scholarly journals Enhancing Esophageal Repair With Bioactive Bilayer Mesh Containing FGF

2021 ◽  
Author(s):  
Ozkan Cesur ◽  
Tugba Endogan Tanir ◽  
Pinar Celepli ◽  
Fatma Ozarslan ◽  
Sema Hucumenoglu ◽  
...  
Keyword(s):  
Tissue Regeneration ◽  
Treatment Efficacy ◽  
Sham Group ◽  
Gelatin Film ◽  
Control Group ◽  
Fibroblast Growth ◽  
Blunt Dissection ◽  
Esophageal Anastomosis ◽  
Film Layer

Abstract We aimed to prepare a bioactive and biodegradable bilayer mesh formed by fibroblast growth factor (FGF) loaded gelatin film layer, and poly ε-caprolactone (PCL) film layer, and to investigate its treatment efficacy on esophageal anastomosis. It is envisaged that the bioactive mesh in in vivo model would improve tissue regeneration in rats. The full thickness semicircular defects of 0.5x0.5 cm2 were created in anterior walls of abdominal esophagus. The control group had abdominal esophagus isolated with distal esophageal blunt dissection, and sham group had primer anastomosis. In the test groups, the defects were covered with bilayer polymeric meshes containing FGF (5µg/2 cm²), or not. All rats were sacrificed for histopathology investigation after 7 or 28 days of operation. The groups are coded as FGF(-)-7th d, FGF(+)-7th d, and FGF(+)-28th d, based on their content and operation day. Highest burst pressures were obtained for FGF(+)-7th d, and FGF(+)-28th d groups (p < 0.005) and decreased inflammation grades were observed. Submucosal and muscular collagen deposition scores were markedly increased in these groups compared to sham and FGF(-)-7th d groups having no FGF (p = 0.002, p = 0.001, respectively). It was proved that FGF loaded bioactive bilayer mesh provided effective repair, reinforcement and tissue regeneration of esophageal defects.

scholarly journals Enhancing esophageal repair with bioactive bilayer mesh containing FGF

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ozkan Cesur ◽  
Tugba Endogan Tanir ◽  
Pinar Celepli ◽  
Fatma Ozarslan ◽  
Sema Hucumenoglu ◽  
...  
Keyword(s):  
Sham Group ◽  
Primary Anastomosis ◽  
Gelatin Film ◽  
In Vivo Model ◽  
Control Group ◽  
Blunt Dissection ◽  
Tissue Healing ◽  
Esophageal Anastomosis ◽  
Film Layer

AbstractWe aimed to prepare a bioactive and biodegradable bilayer mesh formed by fibroblast growth factor (FGF) loaded gelatin film layer, and poly ε-caprolactone (PCL) film layer, and to investigate its treatment efficacy on esophageal anastomosis. It is envisaged that the bioactive mesh in in vivo model would improve tissue healing in rats. The full thickness semicircular defects of 0.5 × 0.5 cm2 were created in anterior walls of abdominal esophagus. The control group had abdominal esophagus isolated with distal esophageal blunt dissection, and sham group had primary anastomosis. In the test groups, the defects were covered with bilayer polymeric meshes containing FGF (5 μg/2 cm2), or not. All rats were sacrificed for histopathology investigation after 7 or 28 days of operation. The groups are coded as FGF(−)-7th day, FGF(+)-7th day, and FGF(+)-28th day, based on their content and operation day. Highest burst pressures were obtained for FGF(+)-7th day, and FGF(+)-28th day groups (p < 0.005) and decreased inflammation grades were observed. Submucosal and muscular collagen deposition scores were markedly increased in these groups compared to sham and FGF(−)-7th day groups having no FGF (p = 0.002, p = 0.001, respectively). It was proved that FGF loaded bioactive bilayer mesh provided effective repair, reinforcement and tissue healing of esophageal defects.

Heparins Inhibit Tumor Angiogenesis by Sequestering Fibroblast Growth Factor (FGF) from Tumor Vascular Endothelial Cells.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2662-2662
Author(s):  
Shannon L. Smiley ◽  
Dale O. Henry ◽  
Shang-Chiung Chen ◽  
Michael K.K. Wong
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Tumor Angiogenesis ◽  
Experimental Models ◽  
Control Group ◽  
Molecular Evidence ◽  
Dependent Manner ◽  
Fibroblast Growth

