Modulation of neo-endothelialization of vascular graft materials by silk fibroin

Abstract Controlled neo-endothelialization is critical to the patency of vascular grafts. Expanded polyethylene terephthalate (PET) vascular grafts were grafted with polyethylene glycol (PEG), irradiated with ultraviolet light, and subsequently coated with silk fibroin (SF) and EDC in a dip-coating process. Endothelial cells were cultivated on the coated samples for 1, 3, 5, and 7 days, and characterized by fluorescence microscopy and scanning electron microscopy (SEM). The quantitative analyse of CCK-8 method was used to assess ECs proliferation. The results reveal the correlation between grafting components and cell adhesion. We demonstrated that PET with SF grafting facilitated cell adhesion and spreading. Following 7 days of cell culture in vitro, PET-PEG6000-SF (PEG molecular weight 6,000) displayed spreading of cells over a significantly larger area. Rapid endothelialization on a modified PET surface resulted in large tissue pack that can be observed by SEM.

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Preparation of Photocatalytic Nanostructured TiO2 Thin Films

Materials Science Forum ◽

10.4028/www.scientific.net/msf.587-588.795 ◽

2008 ◽

Vol 587-588 ◽

pp. 795-799 ◽

Cited By ~ 1

Author(s):

A. Di Paola ◽

M. Addamo ◽

M. Bellardita ◽

E. García-López ◽

G. Marcì ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Dip Coating ◽

Coating Process ◽

X Ray Diffraction ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Glass Slides ◽

Scanning Electron

Photoactive films consisting of pure anatase, brookite or rutile were deposited on glass slides by a dip coating process from water dispersions or solutions obtained by using TiCl4 as the precursor. The films were characterized by X-ray diffraction, scanning electron microscopy and atomic force microscopy. The photocatalytic activity of the various samples was evaluated by using the photooxidation of 2-propanol in gas solid regime as probe reaction. Brookite and anatase films showed a good photoactivity degrading the substrate and the propanone produced during the reaction.

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THROMBOGENISITY OF ENDOTHELIAL SEEDED VASCULAR GRAFT

10.1055/s-0038-1644803 ◽

1987 ◽

Author(s):

Jacek Dryjski ◽

Maciej Dryjski ◽

Charles Demuylder ◽

Th Janssens

Keyword(s):

Electron Microscopy ◽

Vascular Graft ◽

Statistical Difference ◽

Culture Medium ◽

Jugular Vein ◽

Vascular Grafts ◽

Porcine Skin ◽

Aortic Endothelium ◽

Optimal Surface ◽

Scanning Electron

It has recently been suggested that endothelial cell (EC) seeding of vascular grafts surfaces may lead to a less thrombo-genic surface. The present investigation was designed to study the capacity of aortic endothelium and neointima developing on seeded grafts to inactivate thrombin. In order to obtain an optimal surface for EC attachment the lyophylized porcine skin (Zenoderm®, Ethicon, Scotland) were used to form tubular grafts. Grafts seeded with enzymatically derived EC from the jugular vein was compared with control grafts that were shamed seeded with culture medium and blood. Animals with seeded grafts were divided into two groups, one group received dipyridamole treatment, theother one remained untreated. The prosthesis were implanted in the abdominal aorta in 21 dogs. Six dogs died due to different complications after surgery. The remaining 15 were sacrified 2 monthsafter graft implantations. The aorta and the grafts were excised divided into two parts, one was fixed for light and scanning electron microscopy, the otherone was analyzed for capacity to inactivate thrombin which enzymatic activity was assayed by an amiodolytic method. The grafts and aortic segments were exposed for 12 U/ml of thrombin solution. After 10 min incubation the enzyme activity decreased in the supernatant and were found in similar amounts on the grafts and aortic surfaces. Thrombin bound to endothelium was rapidly inhibited after exposure to plasma for 30 sec. In contrast, thrombin retained on the neointima of both seeded and shame seeded grafts were only minor inhibited by plasma. The morphological analyses shown that both seeded and shame seeded grafts developed a thin cellular lining covering up to 100% of the specimens’ surface area. The subcellular layer was equal in all groups. No statistical difference in morphology nor in thrombin inhibiting capacity was noted between dipyridamole treated and untreated animals. It is concluded that both the aorticendothelium and graft neointima can take up thrombin but only aortic endothelium can efficiently inactivate it. Seeding of the grafts with endothelial cellsdid not signifcantly improve its capacity to inhibit activated coagulation enzymes.

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Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100055448 ◽

1982 ◽

Vol 40 ◽

pp. 520-521

Author(s):

Ann Chidester Van Orden ◽

John L. Chidester ◽

Anna C. Fraker ◽

Pei Sung

Keyword(s):

Electron Microscopy ◽

Corrosion Behavior ◽

Anodic Polarization ◽

Saline Solution ◽

Saturated Calomel Electrode ◽

Physiological Saline ◽

X Ray ◽

Physiological Saline Solution ◽

Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

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Scanning Electron Microscopy of Staphylococcus Epidermidis Adherence to Continuous Ambulatory Peritoneal Dialysis Catheters

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100119429 ◽

1985 ◽

Vol 43 ◽

pp. 520-521

Author(s):

