Osso, Giacomo; Guido, Giulio; Petrini, Mario

    2013-01-01

    Background Tissue engineering appears to be an attractive alternative to the traditional approach in the treatment of fracture non-unions. Mesenchymal stromal cells (MSCs) are considered an appealing cell source for clinical intervention. However, ex vivo cell expansion and differentiation towards the osteogenic lineage, together with the design of a suitable scaffold have yet to be optimized. Major concerns exist about the safety of MSC-based therapies, including possible abnormal overgrowth and potential cancer evolution. Aims We examined the long-term efficacy and safety of ex vivo expanded bone marrow MSCs, embedded in autologous fibrin clots, for the healing of atrophic pseudarthrosis of the upper limb. Our research work relied on three main issues: use of an entirely autologous context (cells, serum for ex vivo cell culture, scaffold components), reduced ex vivo cell expansion, and short-term MSC osteoinduction before implantation. Methods and Findings Bone marrow MSCs isolated from 8 patients were expanded ex vivo until passage 1 and short-term osteo-differentiated in autologous-based culture conditions. Tissue-engineered constructs designed to embed MSCs in autologous fibrin clots were locally implanted with bone grafts, calibrating their number on the extension of bone damage. Radiographic healing was evaluated with short- and long-term follow-ups (range averages: 6.7 and 76.0 months, respectively). All patients recovered limb function, with no evidence of tissue overgrowth or tumor formation. Conclusions Our study indicates that highly autologous treatment can be effective and safe in the long-term healing of bone non-unions. This tissue engineering approach resulted in successful clinical and functional outcomes for all patients. PMID:24023694

  16. Biofunctionalized Calcium Phosphate Cement to Enhance the Attachment and Osteodifferentiation of Stem Cells Released from Fast-Degradable Alginate-Fibrin Microbeads

    PubMed Central

    Chen, Wenchuan; Weir, Michael D.

    2012-01-01

    Stem cell-encapsulating microbeads could be mixed into a paste such as calcium phosphate cement (CPC), where the microbeads could protect the cells from the mixing and injection forces. After being placed, the microbeads could quickly degrade to release the cells throughout the scaffold, while creating macropores. The objectives of this study were to (1) construct alginate-fibrin microbeads encapsulating human umbilical cord mesenchymal stem cells (hUCMSCs) embedded in the surface of novel biofunctionalized CPC and (2) investigate microbead degradation, cell release, and osteodifferentiation on CPC. Hydrogel microbeads were fabricated that encapsulated hUCMSCs at 1×106 cells/mL. CPC was biofunctionalized with fibronectin (Fn) and Arg-Gly-Asp (RGD). Four scaffolds were tested: CPC control, CPC mixed with Fn, CPC mixed with RGD, and CPC grafted with RGD. The degradable microbeads released hUCMSCs at 7 days, which attached to CPC. Adding Fn or RGD to CPC greatly improved cell attachment. CPC grafted with RGD showed the fastest cell proliferation, with cell density being ninefold that on CPC control. The released hUCMSCs underwent osteodifferentiation. Alkaline phosphatase, osteocalcin, collagen 1, and runt-related transcription factor 2 (Runx2) gene expression increased by 10 to 30 fold at 7–21 days, compared with day 1. The released cells on CPC synthesized bone minerals, with the mineralization amount at 21 days being two orders of magnitude higher than that at 7 days. In conclusion, alginate-fibrin microbeads embedded in CPC surface were able to quickly release the hUCMSCs that attached to biofunctionalized CPC. Incorporating Fn and RGD into CPC greatly improved cell function, and CPC grafted with RGD had the fastest cell proliferation. The released cells on CPC differentiated into the osteogenic lineage and synthesized bone minerals. The new biofunctionalized CPC with hUCMSC-encapsulating microbeads is promising for bone regeneration applications. PMID:22435653

  17. Suicide reconstruction by glue-lift of gunshot residue.

    PubMed

    Basu, S; Ferriss, S; Horn, R

    1984-07-01

    Based upon the recently developed glue-lift collection of gunshot residue particles for examination in the scanning electron microscope with energy dispersive X-rays, this laboratory has undertaken a research program to determine if reconstruction of gunshot deaths is feasible. Because undisturbed conditions of suicide victims may help in securing unambiguous results and high success rates, the program has been carried out to reconstruct suicides only. Data obtained from 13 firearms suicides and their laboratory reconstruction which involved primarily shotguns and handguns, indicate that reconstruction can be immensely useful to interpretation of the gunshot residue distributions on a suspect's or victim's hands. This reports outlines the basic experiments performed to relate the residue emission from the gun to the deposits found on the firing hand(s) and a description of the reconstruction technique that uses a target to simulate a human body. The technique can determine the specifics of a victim's hand position at the time of firing and which hand was used to pull the trigger. Because the technique is sensitive to the nature of the grasp of the firing hand and of the supporting hand, in the case of a shotgun, it has been possible in all cases to date, to determine which one of the potential eight hand positions existed at the time of shooting. PMID:6747586

  18. Performance of the GlueX Barrel Calorimeter

    NASA Astrophysics Data System (ADS)

    Smith, Elton; Dalton, Mark; McGinley, William; Papandreou, Zisis; GlueX Collaboration

    2015-10-01

    The GlueX experiment at Jefferson Lab will search for exotic hybrid mesons, a new form of hadronic matter that exhibits gluonic degrees of freedom. We have taken data to commission the experiment and report here on the construction and performance of the electromagnetic barrel calorimeter (BCAL). The BCAL is a ``spaghetti calorimeter,'' consisting of layers of corrugated lead sheets, interleaved with planes of 1-mm-diameter, double-clad, scintillating fibers, bonded in the lead grooves using optical epoxy. This detector consists of 48 modules that are readout using 3,840 large-area Multi-Photon Pixel counter (MPPC) arrays. The measured width of the π0 mass peak is approximately 10 MeV, only slightly higher than projections based on prototypes. Systematic studies are underway to understand the contributions to the resolution and improve its performance. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Contract DE-AC05-06OR23177.

  19. From glue to gasoline: how competition turns perspective takers unethical.

    PubMed

    Pierce, Jason R; Kilduff, Gavin J; Galinsky, Adam D; Sivanathan, Niro

    2013-10-01

    Perspective taking is often the glue that binds people together. However, we propose that in competitive contexts, perspective taking is akin to adding gasoline to a fire: It inflames already-aroused competitive impulses and leads people to protect themselves from the potentially insidious actions of their competitors. Overall, we suggest that perspective taking functions as a relational amplifier. In cooperative contexts, it creates the foundation for prosocial impulses, but in competitive contexts, it triggers hypercompetition, leading people to prophylactically engage in unethical behavior to prevent themselves from being exploited. The experiments reported here establish that perspective taking interacts with the relational context--cooperative or competitive--to predict unethical behavior, from using insidious negotiation tactics to materially deceiving one's partner to cheating on an anagram task. In the context of competition, perspective taking can pervert the age-old axiom "do unto others as you would have them do unto you" into "do unto others as you think they will try to do unto you." PMID:23955353

  20. The configuration of fibrin clots determines capillary morphogenesis and endothelial cell migration.

    PubMed

    Nehls, V; Herrmann, R

    1996-05-01

    In the living organism, capillary growth frequently occurs in a fibrin-rich extracellular matrix. The structure and the mechanical properties of fibrin clots are influenced by various macromolecules (i.e., hyaluronic acid and thrombospondin) and also by pH, ionic strength, and thrombin concentrations of the milieu in which they polymerize. The configuration (three-dimensional architecture) and the rigidity of fibrin clots correlate with their opacity measured by spectrophotometric absorbance readings at 350 nm. By using bovine pulmonary artery endothelial cells and bovine fibrinogen, we show here that transparent fibrin clots (A(350) < 1.0), polymerized at > or = pH 7.5 or in the presence of increased thrombin or sodium chloride concentrations, strongly stimulated capillary morphogenesis in vitro. In contrast, opaque fibrin gels (A(350) > 1.5), polymerized at pH 7.2 or in the presence of dextran, stimulated only the migration of endothelial cells but not capillary morphogenesis. We demonstrate that the angiomorphogenic effects of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) are strongly dependent on the structure of the fibrin clots. Our findings suggest that bFGF/VEGF primarily stimulate the proliferation of endothelial cells, whereas the three-dimensional architecture of the fibrin matrix is decisive for capillary morphogenesis. PMID:8992233

  1. Quantification and macroscopic modeling of the nonlinear viscoelastic behavior of strained gels with varying fibrin concentrations.

    PubMed

    Benkherourou, M; Guméry, P Y; Tranqui, L; Tracqui, P

    2000-11-01

    The mechanical properties of fibrin gels under uniaxial strains have been analyzed for low fibrin concentrations using a free-floating gel device. We were able to quantify the viscous and elastic moduli of gels with fibrin concentration ranging from 0.5 to 3 mg/ml, reporting significant differences of biogels moduli and dynamical response according to fibrin concentration. Furthermore, considering sequences of successively imposed step strains has revealed the strain-hardening properties of fibrin gels for strain amplitude below 5%. This nonlinear viscoelastic behavior of the gels has been precisely analyzed through numerical simulations of the overall gel response to the strain steps sequences. Phenomenological power laws relating the instantaneous and relaxed elasticity moduli to fibrin concentration have been validated, with concentration exponent in the order of 1.2 and 1.0, respectively. This continuous description of strain-dependent mechanical moduli was then used to simulate the biogel behavior when continuously time-varying strains are applied. We discuss how this experimental setup and associated macroscopic modeling of fibrin gels enable a further quantification of cell traction forces and mechanotransduction processes induced by biogel compaction or stretching. PMID:11077740

  2. Functional Properties of Cell-Seeded Three-Dimensionally Woven Poly(ε-Caprolactone) Scaffolds for Cartilage Tissue Engineering

    PubMed Central

    Moutos, Franklin T.

    2010-01-01

    Articular cartilage possesses complex mechanical properties that provide healthy joints the ability to bear repeated loads and maintain smooth articulating surfaces over an entire lifetime. In this study, we utilized a fiber-reinforced composite scaffold designed to mimic the anisotropic, nonlinear, and viscoelastic biomechanical characteristics of native cartilage as the basis for developing functional tissue-engineered constructs. Three-dimensionally woven poly(ɛ-caprolactone) (PCL) scaffolds were encapsulated with a fibrin hydrogel, seeded with human adipose-derived stem cells, and cultured for 28 days in chondrogenic culture conditions. Biomechanical testing showed that PCL-based constructs exhibited baseline compressive and shear properties similar to those of native cartilage and maintained these properties throughout the culture period, while supporting the synthesis of a collagen-rich extracellular matrix. Further, constructs displayed an equilibrium coefficient of friction similar to that of native articular cartilage (μeq ∼0.1–0.3) over the prescribed culture period. Our findings show that three-dimensionally woven PCL–fibrin composite scaffolds can be produced with cartilage-like mechanical properties, and that these engineered properties can be maintained in culture while seeded stem cells regenerate a new, functional tissue construct. PMID:19903085

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

    PubMed

    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. PMID:25977585

  4. Thrombin-dependent Incorporation of von Willebrand Factor into a Fibrin Network*

    PubMed Central

    Miszta, Adam; Pelkmans, Leonie; Lindhout, Theo; Krishnamoorthy, Ganeshram; de Groot, Philip G.; Hemker, Coenraad H.; Heemskerk, Johan W. M.; Kelchtermans, Hilde; de Laat, Bas

    2014-01-01

    Attachment of platelets from the circulation onto a growing thrombus is a process involving multiple platelet receptors, endothelial matrix components, and coagulation factors. It has been indicated previously that during a transglutaminase reaction activated factor XIII (FXIIIa) covalently cross-links von Willebrand factor (VWF) to polymerizing fibrin. Bound VWF further recruits and activates platelets via interactions with the platelet receptor complex glycoprotein Ib (GPIb). In the present study we found proof for binding of VWF to a fibrin monomer layer during the process of fibrinogen-to-fibrin conversion in the presence of thrombin, arvin, or a snake venom from Crotalus atrox. Using a domain deletion mutant we demonstrated the involvement of the C domains of VWF in this binding. Substantial binding of VWF to fibrin monomers persisted in the presence of the FXIIIa inhibitor K9-DON, illustrating that cross-linking via factor XIII is not essential for this phenomenon and suggesting the identification of a second mechanism through which VWF multimers incorporate into a fibrin network. Under high shear conditions, platelets were shown to adhere to fibrin only if VWF had been incorporated. In conclusion, our experiments show that the C domains of VWF and the E domain of fibrin monomers are involved in the incorporation of VWF during the polymerization of fibrin and that this incorporation fosters binding and activation of platelets. Fibrin thus is not an inert end product but partakes in further thrombus growth. Our findings help to elucidate the mechanism of thrombus growth and platelet adhesion under conditions of arterial shear rate. PMID:25381443

  5. Fibrin hydrogels for lentiviral gene delivery in vitro and in vivo

    PubMed Central

    Kidd, Martha; Shin, Seungjin; Shea, Lonnie D.

    2011-01-01

    Gene delivery from hydrogels represents a versatile approach for localized expression of tissue inductive factors than can promote cellular processes that lead to regeneration. Lentiviral gene therapy vectors were entrapped within fibrin hydrogels, either alone or complexes with hydroxylapatite (HA) nanoparticles. The inclusion of HA into the hydrogel led to the formation of small aggregates distributed throughout the hydrogel, with no obvious alteration of the pore structure outside the aggregates. The presence of HA slowed hydrogel degradation by collagenase and plasmin relative to fibrin alone, and also decreased the rate of cell migration. Lentivirus had similar release from the fibrin hydrogels formed with or without HA. The altered hydrogel properties suggest an interaction between the nanoparticle and fibrin, which may displace the virus from the particle leading to similar release profiles. Transgene expression by cells migrating into the hydrogel in vitro was reduced in the presence of HA, consistent with the role of cell migration on transgene expression. In vivo, lentivirus loaded fibrin hydrogels promoted localized transgene expression that increased through day 9 and decreased through day 14. For the fibrin only hydrogels, expression continued to decline after day 14. However, hydrogels with HA maintained this transgene expression level for an additional two weeks before declining. Immunostaining identified transgene primarily outside the fibrin-HA gel at day 9; however, at day 21, transgene expression was observed primarily within the fibrin-HA gel. The localized delivery of lentivirus provides an opportunity to enhance the bioactivity of fibrin hydrogels for a wide range of applications in regenerative medicine. PMID:21907251

  6. Fibrin Accumulation Secondary to Loss of Plasmin-Mediated Fibrinolysis Drives Inflammatory Osteoporosis in Mice

    PubMed Central

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

    2015-01-01

    Objective 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 co-morbidities, we undertook this study to test the hypothesis that persistent fibrin deposition causes inflammatory osteoporosis. Methods 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 αMβ2 binding motif. Results 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 αMβ2 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 αMβ2 binding motif prevented the degenerative skeletal phenotypes, resulting in normal local and systemic cytokine levels. Conclusion 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. PMID:24664548

  7. Fibronectin provides a conduit for fibroblast transmigration from collagenous stroma into fibrin clot provisional matrix.

    PubMed

    Greiling, D; Clark, R A

    1997-04-01

    After injury, the wound space is filled with a fibrin/fibronectin clot containing growth factors released by platelets and monocytes. In response to these factors, fibroblasts migrate into the fibrin clot and contribute to the formation of granulation tissue. The functional mechanisms allowing fibroblasts to leave the collagenous matrix of normal connective tissue and invade the provisional matrix of the fibrin clot have not been fully defined. To investigate these mechanisms we established a new in vitro model which simulates specific aspects of early wound healing, that is, the migration of fibroblasts from a three-dimensional collagen matrix into a fibrin clot. This transmigration could be induced by physiological concentrations of platelet releasate or platelet-derived growth factor BB (PDGF-BB) in a concentration-dependent manner. At 24 hours irradiated fibroblasts invaded the fibrin gel almost as well as non-irradiated cells, indicating that transmigration was independent of proliferation. Plasminogen and its activators appear to be necessary for invasion of the fibrin clot since protease inhibitors decreased the amount of migration. These serine proteases, however, were not necessary for exit from the collagen gel as fibroblasts migrated out of the collagen gel onto a surface coated with fibrin fibrils even in the presence of inhibitors. Removal of fibronectin (FN) from either the collagen gel or the fibrin gel markedly decreased the number of migrating cells, suggesting that FN provides a conduit for transmigration. Cell movement in the in vitro model was inhibited by RGD peptide, and by monoclonal antibodies against the subunits of the alpha5 beta1 and alpha v beta3 integrin receptor. Thus, the functional requirements for fibroblast transmigration from collagen-rich to fibrin-rich matrices, such as occurs in early wound healing, have been partially defined using an in vitro paradigm of this important biologic process. PMID:9133673

  8. Mathematical Abstraction through Scaffolding

    ERIC Educational Resources Information Center

    Ozmantar, Mehmet Fatih; Roper, Tom

    2004-01-01

    This paper examines the role of scaffolding in the process of abstraction. An activity-theoretic approach to abstraction in context is taken. This examination is carried out with reference to verbal protocols of two 17 year-old students working together on a task connected to sketching the graph of |f|x|)|. Examination of the data suggests that…

  9. Acute fibrinous and organizing pneumonia: A rare form of nonbacterial pneumonia.

    PubMed

    Saxena, Prashant; Kumar, Kuldeep; Mittal, Sarita; Goyal, Nidhi; Trikha, Sahil; Vashisth, Arti

    2016-04-01

    Acute fibrinous and organizing pneumonia (AFOP) is a rare disease characterized by bilateral basilar infiltrates and histological findings of organizing pneumonia and intra-alveolar fibrin in the form of "fibrin balls." Here, we report a 43-year-old female with complaints of fever, dry cough, and shortness of breath with hypoxemia. High-resolution computed tomography thorax revealed diffuse confluent consolidation in bilateral lung zones. Bronchoscopy and transbronchial biopsy revealed features of AFOP. With prednisolone treatment, there was an improvement in her condition. AFOP is a rare disease and should be taken into consideration and differential diagnosis of severe acute pneumonias with no significant comorbidities. PMID:27303141

  10. Acute fibrinous and organizing pneumonia: A rare form of nonbacterial pneumonia

    PubMed Central

    Saxena, Prashant; Kumar, Kuldeep; Mittal, Sarita; Goyal, Nidhi; Trikha, Sahil; Vashisth, Arti

    2016-01-01

    Acute fibrinous and organizing pneumonia (AFOP) is a rare disease characterized by bilateral basilar infiltrates and histological findings of organizing pneumonia and intra-alveolar fibrin in the form of “fibrin balls.” Here, we report a 43-year-old female with complaints of fever, dry cough, and shortness of breath with hypoxemia. High-resolution computed tomography thorax revealed diffuse confluent consolidation in bilateral lung zones. Bronchoscopy and transbronchial biopsy revealed features of AFOP. With prednisolone treatment, there was an improvement in her condition. AFOP is a rare disease and should be taken into consideration and differential diagnosis of severe acute pneumonias with no significant comorbidities. PMID:27303141

  11. Meniscal Repair of Degenerative Horizontal Cleavage Tears Using Fibrin Clots

    PubMed Central

    Kamimura, Tamiko; Kimura, Masashi

    2014-01-01

    Background: Presently, the treatment options available for patients with horizontal degenerative cleavage tears of the meniscus are limited. These tears are considered an indication for partial or subtotal meniscectomy because when the tear is located within an avascular area, it is difficult to induce healing. However, meniscectomy is not ideal because it disrupts the normal anatomical structure and function of the meniscus. Purpose: To examine the clinical and arthroscopic outcomes following meniscal repair of degenerative horizontal cleavage tears using fibrin clots. Study Design: Case series; Level of evidence, 4. Methods: Vertical sutures were placed in the meniscal tear, and the cleft was filled with fibrin clots before the sutures were tightened. We repaired 18 menisci in 18 consecutive eligible patients using a previously described technique. Three patients with anterior cruciate ligament (ACL) injury who underwent simultaneous ACL reconstruction and 5 patients who did not undergo follow-up arthroscopy within 12 months were excluded. The remaining 10 menisci in 10 patients were evaluated in this study. The mean age of the patients was 35.8 ± 16.5 years, and the mean postoperative follow-up time was 40.8 ± 5.4 months. Pre- and postoperative Lysholm scores, International Knee Documentation Committee (IKDC) subjective scores, and Tegner activity levels were compared. The arthroscopy findings were evaluated at a mean postoperative time of 6.7 ± 2.9 months. Results: The mean Lysholm score improved significantly from 69.3 ± 16.3 points preoperatively to 95.4 ± 3.6 points postoperatively (P < .005). The mean IKDC subjective score also improved significantly from 26.5% ± 19.0% preoperatively to 87.8% ± 7.5% postoperatively (P < .001). The Tegner activity level recovered to the preinjury level in 6 patients and to 1 level below the preinjury level in 4 patients. The follow-up arthroscopies showed complete healing in 7 patients (70%) and incomplete healing in

  12. The polymerization and thrombin-binding properties of des-(B beta 1-42)-fibrin.

    PubMed

    Siebenlist, K R; DiOrio, J P; Budzynski, A Z; Mosesson, M W

    1990-10-25

    Multiple factors affect the thrombin-catalyzed conversion of fibrinogen to fibrin, including: fibrinopeptide (FPA and FPB) release leading to exposure of two types of polymerization domains ("A" and "B," respectively) in the central portion of the molecule, and exposure of a noncatalytic "secondary" thrombin-binding site in fibrin. Fibrinogen containing the FPA sequence but lacking the B beta 1-42 sequence ("des-(B beta 1-42)-fibrinogen"), was compared to native fibrinogen (containing both FPA and FPB) to investigate the role played by B beta 1-42 in the polymerization of alpha-fibrin (i.e. fibrin lacking FPA), to compare reptilase and thrombin cleavage of FPA from fibrinogen, and to explore the location and function of the secondary thrombin-binding site. Electron microscopy of evolving polymer structures (mu, 0.14; pH 7.4) plus turbidity measurements, showed that early thin fibril formation as well as subsequent lateral fibril associations were impaired in des-(B beta 1-42)-alpha-fibrin, thus indicating that the B beta 1-42 sequence contributes to the A polymerization site. Reptilase-activated des-(B beta 1-42)-alpha-fibrin polymerized even more slowly than thrombin-activated des-(B beta 1-42)-alpha-fibrin, differences that disappeared when repolymerization of preformed fibrin monomers was carried out. Since existing data indicate that thrombin releases FPA in a concerted manner, resulting in relatively rapid evolution of fully functional divalent alpha-fibrin monomers, it can be inferred that delayed fibrin assembly of reptilase fibrin is due to slower formation of divalent alpha-fibrin monomers. Thrombin-activated des-(B beta 1-42)-alpha-fibrin polymerized more rapidly at low ionic strength (mu, 0.04) than did native alpha,beta-fibrin, a reversal of their behavior at physiological ionic strength (mu, 0.14). Concomitant measurement of FPA release revealed modest slowing of release at low ionic strength from des-(B beta 1-42)-fibrinogen (t1/2, 36.5 versus 21

  13. Comparison of the Mechanical Properties of Early Leukocyte- and Platelet-Rich Fibrin versus PRGF/Endoret Membranes

    PubMed Central

    Khorshidi, Hooman; Raoofi, Saeed; Bagheri, Rafat; Banihashemi, Hodasadat

    2016-01-01

    Objectives. The mechanical properties of membranes are important factors in the success of treatment and clinical handling. The goal of this study was to compare the mechanical properties of early leukocyte- and platelet-rich fibrin (L-PRF) versus PRGF/Endoret membrane. Materials and Methods. In this experimental study, membranes were obtained from 10 healthy male volunteers. After obtaining 20 cc venous blood from each volunteer, 10 cc was used to prepare early L-PRF (group 1) and the rest was used to get a membrane by PRGF-Endoret system (group 2). Tensile loads were applied to specimens using universal testing machine. Tensile strength, stiffness, and toughness of the two groups of membranes were calculated and compared by paired t-test. Results. The mean tensile strength and toughness were higher in group 1 with a significant difference (P < 0.05). The mean stiffness in group 1 was also higher but not statistically significant (P > 0.05). Conclusions. The results showed that early L-PRF membranes had stronger mechanical properties than membranes produced by PRGF-Endoret system. Early L-PRF membranes might have easier clinical handling and could be a more proper scaffold in periodontal regenerative procedures. The real results of the current L-PRF should be in fact much higher than what is reported here. PMID:26880919

  14. Preparation and characterization of fibrous chitosan-glued phosphate glass fiber scaffolds for bone regeneration.

    PubMed

    Zheng, Kai; Wu, Zhaoying; Wei, Jie; Rűssel, Christian; Liang, Wen; Boccaccini, Aldo R

    2015-08-01

    Phosphate glass fibers (PGF) have emerged as promising building blocks for constructing bone scaffolds. In this study, fibrous scaffolds (PGFS) were fabricated using a facile binding method at room temperature. PGFS exhibited an extracellular matrix-like morphology and were composed of PGF as matrix and chitosan as the natural binding glue. They showed an interconnected porous structure with a porosity of ~87% and pore size of 100-500 µm. PGFS exhibited the typical compressive stress-strain behaviour of highly porous, low-density, open-cell scaffolds. Their yield stress and modulus were ~0.38 and ~2.84 MPa, respectively, with the strength being higher than the lower bound of the compressive strength of cancellous bone. PGFS were degradable and the weight loss was about 25% after immersion in stimulated body fluid (SBF) for 28 days. In addition, the yield stress and the modulus decreased with increasing immersion time in SBF. Apatite formation could be detected on the surface of PGFS within 7 days of immersion in SBF. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay indicated that PGFS were non-cytotoxic against bone marrow stromal cells (bMSCs) after culture for up to 72 h. These results suggest that PGFS could be promising scaffolds for bone regeneration applications. PMID:26271217

  15. Ubiquitous distribution of salts and proteins in spider glue enhances spider silk adhesion

    NASA Astrophysics Data System (ADS)

    Amarpuri, Gaurav; Chaurasia, Vishal; Jain, Dharamdeep; Blackledge, Todd A.; Dhinojwala, Ali

    2015-03-01

    Modern orb-weaving spiders use micron-sized glue droplets on their viscid silk to retain prey in webs. A combination of low molecular weight salts and proteins makes the glue viscoelastic and humidity responsive in a way not easily achieved by synthetic adhesives. Optically, the glue droplet shows a heterogeneous structure, but the spatial arrangement of its chemical components is poorly understood. Here, we use optical and confocal Raman microscopy to show that salts and proteins are present ubiquitously throughout the droplet. The distribution of adhesive proteins in the peripheral region explains the superior prey capture performance of orb webs as it enables the entire surface area of the glue droplet to act as a site for prey capture. The presence of salts throughout the droplet explains the recent Solid-State NMR results that show salts directly facilitate protein mobility. Understanding the function of individual glue components and the role of the droplet's macro-structure can help in designing better synthetic adhesives for humid environments.

  16. Daily streamflow prediction with uncertainty in ephemeral catchments using the GLUE methodology

    NASA Astrophysics Data System (ADS)

    Viola, F.; Noto, L. V.; Cannarozzo, M.; La Loggia, G.