Abstract The association between cancer and thromboembolic disease is a well-known phenomenon and contributes to the morbidity and mortality of cancer patients. Clinical studies of thrombosis in these patients show that heparins may have beneficial effects on survival. Antithrombotic agents have been shown to exert an anti-tumor effect in various experimental models however the underlying mechanism remains unknown. We show that heparins inhibit in vivo tumor angiogenesis and offer molecular evidence that heparins exert an anti-angiogenic effect by directly sequestering fibroblast growth factor (FGF) from its receptor on tumor derived endothelial cells (TDECs). NIH-3T3 fibroblasts were stably transfected with an expression construct that results in the constitutive excretion of FGF-1 (Clone C). Clone C gives rise to aggressive and highly angiogenic xenograft tumors. Clone C was inoculated into nude mice and therapeutic doses of Low Molecular Weight (LMW) heparins were injected daily beginning on Day 2. Tumors in the control group were grossly angiogenic and highly vascularized. In contrast, the heparin treated tumors were pale and possessed only scant peri-tumoral vessels. In order to assess the biologic mechanism of this, murine TDECs were isolated and cultured as previously published. Unfractionated and LMW heparins inhibit FGF-induced TDEC mitogenesis in a concentration- and time-dependent manner. FGF overcame and rescued heparin-induced inhibition suggesting that an FGF-heparin interaction is responsible. In order to test the hypothesis that heparin strips and sequesters FGF off its receptor on TDECs, we used a FGF protein fused to a hemagglutinin peptide tag at the carboxyl-terminus end (FGF-HA). FGF-HA is biologically identical to wild type FGF, but its detection limit is 10X more sensitive. FGF-HA was allowed to bind to FGFR on TDECs. These cells were subsequently incubated with Heparin covalently linked to Sepharose beads (Heparin-Sepharose) or to Sepharose alone. These beads were removed, and TDEC growth analyzed prospectively. Heparin-Sepharose treatment results in significant TDEC growth inhibition as compared to incubation with Sepharose alone. Western blot analysis shows that FGF was sequestered only on the Heparin-Sepharose beads. Conclusion: The anti-angiogenic mechanism of heparins resides, in part, in its ability to sequester angiogenic cytokines such as FGF from its receptor on tumor endothelium.

scholarly journals Evaluation of in Vivo Response of Three Biphasic Scaffolds for Osteochondral Tissue Regeneration in a Sheep Model

2019 ◽  
Vol 6 (4) ◽  
pp. 90 ◽  
Author(s):  
Alberto M. Crovace ◽  
Alessia Di Giancamillo ◽  
Francesca Gervaso ◽  
Laura Mangiavini ◽  
Davide Zani ◽  
...  
Keyword(s):  
Tissue Regeneration ◽  
Collagen Matrix ◽  
Control Group ◽  
The Novel ◽  
Sheep Model ◽  
Complete Restoration ◽  
Different Types ◽  
Ct Analysis ◽  
Reparative Process

Osteochondral defects are a common problem in both human medicine and veterinary practice although with important limits concerning the cartilaginous tissue regeneration. Interest in the subchondral bone has grown, as it is now considered a key element in the osteochondral defect healing. The aim of this work was to generate and to evaluate the architecture of three cell-free scaffolds made of collagen, magnesium/hydroxyapatite and collagen hydroxyapatite/wollastonite to be implanted in a sheep animal model. Scaffolds were designed in a bilayer configuration and a novel “Honey” configuration, where columns of hydroxyapatite were inserted within the collagen matrix. The use of different types of scaffolds allowed us to identify the best scaffold in terms of integration and tissue regeneration. The animals included were divided into four groups: three were treated using different types of scaffold while one was left untreated and represented the control group. Evaluations were made at 3 months through CT analysis. The novel “Honey” configuration of the scaffold with hydroxyapatite seems to allow for a better reparative process, although we are still far from obtaining a complete restoration of the defect at this time point of follow-up.

Treatment Efficacy for Validating MicroCT-Based Theoretical Simulation Approach in Magnetic Nanoparticle Hyperthermia for Cancer Treatment

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Alexander LeBrun ◽  
Tejashree Joglekar ◽  
Charles Bieberich ◽  
Ronghui Ma ◽  
Liang Zhu
Keyword(s):  
Treatment Efficacy ◽  
Magnetic Nanoparticle ◽  
Thermal Damage ◽  
Theoretical Models ◽  
Control Group ◽  
Tumor Shrinkage ◽  
Tumor Cell Death ◽  
Theoretical Simulation ◽  
Magnetic Nanoparticle Hyperthermia