William J. Lamoreaux ◽

David L. Smalley ◽

Larry M. Baddour ◽

Alfred P. Kraus

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Peritoneal Dialysis ◽

Continuous Ambulatory Peritoneal Dialysis ◽

Staphylococcus Epidermidis ◽

Sterile Saline ◽

Intravascular Devices ◽

Capd Patient ◽

Scanning Electron

Infections associated with the use of intravascular devices have been documented and have been reported to be related to duration of catheter usage. Recently, Eaton et al. reported that Staphylococcus epidermidis may attach to silastic catheters used in continuous ambulatory peritoneal dialysis (CAPD) treatment. The following study presents findings using scanning electron microscopy (SEM) of S. epidermidis adherence to silastic catheters in an in vitro model. In addition, sections of polyvinyl chloride (PVC) dialysis bags were also evaluated by SEM.The S. epidermidis strain RP62A which had been obtained in a previous outbreak of coagulase-negative staphylococcal sepsis at local hospitals was used in these experiments. The strain produced surface slime on exposure to glucose, whereas a nonadherent variant RP62A-NA, which was also used in these studies, failed to produce slime. Strains were grown overnight on blood agar plates at 37°C, harvested from the surface and resuspended in sterile saline (0.85%), centrifuged (3,000 rpm for 10 minutes) and then washed twice in 0.1 M phosphate-buffered saline at pH 7.0. Organisms were resuspended at a concentration of ca. 106 CFU/ml in: a) sterile unused dianeal at 4.25% dextrose, b) sterile unused dianeal at 1.5% dextrose, c) sterile used dialysate previously containing 4.25% dextrose taken from a CAPD patient, and d) sterile used dialysate previously containing 1.5% dextrose taken from a CAPD patient.

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The Mesothelial Cell as a Non-Thrombogenic Surface

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661149 ◽

1984 ◽

Vol 52 (02) ◽

pp. 102-104 ◽

Cited By ~ 25

Author(s):

L J Nicholson ◽

J M F Clarke ◽

R M Pittilo ◽

S J Machin ◽

N Woolf

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Blood Flow ◽

Cell Surface ◽

Mesothelial Cell ◽

Mesothelial Cells ◽

Plastic Film ◽

In Vitro System ◽

Scanning Electron

SummaryA technique for harvesting mesothelial cells is described. This entails collagenase digestion of omentum after which the cells can be cultured. The technique has been developed using the rat, but has also been successfully applied to human tissue. Cultured rat mesothelial cells obtained in this way have been examined by scanning electron microscopy. Rat mesothelial cells grown on plastic film have been exposed to blood in an in vitro system using a Baumgartner chamber and have been demonstrated to support blood flow. No adhering platelets were observed on the mesothelial cell surface. Fibroblasts similarily exposed to blood as a control were washed off the plastic.

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Study of Phosphocalcic Glasses from SiO2-CaO-P2O5 System with and Without Silver II. The bioactivity analysis by FTIR, SEM methods and microbiological study of silver-doped glasses

Revista de Chimie ◽

10.37358/rc.17.6.5639 ◽

2017 ◽

Vol 68 (6) ◽

pp. 1188-1192

Author(s):

Daniela Avram ◽

Nicolae Angelescu ◽

Dan Nicolae Ungureanu ◽

Ionica Ionita ◽

Iulian Bancuta ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Body Fluid ◽

Pathogenic Bacteria ◽

De Novo ◽

Microbiological Examination ◽

Doped Glasses ◽

P2o5 System ◽

Scanning Electron

The study in vitro of the glass powders bioactivity was performed by soaking them in simulated body fluid for 3 to 21 days at a temperature of 37�C and pH = 7.20. The synthesis de novo of hydroxyapatite, post soaking was confirmed by Fourier Transform Infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The study of the antimicrobial activity was performed by microbiological examination on two strains of pathogenic bacteria involved in postoperative nosocomial infections.

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Synthesis and Evaluation of AlgNa-g-poly(QCL-co-HEMA) Hydrogels as Platform for Chondrocyte Proliferation and Controlled Release of Betamethasone

International Journal of Molecular Sciences ◽

10.3390/ijms22115730 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5730

Author(s):

Jomarien García-Couce ◽

Marioly Vernhes ◽

Nancy Bada ◽

Lissette Agüero ◽

Oscar Valdés ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Controlled Release ◽

Biomedical Applications ◽

Release Kinetics ◽

Cell Types ◽

Tissue Engineering Scaffolds ◽

Almost All ◽

Scanning Electron

Hydrogels obtained from combining different polymers are an interesting strategy for developing controlled release system platforms and tissue engineering scaffolds. In this study, the applicability of sodium alginate-g-(QCL-co-HEMA) hydrogels for these biomedical applications was evaluated. Hydrogels were synthesized by free-radical polymerization using a different concentration of the components. The hydrogels were characterized by Fourier transform-infrared spectroscopy, scanning electron microscopy, and a swelling degree. Betamethasone release as well as the in vitro cytocompatibility with chondrocytes and fibroblast cells were also evaluated. Scanning electron microscopy confirmed the porous surface morphology of the hydrogels in all cases. The swelling percent was determined at a different pH and was observed to be pH-sensitive. The controlled release behavior of betamethasone from the matrices was investigated in PBS media (pH = 7.4) and the drug was released in a controlled manner for up to 8 h. Human chondrocytes and fibroblasts were cultured on the hydrogels. The MTS assay showed that almost all hydrogels are cytocompatibles and an increase of proliferation in both cell types after one week of incubation was observed by the Live/Dead® assay. These results demonstrate that these hydrogels are attractive materials for pharmaceutical and biomedical applications due to their characteristics, their release kinetics, and biocompatibility.

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