    The Generalised Likelihood Uncertainty Estimation (GLUE) approach is presented here as a tool for estimating the predictive uncertainty of a rainfall-runoff model. The GLUE methodology allows to recognise the possible equifinality of different parameter sets and assesses the likelihood of a parameters set being acceptable simulator when model predictions are compared to observed field data. The results of the GLUE methodology depend greatly on the choice of the likelihood measure and on the choice of the threshold which determines if a parameters set is behavioural or not. Moreover the sampling size has a strong influence on the uncertainty assessment of the response of a rainfall-runoff model. This is one of the most controversial and criticized aspect of the GLUE methodology, because it seems that this procedure does not learn from observations. Following these premises, this paper investigated first on the effect of different likelihood measures on the uncertainty analysis in the rainfall-runoff modelling of a mediterranean catchment. Performance of individual parameter sets has been assessed using three likelihood measures with a shaping factor. The acceptability threshold influence on the uncertainty analysis has been also evaluated. Finally it can be demonstrated how, using the GLUE, the predictive uncertainty grows with the streamflow variance while remains almost the same with the sampling size. In order to overcome these inconsistencies, a new simple likelihood measure, which explicitly takes into account the sample variance and extension, is here proposed.

  17. Ubiquitous distribution of salts and proteins in spider glue enhances spider silk adhesion

    PubMed Central

    Amarpuri, Gaurav; Chaurasia, Vishal; Jain, Dharamdeep; Blackledge, Todd A.; Dhinojwala, Ali

    2015-01-01

    Modern orb-weaving spiders use micron-sized glue droplets on their viscid silk to retain prey in webs. A combination of low molecular weight salts and proteins makes the glue viscoelastic and humidity responsive in a way not easily achieved by synthetic adhesives. Optically, the glue droplet shows a heterogeneous structure, but the spatial arrangement of its chemical components is poorly understood. Here, we use optical and confocal Raman microscopy to show that salts and proteins are present ubiquitously throughout the droplet. The distribution of adhesive proteins in the peripheral region explains the superior prey capture performance of orb webs as it enables the entire surface area of the glue droplet to act as a site for prey capture. The presence of salts throughout the droplet explains the recent Solid-State NMR results that show salts directly facilitate protein mobility. Understanding the function of individual glue components and the role of the droplet's macro-structure can help in designing better synthetic adhesives for humid environments. PMID:25761668

  18. The application of a new cyanoacrylate glue in pediatric surgery for fistula closure.

    PubMed

    Hosseini, Seyed Mohammad Vahid; Bahador, Ali; Foroutan, Hamid Reza; Sabet, Babak; Geramizadeh, Bita; Zarenezhad, Mohammad

    2011-03-01

    Surgical glues have been used in pediatric surgery because of the fragility of tissue, and to prevent major surgeries. The present report describes our experience with using a new cyanoacrylate Glubran 2 (Viareggio, Italy) in the treatment of five cases of tracheoesophageal atresia with fistula (one fistula protection, three recurrent fistula, and one unstable patients), two cases of hypospadias, one case of vesicutanouse fistula after bladder extrophy, and one case of cloacal extrophy from January-December 2008. Three cases of recurrent tracheoesophageal atresia with fistula were treated by bronchoscpic glue injection. The other two cases benefited from glue through its ability to plug the fistula and to act as a protecting layer on anastomosis. In two cases with hypospadias excessive use of the glue caused skin necrosis, which was repaired. The wounds of cloacal extrophy were protected from nearby colostomy contamination and infection, and the vesicocutanouse fistula was closed by deepithelialization and sealing with glue. Based on the outcomes of the cases, it may be possible to suggest that Glubran 2 may be used safely in Pediatric Surgery as a sealant for the prevention and treatment of fistulas. PMID:23365480

  19. The Application of a New Cyanoacrylate Glue in Pediatric Surgery for Fistula Closure

    PubMed Central

    Hosseini, Seyed Mohammad Vahid; Bahador, Ali; Foroutan, Hamid Reza; Sabet, Babak; Geramizadeh, Bita; Zarenezhad, Mohammad

    2011-01-01

    Surgical glues have been used in pediatric surgery because of the fragility of tissue, and to prevent major surgeries. The present report describes our experience with using a new cyanoacrylate Glubran 2 (Viareggio, Italy) in the treatment of five cases of tracheoesophageal atresia with fistula (one fistula protection, three recurrent fistula, and one unstable patients), two cases of hypospadias, one case of vesicutanouse fistula after bladder extrophy, and one case of cloacal extrophy from January–December 2008. Three cases of recurrent tracheoesophageal atresia with fistula were treated by bronchoscpic glue injection. The other two cases benefited from glue through its ability to plug the fistula and to act as a protecting layer on anastomosis. In two cases with hypospadias excessive use of the glue caused skin necrosis, which was repaired. The wounds of cloacal extrophy were protected from nearby colostomy contamination and infection, and the vesicocutanouse fistula was closed by deepithelialization and sealing with glue. Based on the outcomes of the cases, it may be possible to suggest that Glubran 2 may be used safely in Pediatric Surgery as a sealant for the prevention and treatment of fistulas. PMID:23365480

  20. Proangiogenic Hydrogels Within Macroporous Scaffolds Enhance Islet Engraftment in an Extrahepatic Site

    PubMed Central

    Brady, Ann-Christina; Martino, Mikaël M.; Pedraza, Eileen; Sukert, Steve; Pileggi, Antonello; Ricordi, Camillo; Hubbell, Jeffrey A.

    2013-01-01

    The transplantation of allogeneic islets in recent clinical trials has shown substantial promise as a therapy for type 1 diabetes; however, long-term insulin independence remains inadequate. This has been largely attributed to the current intravascular, hepatic transplant site, which exposes islets to mechanical and inflammatory stresses. A highly macroporous scaffold, housed within an alternative transplant site, can support an ideal environment for islet transplantation by providing three-dimensional distribution of islets, while permitting the infiltration of host vasculature. In the present study, we sought to evaluate the synergistic effect of a proangiogenic hydrogel loaded within the void space of a macroporous poly(dimethylsiloxane) (PDMS) scaffold on islet engraftment. The fibrin-based proangiogenic hydrogel tested presents platelet derived growth factor (PDGF-BB), via a fibronectin (FN) fragment containing growth factor and major integrin binding sites in close proximity. The combination of the proangiogenic hydrogel with PDMS scaffolds resulted in a significant decrease in the time to normoglycemia for syngeneic mouse islet transplants. This benefit was associated with an observed increase in competent vessel branching, as well as mature intraislet vessels. Overall, the addition of the proangiogenic factor PDGF-BB, delivered via the FN fragment-functionalized hydrogel, positively influenced the efficiency of engraftment. These characteristics, along with its ease of retrieval, make this combination of a biostable macroporous scaffold and a degradable proangiogenic hydrogel a supportive structure for insulin-producing cells implanted in extrahepatic sites. PMID:23790218

  1. Cartilage Tissue Engineering: Preventing Tissue Scaffold Contraction Using a 3D-Printed Polymeric Cage.

    PubMed

    Visscher, Dafydd O; Bos, Ernst J; Peeters, Mirte; Kuzmin, Nikolay V; Groot, Marie Louise; Helder, Marco N; van Zuijlen, Paul P M

    2016-06-01

    Scaffold contraction is a common but underestimated problem in the field of tissue engineering. It becomes particularly problematic when creating anatomically complex shapes such as the ear. The aim of this study was to develop a contraction-free biocompatible scaffold construct for ear cartilage tissue engineering. To address this aim, we used three constructs: (i) a fibrin/hyaluronic acid (FB/HA) hydrogel, (ii) a FB/HA hydrogel combined with a collagen I/III scaffold, and (iii) a cage construct containing (ii) surrounded by a 3D-printed poly-ɛ-caprolactone mold. A wide range of different cell types were tested within these constructs, including chondrocytes, perichondrocytes, adipose-derived mesenchymal stem cells, and their combinations. After in vitro culturing for 1, 14, and 28 days, all constructs were analyzed. Macroscopic observation showed severe contraction of the cell-seeded hydrogel (i). This could be prevented, in part, by combining the hydrogel with the collagen scaffold (ii) and prevented in total using the 3D-printed cage construct (iii). (Immuno)histological analysis, multiphoton laser scanning microscopy, and biomechanical analysis showed extracellular matrix deposition and increased Young's modulus and thereby the feasibility of ear cartilage engineering. These results demonstrated that the 3D-printed cage construct is an adequate model for contraction-free ear cartilage engineering using a range of cell combinations. PMID:27089896

  2. [THROMBIN-MEDIATED EFFECTS OF BLOOD MICROPARTICLES ON FORMATION, STRUCTURE, AND STABILITY OF FIBRIN CLOTS].

    PubMed

    Nabiullina, R M; Mustafin, I G; Ataullakhanov, F I; Litvinov, R I; Zubairova, L D

    2015-07-01

    The effects of blood microparticles (MPs) on the dynamics of fibrin polymerization, clot structure and susceptibility to fibrinolysis were studied. Kinetics of fibrin polymerization, fibrinolysis, thrombin generation in platelet-free, microparticle-depleted and microparticle-depleted plasma replenished with cephalin, from healthy donors were analyzed in parallel. MPs have profound effects on all stages of fibrin formation, decrease its turbidity. All parameters obtained in the absence of MPs were recovered after reconstitution of phospholipids. Thrombin generation rates were reduced in the absence of MPs. In the presence of MPs the fibrin networks had less poro us structures with thinner fibers, while clots formed in the absence of MPs had larger pores and were built of thicker fibers. Clots formed in the presence of MPs were significantly more resistant to fibrinolysis. Results show that normally circulating MPs can support the formation of stable clots at the sites of vascular injury. PMID:26591054

  3. Fibrin Clot Structure and Mechanics Associated with Specific Oxidation of Methionine Residues in Fibrinogen

    PubMed Central

    Weigandt, Katie M.; White, Nathan; Chung, Dominic; Ellingson, Erica; Wang, Yi; Fu, Xiaoyun; Pozzo, Danilo C.

    2012-01-01

    Using a combination of structural and mechanical characterization, we examine the effect of fibrinogen oxidation on the formation of fibrin clots. We find that treatment with hypochlorous acid preferentially oxidizes specific methionine residues on the α, β, and γ chains of fibrinogen. Oxidation is associated with the formation of a dense network of thin fibers after activation by thrombin. Additionally, both the linear and nonlinear mechanical properties of oxidized fibrin gels are found to be altered with oxidation. Finally, the structural modifications induced by oxidation are associated with delayed fibrin lysis via plasminogen and tissue plasminogen activator. Based on these results, we speculate that methionine oxidation of specific residues may be related to hindered lateral aggregation of protofibrils in fibrin gels. PMID:23283239

  4. Photoclickable dendritic molecular glue: noncovalent-to-covalent photochemical transformation of protein hybrids.

    PubMed

    Uchida, Noriyuki; Okuro, Kou; Niitani, Yamato; Ling, Xiao; Ariga, Takayuki; Tomishige, Michio; Aida, Takuzo

    2013-03-27

    A water-soluble dendron with a fluorescein isothiocyanate (FITC) fluorescent label and bearing nine pendant guanidinium ion (Gu(+))/benzophenone (BP) pairs at its periphery (Glue(BP)-FITC) serves as a "photoclickable molecular glue". By multivalent salt-bridge formation between Gu(+) ions and oxyanions, Glue(BP)-FITC temporarily adheres to a kinesin/microtubule hybrid. Upon subsequent exposure to UV light, this noncovalent binding is made permanent via a cross-linking reaction mediated by carbon radicals derived from the photoexcited BP units. This temporal-to-permanent transformation by light occurs quickly and efficiently in this preorganized state, allowing the movements of microtubules on a kinesin-coated glass plate to be photochemically controlled. A fundamental difference between such temporal and permanent bindings was visualized by the use of "optical tweezers". PMID:23477460

  5. Application of the silicon photomultipliers for detectors in the GlueX experiment

    SciTech Connect

    Somov, Sergey V.; Tolstukhin, Ivan; Somov, Alexander S.

    2015-11-01

    The GlueX detector in Hall D at Jefferson Lab is instrumented with about 5000 Silicon Photomultipliers (SiPM) manufactured by Hamamatsu Corporation [2]. These photo sensors have properties similar to conventional photomultipliers but can be operated at high magnetic fields. Silicon photomultipliers with a sensitive area of 3x3 mm2 are used to detect light from the following GlueX scintillator detectors: the tagger microscope, pair spectrometer, and start counter. Arrays of 4x4 SiPMs sensors were chosen for the instrumentation of the barrel electromagnetic calorimeter. The tagger microscope must operate at high rates (up to 2.5 MHz) and provide time measurements with a resolution better than 0.3 ns. The paper will describe some results of the characterization of SiPMs for various GlueX sub-detectors.

  6. Exotic Hybrid Meson Spectroscopy with the GlueX detector at Jlab

    SciTech Connect

    Lawrence, David W.

    2014-03-01

    The GlueX experiment is scheduled to begin taking data in 2015. The goal is to discover evidence for the existence of exotic hybrid mesons and to map out their spectrum in the light quark sector. Recent theoretical developments using Lattice QCD predict exotic hybrid states in a mass range accessible using the newly upgraded 12GeV electron accelerator at Jefferson Lab. Hybrid mesons, and in particular exotic hybrid mesons, provide the ideal laboratory for testing QCD in the confinement regime since these mesons explicitly manifest the gluonic degrees of freedom. The experiment will use 9 GeV linearly polarized photons produced via coherent bremsstrahlung to produce the exotic hybrids. The decay products will be detected in the solenoid-based GlueX detector currently under construction at Jefferson Lab. The status of the GlueX experiment including detector parameters will be presented along with theoretical motivation for the experiment.

  7. [APPLICATION OF FISTULA PLUG WITH THE FIBRIN ADHESIVE IN TREATMENT OF RECTAL FISTULAS].

    PubMed

    Aydinova, P R; Aliyev, E A

    2015-05-01

    Results of surgical treatment of 21 patients, suffering high transsphincteric and extrasphincteric rectal fistulas, were studied. In patients of Group I the fistula passage was closed, using fistula plug obturator; and in patients of Group II--by the same, but preprocessed by fibrin adhesive. The fistula aperture germeticity, prophylaxis of rude cicatrices development in operative wound zone, promotion of better fixation of bioplastic material were guaranteed, using fistula plug obturator with preprocessing, using fibrin adhesive. PMID:26419026

  8. Efficient therapy of ischaemic lesions with VEGF121-fibrin in an animal model of systemic sclerosis

    PubMed Central

    Allipour Birgani, Shadab; Mailänder, Marion; Wasle, Ines; Dietrich, Hermann; Gruber, Johann; Distler, Oliver; Sgonc, Roswitha

    2016-01-01

    Background In systemic sclerosis (SSc), chronic and uncontrolled overexpression of vascular endothelial growth factor (VEGF) results in chaotic vessels, and intractable fingertip ulcers. Vice versa, VEGF is a potent mediator of angiogenesis if temporally and spatially controlled. We have addressed this therapeutic dilemma in SSc by a novel approach using a VEGF121 variant that covalently binds to fibrin and gets released on demand by cellular enzymatic activity. Using University of California at Davis (UCD)-206 chickens, we tested the hypothesis that cell-demanded release of fibrin-bound VEGF121 leads to the formation of stable blood vessels, and clinical improvement of ischaemic lesions. Methods Ninety-one early and late ischaemic comb and neck skin lesions of UCD-206 chickens were treated locally with VEGF121-fibrin, fibrin alone, or left untreated. After 1 week of treatment the clinical outcome was assessed. Angiogenesis was studied by immunofluorescence staining of vascular markers quantitatively analysed using TissueQuest. Results Overall, 79.3% of the lesions treated with VEGF121-fibrin showed clinical improvement, whereas 71.0% of fibrin treated controls, and 93.1% of untreated lesions deteriorated. This was accompanied by significantly increased growth of stable microvessels, upregulation of the proangiogenic VEGFR-2 and its regulator TAL-1, and increase of endogenous endothelial VEGF expression. Conclusions Our findings in the avian model of SSc suggest that cell-demanded release of VEGF121 from fibrin matrix induces controlled angiogenesis by differential regulation of VEGFR-1 and VEGFR-2 expression, shifting the balance towards the proangiogenic VEGFR-2. The study shows the potential of covalently conjugated VEGF-fibrin matrices for the therapy of ischaemic lesions such as fingertip ulcers. PMID:26362758

  9. Molecular imaging of fibrin in a breast cancer xenograft mouse model

    PubMed Central

    Uppal, Ritika; Medarova, Zdravka; Farrar, Christian T.; Dai, Guangping; Moore, Anna; Caravan, Peter

    2013-01-01

    Rationale and objectives Fibrin deposition has been indicated within the stroma of a majority of solid tumors. Here we assess the feasibility of using the established fibrin-specific probe EP-2104R for the noninvasive imaging of fibrin in the context of breast cancer. Methods EP-2104R, untargeted Gd-DTPA and a newly synthesized non-fibrin binding control linear peptide (CLP) were compared using steady-state and dynamic contrast enhanced MR imaging in a breast cancer xenograft mouse model at 9.4T. Results EP-2104R transiently enhanced both the tumor core and periphery, but only the enhancement in the tumor periphery persisted even 90 min after EP-2104R administration. However, untargeted Gd-DTPA and CLP are not retained in the tumor periphery. The half-life of EP-2104R in the tumor periphery (103±18 min) is significantly longer (p<0.05) than either Gd-DTPA (29.6±2.4 min) or CLP (42.4±1.5 min), but the rate of clearance is similar for all the three probes from the tumor core. The presence of high concentrations of fibrin in the tumor periphery was corroborated using immuno-histochemistry with a fibrin-specific antibody. Conclusions The persistent enhancement observed in the tumor periphery with EP-2104R is likely a result of its fibrin-specific binding rather than its size and demonstrates the feasibility of EP-2104R for molecular imaging of fibrin in tumor stroma. PMID:22960948

  10. Acute and chronic glue sniffing effects and consequences of withdrawal on aggressive behavior.

    PubMed

    Bouchatta, Otmane; Ouhaz, Zakaria; Ba-Mhamed, Saadia; Kerekes, Nóra; Bennis, Mohamed

    2016-05-01

    Drug abuse act on brain mechanisms that cause a high-risk individual to engage in aggressive and violent behavior. While a drug-violence relationship exists, the nature of this relationship is often complex, with intoxication, neurotoxic, and withdrawal effects often being confused and/or confounded. Glue sniffing is often a springboard to the abuse of more addictive drugs. Despite its high prevalence and serious consequences, we know relatively little about the aggressive behavioral effects of volatile inhalants abuse, especially glue. The aim of the present study was to investigate the link between the duration of glue exposure, a common substance abuse problem in Morocco, and the level of aggressive behavior during withdrawal. For this we used the isolation-induced aggression model "residents" in three groups of mice. The first group served as control resident animals (n=10, without exposure); the second group as experimental resident mice (n=10) tested before and after acute (first day) and chronic exposure to the glue, and at 1 and 2weeks of withdrawal; and the third group of 10 intruder animals. The results showed that the number of attacks decreased (halved) and the latency of the first attack increased (doubled) following acute glue sniffing. However, the effects of chronic exposure and of 1week of withdrawal led to an increase in the intensity of agonistic encounters. After 2weeks of withdrawal, the intensity of aggressive behavior decreased again. These results indicated that chronic glue exposure and the first week of withdrawal are associated with increased aggression in mice. PMID:26969766

  11. Scaffolding Student Participation in Mathematical Practices

    ERIC Educational Resources Information Center

    Moschkovich, Judit N.

    2015-01-01

    The concept of scaffolding can be used to describe various types of adult guidance, in multiple settings, across different time scales. This article clarifies what we mean by scaffolding, considering several questions specifically for scaffolding in mathematics: What theoretical assumptions are framing scaffolding? What is being scaffolded? At…

  12. Inhibition of thrombin generation in plasma by fibrin formation (Antithrombin I).

    PubMed

    de Bosch, N B; Mosesson, M W; Ruiz-Sáez, A; Echenagucia, M; Rodriguez-Lemoin, A

    2002-08-01

    The adsorption of thrombin to fibrin during clotting defines "Antithrombin I" activity. We confirmed that thrombin generation in afibrinogenemic or in Reptilase defibrinated normal plasma was higher than in normal plasma. Repletion of these fibrinogen-deficient plasmas with fibrinogen 1 (gamma A/gamma A), whose fibrin has two "low affinity" non-substrate thrombin binding sites, resulted in moderately reduced thrombin generation by 29-37%. Repletion with fibrinogen 2 (gamma'/gamma A), which in addition to low affinity thrombin-binding sites in fibrin, has a "high affinity" non-substrate thrombin binding site in the carboxy-terminal region of its gamma' chain, was even more effective and reduced thrombin generation by 57-67%. Adding peptides that compete for thrombin binding to fibrin [S-Hir53-64 (hirugen) or gamma'414-427] caused a transient delay in the onset of otherwise robust thrombin generation, indicating that fibrin formation is necessary for full expression of Antithrombin I activity. Considered together, 1) the increased thrombin generation in afibrinogenemic or fibrinogen-depleted normal plasma that is mitigated by fibrinogen replacement; 2) evidence that prothrombin activation is increased in afibrinogenemia and normalized by fibrinogen replacement; 3) the severe thrombophilia that is associated with defective thrombin-binding in dysfibrinogenemias Naples I and New York I, and 4) the association of afibrinogenemia or hypofibrinogenemia with venous or arterial thromboembolism, indicate that Antithrombin I (fibrin) modulates thromboembolic potential by inhibiting thrombin generation in blood. PMID:12195697

  13. Endothelial Cells Organize Fibrin Clots into Structures That Are More Resistant to Lysis

    NASA Astrophysics Data System (ADS)

    Gray Jerome, W.; Handt, Stefan; Hantgan, Roy R.

    2005-06-01

    Acute myocardial infarction is a major cause of death and disability in the United States. Introducing thrombolytic agents into the clot to dissolve occlusive coronary artery thrombi is one method of treatment. However, despite advances in our knowledge of thrombosis and thrombolysis, survival rates following thrombolytic therapy have not improved substantially. This failure highlights the need for further study of the factors mediating clot stabilization. Using laser scanning confocal microscopy of clots formed from fluorescein-labeled fibrinogen, we investigated what effect binding of fibrin to the endothelial surface has on clot structure and resistance to lysis. Fluorescent fibrin clots were produced over human umbilical vein endothelial cells (HUVEC) and the clot structure analyzed. In the presence of HUVEC, fibrin near the endothelial surface was more organized and occurred in tighter bundles compared to fibrin just 50 [mu]m above. The HUVEC influence on fibrin architecture was blocked by inhibitory concentrations of antibodies to [alpha]V or [beta]3 integrin subunits. The regions of the clots associated with endothelial cells were more resistant to lysis than the more homogenous regions distal to endothelium. Thus, our data show that binding of fibrin to integrins on endothelial surfaces produces clots that are more resistant to lysis.

  14. Fibrin Sealant: The Only Approved Hemostat, Sealant, and Adhesive—a Laboratory and Clinical Perspective

    PubMed Central

    Spotnitz, William D.

    2014-01-01

    Background. Fibrin sealant became the first modern era material approved as a hemostat in the United States in 1998. It is the only agent presently approved as a hemostat, sealant, and adhesive by the Food and Drug Administration (FDA). The product is now supplied as patches in addition to the original liquid formulations. Both laboratory and clinical uses of fibrin sealant continue to grow. The new literature on this material also continues to proliferate rapidly (approximately 200 papers/year). Methods. An overview of current fibrin sealant products and their approved uses and a comprehensive PubMed based review of the recent literature (February 2012, through March 2013) on the laboratory and clinical use of fibrin sealant are provided. Product information is organized into sections based on a classification system for commercially available materials. Publications are presented in sections based on both laboratory research and clinical topics are listed in order of decreasing frequency. Results. Fibrin sealant remains useful hemostat, sealant, and adhesive. New formulations and applications continue to be developed. Conclusions. This agent remains clinically important with the recent introduction of new commercially available products. Fibrin sealant has multiple new uses that should result in further improvements in patient care. PMID:24729902

  15. Bandwidth-Tunable Fiber Bragg Gratings Based on UV Glue Technique

    NASA Astrophysics Data System (ADS)

    Fu, Ming-Yue; Liu, Wen-Feng; Chen, Hsin-Tsang; Chuang, Chia-Wei; Bor, Sheau-Shong; Tien, Chuen-Lin

    2007-07-01

    In this study, we have demonstrated that a uniform fiber Bragg grating (FBG) can be transformed into a chirped fiber grating by a simple UV glue adhesive technique without shifting the reflection band with respect to the center wavelength of the FBG. The technique is based on the induced strain of an FBG due to the UV glue adhesive force on the fiber surface that causes a grating period variation and an effective index change. This technique can provide a fast and simple method of obtaining the required chirp value of a grating for applications in the dispersion compensators, gain flattening in erbium-doped fiber amplifiers (EDFAs) or optical filters.