The objective is to validate a designed heating protocol in a previous study based on treatment efficacy of magnetic nanoparticle hyperthermia in prostate tumors. In vivo experiments have been performed to induce temperature elevations in implanted PC3 tumors injected with magnetic nanoparticles, following the same heating protocol designed in our previous microCT-based theoretical simulation. A tumor shrinkage study and histological analyses of tumor cell death are conducted after the heating. Tumor shrinkage is observed over a long period of 8 weeks. Histological analyses of the tumors after heating are used to evaluate whether irreversible thermal damage occurs in the entire tumor region. It has been shown that the designed 25 min heating (Arrhenius integral Ω ≥ 4 in the entire tumor) on tumor tissue is effective to cause irreversible thermal damage to PC3 tumors, while reducing the heating time to 12 min (Ω ≥ 1 in the entire tumor) results in an initial shrinkage, however, later tumor recurrence. The treated tumors with 25 min of heating disappear after only a few days. On the other hand, the tumors in the control group without heating show approximately an increase of more than 700% in volume over the 8-week observation period. In the undertreated group with 12 min of heating, its growth rate is smaller than that in the control group. In addition, results of the histological analysis suggest vast regions of apoptotic and necrotic cells, consistent with the regions of significant temperature elevations. In conclusion, this study demonstrates the importance of imaging-based design for individualized treatment planning. The success of the designed heating protocol for completely damaging PC3 tumors validates the theoretical models used in planning heating treatment in magnetic nanoparticle hyperthermia.

Localized lower extremity ischemic preconditioning prevents against local thrombus formation

VASA ◽  
2015 ◽  
Vol 44 (4) ◽  
pp. 285-288 ◽  
Author(s):  
Ye Sun ◽  
Ping Mao ◽  
Jingwei Lu ◽  
Lan Li ◽  
Wanli Lu ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Ischemic Preconditioning ◽  
Sham Group ◽  
Thrombus Formation ◽  
Iliac Vein ◽  
Control Group ◽  
Sprague Dawley ◽  
Coagulation Function ◽  
Thrombosis Model

Abstract. Background: Ischemic preconditioning (IPC) has many beneficial effects on the cardiovascular system. However, whether localized lower extremity IPC could be protective against the thrombogenic activity generated by lower extremity ischemia is unclear. Material and methods: 41 male Sprague-Dawley rats were randomly assigned to either a IPC group or a sham group. The lower extremity blood inflow was previously treated with 4 cycles of 5 min ischemia followed by 5 min of reperfusion by clamping the abdominal aortic just before ligature of the left iliac vein(LIV) in the IPC group. Rats in the sham group had a 40-minute blank before left iliac vein ligation. The rats were euthanized at day 2 after ligation and the thrombosed LIV was carefully dissected out, while thrombi harvested from the LIV were measured with weight (g), length (mm) and weight/length (mg/mm). Influence of IPC on coagulation function was also tested. Results: 21 and 20 rats were randomly assigned to einter the IPC group or the control group. Left iliac vein thrombosis was successfully generated in all 41 rats. IPC significantly protects the rats from experimental lower extremity thrombosis. Compared to control group, generated thrombus in rats in the IPC group showed significantly lower weight (2.73 ± 0.16 mg vs 1.82 ± 0.13 mg, P < 0.001), length (2.99 ± 0.17 mm vs 2.44 ± 0.08 mm, P < 0.009) and density (0.95 ± 0.05 mg/mm vs 0.75 ± 0.05 mg/mm, P = 0.01). Influence on coagulation function by IPC itself was not significant (P > 0.05). Conclusions: Our study demonstrated that localized lower extremity IPC could reduce DVT formation in rats in an in vivo experimental thrombosis model.

In Vivo Evaluation of Strontium-Containing Nanostructured Carbonated Hydroxyapatite

2016 ◽  
Vol 696 ◽  
pp. 212-222
Author(s):  
Gabriel Maia Kammer ◽  
Suelen Cristina Sartoretto ◽  
Rodrigo Resende ◽  
Marcelo Uzeda ◽  
Jhonathan Raphael Nascimento ◽  
...  
Keyword(s):  
Sham Group ◽  
Subcutaneous Tissue ◽  
Biological Response ◽  
Experimental Period ◽  
Giant Cells ◽  
Control Group ◽  
X Ray Diffraction ◽  
Carbonated Hydroxyapatite ◽  
X Ray