  16. Gastric outflow obstruction after ingestion of wood glue in a dog.

    PubMed

    Horstman, Christopher L; Eubig, Paul A; Cornell, Karen K; Khan, Safdar A; Selcer, Barbara A

    2003-01-01

    A 2-year-old, male, mixed-breed dog presented with a 12-day history of vomiting, depression, and weight loss after ingestion of industrial-strength wood glue containing diphenylmethane diisocyanate as its active ingredient. A diagnosis of gastric foreign body was made from survey abdominal radiographs. A large aggregate of solidified wood glue was surgically removed, and the dog recovered uneventfully. Fourteen other cases have been reported to the Animal Poison Control Center at the American Society for the Prevention of Cruelty to Animals (ASPCA). Eight of those 14 cases required surgical intervention. All cases recovered completely. PMID:12549613

  17. Photocurable surgical tissue adhesive glues composed of photoreactive gelatin and poly(ethylene glycol) diacrylate.

    PubMed

    Nakayama, Y; Matsuda, T

    1999-01-01

    This article presents a novel photochemically driven surgical tissue adhesive technology using photoreactive gelatins and a water-soluble difunctional macromer (poly(ethylene glycol) diacrylate: PEGDA).The gelatins were partially derivatized with photoreactive groups, such as ultraviolet light (UV)-reactive benzophenone and visible light-reactive xanthene dye (e.g., fluorescein sodium salt, eosin Y, and rose bengal). A series of the prepared photocurable tissue adhesive glues, consisting of the photoreactive gelatin, PEGDA, and a saline solution with or without ascorbic acid as a reducing agent, were viscous solutions under warming, and their effectiveness was evaluated as hemostasis- and anastomosis-aid in cardiovascular surgery. Regardless of the type of photoreactive groups, the irradiation of the photocurable tissue adhesive glues by UV or visible light within 1 min produced water-swollen gels, which had a high adhesive strength to wet collagen film. These were due to the synergistic action of photoreactive group-initiated photo-cross-linking and photograft polymerization. An increase in the irradiation time resulted in increased gel yield and reduced water swellability. A decrease in the molecular weight of PEGDA and an increase in concentration of both gelatin and PEGDA resulted in reduced water swellability and increased tensile and burst strengths of the resultant gels. In rats whose livers were injured with a trephine in laparotomy, the bleeding spots were coated with the photocurable adhesive glue and irradiated through an optical fiber. The coated solution was immediately converted to a swollen gel. The gel was tightly adhered to the liver tissue presumably by interpenetration, and concomitantly hemostasis was completed. The anastomosis treatment with the photocurable glue in the canine abdominal or thoracic aortas incised with a knife resulted in little bleeding under pulsatile flow after declamping. Histological examination showed that the glues

  18. Bioresorbable Scaffolds for Atheroregression: Understanding of Transient Scaffolding.

    PubMed

    Kharlamov, Alexander N

    2016-01-01

    This review focuses on the clinical and biological features of the bioresorbable scaffolds in interventional cardiology highlighting scientific achievements and challenges of the transient scaffolding with Absorb BVS. Special attention is granted to the vascular biology pathways which, involved in the resorption of scaffold, artery remodeling and mechanisms of Glagovian atheroregression setting the stage for subsequent clinical applications. Twenty five years ago Glagov described the phenomenon of limited external elastic membrane enlargement in response to an increase in plaque burden. We believe this threshold becomes the target for development of strategies that reverse atherosclerosis, and particularly transient scaffolding has a potential to be a tool to ultimately conquer atherosclerosis. PMID:26818488

  19. TGF-β3 encapsulated PLCL scaffold by a supercritical CO2-HFIP co-solvent system for cartilage tissue engineering.

    PubMed

    Kim, Su Hee; Kim, Soo Hyun; Jung, Youngmee

    2015-05-28

    Mimicking the native tissue microenvironment is critical for effective tissue regeneration. Mechanical cues and sustained biological cues are important factors, particularly in load-bearing tissues such as articular cartilage or bone. Carriers including hydrogels and nanoparticles have been investigated to achieve sustained release of protein drugs. However, it is difficult to apply such carriers alone as scaffolds for cartilage regeneration because of their weak mechanical properties, and they must be combined with other biomaterials that have adequate mechanical strength. In this study, we developed the multifunctional scaffold which has similar mechanical properties to those of native cartilage and encapsulates TGF-β3 for chondrogenesis. In our previous work, we confirmed that poly(lactide-co-caprolacton) (PLCL) did not foam when exposed to supercritical CO2 below 45°C. Here, we used a supercritical carbon dioxide (scCO2)-1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) co-solvent system to facilitate processing under mild conditions because high temperature causes protein denaturation and decreases bioactivity of the protein. This processing made it possible to fabricate a TGF-β3 encapsulated elastic porous PLCL scaffold at 37°C. We investigated the tissue regeneration efficiency of the TGF-β3 encapsulated PLCL scaffold using human adipose-derived stem cells (ADSCs) in vitro and in vivo (Groups; i. PLCL scaffold+Fibrin gel+TGF-β3, ii. TGF-β3 encapsulated PLCL scaffold+Fibrin gel, iii. TGF-β3 encapsulated PLCL scaffold). We evaluated the chondrogenic abilities of the scaffolds at 4, 8, and 12weeks after subcutaneous implantation of the constructs in immune-deficient mice. Based on TGF-β3 release studies, we confirmed that TGF-β3 molecules were released by 8weeks and remained in the PLCL matrix. Explants of TGF-β3 encapsulated scaffolds by a co-solvent system exhibited distinct improvement in the compressive E-modulus and deposition of extracellular matrix

  20. [Fibrinogen glue in osteochondral fractures with small fragments of the upper limb].

    PubMed

    Zilch, H; Talke, M

    1987-01-01

    Fibrin sealant presents a satisfactory possibility for reconstruction of the joint surface, especially in cases of little osteochondral fragments. Our experience in 16 patients is detailed. The patients average age was 23 years. 34 osteochondral fragments had been glued in these 16 cases, 10 times at the finger joints, 4 times at the caput radii and 2 times at the trochlea humeri. The patients, who had been operated on from June 1979 to December 1984 have been followed up at an average of 2,1 years after the fibrin gluing. This method can avoid an early arthrodesis or oversized osteosynthetic material. PMID:2447845

  1. Instruction, Cognitive Scaffolding, and Motivational Scaffolding in Writing Center Tutoring

    ERIC Educational Resources Information Center

    Mackiewicz, Jo; Thompson, Isabelle

    2014-01-01

    In this study, we quantitatively analyze the discourse of experienced writing center tutors in 10 highly satisfactory conferences. Specifically, we analyze tutors' instruction, cognitive scaffolding, and motivational scaffolding, all tutoring strategies identified in prior research from other disciplines as educationally effective. We find…

  2. 9 CFR 95.10 - Glue stock; importations permitted subject to restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... disinfection by such method or methods as the Deputy Administrator, Veterinary Services may prescribe unless... permission by the Deputy Administrator, Veterinary Services glue stock may be stored for a temporary period... persons authorized by the Deputy Administrator, Veterinary Services so to do, or without sealing...

  3. 9 CFR 95.10 - Glue stock; importations permitted subject to restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... disinfection by such method or methods as the Deputy Administrator, Veterinary Services may prescribe unless... permission by the Deputy Administrator, Veterinary Services glue stock may be stored for a temporary period... persons authorized by the Deputy Administrator, Veterinary Services so to do, or without sealing...

  4. 9 CFR 95.10 - Glue stock; importations permitted subject to restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... disinfection by such method or methods as the Deputy Administrator, Veterinary Services may prescribe unless... permission by the Deputy Administrator, Veterinary Services glue stock may be stored for a temporary period... persons authorized by the Deputy Administrator, Veterinary Services so to do, or without sealing...

  5. 9 CFR 95.10 - Glue stock; importations permitted subject to restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... disinfection by such method or methods as the Deputy Administrator, Veterinary Services may prescribe unless... permission by the Deputy Administrator, Veterinary Services glue stock may be stored for a temporary period... persons authorized by the Deputy Administrator, Veterinary Services so to do, or without sealing...

  6. Transcatheter Embolization of a Large Symptomatic Pelvic Arteriovenous Malformation with Glubran 2 Acrylic Glue

    SciTech Connect

    Gandini, R.; Angelopoulos, G. Konda, D.; Messina, M.; Chiocchi, M.; Perretta, T.; Simonetti, G.

    2008-09-15

    A young patient affected by a pelvic arteriovenous malformation (pAVM) with recurrent episodes of hematuria following exercise, underwent transcatheter embolization using Glubran 2 acrylic glue (GEM, Viareggio, Italy). All branches of the pAVM were successfully occluded. The patient showed prompt resolution of symptoms and persistent occlusion of the pAVM at the 6 month follow-up.

  7. 9 CFR 95.10 - Glue stock; importations permitted subject to restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Glue stock; importations permitted subject to restrictions. 95.10 Section 95.10 Animals and Animal Products ANIMAL AND PLANT HEALTH... ANIMAL PRODUCTS SANITARY CONTROL OF ANIMAL BYPRODUCTS (EXCEPT CASINGS), AND HAY AND STRAW, OFFERED...

  8. Prosthodontic self-treatment with acrylic resin super glue: a case report.

    PubMed

    Winkler, Sheldon; Wood, Robert; Facchiano, Anne M; Boberick, Kenneth G; Patel, Amita R

    2006-01-01

    A case history is presented of a patient who fabricated 3 prostheses from autopolymerizing acrylic resin intended for fingernail augmentation and then cemented them into her mouth with super glue. Patients must be warned not to attempt self-treatment for esthetics with self-fabricated prostheses because severe adverse and irreversible hard and soft tissue reactions may occur. PMID:16836177

  9. Glueballs, gluon condensate, and pure glue QCD below T{sub c}

    SciTech Connect

    Buisseret, F.

    2011-05-23

    A quasiparticle description of pure glue QCD below T{sub c} is presented. It is shown that the strong decrease of both the gluon condensate and the lightest glueball masses when approaching T{sub c} might be the trigger of the phase transition. The proposed model compares favorably with recent lattice data.

  10. A unique and unexplained ricochet leak post PCI – Successfully treated with intra-coronary glue

    PubMed Central

    Goel, Pravin K.; Syal, Sanjeev K.

    2014-01-01

    We herein describe a unique case of coronary artery perforation treated with covered stent with repeat cardiac tamponade resulting out of a fresh unexplained leak from a remote vessel (Ricochet) and successfully treated with intra-coronary injection of sterile synthetic glue, cyanoacrylate. PMID:24581110

  11. A unique and unexplained ricochet leak post PCI - successfully treated with intra-coronary glue.

    PubMed

    Goel, Pravin K; Syal, Sanjeev K

    2014-01-01

    We herein describe a unique case of coronary artery perforation treated with covered stent with repeat cardiac tamponade resulting out of a fresh unexplained leak from a remote vessel (Ricochet) and successfully treated with intra-coronary injection of sterile synthetic glue, cyanoacrylate. PMID:24581110

  12. Large-area silicon photomultipliers as readout candidates for the GlueX experiment

    NASA Astrophysics Data System (ADS)

    Papandreou, Zisis; Janzen, Kathryn; Lolos, George; Semenov, Andrei; Zorn, Carl

    2009-10-01

    The core mission of the GlueX experiment involves a search for exotic hybrid mesons as evidence of gluonic excitations in an effort to understand confinement in QCD. A key subsystem of the GlueX detector is the electromagnetic barrel calorimeter (BCAL) located inside a 2.5 Tesla superconducting solenoid. Due to this arrangement, light sensors are required that can operate in the high magnetic field environment. Among these, Silicon photomultipliers (SiPMs) are very promising candidates as front-end detectors. To date, routine use of SiPMs has been limited to those with an active area of a few mm^2. GlueX will require 2300 large-area SiPMs, each composed of sixteen 3x3 mm^2 cells arranged in a 4x4 array for a total area of ˜144 mm^2 per array. This has placed the GlueX collaboration in the unique position of driving the technology for such larger-area sensors. In this talk I will present tests carried out at Regina and Jefferson Lab regarding performance parameters of prototype SiPM arrays and their micro subcomponents.

  13. Magnetic Retraction of Bowel by Intraluminal Injectable Cyanoacrylate-Based Magnetic Glue

    PubMed Central

    Brown, Andrew; André, Pascal; Brown, Stuart I.; Florence, Gordon J.; Cuschieri, Alfred

    2013-01-01

    Magnetic retraction offers advantages over physical retraction by graspers because of reduced tissue trauma. The objectives of this study are to investigate a novel method of magnetisation of bowel segments by intraluminal injection of magnetic glue and to demonstrate the feasibility of magnetic retraction of bowel with sufficient force during minimal access surgery. Following an initial materials characterisation study, selected microparticles of stainless steel (SS410-μPs) were mixed with chosen cyanoacrylate glue (Loctite 4014). During intraluminal injection of the magnetic glue using ex vivo porcine colonic segments, a magnetic probe placed at the injected site ensured that the SS410-μPs aggregated during glue polymerisation to form an intraluminal mucosally adherent coagulum. The magnetised colonic segments were retracted by magnetic probes (5 and 10 mm) placed external to the bowel wall. A tensiometer was used to record the retraction force. With an injected volume of 2 mL in a particle concentration of 1 g/mL, this technique produced maximal magnetic retraction forces of 2.24 ± 0.23 N and 5.11 ± 0.34 N (n = 20), with use of 5 and 10 mm probes, respectively. The results indicate that the formation of an intraluminal coagulum based on SS410-μPs and Loctite 4014 produces sufficient magnetic retraction for bowel retraction. PMID:24319684

  14. Embolization with Histoacryl Glue of an Anastomotic Pseudoaneurysm following Surgical Repair of Abdominal Aortic Aneurysm

    PubMed Central

    Walid, Ayesha; Ul Haq, Tanveer; Ur Rehman, Zia

    2013-01-01

    We report a 62-year-old female who had surgical repair of abdominal aortic aneurysm with a bifurcated graft 2 years ago. She presented with a distal anastomotic pseudoaneurysm which was successfully embolized with histoacryl glue. Only one such similar case has been reported in the literature so far (Yamagami et al. (2006)). PMID:23476883

  15. [Fixing of osteochondral fragments with fibrinogen glue. Clinical experiences (author's transl)].

    PubMed

    Zilch, H; Friedebold, G

    1981-08-01

    Small osteochondral fragments are well fixed with the fibrinogen glue. This method is really a progress in comparison with the traditional fixation by screws or K-wires. The fragments were revascularized early. This is demonstrated by 31 glued osteochondral fragments which healed well. The joints must be immobilized during a period of 3 weeks. PMID:6118021

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

    PubMed

    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. PMID:23808842

  17. A Safe and Efficient Method to Retrieve Mesenchymal Stem Cells from Three-Dimensional Fibrin Gels

    PubMed Central

    Carrion, Bita; Janson, Isaac A.; Kong, Yen P.

    2014-01-01

    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. PMID:23808842

  18. GENIPIN-CROSSLINKED FIBRIN HYDROGELS AS A POTENTIAL ADHESIVE TO AUGMENT INTERVERTEBRAL DISC ANNULUS REPAIR

    PubMed Central

    Schek, R.M.; Michalek, A.J.; Iatridis, J.C.

    2011-01-01

    Treatment of damaged intervertebral discs is a significant clinical problem and, despite advances in the repair and replacement of the nucleus pulposus, there are few effective strategies to restore defects in the annulus fibrosus. An annular repair material should meet three specifications: have a modulus similar to the native annulus tissue, support the growth of disc cells, and maintain adhesion to tissue under physiological strain levels. We hypothesized that a genipin crosslinked fibrin gel could meet these requirements. Our mechanical results showed that genipin crosslinked fibrin gels could be created with a modulus in the range of native annular tissue. We also demonstrated that this material is compatible with the in vitro growth of human disc cells, when genipin:fibrin ratios were 0.25:1 or less, although cell proliferation was slower and cell morphology more rounded than for fibrin alone. Finally, lap tests were performed to evaluate adhesion between fibrin gels and pieces of annular tissue. Specimens created without genipin had poor handling properties and readily delaminated, while genipin crosslinked fibrin gels remained adhered to the tissue pieces at strains exceeding physiological levels and failed at 15–30%. This study demonstrated that genipin crosslinked fibrin gels show promise as a gap-filling adhesive biomaterial with tunable material properties, yet the slow cell proliferation suggests this biomaterial may be best suited as a sealant for small annulus fibrosus defects or as an adhesive to augment large annulus repairs. Future studies will evaluate degradation rate, fatigue behaviors, and long-term biocompatibility. PMID:21503869

  19. The influence of type 2 diabetes on fibrin clot properties in patients with coronary artery disease.

    PubMed

    Neergaard-Petersen, S; Hvas, A-M; Kristensen, S D; Grove, E L; Larsen, S B; Phoenix, F; Kurdee, Z; Grant, P J; Ajjan, R A

    2014-12-01

    Type 2 diabetes mellitus (T2DM) increases the risk of coronary thrombosis and both conditions are associated with altered fibrin clot properties. However, the influence of T2DM on fibrin clot properties in patients with coronary artery disease (CAD) remains unclear. We aimed to investigate the influence of T2DM on fibrin clot properties in patients with CAD. Fibrin clot structure and fibrinolysis were investigated in 581 CAD patients (148 with T2DM) using turbidimetric assays, confocal and scanning electron microscopy. Clots made from plasma and plasma-purified fibrinogen were studied, and plasma levels of inflammatory markers were analysed. T2DM patients had increased clot maximum absorbance compared with non-diabetic patients (0.36 ± 0.1 vs 0.33 ± 0.1 au; p=0.01), displayed longer lysis time (804 [618;1002] vs 750 [624;906] seconds; p=0.03) and showed more compact fibrin structure assessed by confocal and electron microscopy. Fibrinogen levels were elevated in T2DM (p< 0.001), but clots made from purified fibrinogen showed no differences in fibrin properties in the two populations. Adjusting for fibrinogen levels, T2DM was associated with C-reactive protein and complement C3 plasma levels, with the former correlating with clot maximum absorbance (r=0.24, p< 0.0001) and the latter with lysis time (r=0.30, p< 0.0001). Independent of fibrinogen levels, females had more compact clots with prolonged lysis time compared with males (all p-values< 0.001). In conclusion, T2DM is associated with prothrombotic changes in fibrin clot properties in patients with CAD. This is related to quantitative rather than qualitative changes in fibrinogen with a possible role for inflammatory proteins. PMID:25187394

  20. A comparative evaluation of the blood clot, platelet-rich plasma, and platelet-rich fibrin in regeneration of necrotic immature permanent teeth: A clinical study

    PubMed Central

    Narang, Isha; Mittal, Neelam; Mishra, Navin

    2015-01-01

    Introduction: This study was designed as a clinical trial to evaluate and compare the regenerative potential of platelet-rich fibrin (PRF), platelet-rich plasma (PRP), and blood clot in immature necrotic permanent teeth with or without associated apical periodontitis. Methods: Access preparation was done under rubber dam isolation. Copious irrigation was done with 2.5% NaOCl and triple antibiotic paste was placed as an intracanal medicament. After 4 weeks, the cases were divided into four groups with five patients in each group. The study design had three test arms and one control arm. Group I in which mineral trioxide aggregate apexification was carried out and it was kept as control group to evaluate the regenerative potential of blood clot and platelet concentrates, Group II in which blood clot was used as scaffold in the canal, Group III in PRF was used as scaffold, and Group IV in which PRP carried on collagen was used as a scaffold. Results: The clinical and radiographic evaluation after 6 and 18 months was done by two independent observers who were blinded from the groups. The scoring was done as: None score was denoted by, Fair by 1, Good by 2, and Excellent by 3. The data were then analyzed statistically by Fisher's exact test using Statistics and Data 11.1(PRP Using harvest Smart PReP2) which showed statistically significant values in Group III as compared to other Groups. Conclusion: PRF has huge potential to accelerate the growth characteristics in immature necrotic permanent teeth as compared to PRP and blood clot. PMID:25684914

  1. Photoinduced Bioorthogonal 1,3-Dipolar Poly-cycloaddition Promoted by Oxyanionic Substrates for Spatiotemporal Operation of Molecular Glues.

    PubMed

    Hatano, Junichi; Okuro, Kou; Aida, Takuzo

    2016-01-01

    PGlue(PZ), a pyrazoline (PZ)-based fluorescent adhesive which can be generated spatiotemporally in living systems, was developed. Since PGlue(PZ) carries many guanidinium ion (Gu(+)) pendants, it strongly adheres to various oxyanionic substrates through a multivalent salt-bridge interaction. PGlue(PZ) is given by bioorthogonal photopolymerization of a Gu(+)-appended monomer (Glue(TZ)), bearing tetrazole (TZ) and olefinic termini. Upon exposure to UV light, Glue(TZ) transforms into a nitrileimine (NI) intermediate (Glue(NI)), which is eligible for 1,3-dipolar polycycloaddition. However, Glue(NI) in aqueous media can concomitantly be deactivated into Glue(WA) by the addition of water, and the polymerization hardly occurs unless Glue(NI) is concentrated. We found that, even under high dilution, Glue(NI) is concentrated on oxyanionic substrates to a sufficient level for the polymerization, so that their surfaces can be point-specifically functionalized with PGlue(PZ) by the use of a focused beam of UV light. PMID:26530322

  2. Enhancement of withstanding pressure of fibrin sealant by modified mixing ratio of fibrin sealant components for skull base reconstruction: technical note.

    PubMed

    Saitoh, Youichi; Oshino, Satoru

    2013-01-01

    A method to enhance the withstanding pressure of fibrin sealant in gasket-seal closure to prevent cerebrospinal fluid (CSF) leakage after extended transsphenoidal surgery (ETSS) was investigated by adjusting the mixing ratio of the components. A plastic chamber (200 ml) was constructed with a lid made of hydroxyapatite with a hole 10 mm in diameter. The chamber could be pressurized via an opening in the side wall. The hole in the hydroxyapatite lid was covered with a Gore-Tex sheet, 15 mm in diameter. The margin of the sheet was free. Solutions A (fibrinogen 80 mg/ml) and B (thrombin 250 units/ml) of fibrin sealant were mixed in volume ratios of 1:1, 2:1, and 5:1, and applied to the Gore-Tex sheet, then water was introduced to cover the fibrin sealant. The pressure was measured at which air leakage occurred from the side of the Gore-Tex sheet. The pressure values for A/B ratios of 1:1, 2:1, and 5:1 were 117 ± 23.8 mmH(2)O (mean ± standard error) (n = 5), 234 ± 38.8 mmH(2)O (n = 5), and 345 ± 36.4 mmH(2)O (n = 5), respectively, in the acute phase (5 minutes after application of fibrin sealant). Pressures were increased after 24 hours, and that for 5:1 was the highest (373 ± 40.4 mmH(2)O, n = 5). The use of devices such as syringes specially designed to mix solutions A and B in the ratio of 5:1 can easily enhance the preventive effect of fibrin sealant against CSF leakage in ETSS. PMID:23358175

  3. Endoscopic variceal ligation caused massive bleeding due to laceration of an esophageal varicose vein with tissue glue emboli

    PubMed Central

    Wei, Xiu-Qing; Gu, Hua-Ying; Wu, Zhi-E; Miao, Hui-Biao; Wang, Pei-Qi; Wen, Zhuo-Fu; Wu, Bin

    2014-01-01

    Endoscopic variceal obturation of gastric varices with tissue glue is considered the first choice for management of gastric varices, and is usually safe and effective. However, there is still a low incidence of complications and some are even fatal. Here, we present a case in which endoscopic variceal ligation caused laceration of the esophageal varicose vein with tissue glue emboli and massive bleeding after 3 mo. Cessation of bleeding was achieved via variceal sclerotherapy using a cap-fitted gastroscope. Methods of recognizing an esophageal varicose vein with tissue glue plug are discussed. PMID:25400482

  4. Endoscopic variceal ligation caused massive bleeding due to laceration of an esophageal varicose vein with tissue glue emboli.

    PubMed

    Wei, Xiu-Qing; Gu, Hua-Ying; Wu, Zhi-E; Miao, Hui-Biao; Wang, Pei-Qi; Wen, Zhuo-Fu; Wu, Bin

    2014-11-14

    Endoscopic variceal obturation of gastric varices with tissue glue is considered the first choice for management of gastric varices, and is usually safe and effective. However, there is still a low incidence of complications and some are even fatal. Here, we present a case in which endoscopic variceal ligation caused laceration of the esophageal varicose vein with tissue glue emboli and massive bleeding after 3 mo. Cessation of bleeding was achieved via variceal sclerotherapy using a cap-fitted gastroscope. Methods of recognizing an esophageal varicose vein with tissue glue plug are discussed. PMID:25400482

  5. Shear flow affects selective monocyte recruitment into MCP-1-loaded scaffolds.

    PubMed

    Smits, Anthal I P M; Ballotta, Virginia; Driessen-Mol, Anita; Bouten, Carlijn V C; Baaijens, Frank P T

    2014-11-01

    Novel cardiovascular replacements are being developed by using degradable synthetic scaffolds, which function as a temporary guide to induce neotissue formation directly in situ. Priming of such scaffolds with fast-releasing monocyte chemoattractant protein-1 (MCP-1) was shown to improve the formation of functional neoarteries in rats. However, the underlying mechanism has not been clarified. Therefore, the goal of this study was to investigate the effect of a burst-release of MCP-1 from a synthetic scaffold on the local recruitment of circulating leucocytes under haemodynamic conditions. Herein, we hypothesized that MCP-1 initiates a desired healing cascade by recruiting favourable monocyte subpopulations into the implanted scaffold. Electrospun poly(ε-caprolactone) scaffolds were loaded with fibrin gel containing various doses of MCP-1 and exposed to a suspension of human peripheral blood mononuclear cells in static or dynamic conditions. In standard migration assay, a dose-dependent migration of specific CD14(+) monocyte subsets was observed, as measured by flow cytometry. In conditions of pulsatile flow, on the other hand, a marked increase in immediate monocyte recruitment was observed, but without evident selectivity in monocyte subsets. This suggests that the selectivity was dependent on the release kinetics of the MCP-1, as it was overruled by the effect of shear stress after the initial burst-release. Furthermore, these findings demonstrate that local recruitment of specific MCP-1-responsive monocytes is not the fundamental principle behind the improved neotissue formation observed in long-term in vivo studies, and mobilization of MCP-1-responsive cells from the bone marrow into the bloodstream is suggested to play a predominant role in vivo. PMID:25103256

  6. Using blocking peptides to control and analyze the mechanical properties of single fibrin fibers

    NASA Astrophysics Data System (ADS)

    Maddi, Pranav; O'Brien, E. Tim, III; Gorkun, Oleg; Falvo, Michael R.

    2011-10-01

    Fibrin is the main structural protein involved in blood clotting, and exhibits high strength and elasticity. Fibrin study traditionally focuses on fully formed clots, whereas we employ new AFM nanoManipulation techniques to study single fibrin fiber mechanics. We used 4 and 10 residue peptides to interfere with the knob-hole and αC interactions involved in fibrin polymerization to evaluate the contribution of each interaction to the fiber's mechanical properties. We varied the concentration of each peptide present during polymerization to find the concentration that inhibited polymerization by half. The presence of either peptide during fibrin polymerization did not affect single fiber breaking strain (δLL0). The breaking force of all treated fibers reduced from 10-50nN to 2-10nN, suggesting treated fibers are thinner or are the same diameter with some inhibition of interactions. Fibers polymerized with the knob-hole targeting peptide visibly lost elasticity after 100% strain, while fibers polymerized with the αC targeting peptide lost elasticity after reaching 150% strain, suggesting that the knob-hole interactions control single fiber elasticity.

  7. A comparative study of skin cell activities in collagen and fibrin constructs.

    PubMed

    Law, Jia Xian; Musa, Faiza; Ruszymah, Bt Hj Idrus; El Haj, Alicia J; Yang, Ying

    2016-09-01

    Collagen and fibrin are widely used in tissue engineering due to their excellent biocompatibility and bioactivities that support in vivo tissue formation. These two hydrogels naturally present in different wound healing stages with different regulatory effects on cells, and both of them are mechanically weak in the reconstructed hydrogels. We conducted a comparative study by the growth of rat dermal fibroblasts or dermal fibroblasts and epidermal keratinocytes together in collagen and fibrin constructs respectively with and without the reinforcement of electrospun poly(lactic acid) nanofiber mesh. Cell proliferation, gel contraction and elastic modulus of the constructs were measured on the same gels at multiple time points during the 22 day culturing period using multiple non-destructive techniques. The results demonstrated considerably different cellular activities within the two types of constructs. Co-culturing keratinocytes with fibroblasts in the collagen constructs reduced the fibroblast proliferation, collagen contraction and mechanical strength at late culture point regardless of the presence of nanofibers. Co-culturing keratinocytes with fibroblasts in the fibrin constructs promoted fibroblast proliferation but exerted no influence on fibrin contraction and mechanical strength. The presence of nanofibers in the collagen and fibrin constructs played a favorable role on the fibroblast proliferation when keratinocytes were absent. Thus, this study exhibited new evidence of the strong cross-talk between keratinocytes and fibroblasts, which can be used to control fibroblast proliferation and construct contraction. This cross-talk activity is extracellular matrix-dependent in terms of the fibrous network morphology, density and strength. PMID:27349492

  8. Flow and delta-P dictate where thrombin, fibrin, and von Willebrand Factor will be found.

    PubMed

    Diamond, Scott L

    2016-05-01

    Hemostasis occurs in two different topological scenarios: complete severing of a vessel or disruption of the vessel wall. Either to meet the daily rigors of active life or during an acute trauma, hemostasis involves the regulated and self-limiting production of thrombin to stop bleeding. In contrast, arterial and venous thrombosis typically involves the unregulated, intraluminal growth of a clot, in the absence of bleeding. For either hemostasis or thrombosis, the presence of flow and pressure gradients (delta-P, ΔP) dictates when and where thrombin and fibrin are located and in what quantity. For hemostatic clots, fibrin formation helped limit clot growth. We found that γ'-fibrinogen had a role in limiting clot growth via anti-thrombin activity at venous, but not arterial conditions. For hemophilic blood, severe factor deficiency (<1% healthy) led to a defect in both platelet and fibrin deposition under flow. However, moderate deficiency, which is associated with a less severe bleeding phenotype, had normalized platelet function but still lacked fibrin production. We conclude signaling levels of thrombin can be generated during moderate hemophilia to sufficiently activate platelets to achieve primary hemostasis, even if fibrin formation remains defective. Finally, as a clot grows, shear stresses can become sufficiently extreme in diseased arteries to drive von Willebrand Factor self-association into massive fibers, potentially the final burst of clot growth towards full thrombotic occlusion. PMID:27207416

  9. Dynamic behaviors of astrocytes in chemically modified fibrin and collagen hydrogels.

    PubMed

    Seyedhassantehrani, Negar; Li, Yongchao; Yao, Li

    2016-05-16

    Astrocytes play a critical role in supporting the normal physiological function of neurons in the central nervous system (CNS). Astrocyte transplantation can potentially promote axonal regeneration and functional recovery after spinal cord injury (SCI). Fibrin and collagen hydrogels provide growth-permissive substrates and serve as carriers for therapeutic cell transplantation into an injured spinal cord. However, the application of fibrin and collagen hydrogels may be limited due to their relatively rapid degradation rate in vivo. In this study, immature astrocytes isolated from neonatal rats were grown in fibrin hydrogels containing aprotinin and collagen hydrogels crosslinked with poly(ethylene glycol) ether tetrasuccinimidyl glutarate (4S-StarPEG), and the cell behavior in these hydrogels was studied. The cell viability of astrocytes in the hydrogels was tested using the LIVE/DEAD® assay and the AlamarBlue® assay, and this study showed that astrocytes maintained good viability in these hydrogels. The cell migration study showed that astrocytes migrated in the fibrin and collagen hydrogels, and the migration speed is similar in these hydrogels. The crosslinking of collagen hydrogels with 4S-StarPEG did not change the astrocyte migration speed. However, the addition of aprotinin in the fibrin hydrogel inhibited astrocyte migration. The expression of chondroitin sulfate proteoglycan (CSPG), including NG2, neurocan, and versican, by astrocytes grown in the hydrogels was analyzed by quantitative RT-PCR. The expression of NG2, neurocan, and versican by the cells in these hydrogels was not significantly different. PMID:27079938

  10. Treatment of gingival recession using free gingival graft with fibrin fibronectin sealing system: A novel approach.

    PubMed

    Srinivas, B V V; Rupa, N; Halini Kumari, K V; Rajender, A; Reddy, M Narendra

    2015-08-01

    Periodontal plastic surgery is the branch of periodontology that is focused mainly on the correction or elimination of mucogingival problems associated with lack of attached gingiva, a shallow vestibule and aberrant frenum. Various mucogingival surgical procedures are used to halt the progression of the gingival recession and to correct poor esthetic appearance. Free gingival autograft is one of the most common techniques used for a gingival recession in areas of inadequate attached gingiva in the mandibular anterior region. Fibrin sealants are human plasma derivatives that mimic the final stages of blood coagulation, forming a fibrin clot. Fibrin Sealants enhances the overall outcome of surgical intervention because of their hemostatic, adhesive, and healing properties. These properties of fibrin sealants may reduce operating time, prevent complications, and enhance the overall outcome of many surgical interventions. Hence, this case report aims to investigate the clinical effectiveness of free gingival graft along with the commercially available fibrin-fibronectin sealing system (Tissucol(®)) in the treatment of Miller's class II gingival recession. PMID:26538956

  11. A Synthetic Fibrin-Crosslinking Polymer for Modulating Clot Properties and Inducing Hemostasis

    PubMed Central

    Chan, Leslie W.-G.; Wang, Xu; Wei, Hua; Pozzo, Lilo D.; White, Nathan J.; Pun, Suzie H.

    2015-01-01

    Clotting factor replacement is the standard management of acute bleeding in congenital and acquired bleeding disorders. We present a synthetic approach to hemostasis using an engineered hemostatic polymer (PolySTAT) that circulates innocuously in the blood, identifies sites of vascular injury, and promotes clot formation to stop bleeding. PolySTAT induces hemostasis by crosslinking the fibrin matrix within clots, mimicking the function of the transglutaminase Factor XIII. Furthermore, synthetic PolySTAT binds specifically to fibrin monomers and is uniformly integrated into fibrin fibers during fibrin polymerization, resulting in a fortified, hybrid polymer network with enhanced resistance to enzymatic degradation. In vivo hemostatic activity was confirmed in a rat model of trauma and fluid resuscitation in which intravenous administration of PolySTAT improved survival by reducing blood loss and resuscitation fluid requirements. PolySTAT-induced fibrin crosslinking is a novel approach to hemostasis utilizing synthetic polymers for non-invasive modulation of clot architecture with potentially wide-ranging therapeutic applications. PMID:25739763

  12. Fibrin-Induced Skin Fibrosis in Mice Deficient in Tissue Plasminogen Activator

    PubMed Central

    de Giorgio-Miller, Alexander; Bottoms, Steve; Laurent, Geoffrey; Carmeliet, Peter; Herrick, Sarah

    2005-01-01

    The deposition of fibrin is an integral part of the tissue repair process, but its persistence is also associated with a number of fibrotic conditions. This study addressed the hypothesis that reduced fibrinolysis and fibrin persistence are associated with an enhanced accumulation of collagen and the development of skin fibrosis. Decreased fibrinolysis was confirmed in fibrin gel cultures that contained human dermal fibroblasts plus the specific plasmin inhibitor α2-antiplasmin or dermal fibroblasts isolated from plasminogen activator (PA)-deficient mice. Collagen accumulation was significantly increased in the presence of inhibitor and in tPA-deficient, but not uPA-deficient, fibroblasts compared with controls. These findings were also confirmed using a skin fibrosis model in which multiple injections of fibrin were given subcutaneously to PA-deficient mice. Injection sites from tPA-deficient mice displayed significantly increased collagen levels compared with uPA-deficient mice and wild-type controls. Up-regulation of fibroblast procollagen gene expression and reduced activation of pro-MMP-1 appeared to mediate the increase in collagen by human dermal fibroblasts in the presence of α2-antiplasmin. These findings suggest that persistent fibrin is associated with enhanced collagen accumulation that may result in the development of fibrotic skin disorders in which reduced fibrinolysis is a feature. PMID:16127152

  13. Characterization of Fibrin and Collagen Gels for Engineering Wound Healing Models

    PubMed Central

    Moreno-Arotzena, Oihana; Meier, Johann G.; del Amo, Cristina; García-Aznar, José Manuel

    2015-01-01

    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. PMID:26290683

  14. Using Scaffolds in Problem-Based Hypermedia

    ERIC Educational Resources Information Center

    Su, Yuyan; Klein, James D.

    2010-01-01

    This study investigated the use of scaffolds in problem-based hypermedia. Three hundred and twelve undergraduate students enrolled in a computer literacy course worked in project teams to use a hypermedia PBL program focused on designing a personal computer. The PBL program included content scaffolds, metacognitive scaffolds, or no scaffolds.…

  15. Electrospun multifunctional tissue engineering scaffolds

    NASA Astrophysics Data System (ADS)

    Wang, Chong; Wang, Min

    2014-03-01

    Tissue engineering holds great promises in providing successful treatments of human body tissue loss that current methods are unable to treat or unable to achieve satisfactory clinical outcomes. In scaffold-based tissue engineering, a highperformance scaffold underpins the success of a tissue engineering strategy and a major direction in the field is to create multifunctional tissue engineering scaffolds for enhanced biological performance and for regenerating complex body tissues. Electrospinning can produce nanofibrous scaffolds that are highly desirable for tissue engineering. The enormous interest in electrospinning and electrospun fibrous structures by the science, engineering and medical communities has led to various developments of the electrospinning technology and wide investigations of electrospun products in many industries, including biomedical engineering, over the past two decades. It is now possible to create novel, multicomponent tissue engineering scaffolds with multiple functions. This article provides a concise review of recent advances in the R & D of electrospun multifunctional tissue engineering scaffolds. It also presents our philosophy and research in the designing and fabrication of electrospun multicomponent scaffolds with multiple functions.

  16. Enhancing Osteoconductivity of Fibrin Gels with Apatite-Coated Polymer Microspheres

    PubMed Central

    Davis, Hillary E.; Binder, Bernard Y.K.; Schaecher, Phillip; Yakoobinsky, Dana D.; Bhat, Archana

    2013-01-01

    Fibrin gels are a promising material for use in promoting bone repair and regeneration due to their ease of implant formation, tailorability, biocompatibility, and degradation by natural processes. However, these materials lack necessary osteoconductivity to nucleate calcium, integrate with surrounding bone, and promote bone formation. Polymeric substrata formed from poly(lactide-co-glycolide) (PLG) are widely used in bone tissue engineering. A carbonated apatite layer of bone-like mineral can be successfully grown on the surface of PLG microspheres after a multiday incubation process in modified simulated body fluid. Such coatings improve the osteoconductivity of the polymer, provide nucleation sites for cell-secreted calcium, and enhance the potential osseointegration with host tissue. We examined the capacity of mineralized polymeric microspheres suspended within fibrin hydrogels to enhance the osteoconductivity of fibrin gels and increase the osteogenic potential of these materials. The inclusion of microparticles, both nonmineralized and mineralized, reduced the capacity of mesenchymal stem cells (MSCs) to contract the gel. When cultured in osteogenic media, we detected a near linear increase in both calcium and phosphate incorporation in gels containing mineralized microspheres and entrapped MSCs. The osteoconductivity of acellular fibrin gels with mineralized and nonmineralized microspheres was assessed in a rodent calvarial bone defect over 12 weeks. Compared to untreated rodent calvarial bone defects, we detected significant increases in early vascularization when treated with fibrin gels, with greater vascularization, on average, occurring with gels containing microspheres. We detected a trend for increased bone mineral density in gels containing mineralized microspheres after 12 weeks. These findings demonstrate that the osteoconductivity of fibrin gels can be increased by inclusion of mineralized microspheres, but additional signals may be required to

  17. C-reactive protein and fibrin clot strength measured by thrombelastography after coronary stenting

    PubMed Central

    Kreutz, Rolf P.; Owens, Janelle; Breall, Jeffrey A.; Lu, Deshun; von der Lohe, Elisabeth; Bolad, Islam; Sinha, Anjan; Flockhart, David A.

    2014-01-01

    Inflammation is implicated in the progression of coronary artery disease and the molecular processes of inflammation and thrombosis are closely intertwined. Elevated levels of C-reactive protein (CRP) have been associated with an elevated risk of adverse ischaemic events after coronary stenting and hypercoagulability. Heightened whole blood clot strength measured by thrombelastography (TEG) has been associated with adverse ischaemic events after stenting. We intended to examine the relationship of CRP to plasma fibrin clot strength in patients after coronary stenting. Plasma fibrin clot strength was measured by TEG in 54 patients 16–24 h after undergoing elective percutaneous coronary intervention (PCI). Coagulation was induced in citrated plasma by addition of kaolin and CaCl2. Plasma levels of CRP and fibrinogen were measured by enzyme-linked immunoassay. Increasing quartiles of CRP were associated with increasing levels of maximal plasma fibrin clot strength measured by TEG (P < 0.001) and increasing BMI (P =0.04). Patients in the highest quartile of CRP had significantly higher maximal fibrin clot strength (G) than the patients in the lowest quartile (G: 3438 ± 623 vs. 2184 ± 576 dyn/cm2, P < 0.0001). Fibrinogen concentration was not significantly different across quartiles of CRP (P =0.97). Patients with established coronary artery disease undergoing coronary stenting who have elevated CRP after PCI exhibit heightened maximal plasma fibrin clot strength as compared with those with low CRP. Thrombotic risk associated with elevated CRP may be linked to procoagulant changes and high tensile fibrin clot strength independent of fibrinogen concentration. PMID:23429252

  18. C-reactive protein and fibrin clot strength measured by thrombelastography after coronary stenting.

    PubMed

    Kreutz, Rolf P; Owens, Janelle; Breall, Jeffrey A; Lu, Deshun; von der Lohe, Elisabeth; Bolad, Islam; Sinha, Anjan; Flockhart, David A

    2013-04-01

    Inflammation is implicated in the progression of coronary artery disease and the molecular processes of inflammation and thrombosis are closely intertwined. Elevated levels of C-reactive protein (CRP) have been associated with an elevated risk of adverse ischaemic events after coronary stenting and hypercoagulability. Heightened whole blood clot strength measured by thrombelastography (TEG) has been associated with adverse ischaemic events after stenting. We intended to examine the relationship of CRP to plasma fibrin clot strength in patients after coronary stenting. Plasma fibrin clot strength was measured by TEG in 54 patients 16-24 h after undergoing elective percutaneous coronary intervention (PCI). Coagulation was induced in citrated plasma by addition of kaolin and CaCl2. Plasma levels of CRP and fibrinogen were measured by enzyme-linked immunoassay. Increasing quartiles of CRP were associated with increasing levels of maximal plasma fibrin clot strength measured by TEG (P < 0.001) and increasing BMI (P = 0.04). Patients in the highest quartile of CRP had significantly higher maximal fibrin clot strength (G) than the patients in the lowest quartile (G: 3438 ± 623 vs. 2184 ± 576 dyn/cm, P < 0.0001). Fibrinogen concentration was not significantly different across quartiles of CRP (P = 0.97). Patients with established coronary artery disease undergoing coronary stenting who have elevated CRP after PCI exhibit heightened maximal plasma fibrin clot strength as compared with those with low CRP. Thrombotic risk associated with elevated CRP may be linked to procoagulant changes and high tensile fibrin clot strength independent of fibrinogen concentration. PMID:23429252

  19. Mesenchymal stromal cells form vascular tubes when placed in fibrin sealant and accelerate wound healing in vivo.

    PubMed

    Mendez, Julio J; Ghaedi, Mahboobe; Sivarapatna, Amogh; Dimitrievska, Sashka; Shao, Zhen; Osuji, Chinedum O; Steinbacher, Derek M; Leffell, David J; Niklason, Laura E

    2015-02-01

    Non-healing, chronic wounds are a growing public health problem and may stem from insufficient angiogenesis in affected sites. Here, we have developed a fibrin formulation that allows adipose-derived mesenchymal stromal cells (ADSCs) to form tubular structures in vitro. The tubular structures express markers of endothelium, including CD31 and VE-Cadherin, as well as the pericyte marker NG2. The ability for the MSCs to form tubular structures within the fibrin gels was directly dependent on the stoichiometric ratios of thrombin and fibrinogen and the resulting gel concentration, as well as on the presence of bFGF. Fibrin gel formulations that varied in stiffness were tested. ADSCs that are embedded in a stiff fibrin formulation express VE-cadherin and CD31 as shown by PCR, FACS and immunostaining. Confocal imaging analysis demonstrated that tubular structures formed, containing visible lumens, in the stiff fibrin gels in vitro. There was also a difference in the amounts of bFGF secreted by ADSCs grown in the stiffer gels as compared to softer gels. Additionally, hAT-MSCs gave rise to perfusable vessels that were VE-cadherin positive after subcutaneous injection into mice, whereas the softer fibrin formulation containing ADSCs did not. The application of ADSCs delivered in the stiff fibrin gels allowed for the wounds to heal more quickly, as assessed by wound size, amount of granulation tissue and collagen content. Interestingly, following 5 days of healing, the ADSCs remained within the fibrin gel and did not integrate into the granulation tissue of healing wounds in vivo. These data show that ADSCs are able to form tubular structures within fibrin gels, and may also contribute to faster wound healing, as compared with no treatment or to wounds treated with fibrin gels devoid of ADSCs. PMID:25433608

  20. Thrombus on Indwelling Central Venous Catheters: The Histopathology of 'Fibrin Sheaths'

    SciTech Connect

    Suojanen, James Norman; Brophy, David Paul; Nasser, Imad

    2000-03-15

    Purpose: Central venous catheters (CVC) may fail for many reasons, though 'fibrin sheaths' blocking catheter ports are usually implicated. We examined the sheaths removed from dialysis catheters to determine their histopathology.Methods: Ten catheter strippings were performed and the removed material was studied grossly and microscopically.Results: The histologic specimens showed thrombus both with and without a proteinaceous sheath.Conclusion: Dialysis catheters fail because of thrombus formation. This can occur in either the absence or presence of a protein coating on the catheter, the so-called 'fibrin sheath.'.

  1. Plasma fibrin clot phenotype independently affects intracoronary thrombus ultrastructure in patients with acute myocardial infarction.

    PubMed

    Zalewski, Jaroslaw; Bogaert, Jan; Sadowski, Marcin; Woznicka, Olga; Doulaptsis, Konstantinos; Ntoumpanaki, Maria; Ząbczyk, Michal; Nessler, Jadwiga; Undas, Anetta

    2015-06-01

    Determinants of intracoronary thrombus (ICT) composition in patients with ST-elevation myocardial infarction (STEMI) are largely unknown. We sought to investigate whether plasma fibrin phenotype and platelet reactivity affect ICT ultrastructure. We assessed the content of fibrin, platelets and erythrocytes including polyhedrocytes by scanning electron microscopy on the surface and inside ICT aspirated from 80 STEMI patients within 12 hours since chest pain onset. Plasma fibrin clot permeability (Ks), which indicates the average pore size, lysis time (t50 %), platelet reactivity index (PRI) and ADP-induced platelet aggregation (ADP5, 20µM) were evaluated on admission. All patients received aspirin and 45 (56.3 %) 600 mg of clopidogrel, 80 (60-120) min prior to aspiration. Higher content of fibrin (61.6 vs 34.3 %, P< 0.0001) and platelets (8.2 vs 4.8 %, P=0.018) and lower erythrocyte content (15.8 vs 42.9 %, P< 0.0001) were found on ICT surface compared with its inner part. After adjustment for fibrinogen, in both ICT parts fibrin content was correlated with Ks (r≤-0.55, P< 0.0001) and t50 % (r≥ 0.29, P≤ 0.02) but not with PRI and ADP5,20µM. Polyhedrocytes were observed in 16 (20 %) patients and their large amount expressed as ≥ 50 % fields of view covered by polyhedrocytes was associated with the lower PRI values (40 vs 69 %, P=0.015), but not Ks or t50 %. By multivariate regression, Ks (β=-0.62, P< 0.0001), clopidogrel pretreatment (β=-0.36, P< 0.001), ischemia time (β=0.19, P=0.044) and family history (β=0.18, P=0.049) independently predicted fibrin content in the whole ICT (R²=0.65, P< 0.0001). Formation of denser plasma fibrin clots is independently associated with high fibrin content within the ICT in STEMI. PMID:25739375

  2. Study of nano imprinting using soft lithography on Krafty glue and PVDF polymer thin films

    SciTech Connect

    Sankar, M. S. Ravi Gangineni, Ramesh Babu

    2014-04-24

    The present work reveals soft lithography strategy based on self assembly and replica molding for carrying out micro and nanofabrication. It provides a convenient, effective and very low cost method for the formation and manufacturing of micro and nano structures. Al-layer of compact disc (sony CD-R) used as a stamp with patterned relief structures to generate patterns and structures with pattern size of 100nm height, 1.7 μm wide. In literature, PDMS (Polydimethylsiloxane) solution is widely used to get negative copy of the Al-layer. In this work, we have used inexpensive white glue (Polyvinylacetate + water), 15gm (□5) and PVDF (Polyvinylidene difluoride) spin coated films and successfully transferred the nano patterns of Al layer on to white glue and PVDF films.

  3. Development of silicon photomultipliers and their applications to GlueX calorimetry

    NASA Astrophysics Data System (ADS)

    Smith, Elton S.

    2016-07-01

    The GlueX experiment is a photoproduction experiment in Hall D at Jefferson Lab that is being commissioned for use with the new 12 GeV accelerator. The purpose of the experiment is to search for Hybrid mesons, which are mesons with quark and gluon degrees of freedom. The barrel calorimeter of GlueX is instrumented with 4000 large-area (1.2 × 1.2 cm2) silicon photomultipliers (SiPMs). These photon sensors have properties similar to vacuum photomultipliers, but are unaffected by high magnetic fields. In our experiment they operate in magnetic fields exceeding 1T. After extensive tests with a variety of sensors, we chose the S12045(X) custom SiPM arrays manufactured by Hamamatsu Corporation, also known as multi-pixel photon counters (MPPCs). We will give an overview of this new technology as well as the experience gained during two commissioning periods with beam.

  4. Successful percutaneous angioembolisation of bleeding jejunal varix by acrylate glue and coils

    PubMed Central

    Haq, Tanveer Ul; AlQamari, Nauman; Sayani, Raza; Hilal, Kiran

    2013-01-01

    Portal hypertension is a common disease worldwide. One of its rare complications is bleeding jejunal varices which is usually asymptomatic and may present with gastrointestinal bleeding. We present a case of a jejunal bleeding that was successfully embolised with acrylate glue and embolisation coils. A middle-aged woman with a history of multiple abdominal surgeries for adenocarcinoma of right ovary, presented to us with multiple episodes of haematochezia. On a CT scan of the abdomen, she was diagnosed with chronic liver disease with portal hypertension, multiple varices at porto-systemic anastomosis and ectopic jejunal varix. She was treated by interventional radiologists by percutaneous embolisation of bleeding varix using glue and embolisation coils through a portal venous approach. PMID:24158303

  5. The Research of Improving the Particleboard Glue Dosing Process Based on TRIZ Analysis

    NASA Astrophysics Data System (ADS)

    Yu, Huiling; Fan, Delin; Zhang, Yizhuo

    This research creates a design methodology by synthesizing the Theory of Inventive Problem Solving (TRIZ) and cascade control based on Smith predictor. The particleboard glue supplying and dosing system case study defines the problem and the solution using the methodology proposed in the paper. Status difference existing in the gluing dosing process of particleboard production usually causes gluing volume inaccurately. In order to solve the problem above, we applied the TRIZ technical contradiction and inventive principle to improve the key process of particleboard production. The improving method mapped inaccurate problem to TRIZ technical contradiction, the prior action proposed Smith predictor as the control algorithm in the glue dosing system. This research examines the usefulness of a TRIZ based problem-solving process designed to improve the problem-solving ability of users in addressing difficult or reoccurring problems and also testify TRIZ is practicality and validity. Several suggestions are presented on how to approach this problem.

  6. Critical Speed of The Glass Glue Machine's Creep and Influence Factors Analysis

    NASA Astrophysics Data System (ADS)

    Yang, Jianxi; Huang, Jian; Wang, Liying; Shi, Jintai

    When automatic glass glue machine works, two questions of the machine starting vibrating and stick-slip motion are existing. These problems should be solved. According to these questions, a glue machine's model for studying stick-slip is established. Based on the dynamics system describing of the model, mathematical expression is presented. The creep critical speed expression is constructed referring to existing research achievement and a new conclusion is found. The influencing factors of stiffness, dampness, mass, velocity, difference of static and kinetic coefficient of friction are analyzed through Matlab simulation. Research shows that reasonable choice of influence parameters can improve the creep phenomenon. These all supply the theory evidence for improving the machine's motion stability.

  7. Full thickness burns caused by cyanoacrylate nail glue: A case series.

    PubMed

    Kelemen, Noemi; Karagergou, Eleni; Jones, Sarah L; Morritt, Andrew N

    2016-06-01

    Artificial (acrylic) nails are popular cosmetic enhancements that provide the user with the appearance of manicured nails, do not chip or crack, and are generally considered very safe to apply. We report three cases where full thickness thermal burns were sustained from nail glue adhesive (cyanoacrylate) during the application of artificial nails. All three cases underwent surgical debridement and split skin graft reconstruction. We carried out an experiment to characterize the exothermic reaction between nail glue and cotton leggings. The average high temperature produced was 68°C which was sustained for 12.2s which is more than sufficient to cause full thickness burns on skin. We report these cases to increase both professional and public awareness of this serious potential complication associated with the application of artificial nails. PMID:26777605

  8. Dendrimeric nano-glue material for localized surface plasmon resonance-based fiber-optic sensors

    NASA Astrophysics Data System (ADS)

    Satija, Jitendra; Mukherji, Soumyo

    2012-09-01

    In this study, we have investigated dendrimeric architecture as "nano-glue" material for RI-sensitive fiber-optic sensors. Dendrimers are immobilized on fiber-optic probes using a simple method that includes dipping, rinsing and drying of probes at room temperature. Dendrimer binding was confirmed by contact angle measurement and fluorescein isothiocyanate binding studies. These functionalized probes were coated with gold nanoparticles to develop localized surface plasmon resonance-based refractive index sensor. RI sensitivity measurement revealed that the dendrimeric matrix enhanced the RI sensitivity by 1.4-fold compared to two-dimensional amino-silanized sensor matrices. This suggests that dendrimer molecules are better choice as "nano-glue" material for fiber-optic sensors.