Bone tissue is a composite material that has hydroxyapatite (HA) as its main inorganic phase component. The biological apatites have low crystallinity and contain cationic and anionic substitutions in their structure, which differ from the available synthetic ceramics. The purpose of this study is to evaluate the biocompatibility of nanostructured carbonated hydroxyapatite microspheres containing 5 wt% strontium (SrcHA) compared with the biocompatibility of carbonated hydroxyapatite (cHA), both synthesized at 37°C and non-sintered, used to control stoichiometric HA microspheres in subcutaneous tissue of mice. The biomaterials (BM) were characterized using X-ray Diffraction (XRD), Vibrational Spectroscopy in an Infrared Fourier Transform (VSIRFT) and Scanning Electron Microscopy (SEM). Forty five balb-C mice were randomly divided into four groups of 15 animals each: SrcHA, cHA, HA, and without material implantation (Sham group). All samples were histologically processed for descriptive evaluation of the biological effect. At each experimental period (1, 3 and 9 weeks), there was a higher biosorption of the tested biomaterials observed in contrast with the HA. The cHA group was the only group completely phagocytosed by macrophages and giant cells after 9 weeks. All biomaterials proved to be biocompatible, and the cHA and SrcHA 3% groups exhibited a faster bioabsorption in comparison with the control group. The doping of strontium did not cause a greater biological response after the 3 experimental periods.

scholarly journals Polydioxanone-Based Membranes for Bone Regeneration

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1685
Author(s):  
Sybele Saska ◽  
Livia Pilatti ◽  
Edvaldo Santos de Sousa Silva ◽  
Magda Aline Nagasawa ◽  
Diana Câmara ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Tissue Regeneration ◽  
Clinical Signs ◽  
Systemic Toxicity ◽  
Bone Tissue Regeneration ◽  
Control Group ◽  
Crystallinity Degree ◽  
Reaction Index ◽  
Collagen Membranes

Resorbable synthetic and natural polymer-based membranes have been extensively studied for guided tissue regeneration. Alloplastic biomaterials are often used for tissue regeneration due to their lower immunoreactivity when compared with allogeneic and xenogeneic materials. Plenum® Guide is a synthetic membrane material based on polydioxanone (PDO), whose surface morphology closely mimics the extracellular matrix. In this study, Plenum® Guide was compared with collagen membranes as a barrier material for bone-tissue regeneration in terms of acute and subchronic systemic toxicity. Moreover, characterizations such as morphology, thermal analysis (Tm = 107.35 °C and crystallinity degree = 52.86 ± 2.97 %, final product), swelling (thickness: 0.25 mm ≅ 436% and 0.5 mm ≅ 425% within 24 h), and mechanical tests (E = 30.1 ± 6.25 MPa; σ = 3.92 ± 0.28 MPa; ε = 287.96 ± 34.68%, final product) were performed. The in vivo results revealed that the PDO membranes induced a slightly higher quantity of newly formed bone tissue than the control group (score: treated group = 15, control group = 13) without detectable systemic toxicity (clinical signs and evaluation of the membranes after necropsy did not result in differences between groups, i.e., non-reaction -> tissue-reaction index = 1.3), showing that these synthetic membranes have the essential characteristics for an effective tissue regeneration. Human adipose-derived stem cells (hASCs) were seeded on PDO membranes; results demonstrated efficient cell migration, adhesion, spread, and proliferation, such that there was a slightly better hASC osteogenic differentiation on PDO than on collagen membranes. Hence, Plenum® Guide membranes are a safe and efficient alternative for resorbable membranes for tissue regeneration.

scholarly journals Terazosin treatment suppresses basic fibroblast growth factor expression in the rat ventral prostate

2009 ◽  
Vol 32 (1) ◽  
pp. 1 ◽  
Author(s):  
Dionisios Mitropoulos ◽  
Aspasia Kyroudi-Voulgari ◽  
Evangelia Christelli ◽  
Anastasios Zervas ◽  
Panagiotis Karayannacos
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Basic Fibroblast Growth Factor ◽  
Ventral Prostate ◽  
Control Group ◽  
Positive Staining ◽  
Fibroblast Growth ◽  
Smooth Muscle Contractility ◽  
Rat Ventral Prostate

Purpose: Alpha1-adrenergic receptor antagonists may not act solely on smooth muscle contractility. We evaluated the in vivo effect of the alpha1 blocker, terazosin, on the expression of basic fibroblast growth factor (bFGF) in the rat ventral prostate. Methods: Wistar rats were treated with terazosin (1.2 mg/kg body weight, po, every second day) for 120 days. The expression of bFGF was assessed immuno-histochemically in tissue sections and by Western blotting in whole tissue preparations. Results: Terazosin treatment did not affect prostate weight or histomorphology. In the control group, epithelial and stromal cells demonstrated positive staining for the anti-bFGF antibody. In contrast, the same staining in terazosin-treated specimens was either absent or extremely weak. An analogous difference was observed among the corresponding immunoblots. Conclusions: These findings implicate the reduction of bFGF expression by terazosin as a potential additional molecular mechanism of its action that may include alterations in peptide growth factor mediated prostate homeostasis.