  9. Nanotechnology Biomimetic Cartilage Regenerative Scaffolds

    PubMed Central

    Sardinha, Jose Paulo; Myers, Simon

    2014-01-01

    Cartilage has a limited regenerative capacity. Faced with the clinical challenge of reconstruction of cartilage defects, the field of cartilage engineering has evolved. This article reviews current concepts and strategies in cartilage engineering with an emphasis on the application of nanotechnology in the production of biomimetic cartilage regenerative scaffolds. The structural architecture and composition of the cartilage extracellular matrix and the evolution of tissue engineering concepts and scaffold technology over the last two decades are outlined. Current advances in biomimetic techniques to produce nanoscaled fibrous scaffolds, together with innovative methods to improve scaffold biofunctionality with bioactive cues are highlighted. To date, the majority of research into cartilage regeneration has been focused on articular cartilage due to the high prevalence of large joint osteoarthritis in an increasingly aging population. Nevertheless, the principles and advances are applicable to cartilage engineering for plastic and reconstructive surgery. PMID:24883273

  10. Multilayered Magnetic Gelatin Membrane Scaffolds.

    PubMed

    Samal, Sangram K; Goranov, Vitaly; Dash, Mamoni; Russo, Alessandro; Shelyakova, Tatiana; Graziosi, Patrizio; Lungaro, Lisa; Riminucci, Alberto; Uhlarz, Marc; Bañobre-López, Manuel; Rivas, Jose; Herrmannsdörfer, Thomas; Rajadas, Jayakumar; De Smedt, Stefaan; Braeckmans, Kevin; Kaplan, David L; Dediu, V Alek

    2015-10-21

    A versatile approach for the design and fabrication of multilayer magnetic scaffolds with tunable magnetic gradients is described. Multilayer magnetic gelatin membrane scaffolds with intrinsic magnetic gradients were designed to encapsulate magnetized bioagents under an externally applied magnetic field for use in magnetic-field-assisted tissue engineering. The temperature of the individual membranes increased up to 43.7 °C under an applied oscillating magnetic field for 70 s by magnetic hyperthermia, enabling the possibility of inducing a thermal gradient inside the final 3D multilayer magnetic scaffolds. On the basis of finite element method simulations, magnetic gelatin membranes with different concentrations of magnetic nanoparticles were assembled into 3D multilayered scaffolds. A magnetic-gradient-controlled distribution of magnetically labeled stem cells was demonstrated in vitro. This magnetic biomaterial-magnetic cell strategy can be expanded to a number of different magnetic biomaterials for various tissue engineering applications. PMID:26451743

  11. Efficacy and Limitations of Transarterial Acrylic Glue Embolization for Intracranial Dural Arteriovenous Fistulas

    PubMed Central

    MIYAMOTO, Naoko; NAITO, Isao; SHIMIZU, Tatsuya; YOSHIMOTO, Yuhei

    2015-01-01

    The efficacy and limitations of transarterial acrylic glue embolization for the treatment of intracranial dural arteriovenous fistulas (DAVFs) were investigated. Thirty-four DAVFs treated by transarterial embolization using n-butyl cyanoacrylate were retrospectively reviewed. The locations of DAVFs were the transverse-sigmoid sinus in 11, tentorium in 10, cranial vault in 9, and superior sagittal sinus, jugular bulb, foramen magnum, and middle cranial fossa in 1 each. Borden classification was type I in 7, type II in 3, and type III in 24. Eight patients had undergone prior transvenous coil embolization. Complete obliteration rate was 56% immediately after embolization, 71% at follow-up angiography, and 85% after additional treatments (1 transvenous embolization and 4 direct surgery). Complications occurred in three patients, consisting of asymptomatic vessel perforations during cannulation in two patients and leakage of contrast medium resulting in medullary infarction in one patient. Transarterial glue embolization is highly effective for Borden type III DAVF with direct cortical venous drainage, but has limitations for Borden type I and II DAVFs in which the affected sinus is part of the normal venous circulation. Onyx is a new liquid embolic material and is becoming the treatment of choice for DAVF. The benefits of glue embolization compared to Onyx embolization are high thrombogenicity, and relatively low risks of cranial nerve palsies and of excessive migration into the draining veins of high flow fistula. Transarterial glue embolization continues to be useful for selected patients, and complete cure can be expected in most patients with fewer complications if combined with transvenous embolization or direct surgery. PMID:25746311

  12. Percutaneous Cyanoacrylate Glue Injection into the Renal Pseudoaneurysm to Control Intractable Hematuria After Percutaneous Nephrolithotomy

    SciTech Connect

    Lal, Anupam Kumar, Ajay; Prakash, Mahesh; Singhal, Manphool; Agarwal, Mayank Mohan; Sarkar, Debansu; Khandelwal, Niranjan

    2009-07-15

    We report a case of a 43-year-old man who developed intractable hematuria after percutaneous nephrolithotomy. Angiography detected a pseudoaneurysm arising from the lower polar artery; however, embolization could not be performed because of unfavorable vascular anatomy. A percutaneous thrombin injection under ultrasound guidance initially controlled the bleeding, but hematuria subsequently recurred as a result of recanalization of the aneurysm. The case was successfully managed with ultrasound- and fluoroscopic-guided direct injection of cyanoacrylate glue into the pseudoaneurysm.

  13. A drift detector system with anode and cathode readout in the GlueX experiment

    SciTech Connect

    Berdnikov, V V; Somov, S V; Pentchev, L; Zihlmann, B

    2015-01-01

    A drift detector system designed to detect charged particle tracks in the GlueX experiment dedicated to study the nature of confinement is described. The key design features of the drift chambers associated with the requirement of a minimum material budget in the path of secondary particles are presented. The spatial resolution and the detection efficiency have been measured with cosmic rays using the automatic data acquisition system.

  14. [Articular cartilage regeneration using scaffold].

    PubMed

    Ishimoto, Yoshiyuki; Hattori, Koji; Ohgushi, Hajime

    2008-12-01

    The self-healing capacity of articular cartilage for repair is limited. For articular cartilage injury, several surgical techniques are used in clinical practice, namely drilling, abrasion arthroplasty, microfracture, or autologous osteochondral grafting, while various methods of autologous chondrocyte transplantation to cartilage defect sites have been reported since 1990s. In a case of chondrocyte transplantation to cartilage defect site, the use of proper scaffold is important. Currently, collagen gel or PLGA is used widely as a scaffold. PMID:19043192

  15. The impact of UVB radiation on the glycoprotein glue of orb-weaving spider capture thread.

    PubMed

    Stellwagen, Sarah D; Opell, Brent D; Clouse, Mary E

    2015-09-01

    Many spider orb-webs are exposed to sunlight and the potentially damaging effects of ultraviolet B (UVB) radiation. We examined the effect of UVB on the viscoelastic glycoprotein core of glue droplets deposited on the prey capture threads of these webs, hypothesizing that webs built by species that occupy sunny habitats are less susceptible to UVB damage than are webs built by species that prefer shaded forest habitats or by nocturnal species. Threads were tested shortly after being collected in the early morning and after being exposed to UVB energy equivalent to a day of summer sun and three times this amount. Droplets kept in a dark chamber allowed us to evaluate post-production changes. Droplet volume was unaffected by treatments, indicating that UVB did not damage the hygroscopic compounds in the aqueous layer that covers droplets. UVB exposure did not affect energies of droplet extension for species from exposed and partially to mostly shaded habitats (Argiope aurantia, Leucauge venusta and Verrucosa arenata). However, UVB exposure reduced the energy of droplet extension in Micrathena gracilis from shaded forests and Neoscona crucifera, which forages at night. Only in L. venusta did the energy of droplet extension increase after the dark treatment, suggesting endogenous molecular alignment. This study adds UVB irradiation to the list of factors (humidity, temperature and strain rate) known to affect the performance of spider glycoprotein glue, factors that must be more fully understood if adhesives that mimic spider glycoprotein glue are to be produced. PMID:26333924

  16. Composition and Function of Spider Glues Maintained During the Evolution of Cobwebs.

    PubMed

    Jain, Dharamdeep; Zhang, Ci; Cool, Lydia Rose; Blackledge, Todd A; Wesdemiotis, Chrys; Miyoshi, Toshikazu; Dhinojwala, Ali

    2015-10-12

    Capture silks are an interesting class of biological glues that help spiders subdue their prey. Viscid capture silk produced by the orb web spiders is a combination of hygroscopic salts that aid in water uptake and interact with adhesive glycoproteins to make them soft and sticky. The orb was a stepping stone to the evolution of new web types, but little is known about the adhesives in these webs. For instance, cobweb spiders evolved from orb-weaving ancestors and utilize glue in specialized sticky gumfoot threads rather than an elastic spiral. Early investigation suggests that gumfoot adhesives are quite different viscid glues because they lack a visible glycoprotein core, act as viscoelastic fluids rather than solids, and are largely invariant to humidity. Here, we use spectroscopic and staining methods to show that the gumfoot silk produced by Latrodectus hesperus (western black widow) is composed of hygroscopic organic salts and water insoluble glycoproteins, similar to viscid silk, in addition to a low concentration of spider coating peptides reported before. Our adhesion studies reveal that the organic salts play an important role in adhesion, similar to that seen in orb web spiders, but modulating function at much lower humidity. Our work shows more similarities in the viscid silk produced by orb web and cobweb spiders than previously anticipated and provide guidelines for developing synthetic adhesives that can work in dry to humid environments. PMID:26322742

  17. Rapid cultivation of aerobic granular sludge by bone glue augmentation and contaminant removal characteristics.

    PubMed

    Wang, Shuo; Shi, Wenxin; Yu, Shuili; Yi, Xuesong

    2013-01-01

    To achieve a quick start-up and stable operation, aerobic granular sludge (AGS) was cultivated in a sequencing batch airlift reactor (SBAR) with the addition of bone glue augmentation. Adding an amount of bone glue (40 mg L(-1)) can accelerate granulation, which advanced by 10 d on average. Aerobic granules of size 0.5-3.0 mm were dominant in the SBAR and the settling velocity acquired a better correlation with the size of the AGS. In addition, the content of total polysaccharides was 19.54 mg gMLSS(-1) (grams of mixed liquor suspended solids) (an increase of 34.0%), the content of total protein was 60.59 mg gMLSS(-1) (an increase of a factor of 33) and the total proteins/total polysaccharides ratio was 3.3. The relatively high protein content was an essential feature for cultivation of AGS, which may indicate that extracellular polymeric substance was the mechanism for granulation due to the adhesion of microorganisms by bone glue. AGS possessed better chemical oxygen demand, NH4(+)-N and PO4(3-)-P removal efficiency (of 86.7, 90.6 and 93.8%, respectively) and no nitrite accumulation was observed in the whole process. PMID:23552254

  18. A Self-assembly Model of Time-Dependent Glue Strength

    NASA Astrophysics Data System (ADS)

    Sahu, Sudheer; Yin, Peng; Reif, John H.

    Self-assembly is a ubiquitous process in which small objects self-organize into larger and complex structures. In 2000, Rothemund and Winfree proposed a Tile Assembly Model as a mathematical model for theoretical studies of self-assembly. We propose a refined self-assembly model in which the glue strength between two juxtaposed tiles is a function of the time they have been in neighboring positions. We then present an implementation of our model using strand displacement reactions on DNA tiles. Under our model, we can demonstrate and study catalysis and self-replication in the tile assembly. We then study the tile complexity for assembling shapes in our model and show that a thin rectangle of size k×N can be assembled using O((log (N))/log log (N)) types of tiles, demonstrating the glue model has additional capabilities over the prior tiling assembly model. We also describe a method to implement with DNA tiles our model of time-dependant glue strength.

  19. EXPERIMENTAL-MORPHOLOGICAL SUBSTANTIATION OF EXPEDIENCY TO USE THE SKIN GLUE "DERMABOND" FOR POSTOPERATIVE WOUND CLOSURE.

    PubMed

    Avetikov, D; Loza, K; Starchenko, I; Loza, E; Marushchak, M

    2015-01-01

    We aimed to investigate the morphological features of healing of postoperative wounds in the early stages of reparative process in the experiment, depending on the used type of the wound closure. It is proved that the nature and type of the scar depends on the processes that occur in the wound at the early postoperative stage, which in turn greatly affects the form of suture material used. The experiment included 20 male rats, weighing 180-200 g. All rats were anesthetized by a single intraperitoneal injection of sodium thiopental. After the shaving operative field, 2 cm full-thickness incision wound was made on the anterior surface of the abdomen in the longitudinal direction. As suture material for wound closure in the 1st experimental group (10 rats) we used surgical filament "Polyamide 4-0». In the 2nd experimental group (10 rats) wounds were closured by using skin glue "Dermabond". According from our experiment, the usage of skin glue creates better conditions for wound healing. Thus, to achieve a more aesthetic scar, we recommend applying skin glue instead of using nodal joints. PMID:26177141

  20. Glue-induced birefringence in surface-attached FBG strain sensors

    NASA Astrophysics Data System (ADS)

    Helminger, Dominik; Daitche, Alexej; Roths, Johannes

    2014-05-01

    The influence of the gluing process on the birefringence of surface-glued FBGs that were inscribed in highly birefringence (HiBi) optical fibers of type Panda was studied by monitoring the variation of the birefringence during the gluing procedure. The isothermal curing process at 100°C of the epoxy-based adhesive is characterized by the reduction of birefringence during curing. Significant transversal strain is introduced into the fiber during the cool down period, which is due to different thermal expansion coefficients of the silica and the glue. When the slow axis of the HiBi fiber is oriented parallel to the surface, the glue-induced transversal strain reduces the birefringence of the fiber by ΔB = -6.6 10-5 and when it is perpendicular to the surface, it is increased by ΔB = 1.1 10-5. It can be estimated that for conventional FBGs in single mode fibers a glue-induced birefringence in the order of ΔB = 3.4 10-5 can be expected, which has to be taken into account if in surface-mounted FBG-based strain measurements a high accuracy has to be achieved.

  1. Bone Glue Modified Asphalt: A Step towards Energy Conservation and Environment Friendly Modified Asphalts

    PubMed Central

    Rizvi, Hashim Raza; Gallo, August A.

    2014-01-01

    Asphalt has been modified for the past several decades using various additives, including synthetic polymers. Polymer modification improves structural and engineering characteristics of the binder, which is a result of improvement in rheological characteristics of binder as well as its adhesion capability with the aggregate. Such enhancement inevitably enhances the performance characteristics of hot mix asphalts (HMA) such as fatigue life, resistance to rutting, and thermal cracking. Even though polymer-modified HMA is popular in North America and European countries, its use is still limited in developing countries of Southeast Asia due to high costs associated with its manufacturing, processing, and energy consumption. In this study, a new kind of asphalt modifier derived from animal wastes, such as bones, hides, and flesh commonly known as Bone Glue, is studied. This biomaterial which is a by-product of food and cattle industries is cheap, conveniently available, and produced locally in developing countries. The results of the research study showed that the bone glue can easily be mixed with asphalt without significantly altering the asphalt binder's viscosity and mixing and compaction temperatures of HMA. Additionally, improvements in complex shear modulus for a range of temperatures were also determined and it was found that complex shear modulus was improved by bone glue modification. PMID:27437456

  2. Percutaneous Glue Embolization of a Visceral Artery Pseudoaneurysm in a Case of Sickle Cell Anemia

    SciTech Connect

    Gulati, Gurpreet S.; Gulati, Manpreet S. Makharia, Govind; Hatimota, Pradeep; Saikia, Nripen; Paul, Shashi B.; Acharya, Subrat

    2006-08-15

    Although aneurysmal complications of sickle cell anemia have been described in the intracranial circulation, visceral artery pseudoaneurysms in this disease entity have not previously been reported in the literature. Conventional treatment of visceral pseudoaneurysms has been surgical ligation or resection of the aneurysm. Transcatheter embolization has emerged as an attractive, minimally invasive alternative to surgery in the treatment of these lesions. In certain situations, however, due to the unfavorable angiographic anatomy precluding safe transcatheter embolization, direct percutaneous glue injection of the pseudoaneurysm sac may be considered to achieve successful occlusion of the sac. The procedure may be rendered safer by simultaneous balloon protection of the parent artery. We describe this novel treatment modality in a case of inferior pancreaticoduodenal artery pseudoaneurysm in a patient with sickle cell anemia. Although a complication in the form of glue reflux into the parent vessel occurred that necessitated surgery, this treatment modality may be used in very selected cases (where conventional endovascular embolization techniques are not applicable) after careful selection of the balloon diameter and appropriate concentration of the glue-lipiodol mixture.

  3. Proteinaceous adhesive secretions from insects, and in particular the egg attachment glue of Opodiphthera sp. moths.

    PubMed

    Li, Dongmei; Huson, Mickey G; Graham, Lloyd D

    2008-10-01

    Biochemical and electrophoretic screening of 29 adhesive secretions from Australian insects identified six types that appeared to consist largely of protein. Most were involved in terrestrial egg attachment. Hydrogel glues were subjected to gravimetric analyses and assessed for overall amino acid composition. When 32 proteins in glues from eight insect species were analyzed individually, many proved to be rich in Gly, Ser, and/or Pro, and some contained substantial levels of 4-hydroxyproline. A few proteins were heavily glycosylated. Abundant protein-based secretions were tested as adhesives, mainly by measuring dry shear strength on wood. The strongest (1-2 MPa) was an egg attachment glue produced by saturniid gum moths of the genus Opodiphthera. It was harvested from female colleterial gland reservoirs as a treacle-like liquid that underwent irreversible gelation, and recovered from the capsules of laid eggs as a highly elastic orange-brown hydrogel that could also display high tack. Its protein-based nature was confirmed and explored by spectroscopy, enzymatic degradation, and 2D gel electrophoresis. Its proteins are mostly 80-95 kDa, and sequences (almost all novel) were established for 23 tryptic peptides. Scanning probe microscopy of Opodiphthera hydrogel in water returned median values of 0.83 nN for adhesion, 63 kPa for modulus, and 87% for resilience. Recombinant mimics of this material might be useful as biodegradable commodity adhesives or as specialty biomedical products. PMID:18780346

  4. [Quantification of D-dimer and soluble fibrin in blood plasma of people with ischemic heart disease and hypertension].

    PubMed

    Lugovskoĭ, E V; Kolesnikova, I N; Lugovskaia, N E; Litvinova, L M; Gritsenko, P G; Gogolinskaia, G K; Liashko, E D; Kostiuchenko, E P; Remizovskiĭ, G A; Pedchenko, V N; Komisarenko, S V

    2004-01-01

    The method of D-dimer quantification in the human blood plasma has been developed using monoclonal antibodies 111-3b and II-4d. The method has been verified on the blood plasma of the patients with ischemic heart disease with and without stenocardia and with hypertension. The results showed that at ischemic heart disease with and without stenocardia and at hypertension the quantities of D-dimer in the blood plasma were generally less than the highest normal level 500 ng/ml (64.3%, 76.2% and 95%, correspondingly). The semiquantitative measurements of soluble fibrin levels in blood plasmas of the patients with ischemic heart disease and hypertension have been performed. It has been shown that the quantity of soluble fibrin at these diseases range greatly from < 0.03 mg/ml to 0.15 mg/ml. There was no correlation between the quantities of D-dimer and soluble fibrin in blood plasmas of the patients. Electrophoresis in PAAG with SDS showed that the soluble fibrin at these diseases had the mo- lecular mass of the fibrin (ogen). Thus the soluble fibrin in blood plasmas analysed consisted mainly of fibrin desAA oligomers (may be with fibrinogen incorporation) which are not stabilized by the factor XIIIa. PMID:16350758

  5. [Propolis. The bee glue as presented by the Graeco-Roman literature].

    PubMed

    Golder, Werner

    2004-01-01

    The bee glue, commonly known as propolis, has been employed for medical purposes already in teh ancient world. More than 15 Greek and Roman authors report on the preparation and application of the so-called third natural product of the bees (besides honey and wax). Aristoteles described the fundamental issues of its biology in his 'Historia Animalium' correctly. The bulk of propolis is obtained from the barks of poplars. Once carried in the hives, the glue is used to stabilize the cells and honeycombs and to protect the bees against invaders and cold weather. Propolis has been chiefly employed for the preparation of ointment and plasters. For this purpose, the viscous raw material was purified, moulded and boiled. In most preparations, the bee glue was only one of many (up to 20) pharmacologically active constituents and came to five to 20% of the mixture. Only rarely, a single drug therapy was using propolis was carried out. The application of the glue was most successful in general surgery and casualties. In that respect, the ancient physicians took advantage of the anti-edematous and anti-infectious properties of the substance. Thus, it was used to treat bumps, indurations, and slow-healing wounds. Moreover, cataplasms against swollen cervical nodes and indurations of the female breast often contained propolis. Finally, bee glue proved successful for the treatment of chronic backache and pain in the hip as well as fresh injuries of muscles and tendons. In the sector of skin diseases, lichens and condylomata were found to respond well to propolis. ALl this indications have been a matter of several records. However, the successful use of propolis in diseases of the stomach and liver has ben reported solely by Alexander of Tralles (6th century AD). Not counting the internal diseases, the spectrum of indications for propolis has not substantially changed as compared to the classical antiquity. Interestingly, radiation therapists have adopted the ancient remedy and

  6. Fundamental Investigations of the Extracellular Proteins Fibrin and Collagen in Microchannel Devices

    NASA Astrophysics Data System (ADS)

    Evans, Heather M.; Koester, Sarah; Pfohl, Thomas

    2007-03-01

    Microfluidic structures are particularly amenable to controlled investigations of protein bundle and network formation. Hydrodynamic focusing is utilized to create a diffusion-controlled gradient of reactants, enabling non-equilibrium investigations. We present studies of the blood clotting protein fibrin, a three-dimensional network formed from the enzymatic cleavage of fibrinogen monomers by the protein thrombin. Fibrin is a vital component of blood clots, and has been implicated in a variety of diseases. Real-time fluorescence microscopy and x-ray micro-diffraction are used to quantify supramolecular assembly and provide snapshots of the evolution of fibrin network formation. We also show that collagen, a ubiquitous extracellular protein, can be bundled in situ through the use of a pH gradient. An outlook toward artificial blood vessels arises from the insight that both fibrin and collagen can easily be used to coat microchannel structures. The resulting mesh forms an ideal environment for red blood cells and other cell types.

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

    PubMed

    Perussi Biscola, Natalia; Politti Cartarozzi, Luciana; Ferreira Junior, Rui Seabra; Barraviera, Benedito; Leite Rodrigues de Oliveira, Alexandre

    2016-01-01

    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. PMID:27446617

  8. A Comparison of the Mechanical and Structural Properties of Fibrin Fibers with Other Protein Fibers

    PubMed Central

    Guthold, M.; Liu, W.; Sparks, E. A.; Jawerth, L. M.; Peng, L.; Falvo, M.; Superfine, R.; Hantgan, R. R.; Lord, S. T.

    2010-01-01

    In the past few years a great deal of progress has been made in studying the mechanical and structural properties of biological protein fibers. Here, we compare and review the stiffness (Young's modulus, E) and breaking strain (also called rupture strain or extensibility, εmax) of numerous biological protein fibers in light of the recently reported mechanical properties of fibrin fibers. Emphasis is also placed on the structural features and molecular mechanisms that endow biological protein fibers with their respective mechanical properties. Generally, stiff biological protein fibers have a Young's modulus on the order of a few Gigapascal and are not very extensible (εmax < 20%). They also display a very regular arrangement of their monomeric units. Soft biological protein fibers have a Young's modulus on the order of a few Megapascal and are very extensible (εmax > 100%). These soft, extensible fibers employ a variety of molecular mechanisms, such as extending amorphous regions or unfolding protein domains, to accommodate large strains. We conclude our review by proposing a novel model of how fibrin fibers might achieve their extremely large extensibility, despite the regular arrangement of the monomeric fibrin units within a fiber. We propose that fibrin fibers accommodate large strains by two major mechanisms: (1) an α-helix to β-strand conversion of the coiled coils; (2) a partial unfolding of the globular C-terminal domain of the γ-chain. PMID:17952642

  9. Experimental and Imaging Techniques for Examining Fibrin Clot Structures in Normal and Diseased States

    PubMed Central

    Fan, Natalie K.; Keegan, Philip M.; Platt, Manu O.; Averett, Rodney D.

    2015-01-01

    Fibrin is an extracellular matrix protein that is responsible for maintaining the structural integrity of blood clots. Much research has been done on fibrin in the past years to include the investigation of synthesis, structure-function, and lysis of clots. However, there is still much unknown about the morphological and structural features of clots that ensue from patients with disease. In this research study, experimental techniques are presented that allow for the examination of morphological differences of abnormal clot structures due to diseased states such as diabetes and sickle cell anemia. Our study focuses on the preparation and evaluation of fibrin clots in order to assess morphological differences using various experimental assays and confocal microscopy. In addition, a method is also described that allows for continuous, real-time calculation of lysis rates in fibrin clots. The techniques described herein are important for researchers and clinicians seeking to elucidate comorbid thrombotic pathologies such as myocardial infarctions, ischemic heart disease, and strokes in patients with diabetes or sickle cell disease. PMID:25867016

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

    PubMed Central

    Ferreira Junior, Rui Seabra

    2016-01-01

    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. PMID:27446617

  11. Plasma fibronectin promotes lung metastasis by contributions to fibrin clots and tumor cell invasion.

    PubMed

    Malik, Gunjan; Knowles, Lynn M; Dhir, Rajiv; Xu, Shuping; Yang, Shuting; Ruoslahti, Erkki; Pilch, Jan

    2010-06-01

    The attachment of circulating tumor cells to the blood vessels of distant organs is an important step in metastasis. We show here that experimental lung metastasis by two cell lines, B16F1 melanoma and 3LL lung carcinoma, is greatly reduced in transgenic mice that lack plasma fibronectin. This multifunctional adhesive glycoprotein becomes cross-linked to fibrin during clotting. Here, we report that eliminating plasma fibronectin from the blood circulation reverses the prometastatic effects of blood clotting and tumor cell integrin alphavbeta3. In vitro studies showed that fibrin-fibronectin complexes, but not purified fibrin, supported tumor cell attachment and invasion. These functions correlate with the ability of fibrin-fibronectin complexes to induce the activation of integrin alphavbeta3. Our findings reveal an important contribution of plasma fibronectin in lung metastasis. Furthermore, they suggest that the previously noted effects of blood clotting on lung metastasis might be mediated in part by a fibronectin-alphavbeta3 integrin axis, in which plasma fibronectin has to be incorporated into the blood clot. PMID:20501851

  12. Platelet Rich Fibrin Matrix Improves Wound Angiogenesis via Inducing Endothelial Cell Proliferation

    PubMed Central

    Roy, Sashwati; Driggs, Jason; Elgharably, Haytham; Biswas, Sabyasachi; Findley, Muna; Khanna, Savita; Gnyawali, Urmila; Bergdall, Valerie K.; Sen, Chandan K.

    2013-01-01

    The economic, social and public health burden of chronic ulcers and other compromised wounds are enormous and rapidly increasing with the aging population. The growth factors derived from platelets play an important role in tissue remodeling including neovascularization. Platelet-rich plasma (PRP) has been utilized and studied for the last four decades. Platelet gel and fibrin sealant, derived from PRP mixed with thrombin and calcium chloride, have been exogenously applied to tissues to promote wound healing, bone growth, hemostasis and tissue sealing. In this study we first characterized recovery and viability of as well as growth factor release from platelets in a novel preparation of platelet gel and fibrin matrix, namely, platelet rich fibrin matrix (PRFM). Next, the effect of PRFM application in a delayed model of ischemic wound angiogenesis was investigated. The study for the first-time shows the kinetics of the viability of platelet embedded fibrin matrix. A slow and steady release of growth factors from PRFM was observed. The VEGF released from PRFM was primarily responsible for endothelial mitogenic response via ERK activation pathway. Finally, this preparation of PRFM effectively induced endothelial cell proliferation and improved wound angiogenesis in chronic wounds, providing evidence of probable mechanisms of action of PRFM in healing of chronic ulcers. PMID:22092846

  13. Therapeutic assessment of mesenchymal stem cells delivered within a PEGylated fibrin gel following an ischemic injury.

    PubMed

    Ricles, Laura M; Hsieh, Pei-Ling; Dana, Nicholas; Rybalko, Viktoriya; Kraynak, Chelsea; Farrar, Roger P; Suggs, Laura J

    2016-09-01

    The intent of the current study was to investigate the therapeutic contribution of MSCs to vascular regeneration and functional recovery of ischemic tissue. We used a rodent hind limb ischemia model and intramuscularly delivered MSCs within a PEGylated fibrin gel matrix. Within this model, we demonstrated that MSC therapy, when delivered in PEGylated fibrin, results in significantly higher mature blood vessel formation, which allows for greater functional recovery of skeletal muscle tissue as assessed using force production measurements. We observed initial signs of vascular repair at early time points when MSCs were delivered without PEGylated fibrin, but this did not persist or lead to recovery of the tissue in the long-term. Furthermore, animals which were treated with PEGylated fibrin alone exhibited a greater number of mature blood vessels, but they did not arterialize and did not show improvements in force production. These results demonstrate that revascularization of ischemic tissue may be a necessary but not sufficient step to complete functional repair of the injured tissue. This work has implications on stem cell therapies for ischemic diseases and also potentially on how such therapies are evaluated. PMID:27318932

  14. Role of clot-associated (-derived) thrombin in cell proliferation induced by fibrin clots in vitro

    PubMed Central

    Gandossi, E; Lunven, C; Berry, C N

    2000-01-01

    Thrombin is a potent mitogenic agent. Clot-associated thrombin retains its amidolytic and pro-aggregant activity. We therefore studied the ability of fibrin clots to induce proliferation in CCL39 cells (Chinese hamster lung fibroblasts), in the absence and presence of the thrombin inhibitors PPACK, recombinant hirudin (rHV2 Lys47) and heparin:antithrombin III. Fibrin clots incubated for 48 h with CCL39 cells led to significant cell proliferation, which was dependent on the concentration of thrombin used to prepare the clots. Thus, clots prepared with 91 nmol l−1 thrombin produced a similar proliferation (231±21%) to that obtained with 50 nmol l−1 thrombin in solution (213±29%). Rabbit plasma clots led to a 499±41% increase in cell number under identical conditions. Fibrin clot-induced cell proliferation was inhibited by all three thrombin inhibitors with no difference in IC50 values compared to those obtained against thrombin in solution, suggesting that cell proliferation be due to thrombin leaching from the clots. We found a time-dependent increase in thrombin release from the clots attaining a plateau at 24 h (∼61% of the total thrombin used in clot formation). Clots separated from the cells using porous cell culture chamber inserts led to similar proliferation to that of clots in contact with the cells. Thus fibrin-clot induced CCL39 proliferation is due to thrombin released from the clots. PMID:10696104

  15. Laser microstructured biodegradable scaffolds.

    PubMed

    Koroleva, Anastasia; Kufelt, Olga; Schlie-Wolter, Sabrina; Hinze, Ulf; Chichkov, Boris

    2013-10-01

    The two-photon polymerization technique (2PP) uses non-linear absorption of femtosecond laser pulses to selectively polymerize photosensitive materials. 2PP has the ability to fabricate structures with a resolution from tens of micrometers down to hundreds of nanometers. Three-dimensional microstructuring by the 2PP technique provides many interesting possibilities for biomedical applications. This microstructuring technique is suitable with many biocompatible polymeric materials, such as polyethylene glycol, polylactic acid, polycaprolactone, gelatin, zirconium-based hybrids, and others. The process of fabrication does not require clean room conditions and does not use hazard chemicals or high temperatures. The most beneficial property of 2PP is that it is capable of producing especially complex three-dimensional (3-D) structures, including devices with overhangs, without using any supportive structure. The flexibility in controlling geometries and feature sizes and the possibility to fabricate structures without the addition of new material layers makes this technique particularly appealing for fabrication of 3-D scaffolds for tissue engineering. PMID:23729598

  16. Fibrin deposition following bile duct injury limits fibrosis through an αMβ2-dependent mechanism.

    PubMed

    Joshi, Nikita; Kopec, Anna K; Ray, Jessica L; Cline-Fedewa, Holly; Nawabi, Atta; Schmitt, Timothy; Nault, Rance; Zacharewski, Timothy R; Rockwell, Cheryl E; Flick, Matthew J; Luyendyk, James P

    2016-06-01

    Coagulation cascade activation and fibrin deposits have been implicated or observed in diverse forms of liver damage. Given that fibrin amplifies pathological inflammation in several diseases through the integrin receptor αMβ2, we tested the hypothesis that disruption of the fibrin(ogen)-αMβ2 interaction in Fibγ(390-396A) mice would reduce hepatic inflammation and fibrosis in an experimental setting of chemical liver injury. Contrary to our hypothesis, α-naphthylisothiocyanate (ANIT)-induced liver fibrosis increased in Fibγ(390-396A) mice, whereas inflammatory cytokine expression and hepatic necrosis were similar to ANIT-challenged wild-type (WT) mice. Increased fibrosis in Fibγ(390-396A) mice appeared to be independent of coagulation factor 13 (FXIII) transglutaminase, as ANIT challenge in FXIII-deficient mice resulted in a distinct pathological phenotype characterized by increased hepatic necrosis. Rather, bile duct proliferation underpinned the increased fibrosis in ANIT-exposed Fibγ(390-396A) mice. The mechanism of fibrin-mediated fibrosis was linked to interferon (IFN)γ induction of inducible nitric oxide synthase (iNOS), a gene linked to bile duct hyperplasia and liver fibrosis. Expression of iNOS messenger RNA was significantly increased in livers of ANIT-exposed Fibγ(390-396A) mice. Fibrin(ogen)-αMβ2 interaction inhibited iNOS induction in macrophages stimulated with IFNγ in vitro and ANIT-challenged IFNγ-deficient mice had reduced iNOS induction, bile duct hyperplasia, and liver fibrosis. Further, ANIT-induced iNOS expression, liver fibrosis, and bile duct hyperplasia were significantly reduced in WT mice administered leukadherin-1, a small molecule that allosterically enhances αMβ2-dependent cell adhesion to fibrin. These studies characterize a novel mechanism whereby the fibrin(ogen)-integrin-αMβ2 interaction reduces biliary fibrosis and suggests a novel putative therapeutic target for this difficult-to-treat fibrotic disease. PMID

  17. Neuronal Networks on Nanocellulose Scaffolds.

    PubMed

    Jonsson, Malin; Brackmann, Christian; Puchades, Maja; Brattås, Karoline; Ewing, Andrew; Gatenholm, Paul; Enejder, Annika

    2015-11-01

    Proliferation, integration, and neurite extension of PC12 cells, a widely used culture model for cholinergic neurons, were studied in nanocellulose scaffolds biosynthesized by Gluconacetobacter xylinus to allow a three-dimensional (3D) extension of neurites better mimicking neuronal networks in tissue. The interaction with control scaffolds was compared with cationized nanocellulose (trimethyl ammonium betahydroxy propyl [TMAHP] cellulose) to investigate the impact of surface charges on the cell interaction mechanisms. Furthermore, coatings with extracellular matrix proteins (collagen, fibronectin, and laminin) were investigated to determine the importance of integrin-mediated cell attachment. Cell proliferation was evaluated by a cellular proliferation assay, while cell integration and neurite propagation were studied by simultaneous label-free Coherent anti-Stokes Raman Scattering and second harmonic generation microscopy, providing 3D images of PC12 cells and arrangement of nanocellulose fibrils, respectively. Cell attachment and proliferation were enhanced by TMAHP modification, but not by protein coating. Protein coating instead promoted active interaction between the cells and the scaffold, hence lateral cell migration and integration. Irrespective of surface modification, deepest cell integration measured was one to two cell layers, whereas neurites have a capacity to integrate deeper than the cell bodies in the scaffold due to their fine dimensions and amoeba-like migration pattern. Neurites with lengths of >50 μm were observed, successfully connecting individual cells and cell clusters. In conclusion, TMAHP-modified nanocellulose scaffolds promote initial cellular scaffold adhesion, which combined with additional cell-scaffold treatments enables further formation of 3D neuronal networks. PMID:26398224

  18. Alternative glues for the production of ATLAS silicon strip modules for the Phase-II upgrade of the ATLAS Inner Detector

    NASA Astrophysics Data System (ADS)

    Poley, L.; Bloch, I.; Edwards, S.; Friedrich, C.; Gregor, I.-M.; Jones, T.; Lacker, H.; Pyatt, S.; Rehnisch, L.; Sperlich, D.; Wilson, J.

    2016-05-01

    The Phase-II upgrade of the ATLAS detector for the High Luminosity Large Hadron Collider (HL-LHC) includes the replacement of the current Inner Detector with an all-silicon tracker consisting of pixel and strip detectors. The current Phase-II detector layout requires the construction of 20,000 strip detector modules consisting of sensor, circuit boards and readout chips, which are connected mechanically using adhesives. The adhesive used initially between readout chips and circuit board is a silver epoxy glue as was used in the current ATLAS SemiConductor Tracker (SCT). However, this glue has several disadvantages, which motivated the search for an alternative. This paper presents a study of six ultra-violet (UV) cure glues and a glue pad for possible use in the assembly of silicon strip detector modules for the ATLAS upgrade. Trials were carried out to determine the ease of use, thermal conduction and shear strength. Samples were thermally cycled, radiation hardness and corrosion resistance were also determined. These investigations led to the exclusion of three UV cure glues as well as the glue pad. Three UV cure glues were found to be possible better alternatives than silver loaded glue. Results from electrical tests of first prototype modules constructed using these glues are presented.

  19. Label-free, sensitivity detection of fibrillar fibrin using gold nanoparticle-based chemiluminescence system.

    PubMed

    Zhang, Yuanfu; Liu, Jifeng; Liu, Ting; Li, Haibo; Xue, Qingwang; Li, Rui; Wang, Lei; Yue, Qiaoli; Wang, Shuhao

    2016-03-15

    A novel, label-free, gold nanoparticles (AuNPs)-based chemiluminescence assay has been developed for the detection of fibrillar fibrin. The method relied on the interaction of fibrinogen (Fib) with AuNPs and the aggregated AuNPs induce a strong luminol-H2O2 chemiluminesecence (CL) signal. We prepared the 12-nm-diameter AuNPs which well dispersed in the solution. Fib was absorbed on the surface of AuNPs against the aggregation of AuNPs in 1.0M NaCl. Otherwise, Fib was catalyzed to form fibrillar fibrin in the presence of thrombin. The fibrin induced AuNPs aggregated in the presence of NaCl solution. The catalytic activity of aggregated AuNPs on the luminol-H2O2 CL reaction is greatly enhanced. This allows us to utilize the luminol-H2O2 CL system for quantitative analysis of thrombin, which was used to denote fibrosis degree of Fib. The assay showed a linear toward fibrillar fibrin concentration in the range of 2.7 × 10(-15)-2.7 × 10(-13)M with a correlation of 0.9920. The limit of detection for fibrin was experimentally determined to be 1 fM, based on a signal-to-noise ratio (S/N) of 3. Relative to conventional methods, this method offers the advantages of higher sensitivity and selectivity and lower cost, showing great potential for medical diagnosis. PMID:26397422

  20. The role of leukocytes in the pathogenesis of fibrin deposition in bovine acute lung injury.

    PubMed Central

    Car, B. D.; Suyemoto, M. M.; Neilsen, N. R.; Slauson, D. O.

    1991-01-01

    The peculiarly fibrinous nature of bovine acute lung injury due to infection with Pasteurella haemolytica A1 suggests an imbalance between leukocyte-directed procoagulant and profibrinolytic influences in the inflamed bovine lung. Calves with experimental pneumonia produced by intratracheal inoculation with P. haemolytica A1 developed acute locally extensive cranioventral fibrinopurulent bronchopneumonia. Pulmonary alveolar macrophages (PAM) recovered by segmental lavage from affected lung lobes were 30 times more procoagulant than PAM obtained from unaffected lung lobes and 37-fold more procoagulant than PAM from control calf lungs. Unlike the enhancement of procoagulant activity, profibrinolytic activity (plasminogen activator amidolysis) of total lung leukocytes (PAM and plasminogen activator neutrophils [PMN]) was decreased 23 times in cells obtained from affected lung lobes and also was decreased four times in cells obtained from unaffected lobes of infected animals. This marked imbalance in cellular procoagulant and fibrinolytic activity probably contributes significantly to enhanced fibrin deposition and retarded fibrin removal. In addition, PAM from inflamed lungs were strongly positive for bovine tissue factor antigen as demonstrated by immunocytochemistry. Intensely tissue factor-positive PAM enmeshed in fibrinocellular exudates and positive alveolar walls were situated such that they were likely to have, in concert, initiated extrinsic activation of coagulation in the acutely inflamed lung. These data collectively suggest that enhanced PAM-directed procoagulant activity and diminished PAM- and PMN-directed profibrinolytic activity represent important modifications of local leukocyte function in bovine acute lung injury that are central to the pathogenesis of lesion development with extensive fibrin deposition and retarded fibrin removal. Images Figure 2 Figure 3 PMID:2024707

  1. Imaging Thromboembolism with Fibrin-Avid 99mTc-Peptide: Evaluation in Swine

    PubMed Central

    Aruva, Mohan R.; Daviau, Judy; Sharma, Shubh S.; Thakur, Mathew L.

    2006-01-01

    A pentapeptide, Gly-Pro-Arg-Pro-Pro, with high affinity for α-chain-fibrin was labeled with 99mTc (99mTc-TP850) and evaluated in swine to image experimental venous thromboembolism (deep vein thrombosis [DVT]) and pulmonary embolism (PE). Methods Scatchard analysis was performed to determine fibrin affinity for TP850 and the number of binding sites (receptors) per milligram of fibrin. DVT was induced in the left jugular vein and PE was induced by introducing a preformed autologous blood clot into the right atrium using a 7-French introducer sheath inserted into the right jugular vein. 99mTc-TP850 was injected at 4, 24, 48, 72, 96, or 120 h later. Animals were imaged for up to 4 h after injection, heparinized, and sacrificed. Lungs were extirpated, radiographed, and imaged, and the PE was removed. Other tissues, including blood and normal lungs, were harvested and, concomitantly, 99mTc was counted for determination of target-to-tissue ratios and the percentage injected dose per gram of tissue. Results The affinity for human fibrin was 10−9 mol/L and there were >1015 receptors per milligram of fibrin. DVT and PE were visualized for up to 4 h after injection with high DVT/blood (7.9–22.6), DVT/muscle (31.1–89.4), PE/blood (1–155), and PE/lung (0.8–245) ratios. Thereafter, the PEs fragmented spontaneously below the spatial resolution of the γ-camera and, despite the high associated radioactivity, could not be localized in vivo. The fragmented clots were detectable by scintigraphy on excised lungs and provided excellent concordance with radiograms. Conclusion 99mTc-TP850 with its modest affinity (10−9 mol/L), rapid blood clearance, and high DVT and PE uptake is a promising agent for imaging vascular thrombosis. PMID:16391200

  2. Immunohistochemical evaluation of tissue factor, fibrin/fibrinogen and D-dimers in canine gliomas.

    PubMed

    de la Fuente, Cristian; Pumarola, Martí; Blasco, Ester; Fernández, Francisco; Viu, Judit; Añor, Sònia

    2014-06-01

    In human gliomas, tissue factor (TF) is overexpressed, associated with the grade of malignancy and influences tumour biology. Intra-tumoural fibrin/fibrinogen deposition and activation of the fibrinolytic system also play a role in tumour cell proliferation and angiogenesis. The first aim of the present study was to investigate TF expression and the presence of fibrin/fibrinogen and D-dimers in canine glioma biopsies, graded according to the World Health Organization (WHO) classification of tumours of the central nervous system. The second aim was to investigate the occurrence of intravascular thrombosis (IVT) in canine gliomas, as a potential histological marker of glioma type or grade of malignancy. An immunohistochemical study using antibodies against TF, fibrin/fibrinogen and D-dimers was performed with 24 glioma samples, including 15 oligodendrogliomas, 6 astrocytomas and 3 mixed gliomas. Immunohistochemical data were statistically analysed to determine whether there was any relationship between glioma type and grade of malignancy. All gliomas were moderate to strongly positive for TF and the staining score was significantly higher (P = 0.04) in high-grade (III or IV) than in low-grade (II) gliomas. Intra-tumoural fibrin/fibrinogen deposition was detected in all tumour biopsies assessed, and D-dimers were detected in 17/24 gliomas. IVT was a frequent finding, but was not linked to a specific glioma type or malignancy grade. TF expression, fibrin/fibrinogen deposition, extravascular fibrinolytic system activation and IVT occur in canine gliomas. Canine glioma might be a suitable model for studying coagulation and fibrinolysis as potential therapeutic targets for human gliomas. PMID:24745770

  3. Inhibition of fibrin polymerization by fragment d is affected by calcium, Gly-Pro-Arg and Gly-His-Arg.

    PubMed

    Furlan, M; Rupp, C; Beck, E A

    1983-01-12

    Fibrinopeptides A and B were removed from purified human fibrinogen by bovine thrombin, whereas the snake venom protease batroxobin only split fibrinopeptide A from fibrinogen. Aggregation of the resulting desAB- and desA-fibrin monomers was evaluated by recording the turbidity of incubation mixtures. Fibrin assembly was strongly accelerated by increasing the calcium concentration from 10(-5) to 10(-3) M. Fragment D was obtained from fibrinogen by proteolytic degradation with plasmin in the presence of Ca2+. At a 4-fold molar concentration relative to fibrinogen, fragment D dramatically inhibited fibrin polymerization at up to 10(-4) M Ca2+. This anticlotting activity was, however, much less pronounced at 10(-3) M Ca2+. The thrombin clotting time, measured on human plasma, was prolonged by fragment D in a dose-dependent manner. In citrate-containing plasma, the fibrinogen clotting was significantly delayed by an equimolar concentration of fragment D. In barium sulfate-adsorbed oxalated plasma, containing 2.5 mM Ca2+, the same amount of fragment D hardly affected fibrin polymerization. We conclude that fragment D has no important anticlotting effect under physiological conditions. The synthetic peptide Gly-Pro-Arg, corresponding to the amino-terminal sequence of the fibrin alpha-chain, inhibited aggregation of both desA-fibrin and desAB-fibrin at 10(-3) M Ca2+. The inhibition of desAB-fibrin polymerization by Gly-Pro-Arg was abolished at 10(-5) M Ca2+. In addition, Gly-Pro-Arg depressed the anticlotting activity of fragment D at low calcium concentration. An analogue of the amino-terminus of fibrin beta-chain, Gly-His-Arg, strongly accelerated aggregation of desA-fibrin monomers, but only moderately enhanced polymerization of desAB-fibrin monomers at 10(-5) M Ca2+, both in the presence and in the absence of fragment D. This activating effect of Gly-His-Arg was abolished at 10(-3) M Ca2+. It is suggested that the binding of calcium, Gly-His-Arg, and possibly also Gly

  4. Osteogenic Scaffolds for Bone Reconstruction

    PubMed Central

    Li, Ling-jiang; Liu, Ning; Liu, Qing; Jia, Lian-shun; Yuan, Wen

    2012-01-01

    Abstract A highly osteogenic hybrid bioabsorbable scaffold was developed for bone reconstruction/augmentation. Through the use of a solid free-form fabrication technology, a bioabsorbable polycaprolactone (PCL) cage scaffold with a desired size and shape was produced and then filled with osteogenic bone graft particles, that is, morselized autologous bone chips. A rabbit total lamina defect model was chosen to demonstrate its efficacy in regenerating bone with a complicated anatomic shape. Both iliac bone and morselized iliac bone grafts were used in this study for comparison purposes. Serum osteocalcin and collagen type I cross-linked C-terminal telopeptide (CTx) determination showed that active bone remodeling occurred after bone grafts were implanted. X-ray images showed that the bony defects were completely filled with bone mass in all the groups with bone grafts. However, biomechanical tests showed that only the iliac bone and hybrid scaffold groups could restore the mechanical properties to the normal level after 10 weeks of implantation. A histology study showed that both iliac and hybrid scaffold groups had extensive new bone formation, and no adhesion and fibrosis were found. These results indicated that this osteogenic hybrid scaffold can be a good alternative to autologous iliac bone, because it does not need a second iliac bone-harvesting surgery, and thus the morbidity and the possible infections that are often associated with the bone harvesting surgery can be avoided. PMID:23515416

  5. Engineering microporosity in bacterial cellulose scaffolds.

    PubMed

    Bäckdahl, Henrik; Esguerra, Maricris; Delbro, Dick; Risberg, Bo; Gatenholm, Paul

    2008-08-01

    The scaffold is an essential component in tissue engineering. A novel method to prepare three-dimensional (3D) nanofibril network scaffolds with controlled microporosity has been developed. By placing paraffin wax and starch particles of various sizes in a growing culture of Acetobacter xylinum, bacterial cellulose scaffolds of different morphologies and interconnectivity were prepared. Paraffin particles were incorporated throughout the scaffold, while starch particles were found only in the outermost area of the resulting scaffold. The porogens were successfully removed after culture with bacteria and no residues were detected with electron spectroscopy for chemical analysis (ESCA) or Fourier transform infra-red spectroscopy (FT-IR). Resulting scaffolds were seeded with smooth muscle cells (SMCs) and investigated using histology and organ bath techniques. SMC were selected as the cell type since the main purpose of the resulting scaffolds is for tissue engineered blood vessels. SMCs attached to and proliferated on and partly into the scaffolds. PMID:18615821

  6. MAP kinase cascades: scaffolding signal specificity.

    PubMed

    van Drogen, Frank; Peter, Matthias

    2002-01-22

    Scaffold proteins organize many MAP kinase pathways by interacting with several components of these cascades. Recent studies suggest that scaffold proteins provide local activation platforms that contribute to signal specificity by insulating different MAP kinase pathways. PMID:11818078

  7. Quantitative analysis of AgNOR proteins in buccal epithelial cells of Indian street boys addicted to gasp 'golden glue'.

    PubMed

    Mondal, Nandan Kumar; Ghosh, Sreenita; Ray, Manas Ranjan

    2011-11-01

    The effect of glue snuffle on the expression of argyrophilic nucleolar organizer regions (AgNORs), an indicator of ribosome biosynthesis, in epithelial cells of oral mucosa has been investigated. AgNOR was evaluated by cytochemical staining in 148 Indian street boys (median age 12 year) who had different bad addictions like tobacco smoking, chewing and most importantly inhaling glue and 20 age- and body mass index-matched school boys who had no such type of bad habit. Compared with school boys, glue addicted street boys showed remarkably increased number of AgNOR dots per nucleus (9.38±1.84 vs. 3.12±0.87, p<0.001), AgNOR size (1.34±0.52 vs. 0.43±0.02 μm(2), p<0.001) and percentage of AgNOR occupied nuclear area (9.38±2.12 vs. 0.99±0.03%, p<0.001). Increase in number and size of the dots is also higher in tobacco smokers and chewers when compared with school boys but a remarkable difference was recorded in glue addicted boys. The changes in AgNOR expression were positively associated with years of addiction after controlling potential confounders. Thus, glue snuffle appeared to be a risk factor for abnormal cell growth via up-regulation of ribosome biogenesis. PMID:20541922

  8. Comparison of a CO2 (Carbon Dioxide) Laser and Tissue Glue with Conventional Surgical Techniques in Circumcision

    PubMed Central

    Mungnirandr, Akkrapol; Wiriyakamolphan, Suwanna; Ruangtrakool, Ravit; Ngerncham, Monawat; Tumrongsombutsakul, Sureerat; Leumcharoen, Bungorn

    2015-01-01

    Introduction: CO2 (Carbon Dioxide) laser application in circumcision, for cutting and coagulation, has been reported to have excellent results. Also, tissue glue has been reported to have advantages over sutures for approximation of wound edges. Most previous studies focused on comparisons between CO2 laser and scalpel, or between tissue glue and sutures. This study prospectively compared the results and complications CO2 laser and tissue glue, with standard surgical techniques in circumcision. Methods: Thirty boys were prospectively divided into two groups. Group 1 (n = 17) underwent circumcision by scalpel with approximation of the wound edges using chromic catgut sutures. Group 2 (n = 13) underwent circumcision with CO2 laser and approximation of the wound edges using tissue glue. Patient age, indications for surgery, operative time, wound swelling, bleeding, wound infection, local irritation, pain score, and cosmetic appearance were recorded. Results: Group 1 had a significantly longer operative time (P= 0.011), higher rate of local irritation (P= 0.016), and poorer cosmetic appearance (P< 0.001) than group 2. Bleeding only occurred in one patient in group 1. There were no significant differences in pain score, wound infection rate, or cost of surgery between the two groups. Conclusions: CO2 laser and tissue glue have advantages over standard surgical techniques in circumcision, with a significantly shorter operative time, lower rate of local irritation, and better cosmetic appearance. The cost of surgery is similar between the two groups. PMID:25699165

  9. Identification of animal glue species in artworks using proteomics: application to a 18th century gilt sample.

    PubMed

    Dallongeville, Sophie; Koperska, Monika; Garnier, Nicolas; Reille-Taillefert, Geneviève; Rolando, Christian; Tokarski, Caroline

    2011-12-15

    This study proposes a proteomic-based strategy for the identification of the origin species of glues used as binding media and adhesives in artworks. The methodology, based on FTICR high resolution mass spectrometry, was evaluated on glues from different animal origin (i.e., bovine, rabbit, and fish). The analysis of the peptide mixture resulting from the enzymatic hydrolysis of the proteins led to the identification of species-specific peptides. Up to 15 specific peptides were identified for the bovine species and three for the rabbit species and, in the case of sturgeon glue, three fish-specific peptides were found by sequence homology to the rainbow trout. Then, the method was applied to authenticate different rabbit skin glue samples, including a 100 year-old sample named "Colle à Doreurs" coming from the "Maison Totin-Frères". For this sample, two specific peptides of rabbit collagen were identified. To evaluate the method in a complex matrix, model paints composed of lead white, linseed oil, and animal glue were prepared. Species-specific peptides were identified in each paint sample. Finally, a gilt sample from St Maximin church dating from the eighteenth century was analyzed, and 13 peptides specific to bovine collagens were identified starting from very low sample amount (50 μg). PMID:22014085

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

    PubMed

    Sotiriadis, Charalampos; Hajdu, Steven David; Degrauwe, Sophie; Barras, Heloise; Qanadli, Salah Dine

    2016-08-01

    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. PMID:27016091

  11. Designing Online Scaffolds for Interactive Computer Simulation

    ERIC Educational Resources Information Center

    Chen, Ching-Huei; Wu, I-Chia; Jen, Fen-Lan

    2013-01-01

    The purpose of this study was to examine the effectiveness of online scaffolds in computer simulation to facilitate students' science learning. We first introduced online scaffolds to assist and model students' science learning and to demonstrate how a system embedded with online scaffolds can be designed and implemented to help high…

  12. Rethinking Scaffolding in the Information Age

    ERIC Educational Resources Information Center

    Yelland, Nicola; Masters, Jennifer

    2007-01-01

    This paper addresses the use of scaffolding in learning contexts that incorporate technologically based novel problems. We suggest that in computer contexts extended conceptualisations of scaffolding are needed in order to gain greater insights into teaching and learning processes. Our work has revealed that traditional forms of scaffolding, based…

  13. Bispidine as a Privileged Scaffold.

    PubMed

    Tomassoli, Isabelle; Gündisch, Daniela

    2016-01-01

    Thediazabicyclic molecule bispidine named by the chemist Carl Mannich in 1930, is a naturally occurring scaffold with interesting features. Bispidine can form different conformers, has high basicity, can attack dichloromethane, has metal ion coordination properties and interacts with nicotinic acetylcholine receptors. In this review we will discuss important properties, synthetic pathways and biological activities of bispidine and some derivatives. Bispidine can function as a scaffold for compounds with very diverse biological activities, e.g. interacting with ion channels, G-protein coupled receptors, and enzymes, and is even used for the development of new in vivo radiotracers. PMID:26369817

  14. Synthesis of the TACO scaffold as a new selectively deprotectable conformationally restricted triazacyclophane based scaffold.