Targeting angiogenesis driven by fibroblast growth factor using RPT835, an FGFR2 inhibitor.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e22097-e22097
Author(s):  
Evgenia Stepanova ◽  
Eliso Solomko ◽  
Oxana Ryabaya ◽  
Nina Peretolchina ◽  
Ilya Tsimafeyeu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Umbilical Vein ◽  
Endothelial Cell Proliferation ◽  
Control Group ◽  
Fibroblast Growth ◽  
Basic Fgf ◽  
Signaling Axis

e22097 Background: The fibroblast growth factor (FGF)/FGF receptors (FGFR) signaling axis plays a key role in driving tumor angiogenesis. There is little data on the targeting of FGF-induced angiogenesis. We describe here the targeting angiogenesis driven by FGF using RPT835, novel inhibitor of the FGFR2 extracellular domain (received from RusPharmTech, LLC). Methods: To assess the efficacy of RPT835 on FGF-mediated endothelial cells proliferation, the human umbilical vein endothelial FGFR-expressing cells (HUVEC) were incubated in a 96-well microculture plate and were treated with serially diluted RPT835 or Brivanib as a control. Basic FGF was added at a concentration of 25 ng/ml. Control wells were left untreated. Cell growth inhibition was determined using Promega’s Cell Titer-Glo assay. In vivo angiogenesis was measured with subcutaneously implanted Matrigel plugs containing bFGF (100 ng/ml) or bFGF (100 ng/ml) + bevacizumab (10 mg/kg) or bFGF (100 ng/ml) + RPT835 (15 mg/kg). Control group was without stimulation and treatment. Each group included 3 mice. Number of endothelial cells/vessels was calculated. Results: Basic FGF significantly increased proliferation of the HUVEC cells (P=0.001) in untreated control group. RPT835 significantly inhibited FGF-triggered endothelial cell proliferation when compared with control (P<0.001) or brivanib (P<0.001, IC50=289 nmol/L) with IC50 of 11 nmol/L. In vivo, bFGF induced proliferation of endotheliocytes and mature vessels formation (P<0.001). There were no vessels in FGFR2 inhibitor group. Bevacizumab did not decrease number of vessels in comparison with FGF-stimulated angiogenesis (P=0.9). Conclusions: Inhibition of bFGF/FGFR2 pathway resulted in effects on endothelial cells proliferation andmature vessels formation. Bevacizumab had no activity in FGF-induced angiogenesis.

Facilitated migration of cells from a transected peripheral nerve over collagen fibers: in vivo observations

1989 ◽  
Vol 47 ◽  
pp. 888-889
Author(s):  
Arthur J. Wasserman ◽  
Azam Rizvi ◽  
George Zazanis ◽  
Frederick H. Silver
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Collagen Gel ◽  
Collagen Fibers ◽  
Control Group ◽  
Guide Tube ◽  
Sprague Dawley ◽  
Silicone Tube ◽  
Thin Sections

In cases of peripheral nerve damage the gap between proximal and distal stumps can be closed by suturing the ends together, using a nerve graft, or by nerve tubulization. Suturing allows regeneration but does not prevent formation of painful neuromas which adhere to adjacent tissues. Autografts are not reported to be as good as tubulization and require a second surgical site with additional risks and complications. Tubulization involves implanting a nerve guide tube that will provide a stable environment for axon proliferation while simultaneously preventing formation of fibrous scar tissue. Supplementing tubes with a collagen gel or collagen plus extracellular matrix factors is reported to increase axon proliferation when compared to controls. But there is no information regarding the use of collagen fibers to guide nerve cell migration through a tube. This communication reports ultrastructural observations on rat sciatic nerve regeneration through a silicone nerve stent containing crosslinked collagen fibers.Collagen fibers were prepared as described previously. The fibers were threaded through a silicone tube to form a central plug. One cm segments of sciatic nerve were excised from Sprague Dawley rats. A control group of rats received a silicone tube implant without collagen while an experimental group received the silicone tube containing a collagen fiber plug. At 4 and 6 weeks postoperatively, the implants were removed and fixed in 2.5% glutaraldehyde buffered by 0.1 M cacodylate containing 1.5 mM CaCl2 and balanced by 0.1 M sucrose. The explants were post-fixed in 1% OSO4, block stained in 1% uranyl acetate, dehydrated and embedded in Epon. Axons were counted on montages prepared at a total magnification of 1700x. Montages were viewed through a dissecting microscope. Thin sections were sampled from the proximal, middle and distal regions of regenerating sciatic plugs.

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