    PubMed

    Brouwer, Arwin J; van de Langemheen, Helmus; Ciaffoni, Adriano; Schilder, Kitty E; Liskamp, Rob M J

    2014-06-01

    The synthesis of a new triazacyclophane scaffold (TACO scaffold) containing three selectively deprotectable amines is described. The TACO scaffold is conformationally more constrained than our frequently used TAC scaffold, due to introduction of a substituent on the para position of the benzoic acid hinge, which prevents ring flipping and makes it more attractive than the TAC scaffold for preparation of artificial receptor molecules or for mimicking discontinuous epitopes toward protein mimics when more preorganization is required. PMID:24856258

  15. Non-Covalent Interaction of α2-Antiplasmin with Fibrin(ogen): Localization of α2-Antiplasmin Binding Sites

    PubMed Central

    Tsurupa, Galina; Yakovlev, Sergiy; McKee, Patrick; Medved, Leonid

    2010-01-01

    Covalent incorporation (cross-linking) of plasmin inhibitor α2-antiplasmin (α2-AP) into fibrin clots increases their resistance to fibrinolysis. We hypothesized that α2-AP may also interact non-covalently with fibrin prior to its covalent cross-linking. To test this hypothesis, we studied binding of α2-AP to fibrin(ogen) and its fragments by ELISA and Surface Plasmon Resonance. The experiments revealed that α2-AP binds to polymeric fibrin and surface-adsorbed fibrin(ogen) while no binding was observed with fibrinogen in solution. To localize the α2-AP-binding sites, we studied the interaction of α2-AP with the fibrin(ogen)-derived D1, D-D and E3 fragments, and the recombinant αC region and its constituents, αC-connector and αC-domain and its sub-domains, which together encompass practically the whole fibrin(ogen) molecule. In ELISA, α2-AP bound to immobilized D1, D-D, αC region, αC-domain and its C-terminal sub-domain. The binding was Lys-independent and was not inhibited by plasminogen or tPA. Furthermore, the affinity of α2-AP to D-D was significantly increased in the presence of plasminogen while that to the αC-domain remained unaffected. Altogether, these results indicate that the fibrin(ogen) D region and the C-terminal sub-domain of the αC-domain contain high affinity α2-AP-binding sites that are cryptic in fibrinogen and exposed in fibrin or adsorbed fibrinogen, and the presence of plasminogen facilitates interaction of α2-AP with the D regions. The discovered non-covalent interaction of α2-AP with fibrin may contribute to regulation of the initial stage of fibrinolysis and provide proper orientation of the cross-linking sites to facilitate covalent cross-linking of α2-AP to the fibrin clot. PMID:20687529

  16. Vascular tissue construction on poly(ε-caprolactone) scaffolds by dynamic endothelial cell seeding: effect of pore size.

    PubMed

    Mathews, Asha; Colombus, Soumya; Krishnan, V Kalliyana; Krishnan, Lissy K

    2012-06-01

    In vitro tissue engineering for fabrication of small diameter vascular grafts probably undergoes a sequence of events similar to the in vivo angiogenesis process. In both cases endothelial cells (ECs) play the crucial role in generating a non-thrombogenic vessel lumen and stabilization of ECs in the lumen of new vessels requires the deposition of collagen IV and elastin. Shear stress is an important in vivo signal for inducing synthesis of extracellular matrix (ECM) components, collagen IV and elastin, which form the basement membrane in the case of new blood vessels. Stimulation of ECs may therefore produce collagen and elastin in the lumen of a polymeric scaffold during the vascular tissue-engineering process if appropriate biochemical and mechanical signals are presented. However, the morphology and physicochemical characteristics of polymer scaffolds may also be crucial for EC monolayer formation and ECM deposition. In this study, tubular scaffolds made of biodegradable poly(ε-caprolactone) (PCL) with biomimetic fibrin-based coating were evaluated to compare the effects of pore sizes on surface coverage of ECs and synthesis of ECM under dynamic culture conditions. Actin was stained for identification of cells, while specific antibodies were used for locating collagen IV and elastin deposition on the scaffolds. It was found that dynamic seeding of ECs in the lumen stabilized the cells and aligned them along the direction of flow, with better deposition of insoluble elastin and collagen IV when ∼75% of pores were < 24 µm in diameter. In addition, monolayer on the ε-PCL scaffolds with lower pore sizes was found to produce nitric oxide (NO), indicating a non-thrombogenic EC layer in the lumen. PMID:21800434

  17. A Blinded, Randomised, Controlled Trial of Stapled Versus Tissue Glue Closure of Neck Surgery Incisions

    PubMed Central

    Ridgway, DM; Mahmood, F; Moore, L; Bramley, D; Moore, PJ

    2007-01-01

    INTRODUCTION Cosmetic acceptability of scar and neck mobility are important outcomes after collar line incision for neck surgery. This randomised, controlled trial compares these parameters in closures using tissue glue (Dermabond™, Ethicon, UK) and skin staples. PATIENTS AND METHODS Patients requiring a collar line incision were randomised to receiving tissue glue or staples for skin closure. Time for closure to be completed was recorded. Mobility of the neck was assessed using a visual analogue scale at 48 h and 1 week after surgery. At 6 weeks, cosmetic appearance was assessed using a linear 1–10 visual analogue scale by the patient, surgeon and an independent blinded assessor. Results were compared using appropriate statistical tests. RESULTS Glued (n = 14) and stapled (n = 15) closures were performed for hemithyroidectomy (n = 8 versus 6), sub-total thyroidectomy (n = 2 versus 4), total thyroidectomy (n = 1 versus 4) and parathyroidectomy (n = 3 versus 1). Closure with tissue glue took significantly longer than with staples (mean, 95 versus 28 s; P < 0.001). Neck mobility scores were comparable at 48 h and 1 week (mean, 4.8 versus 4.4; P = 0.552: and 2.7 versus 2.6; P = 0.886). Cosmetic appearance at 6 weeks was comparable when patient (mean, 1.7 versus 1.8; P = 0.898), surgeon (mean, 2.6 versus 2.3; P = 0.633) and independent assessment (mean, 1.4 versus 1.9; P = 0.365) was performed. CONCLUSIONS The use of glued skin closure may increase the duration of surgery but acceptable neck mobility and wound cosmesis can be achieved by the more rapid application of stapled skin closure in cervicotomy incisions. PMID:17394707

  18. Fibrin Sealant: A Review of the History, Biomechanics, and Current Applications for Prosthetic Fixation in Hernia Repair.

    PubMed

    Watson, Jefferson Tyler; Webb, David L; Stoikes, Nathaniel F N; Voeller, Guy R

    2015-11-01

    The role of surgical adhesives in hernia repair has continued to evolve. The purpose of this chapter is to review the role of fibrin sealant and its application in general surgery for mesh fixation, specifically the history, biomechanics, and clinical utilization. The utilization of fibrin sealant for repair of groin hernias, both open and laparoscopic, ventral hernias, and hiatal hernias will be discussed. PMID:26696538

  19. Uncertainty and sensitivity assessments of an agricultural-hydrological model (RZWQM2) using the GLUE method

    NASA Astrophysics Data System (ADS)

    Sun, Mei; Zhang, Xiaolin; Huo, Zailin; Feng, Shaoyuan; Huang, Guanhua; Mao, Xiaomin

    2016-03-01

    Quantitatively ascertaining and analyzing the effects of model uncertainty on model reliability is a focal point for agricultural-hydrological models due to more uncertainties of inputs and processes. In this study, the generalized likelihood uncertainty estimation (GLUE) method with Latin hypercube sampling (LHS) was used to evaluate the uncertainty of the RZWQM-DSSAT (RZWQM2) model outputs responses and the sensitivity of 25 parameters related to soil properties, nutrient transport and crop genetics. To avoid the one-sided risk of model prediction caused by using a single calibration criterion, the combined likelihood (CL) function integrated information concerning water, nitrogen, and crop production was introduced in GLUE analysis for the predictions of the following four model output responses: the total amount of water content (T-SWC) and the nitrate nitrogen (T-NIT) within the 1-m soil profile, the seed yields of waxy maize (Y-Maize) and winter wheat (Y-Wheat). In the process of evaluating RZWQM2, measurements and meteorological data were obtained from a field experiment that involved a winter wheat and waxy maize crop rotation system conducted from 2003 to 2004 in southern Beijing. The calibration and validation results indicated that RZWQM2 model can be used to simulate the crop growth and water-nitrogen migration and transformation in wheat-maize crop rotation planting system. The results of uncertainty analysis using of GLUE method showed T-NIT was sensitive to parameters relative to nitrification coefficient, maize growth characteristics on seedling period, wheat vernalization period, and wheat photoperiod. Parameters on soil saturated hydraulic conductivity, nitrogen nitrification and denitrification, and urea hydrolysis played an important role in crop yield component. The prediction errors for RZWQM2 outputs with CL function were relatively lower and uniform compared with other likelihood functions composed of individual calibration criterion. This

  20. [Use of Tissucol, a tissue glue, in reconstructive surgery of large scleral defects].

    PubMed

    Karel, I; Dolezalová, J

    1991-05-01

    In a 14-year-old female patient the postoperative course of myectomy of the musculus rectus oculi externus on account of concomittant strabism was complicated by necrosis of the sclera (diameter 9 mm) at the site of intrascleral stitches and exudation into the anterior chamber and the vitreous body. For fixation of the transplant from lyophilized sclera the tissue glue Tissucol Kit was used. Tissucol rapidly and firmly joined the wound areas, its direct contact with uveal tissue did not produce an inflammatory reaction and the exudate from the anterior chamber and vitreous body was absorbed rapidly and completely. PMID:1913913

  1. Solvent constituents in paint, glue and thinner for plastic miniature hobby.

    PubMed

    Saito, J; Ikeda, M

    1988-07-01

    Solvent-containing products (8 paint, 29 glue and 4 thinner preparations) for plastic miniature hobby were analyzed for solvent constituents by capillary gas-chromatography. Acetone and methyl isobutyl ketone were two most extensively used solvents both in terms of frequency and concentration. Other popular solvents included ethyl alcohol and two esters of ethyl acetate and butyl acetate. In contrast, aromatics, chlorinated hydrocarbons and ethylene glycol derivatives were seldomly detected. The present findings were discussed in comparison with the observation on the materials abused for sniffing in the past, as well as constituents in the products for industrial application. PMID:3176022

  2. GlueX a new facility to search for gluonic degrees of freedom in mesons

    SciTech Connect

    Zihlmann, Benedikt

    2010-08-01

    The GlueX detector facility in Hall-D at Jefferson lab in Newport News is part of the 12 GeV upgrade and dedicated to the search for gluonic degrees of freedom in mesons by scattering high energy linearly polarized real photons of up to 9 GeV from nucleon targets. Civil construction of the Hall-D complex has started as well as the construction of the various detector components. The current status of the project is outlined here.

  3. The pattern of fatal fibrinous pneumonia (shipping fever) affecting calves in a large feedlot in Alberta (1985-1988).

    PubMed Central

    Ribble, C S; Meek, A H; Jim, G K; Guichon, P T

    1995-01-01

    Data from a retrospective field study were used to describe the epidemiology of fatal fibrinous pneumonia as it affected beef calves entering a large commercial feedlot in southwestern Alberta during the fall months of y 1985 to 1988. A chute-side computer system was used to record processing and health data on 58885 calves during this period. The large annual variation (10%-57%) in the proportion of total mortality due to fibrinous pneumonia indicated that crude mortality cannot be used in epidemiological studies as a surrogate measure of fibrinous pneumonia mortality. Yearly epidemic curves for fatal fibrinous pneumonia were very similar, with a short time interval (median, 19-22 d) between arrival and fatal disease. Fully 75% of the calves that died of fibrinous pneumonia already were sick within 2 weeks of arrival. Studies of the biological, environmental, and population factors that are present before and shortly after arrival at the feedlot are needed to identify strategies for reducing the incidence of fatal fibrinous pneumonia. PMID:8748443

  4. "Fibrinogen Tokyo II". An abnormal fibrinogen with an impaired polymerization site on the aligned DD domain of fibrin molecules.

    PubMed Central

    Matsuda, M; Baba, M; Morimoto, K; Nakamikawa, C

    1983-01-01

    A hereditary dysfibrinogenemia associated with defective aggregation of fibrin monomers was found in a 39-yr-old female and in the members of her immediate family, who had all been asymptomatic. The abnormality was probably due to an impaired polymerization site exposed in the DD domain of two adjacent fibrin molecules, because plasmic fragment DD derived from the propositus' cross-linked fibrin bound far less tightly to insolubilized normal fragment E than that from the normal one. Its complementary polymerization site in the E domain of fibrin, which was exposed by thrombin cleavage, and the polymerization site in the D domain of fibrinogen, which was available without activation by thrombin, were both found to be normal. More anodal migration of the abnormal fragment DD than the normal one, as shown by immunoelectrophoresis, seemed to support our concept that the mutation most likely resides in the D domain of the abnormal fibrinogen molecule at or near a region closely related to the polymerization site that is exposed when two fibrin molecules are linearly aligned. The work of others on the polymerization of normal fibrin with different techniques yielded results consistent with our conclusions. We tentatively designate this type of abnormal fibrinogen "fibrinogen Tokyo II," but its possible identity with other abnormalities of fibrinogen reported heretofore is not excluded. Images FIGURE 1 FIGURE 5 FIGURE 7 PMID:6886002

  5. Addressing subjective decision-making inherent in GLUE-based multi-criteria rainfall-runoff model calibration

    NASA Astrophysics Data System (ADS)

    Shafii, Mahyar; Tolson, Bryan; Shawn Matott, L.

    2015-04-01

    GLUE is one of the most commonly used informal methodologies for uncertainty estimation in hydrological modelling. Despite the ease-of-use of GLUE, it involves a number of subjective decisions such as the strategy for identifying the behavioural solutions. This study evaluates the impact of behavioural solution identification strategies in GLUE on the quality of model output uncertainty. Moreover, two new strategies are developed to objectively identify behavioural solutions. The first strategy considers Pareto-based ranking of parameter sets, while the second one is based on ranking the parameter sets based on an aggregated criterion. The proposed strategies, as well as the traditional strategies in the literature, are evaluated with respect to reliability (coverage of observations by the envelope of model outcomes) and sharpness (width of the envelope of model outcomes) in different numerical experiments. These experiments include multi-criteria calibration and uncertainty estimation of three rainfall-runoff models with different number of parameters. To demonstrate the importance of behavioural solution identification strategy more appropriately, GLUE is also compared with two other informal multi-criteria calibration and uncertainty estimation methods (Pareto optimization and DDS-AU). The results show that the model output uncertainty varies with the behavioural solution identification strategy, and furthermore, a robust GLUE implementation would require considering multiple behavioural solution identification strategies and choosing the one that generates the desired balance between sharpness and reliability. The proposed objective strategies prove to be the best options in most of the case studies investigated in this research. Implementing such an approach for a high-dimensional calibration problem enables GLUE to generate robust results in comparison with Pareto optimization and DDS-AU.

  6. Strategic Scaffolding for Scientific Inquiry

    ERIC Educational Resources Information Center

    Shelton, Angela; Natarajan, Uma; Willard, Catherine; Kane, Tera; Ketelhut, Diane Jass; Schifter, Catherine

    2013-01-01

    Though many national and international science organizations stress the importance of integrating scientific inquiry into classroom instruction, this is often difficult for teachers. Moreover, assessing and scaffolding inquiry skills for students can be even more of a challenge. This paper investigated the student performances in an inquiry-based,…

  7. Problem Solving, Scaffolding and Learning

    ERIC Educational Resources Information Center

    Lin, Shih-Yin

    2012-01-01

    Helping students to construct robust understanding of physics concepts and develop good solving skills is a central goal in many physics classrooms. This thesis examine students' problem solving abilities from different perspectives and explores strategies to scaffold students' learning. In studies involving analogical problem solving…

  8. Proton NMR study of the state of water in fibrin gels, plasma, and blood clots

    SciTech Connect

    Blinc, A.; Lahajnar, G.; Blinc, R.; Zidansek, A.; Sepe, A. )

    1990-04-01

    A proton NMR relaxation and pulsed field gradient self-diffusion study of water in fibrin gels, plasma, and blood clots has been performed with special emphasis on the effect of the sol-gel and shrinkage transitions. Deuteron NMR in fibrin gels was also studied to supplement the proton data. It is shown that a measurement of the water proton or deuteron T1/T2 ratio allows for a determination of the bound water fraction in all these systems. The change in the T1/T2 ratio at the shrinkage transition further allows for a determination of the surface fractal dimension of the gel if the change in the volume of the gel is known. The self-diffusion coefficient of water in these systems, which determines the transport properties of the gel, is found to be proportional to the free water fraction in both the nonshrunken and shrunken state.

  9. Acute fibrinous and organising pneumonia: a rare histopathological variant of chemotherapy-induced lung injury.

    PubMed

    Gupta, Arjun; Sen, Shiraj; Naina, Harris

    2016-01-01

    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. PMID:27053543

  10. Localization of the binding site of tissue-type plasminogen activator to fibrin.

    PubMed Central

    Ichinose, A; Takio, K; Fujikawa, K

    1986-01-01

    Functionally active A and B chains were separated from a two-chain form of recombinant tissue-type plasminogen activator after mild reduction and alkylation. The A chain was found to be responsible for the binding to lysine-Sepharose or fibrin and the B chain contained the catalytic activity of tissue-type plasminogen activator. An extensive reduction of two-chain tissue-type plasminogen activator, however, destroyed both the binding and catalytic activities. A thermolytic fragment, Fr. 1, of tissue-type plasminogen activator that contained a growth factor and two kringle segments retained its lysine binding activity. Additional thermolytic cleavages in the kringle-2 segment of Fr. 1 caused a total loss of the binding activity. These results indicated that the binding site of tissue-type plasminogen activator to fibrin was located in the kringle-2 segment. Images PMID:3088041

  11. Acute Fibrinous and Organizing Pneumonia Associated With Allogenic Hematopoietic Stem Cell Transplant Successfully Treated With Corticosteroids

    PubMed Central

    Nguyen, Lam-Phuong; Ahdoot, Stella; Sriratanaviriyakul, Narin; Zhang, Yanhong; Stollenwerk, Nicholas; Schivo, Michael; Harper, Richart

    2016-01-01

    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. PMID:27152316

  12. Spirulan from blue-green algae inhibits fibrin and blood clots: its potent antithrombotic effects.

    PubMed

    Choi, Jun-Hui; Kim, Seung; Kim, Sung-Jun

    2015-05-01

    We investigated in vitro and in vivo fibrinolytic and antithrombotic activity of spirulan and analyzed its partial biochemical properties. Spirulan, a sulfated polysaccharide from the blue-green alga Arthrospira platensis, exhibits antithrombotic potency. Spirulan showed a strong fibrin zymogram lysis band corresponding to its molecular mass. It specifically cleaved Aα and Bβ, the major chains of fibrinogen. Spirulan directly decreased the activity of thrombin and factor X activated (FXa), procoagulant proteins. In vitro assays using human fibrin and mouse blood clots showed fibrinolytic and hemolytic activities of spirulan. Spirulan (2 mg/kg) showed antithrombotic effects in the ferric chloride (FeCl3 )-induced carotid arterial thrombus model and collagen and epinephrine-induced pulmonary thromboembolism mouse model. These results may be attributable to the prevention of thrombus formation and partial lysis of thrombus. Therefore, we suggest that spirulan may be a potential antithrombotic agent for thrombosis-related diseases. PMID:25651404

  13. Canine intracranial meningiomas: Immunohistochemical evaluation of tissue factor, fibrin/fibrinogen and D-dimers.

    PubMed

    Font, Cristina; de la Fuente, Cristian; Pumarola, Martí; Blasco, Ester; Fernández, Francisco; Viu, Judit; Añor, Sònia

    2015-12-01

    The haemostatic system influences angiogenesis, cell growth and metastasis in solid tumours. The aim of this study was to investigate tissue factor (TF) expression, fibrin/fibrinogen and D-dimer deposition, as well as the occurrence of intravascular thrombosis (IVT) in canine intracranial meningiomas using immunohistochemistry. All but three (26/29) meningiomas expressed TF. TF immunolabelling was significantly higher in high-grade (grades II and III) than in low-grade (grade I) meningiomas. Fibrin/fibrinogen and D-dimer deposits were detected in all meningiomas and staining scores were statistically different between different meningioma grades. IVT was detected in 19/29 specimens, but no statistical differences were observed between different malignancy grades. In conclusion, the haemostatic system may be involved in meningioma pathobiology and may be a potential therapeutic target for canine meningiomas, as also suggested for human meningiomas. PMID:26526524

  14. Enhancing Interfacial Bonding between Anisotropically Oriented Grains Using a Glue-Nanofiller for Advanced Li-Ion Battery Cathode.

    PubMed

    Kim, Hyejung; Lee, Sanghan; Cho, Hyeon; Kim, Junhyeok; Lee, Jieun; Park, Suhyeon; Joo, Se Hun; Kim, Su Hwan; Cho, Yoon-Gyo; Song, Hyun-Kon; Kwak, Sang Kyu; Cho, Jaephil

    2016-06-01

    Formation of a glue-nanofiller layer between grains, consisting of a middle-temperature spinel-like Lix CoO2 phase, reinforces the strength of the incoherent interfacial binding between anisotropically oriented grains by enhancing the face-to-face adhesion strength. The cathode treated with the glue-layer exhibits steady cycling performance at both room-temperature and 60 °C. These results represent a step forward in advanced lithium-ion batteries via simple cathode coating. PMID:27074141

  15. Chitin Scaffolds in Tissue Engineering

    PubMed Central

    Jayakumar, Rangasamy; Chennazhi, Krishna Prasad; Srinivasan, Sowmya; Nair, Shantikumar V.; Furuike, Tetsuya; Tamura, Hiroshi

    2011-01-01

    Tissue engineering/regeneration is based on the hypothesis that healthy stem/progenitor cells either recruited or delivered to an injured site, can eventually regenerate lost or damaged tissue. Most of the researchers working in tissue engineering and regenerative technology attempt to create tissue replacements by culturing cells onto synthetic porous three-dimensional polymeric scaffolds, which is currently regarded as an ideal approach to enhance functional tissue regeneration by creating and maintaining channels that facilitate progenitor cell migration, proliferation and differentiation. The requirements that must be satisfied by such scaffolds include providing a space with the proper size, shape and porosity for tissue development and permitting cells from the surrounding tissue to migrate into the matrix. Recently, chitin scaffolds have been widely used in tissue engineering due to their non-toxic, biodegradable and biocompatible nature. The advantage of chitin as a tissue engineering biomaterial lies in that it can be easily processed into gel and scaffold forms for a variety of biomedical applications. Moreover, chitin has been shown to enhance some biological activities such as immunological, antibacterial, drug delivery and have been shown to promote better healing at a faster rate and exhibit greater compatibility with humans. This review provides an overview of the current status of tissue engineering/regenerative medicine research using chitin scaffolds for bone, cartilage and wound healing applications. We also outline the key challenges in this field and the most likely directions for future development and we hope that this review will be helpful to the researchers working in the field of tissue engineering and regenerative medicine. PMID:21673928

  16. The Fibrin slide assay for detecting urokinase activity in human fetal kidney cells

    NASA Technical Reports Server (NTRS)

    Sedor, K.

    1985-01-01

    The Fibrin Slide Technique of Hau C. Kwaan and Tage Astrup is discussed. This relatively simple assay involves two steps: the formation of an artificial clot and then the addition of an enzyme (UKOKINASE) to dissolve the clot. The actual dissolving away of the clot is detected by the appearance of holes (lysis zones) in the stained clot. The procedure of Kwaan and Astrup is repeated, along with modifications and suggestions for improvements based on experience with the technique.

  17. Adhesins of Leptospira interrogans Mediate the Interaction to Fibrinogen and Inhibit Fibrin Clot Formation In Vitro

    PubMed Central

    Oliveira, Rosane; Domingos, Renan F.; Siqueira, Gabriela H.; Fernandes, Luis G.; Souza, Natalie M.; Vieira, Monica L.; de Morais, Zenaide M.; Vasconcellos, Silvio A.; Nascimento, Ana L. T. O.

    2013-01-01

    We report in this work that Leptospira strains, virulent L. interrogans serovar Copenhageni, attenuated L. interrogans serovar Copenhageni and saprophytic L. biflexa serovar Patoc are capable of binding fibrinogen (Fg). The interaction of leptospires with Fg inhibits thrombin- induced fibrin clot formation that may affect the haemostatic equilibrium. Additionally, we show that plasminogen (PLG)/plasmin (PLA) generation on the surface of Leptospira causes degradation of human Fg. The data suggest that PLA-coated leptospires were capable to employ their proteolytic activity to decrease one substrate of the coagulation cascade. We also present six leptospiral adhesins and PLG- interacting proteins, rLIC12238, Lsa33, Lsa30, OmpL1, rLIC11360 and rLIC11975, as novel Fg-binding proteins. The recombinant proteins interact with Fg in a dose-dependent and saturable fashion when increasing protein concentration was set to react to a fix human Fg concentration. The calculated dissociation equilibrium constants (KD) of these reactions ranged from 733.3±276.8 to 128±89.9 nM for rLIC12238 and Lsa33, respectively. The interaction of recombinant proteins with human Fg resulted in inhibition of fibrin clot by thrombin-catalyzed reaction, suggesting that these versatile proteins could mediate Fg interaction in Leptospira. Our data reveal for the first time the inhibition of fibrin clot by Leptospira spp. and presents adhesins that could mediate these interactions. Decreasing fibrin clot would cause an imbalance of the coagulation cascade that may facilitate bleeding and help bacteria dissemination PMID:24009788

  18. Internal Iliac Artery Aneurysm Embolization with Fibrin Sealant: A Simple and Effective Solution

    SciTech Connect

    Brountzos, Elias N.; Malagari, Katerina; Papathanasiou, Mathildi A.; Gougoulakis, Alexandros; Kelekis, Dimitrios A.

    2003-02-15

    Endovascular treatment of internal iliac artery (IIA) aneurysms is an attractive alternative to surgical management, because the former is associated with less morbidity and mortality.Embolization with coils or exclusion of the IIA orifice with stent -grafts are the preferred techniques. Although uncommon, technical failures occur with reported aneurysm rupture. Two patients with IIA aneurysms are reported here, where we describe successful occlusion of their IIA aneurysms with the use of fibrin sealant, after initial failure of coil embolization.

  19. Our experience of fibrin sealant-assisted implantation of Ahmed glaucoma valve

    PubMed Central

    Choudhari, Nikhil S; Neog, Aditya; Sharma, Anuj; Iyer, Geetha K; Srinivasan, Bhaskar

    2013-01-01

    Aim: To report our experience with the fibrin sealant as a suture substitute for securing the human scleral patch graft during implantation of Ahmed glaucoma valve (AGV). Materials and Methods: A retrospective, non-comparative study of 12 eyes of 12 patients who underwent an AGV implantation with fibrin sealant for part of the procedure during June 2009 to September 2010. Results: The mean patient age was 21.5 ± 20.6 years. Male: Female ratio was 2 : 1. Seven (58.3%) patients were monocular. The indications for AGV were varied. The mean number of intra-ocular surgeries prior to an implantation of AGV was 1.8. The mean follow-up duration was 24.5 ± 17.9 weeks. There was a statistically significant reduction in the mean IOP and in the mean number of anti-glaucoma medications at the final visit compared to the pre-operative values (P < 0.01, paired t test). Conjunctival retraction was seen in 1 (8.3%) case. The scleral patch graft was retracted posteriorly in another (8.3%) case. There was no case of AGV tube exposure, tube-cornea touch, or conjunctival erosion. Vision threatening complication viz. late post-operative rhegmatogenous retinal detachment, unlikely to be related to the use of the fibrin sealant, occurred in 2 (16.6%) eyes. Conclusion: The fibrin sealant offers the advantages of safety and convenience to the placement of a scleral patch graft during an AGV implantation. PMID:23275217

  20. [Fibrin-collagen substance as a vehicle for local application of antibacterial agents].

    PubMed

    Gorskiĭ, V A; Gertsog, A A; Leonenko, I V; Shamanek, T P; Sokov, B N

    2002-01-01

    Inhibitory activity of fibrin-collagen substance (FCS) impregnated by various antibacterial agents against various microorganisms was investigated. It was demonstrated that antibacterials bind well with FCS, providing its sufficient antibacterial activity. Determination of growth-inhibition zones showed that antibacterial agents diffuse into medium well and demonstrated the same activity as discs with antibiotics. For clinical practice it is recommended to use for impregnation the following drugs: gentamycin, meropenem, cefriaxone and ciprofloxacin. PMID:12422648

  1. Pathological findings of saccular cerebral aneurysms-impact of subintimal fibrin deposition on aneurysm rupture.

    PubMed

    Hokari, Masaaki; Nakayama, Naoki; Nishihara, Hiroshi; Houkin, Kiyohiro

    2015-07-01

    Although several studies have suggested that aneurysmal wall inflammation and laminar thrombus are associated with the rupture of saccular aneurysms, the mechanisms leading to the rupture remain obscure. We performed full exposure of aneurysms before clip application and attempted to keep the fibrin cap on the rupture point. Using these specimens in a nearly original state before surgery, we conducted a pathological analysis and studied the differences between ruptured and unruptured aneurysms to clarify the mechanism of aneurysmal wall degeneration. This study included ruptured (n = 28) and unruptured (n = 12) saccular aneurysms resected after clipping. All of the ruptured aneurysms were obtained within 24 h of onset. Immunostainings for markers of inflammatory cells (CD68) and classical histological staining techniques were performed. Clinical variables and pathological findings from ruptured and unruptured aneurysms were compared. Patients with ruptured or unruptured aneurysms did not differ by age, gender, size, location, and risk factors, such as hypertension, smoking, and hyperlipidemia. The absence or fragmentation of the internal elastica lamina, the myointimal hyperplasia, and the thinning of the aneurysmal wall were generally observed in both aneurysms. The existence of subintimal fibrin deposition, organized laminar thrombus, intramural hemorrhage, neovascularization, and monocyte infiltration are more frequently observed in ruptured aneurysms. Multivariate logistic regression analysis showed that ruptured aneurysm was associated with presence of subintimal fibrin deposition and monocyte infiltration. These findings suggest that subintimal fibrin deposition and chronic inflammation have a strong impact on degeneration of the aneurysmal wall leading to their rupture, and this finding may be caused by endothelial dysfunction. PMID:25860660

  2. N-butyl Cyanoacrylate Glue Embolization of Arterial Networks to Facilitate Hepatic Arterial Skeletonization before Radioembolization

    SciTech Connect

    Samuelson, Shaun D.; Louie, John D.; Sze, Daniel Y.

    2013-06-15

    Purpose. Avoidance of nontarget microsphere deposition via hepatoenteric anastomoses is essential to the safety of yttrium-90 radioembolization (RE). The hepatic hilar arterial network may remain partially patent after coil embolization of major arteries, resulting in persistent risk. We retrospectively reviewed cases where n-butyl cyanoacrylate (n-BCA) glue embolization was used to facilitate endovascular hepatic arterial skeletonization before RE. Methods. A total of 543 RE procedures performed between June 2004 and March 2012 were reviewed, and 10 were identified where n-BCA was used to embolize hepatoenteric anastomoses. Arterial anatomy, prior coil embolization, and technical details were recorded. Outcomes were reviewed to identify subsequent complications of n-BCA embolization or nontarget RE. Results. The rate of complete technical success was 80 % and partial success 20 %, with one nontarget embolization complication resulting in a minor change in treatment plan. No evidence of gastrointestinal or biliary ischemia or infarction was identified, and no microsphere-related gastroduodenal ulcerations or other evidence of nontarget RE were seen. Median volume of n-BCA used was <0.1 ml. Conclusion. n-BCA glue embolization is useful to eliminate hepatoenteric networks that may result in nontarget RE, especially in those that persist after coil embolization of major vessels such as the gastroduodenal and right gastric arteries.

  3. Study of the nature of the confinement in the GlueX experiment

    SciTech Connect

    Somov, S.; Berdnikov, Vladmir; Tolstukhin, Ivan; Somov, Alexander S.

    2015-11-01

    Confinement is a fundamental property of quantum chromodynamics (QCD) associated with the unique role of the gluonic field responsible for binding quarks in hadrons. Understanding the role of gluons in the confinement of quarks is one of the most tantalizing topics in modern particle physics to be explored. The new experiment GlueX has been recently constructed at Jefferson Lab. The experiment was designed to search for hybrid mesons with exotic quantum numbers using a beam of linearly polarized photons incident on a liquid hydrogen target. The spectrum of these states and their mass splitting from normal mesons may yield information on confinement. In addition, these observations in combination with detailed chromodynamics calculations such as on the Lattice can provide important tests for our understanding of the role of gluons. The production of exotic mesons is expected to be enhanced in p interactions, where the experimental data is very limited. We present the description of the GlueX detector, beam line, and first results of the commissioning with photon beam.

  4. Characteristics of S12045(X) photon sensors for GlueX

    NASA Astrophysics Data System (ADS)

    Smith, E. S.; Qiang, Y.; Tolstukhin, I.; Brooks, W. K.; Hakobyan, H.; Kuleshov, S.; Soto, O.; Toro, A.

    2013-04-01

    The barrel calorimeter of the GlueX detector in Hall D at Jefferson Lab will be instrumented with 4000 large-area (1.2x1.2 cm^2) silicon photomultipliers (SiPMs) [1]. These photon sensors have properties similar to vacuum photomultipliers, but are unaffected by high magnetic fields. In our experiment, they will operate in magnetic fields exceeding 1,. After extensive tests with a variety of sensors, we chose the S12045(X) custom SiPM arrays manufactured by Hamamatsu Corporation, also known as multi-pixel photon counters (MPPCs) [2]. All production units have been delivered and we have measured the photon detection efficiency (PDE), gain, dark rate, cross talk and after pulsing at three different temperatures (5, 7 and 20^oC). We will present a summary of these measurements and the plan for use of these sensors in the GlueX experiment.[4pt] [1] F. Barbosa et al., NIM A695 (2012) 100.[0pt] [2] Y. Qiang et al., NIM A698 (2013) 234.

  5. Equifinality of formal (DREAM) and informal (GLUE) bayesian approaches in hydrologic modeling?

    SciTech Connect

    Vrugt, Jasper A; Robinson, Bruce A; Ter Braak, Cajo J F; Gupta, Hoshin V

    2008-01-01

    In recent years, a strong debate has emerged in the hydrologic literature regarding what constitutes an appropriate framework for uncertainty estimation. Particularly, there is strong disagreement whether an uncertainty framework should have its roots within a proper statistical (Bayesian) context, or whether such a framework should be based on a different philosophy and implement informal measures and weaker inference to summarize parameter and predictive distributions. In this paper, we compare a formal Bayesian approach using Markov Chain Monte Carlo (MCMC) with generalized likelihood uncertainty estimation (GLUE) for assessing uncertainty in conceptual watershed modeling. Our formal Bayesian approach is implemented using the recently developed differential evolution adaptive metropolis (DREAM) MCMC scheme with a likelihood function that explicitly considers model structural, input and parameter uncertainty. Our results demonstrate that DREAM and GLUE can generate very similar estimates of total streamflow uncertainty. This suggests that formal and informal Bayesian approaches have more common ground than the hydrologic literature and ongoing debate might suggest. The main advantage of formal approaches is, however, that they attempt to disentangle the effect of forcing, parameter and model structural error on total predictive uncertainty. This is key to improving hydrologic theory and to better understand and predict the flow of water through catchments.

  6. A first look at reconstructed data from the GlueX detector

    NASA Astrophysics Data System (ADS)

    Taylor, Simon; GlueX Collaboration

    2015-10-01

    Construction of the GlueX detector in Hall D at the Thomas Jefferson National Accelerator Facility has recently been completed as part of the 12 GeV Upgrade to the facility. The detector consists of a barrel region containing devices for tracking charged particles and a lead-scintillator calorimeter for detecting photons, and a forward region consisting of two layers of scintillator paddles for time-of-flight measurements and a lead-glass electromagnetic calorimeter. The electron beam from the accelerator is converted into a photon beam by inserting a diamond radiator, thereby producing a coherent bremsstrahlung spectrum of photons impinging on a 30 cm-long LH2 target. The energy of the photon beam is determined using a tagging spectrometer. A commissioning run took place in Spring of 2015 during which all of the detector components were read out. Preliminary calibrations have been determined to a level sufficient to allow reconstruction of final states with several charged tracks and neutral particles. A first look at results of reconstruction of events using the GlueX detector will be presented. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Contract DE-AC05-06OR23177.

  7. Characteristics of SiPM Photo Sensors for GlueX

    NASA Astrophysics Data System (ADS)

    Qiang, Yi; Smith, Elton; Tolstukhin, Ivan; Brooks, Will; Hakobyan, Hayk; Kuleshov, Sergey; Soto, Orlando; Toro, Alam; Lolos, George; Papandreou, Zisis; Semenov, Andrey

    2013-10-01

    The barrel calorimeter of the GlueX detector in Hall D at Jefferson Lab will be instrumented with 3840 large-area (1.2 ×1.2 cm2) custom silicon photomultiplier (SiPM) arrays manufactured by Hamamatsu Corporation. These photon sensors have properties similar to vacuum photomultipliers, but are unaffected by high magnetic fields. In our experiment, they will operate in magnetic fields exceeding 1 T. A series of measurements have been carried out by several groups to characterize these SiPMs including the photon detection efficiency (PDE), gain, dark rate, cross talk and after-pulsing at different bias voltages and temperatures. A special study was performed for the first time to separate the cross talk and after pulsing by analyzing ADC spectra with different gate widths. These measurements allow a unique extraction of after-pulsing parameters. We will present a summary of these measurements and the plan for use of these sensors in the GlueX experiment.

  8. Flash ADC readout of the GlueX forward electromagnetic calorimeter

    NASA Astrophysics Data System (ADS)

    Kornicer, Mihajlo

    2008-10-01

    The GlueX experiment at Jefferson Lab will use a 9 GeV high-rate (10^7 -10^8/s) photon beam, incident on a liquid hydrogen target, to search for hybrid-meson production in the mass range of 1.5-2.5 GeV/c^2. Abundant photon production from neutral meson decays is expected in the decay chains of hybrid mesons, which will result in several photons in the forward region. The forward electromagnetic calorimeter (FCAL) of the GlueX detector is designed to reconstruct final state photons using an array of 2800 lead-glass blocks. The FCAL will employ flash analog-to-digital converter (FADC) technology to measure both deposited energy and photon arrival time using pulses from FEU-84-3 photomultiplier tubes. A real-time sum of the total calorimeter energy will be used as an input to the trigger. Timing information from individual crystals will be used to suppress the expected high-level of electromagnetic background from the photon beam and forward-going charged particles. We present the performance characteristics of the calorimeter readout based on simulation and data taken with a prototype 12-bit, 250 MHz flash ADC.

  9. Double-network gels and the toughness of terrestrial slug glue.

    PubMed

    Wilks, Alex M; Rabice, Sarah R; Garbacz, Holland S; Harro, Cailin C; Smith, Andrew M

    2015-10-01

    The terrestrial slug Arion subfuscus produces a defensive secretion that is sticky and tough, despite being a dilute gel. It is unusual in having high stiffness for a gel, yet retaining the high extensibility typical of mucus. In tensile tests, it sustains an average peak stress of 101 kPa, and fails at an average strain of 9.5. This gives the gel toughness; it requires much greater strain energy to fracture than most gels. This toughness may arise from a double-network type mechanism. In this mechanism, two separate, interpenetrating networks of polymers with different properties combine to give toughness that can be several orders of magnitude greater than either network individually. Native gel electrophoresis suggests that A. subfuscus glue consists of two networks: a network of negatively charged proteins ranging in Mr from 40×10(3) to 220×10(3) that can be dissociated by hydroxylamine and a network of heparan sulfate-like proteoglycans. The two networks are not tightly linked, though proteins of Mr 40×10(3) and 165×10(3) may associate with the carbohydrates. Targeted disruption of either network separately, using enzymatic hydrolysis, disulfide bond breakage or imine bond disruption completely disrupted the glue, resulting in no measurable toughness. Thus, the two networks separately provide little toughness, but together they work synergistically to create a tough material, as predicted in the double-network mechanism. PMID:26276864

  10. Calibrations for Charged Particle Tracking with the GlueX Detector

    NASA Astrophysics Data System (ADS)

    Staib, Michael; GlueX Collaboration

    2015-10-01

    Two gas detectors comprise the tracking system for the GlueX experiment, the Central Drift Chamber (CDC) and the Forward Drift Chamber (FDC). The CDC is a cylindrical straw-tube detector covering polar angles between 6° and 168°, delivering spatial resolution of ~150 μm. The FDC is a Cathode Strip Chamber consisting of four packages, each with six alternating layers of anode wires and cathode strips. The FDC is designed to track forward-going charged particles with polar angles between 1° and 20° with a spatial resolution of ~200 μm. Both tracking detectors record timing information and energy loss measurements useful for particle identification. During Fall 2014 and Spring 2015, the first photon beam was delivered on target for commissioning of the GlueX detector in Hall-D at Jefferson Lab. These data are currently being used in a large effort to calibrate the individual detector subsystems to achieve design performance. Methods and results for calibrations of each of the tracking detectors are presented. Techniques for alignment of the tracking system using a combination of cosmic rays and beam data is discussed. Finally, some early results of physics measurements including charged final-state particles are presented. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Contract DE-AC05-06OR23177.

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

    PubMed

    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. PMID:27577905

  12. How to Assess Fibrinogen Levels and Fibrin Clot Properties in Clinical Practice?

    PubMed

    Undas, Anetta

    2016-06-01

    Fibrin formed from fibrinogen is the main component of thrombi. Clot structure is characterized by fiber thickness and pore size, which differs within a given clot and between individuals. Plasma clot architecture is largely determined by the quantity and quality of fibrinogen. Plasma fibrinogen concentrations are most commonly measured in citrated plasma using the Clauss method. However, several factors, including instrument type and reagent, may affect results. Other approaches to express the ability of fibrinogen to clot involve prothrombin time-derived or clottable protein assays, while fibrinogen antigen levels in clinical settings are measured using immunological or precipitation assays. Fibrin clot permeability (reflected by the Darcy constant, K s) being proportional to a buffer volume percolating through a clot under a given hydrostatic pressure is now the most commonly used measure of clot structure. Low K s values indicating tightly packed fibrin structure have been shown to be associated with venous and arterial thrombotic complications, while high K s might contribute to bleeding disorders. The measurement of K s, however, is not standardized and validated. This review summarizes the current knowledge on practical aspects of the measurement of fibrinogen levels and K s in patients. PMID:27071050

  13. Clot contraction: compression of erythrocytes into tightly packed polyhedra and redistribution of platelets and fibrin.

    PubMed

    Cines, Douglas B; Lebedeva, Tatiana; Nagaswami, Chandrasekaran; Hayes, Vincent; Massefski, Walter; Litvinov, Rustem I; Rauova, Lubica; Lowery, Thomas J; Weisel, John W

    2014-03-01

    Contraction of blood clots is necessary for hemostasis and wound healing and to restore flow past obstructive thrombi, but little is known about the structure of contracted clots or the role of erythrocytes in contraction. We found that contracted blood clots develop a remarkable structure, with a meshwork of fibrin and platelet aggregates on the exterior of the clot and a close-packed, tessellated array of compressed polyhedral erythrocytes within. The same results were obtained after initiation of clotting with various activators and also with clots from reconstituted human blood and mouse blood. Such close-packed arrays of polyhedral erythrocytes, or polyhedrocytes, were also observed in human arterial thrombi taken from patients. The mechanical nature of this shape change was confirmed by polyhedrocyte formation from the forces of centrifugation of blood without clotting. Platelets (with their cytoskeletal motility proteins) and fibrin(ogen) (as the substrate bridging platelets for contraction) are required to generate the forces necessary to segregate platelets/fibrin from erythrocytes and to compress erythrocytes into a tightly packed array. These results demonstrate how contracted clots form an impermeable barrier important for hemostasis and wound healing and help explain how fibrinolysis is greatly retarded as clots contract. PMID:24335500

  14. Fibrin Encapsulation and Vascular Endothelial Growth Factor Delivery Promotes Ovarian Graft Survival in Mice

    PubMed Central

    Shikanov, Ariella; Zhang, Zheng; Xu, Min; Smith, Rachel M.; Rajan, Aniruddha; Woodruff, Teresa K.

    2011-01-01

    Ovarian cryopreservation before chemotherapy and autotransplantation post-treatment can restore fertility to women with premature ovarian failure. Although the majority of primordial follicles survive the cryopreservation cycle, the follicular pool is reduced after transplantation due to ischemic death. Therefore, we engineered a biomaterial-based system to promote angiogenesis in a mouse model of ovarian transplantation. To mimic the clinical situation of sterility, a bilateral ovariectomy was performed 2 weeks before transplantation, during which time serum levels of follicular stimulating hormone rose to menopausal levels. Before transplantation, vitrified/thawed ovarian tissue from 12-day-old C57Bl/6J pups was encapsulated in fibrin modified with heparin-binding peptide (HBP), heparin, and loaded with 0.5 μg vascular endothelial growth factor (VEGF). The group transplanted with fibrin-HBP-VEGF had twice as many surviving primordial follicles and an increased number of blood vessels relative to the no biomaterial control. Transplanted tissue was viable and supported natural conception that led to live and healthy offspring. The timeline of live births with VEGF delivery suggested that primary follicles survived transplantation, and provided the gametes for the first litter. Thus, VEGF delivery from fibrin supported integration of the transplant with the host, promoted angiogenesis, and enhanced engraftment and function of the tissue. PMID:21740332

  15. Influence of vanadate on migrating fibroblast orientation within a fibrin matrix.

    PubMed

    Lee, Michael Y; Ehrlich, H Paul

    2008-10-01

    Treating rats with vanadate, a nonspecific inhibitor of protein tyrosine phosphatases, optimizes the uniform packing of collagen fiber bundles in wound granulation tissue and doubles wound breaking strength in rat incisional wounds. The speculation is vanadate optimizes the packing of collagen fiber bundles through the orientation of newly arrived wound fibroblasts in the fibrin clot filling the defect. Segments of 14 day chick embryo tendons were placed on fibrin clots and maintained in organ culture with and without 30 microM vanadate. On day 7 explants were examined histologically and biochemically. Tendon fibroblast outgrowth from untreated explants migrated in a random fashion, while fibroblasts from vanadate-treated explants migrated out in linear arrays. Fibroblasts were elongated by 20% form vanadate treated explant compared to controls. Myosin ATPase, required for optimal cell motility, is optimized by the phosphorylation of its myosin light chain (MLC). Western blot analysis of lysates from the fibroblasts that migrated into the fibrin showed vanadate increased MLC-P levles. These findings support the notion that vanadate promotes the deposition of regular, parallel collagen fiber bundles by advancing the orientation of fibroblasts in parallel linear arrays early in the wound repair process. PMID:18498123

  16. Laparoscopic Repair of Inguinal Hernia Using Surgisis Mesh and Fibrin Sealant

    PubMed Central

    2006-01-01

    Objective: We tested the hypothesis that laparoscopic inguinal herniorrhaphy using Surgisis mesh secured with fibrin sealant is an effective long-term treatment for repair of inguinal hernia. This case series involved 38 adult patients with 51 inguinal hernias treated in a primary care center. Methods: Between December 2002 and May 2005, 38 patients with 45 primary and 6 recurrent inguinal hernias were treated with laparoscopic repair by the total extra-peritoneal mesh placement (TEP) technique using Surgisis mesh secured into place with fibrin sealant. Postoperative complications, incidence of pain, and recurrence were recorded, as evaluated at 2 weeks, 6 weeks, 1 year, and with a follow-up questionnaire and telephone interview conducted in May and June 2005. Results: The operations were successfully performed on all patients with no complications or revisions to an open procedure. Average follow-up was 13 months (range, 1 to 30). One hernia recurred (second recurrence of unilateral direct hernia), indicating a 2% recurrence rate. Conclusions: Laparoscopic repair of inguinal hernia using Surgisis mesh secured with fibrin sealant can be effectively used to treat primary, recurrent, direct, indirect, and bilateral inguinal hernias in adults without complications and minimal recurrence within 1-year of follow-up. PMID:17575758

  17. Interpenetrating Fibrin-Alginate Matrices for in vitro Ovarian Follicle Development

    PubMed Central

    Shikanov, Ariella; Xu, Min; Woodruff, Teresa K.; Shea, Lonnie D.

    2010-01-01

    In this report, we investigate the fibrin-alginate inter penetrating network (FA-IPN) to provide dynamic cell-responsive mechanical properties, which we apply to the in vitro growth of ovarian follicles. The mechanical properties and polymerization rate of the gels were investigated by rheology, and the fiber structure was imaged by electron microscopy. Using a mouse model, two-layered secondary follicles were encapsulated in FA-IPNs, and growth, morphology, hormone production, fibrin degradation rate and the numbers of competent eggs were assessed. The initial mechanics of the FA-IPN are determined by the composite material, and subsequent degradation of fibrin by the encapsulated cells would produce a material with mechanical properties due to the alginate alone. The rate of meotically competent oocytes produced by culture in FA-IPN was 82%, which was significantly greater than in alginate alone. This increase in oocyte quality is an important step in identifying 3D culture systems that can provide a fundamental tool to investigate follicle maturation, and may be applied to promote the growth of human follicles, which can be used to provide reproductive options for women facing a cancer diagnosis PMID:19616843

  18. Plasma D dimer: a useful marker of fibrin breakdown in renal failure.

    PubMed

    Gordge, M P; Faint, R W; Rylance, P B; Ireland, H; Lane, D A; Neild, G H

    1989-06-30

    D dimer and other large fragments produced during the breakdown of crosslinked fibrin may be measured by enzyme immunoassay using monoclonal antibodies. In 91 patients with renal disease and varying degrees of renal dysfunction, plasma D dimer showed no correlation with renal function, whereas FgE antigen, a fibrinogen derivative which is known to be cleared in part by the kidney, showed a significant negative correlation with creatinine clearance. Plasma concentrations of D dimer were, however, increased in patients with chronic renal failure (244 +/- 31 ng/ml) (mean +/- SEM) and diabetic nephropathy (308 +/- 74 ng/ml), when compared with healthy controls (96 +/- 13 ng/ml), and grossly elevated in patients with acute renal failure (2,451 +/- 1,007 ng/ml). The results indicate an increase in fibrin formation and lysis, and not simply reduced elimination of D dimer by the kidneys, and are further evidence of activated coagulation in renal disease. D dimer appears to be a useful marker of fibrin breakdown in renal failure. PMID:2799764

  19. Sandwiched polymer fibre in fibrin matrices for the dictation of endothelial cells undergoing angiogenesis

    NASA Astrophysics Data System (ADS)

    Sukmana, I.; Djuansjah, J. R. P.

    2013-04-01

    We present here a three-dimensional (3D) sandwich system made by poly(ethylene terephthalate) (PET) fibre and fibrin extracellular matrix (ECM) for endothelial cell dictation and angiogenesis guidance. In this three-dimensional system, Human Umbilical Vein Endothelial cells (HUVECs) were firstly cultured for 2 (two) days to cover the PET fibre before sandwiched in two layer fibrin gel containing HUVECs. After 4 (four) days of culture, cel-to-cel connection, tube-like structure and multi-cellular lumen formation were then assessed and validated. Phase contrast and fluorescence imaging using an inverted microscope were used to determine cell-to-cell and cell-ECM interactions. Laser scanning confocal microscopy and histological techniques were used to confirm the development of tube-like structure and multi-cellular lumen formation. This study shows that polymer fibres sandwiched in fibrin gel can be used to dictate endothelial cells undergoing angiogenesis with potential application in cancer and cardiovascular study and tissue engineering vascularisation.

  20. Leukocyte accumulation promoting fibrin deposition is mediated in vivo by P-selectin on adherent platelets

    NASA Astrophysics Data System (ADS)

    Palabrica, Theresa; Lobb, Roy; Furie, Barbara C.; Aronovitz, Mark; Benjamin, Christopher; Hsu, Yen-Ming; Sajer, Susan A.; Furie, Bruce

    1992-10-01

    THE glycoprotein P-selectin is a cell adhesion molecule of stimulated platelets and endothelial cells, which mediates the interaction of these cells with neutrophils and monocytes1,2. It is a membrane component of cell storage granules3-6, and is a member of the selectin family which includes E-selectin and L-selectin7,8. P-selectin recognizes both lineage-specific carbohydrate ligands on monocytes and neutrophils, including the Lewis x antigen, sialic acid, and a protein component9-12. In inflammation and thrombosis, P-selectin may mediate the interaction of leukocytes with platelets bound in the region of tissue injury and with stimulated endothelium1,2. To evaluate the role of P-selectin in platelet-leukocyte adhesion in vivo, the accumulation of leukocytes within an experimental thrombus was explored in an arteriovenous shunt model in baboons13. A Dacron graft implanted within an arteriovenous shunt is thrombogenic, accumulating platelets and fibrin within its lumen. These bound platelets express P-selectin14. Here we show that antibody inhibition of leukocyte binding to P-selectin expressed on platelets immobilized on the graft blocks leukocyte accumulation and inhibits the deposition of fibrin within the thrombus. These results indicate that P-selectin is an important adhesion molecule on platelets, mediating platelet-leukocyte binding in vivo, that the presence of leukocytes in thrombi is mediated by P-selectin, and that these leukocytes promote fibrin deposition.