scholarly journals Polycaprolactone-Chitin Nanofibrous Mats as Potential Scaffolds for Tissue Engineering

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Min Sup Kim ◽  
Sang Jun Park ◽  
Bon Kang Gu ◽  
Chun-Ho Kim
Keyword(s):  
Electron Microscopy ◽  
Tissue Engineering ◽  
Contact Angles ◽  
Dermal Fibroblasts ◽  
Human Dermal Fibroblasts ◽  
Water Contact ◽  
Mean Diameter ◽  
Poly Caprolactone ◽  
Scanning Electron

We describe here the preparation of poly(caprolactone) (PCL)-chitin nanofibrous mats by electrospinning from a blended solution of PCL and chitin dissolved in a cosolvent, 1,1,1,3,3,3-hexafluoro-2-propanol and trifluoroacetic acid. Scanning electron microscopy showed that the neutralized PCL-chitin nanofibrous mats were morphologically stable, with a mean diameter of340.5±2.6 nm, compared with a diameter of524.2±12.1 nm for PCL mats. The nanofibrous mats showed decreased water contact angles as the proportion of chitin increased. However, the tensile properties of nanofibrous mats containing30~50% (wt/wt) chitin were enhanced compared with PCL-only mats.In vitrostudies showed that the viability of human dermal fibroblasts (HDFs) for up to 7 days in culture was higher on composite (OD value:1.42±0.09) than on PCL-only (0.51±0.14) nanofibrous mats, with viability correlated with chitin concentration. Together, our results suggest that PCL-chitin nanofibrous mats can be used as an implantable substrate to modulate HDF viability in tissue engineering.

scholarly journals Enhanced Anti-Mold Property and Mechanism Description of Ag/TiO2 Wood-Based Nanocomposites Formation by Ultrasound- and Vacuum-Impregnation

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 682
Author(s):  
Lin Lin ◽  
Jiaming Cao ◽  
Jian Zhang ◽  
Qiliang Cui ◽  
Yi Liu
Keyword(s):  
Electron Microscopy ◽  
Cell Walls ◽  
Mercury Intrusion Porosimetry ◽  
Water Source ◽  
Contact Angles ◽  
Vacuum Impregnation ◽  
Water Contact ◽  
Mercury Intrusion ◽  
Wood Surfaces ◽  
Scanning Electron

Ag/TiO2 wood-based nanocomposites were prepared by the methods of ultrasound impregnation and vacuum impregnation. The as-prepared samples were characterized by field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), mercury intrusion porosimetry (MIP), and water contact angles (WCAs). The anti-mold properties of the Ag/TiO2 wood-based nanocomposites were improved by 14 times compared to those of the original wood. The nano-Ag/TiO2, which was impregnated in the tracheid and attached to the cell walls, was able to form a two-stage rough structure and reduce the number of hydroxyl functional groups on the wood surfaces. The resulting decline of wood hydrophobic and equilibrium moisture content (EMC) destroyed the moisture environment necessary for mold survival. Ag/TiO2 was deposited in the wood pores, which reduced the number and volume of pores and blocked the path of mold infection. Thus, the anti-mold properties of the Ag/TiO2 wood-based nanocomposite were improved by cutting off the water source and blocking the mold infection path. This study reveals the anti-mold mechanism of Ag/TiO2 wood-based nanocomposites and provides a feasible pathway for wood-based nanocomposites with anti-mold functions.

scholarly journals DETERMINATION OF BIOCOMPATIBILITY AND CYTOTOXICITY OF POROUS TITANIUM-BASED MATERIALS IN EXPERIMENT

2017 ◽  
Vol 2 (3) ◽  
pp. 18-22
Author(s):  
AV V Kolsanov ◽  
AN N Nikolaenko ◽  
VV V Ivanov ◽  
SA A Prikhodko ◽  
PV V Platonov
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Proliferative Activity ◽  
Dermal Fibroblasts ◽  
Titanium Silicide ◽  
Proliferation Index ◽  
Contact Method ◽  
Test Materials ◽  
Scanning Electron

Aim - to evaluate the proliferative activity of dermal fibroblast cultures in the presence of composite materials based on titanium silicides in vitro. Materials and methods. To assess the proliferative activity of dermal fibroblasts in vitro, the following materials were used: titanium silicide, titanium carbosilicide oxidized in vacuum and without vacuum, titanium VT-00 (comparison group). Testing of proliferative activity was carried out by the direct contact method. The proliferation index, the doubling time and the number of culture doubling during the cultivation period were calculated. Attachment of dermal fibroblasts to the surface of the test materials and their presence on it during cultivation was assessed by scanning electron microscopy. Results. The study of the morphofunctional characteristics of dermal fibroblasts cultured in the presence of the test samples of material showed that during the entire experiment no major changes occurred in any of the series, the cells retained the monolayer growth characteristic of fibroblasts, preferably spindleshaped with 2-4 shoots. Moreover, all cultures of dermal fibroblasts underwent the same number of doublings during the experiment and reached saturation density 7 days after sowing, which indicates good proliferative activity of cells in the presence of test materials. The results of scanning electron microscopy demonstrate the high affinity of human dermal fibroblasts for both titanium silicide and titanium carbosilicides. Conclusion. Absence of morphofunctional changes in dermal fibroblasts and active proliferation testify to the absence of cytotoxicity of the investigated alloys, and the ability of cells to adhere to the surface of materials indicates their good biocompatibility.

Alginate Scaffolds with Modified Micro Pores for Tissue Engineering Applications

2015 ◽  
Vol 749 ◽  
pp. 457-460
Author(s):  
Bon Kang Gu ◽  
Sang Jun Park ◽  
Min Sup Kim ◽  
Chun Ho Kim
Keyword(s):  
Tissue Engineering ◽  
Pore Size ◽  
Tissue Regeneration ◽  
Dermal Fibroblasts ◽  
Swelling Kinetics ◽  
Human Dermal Fibroblasts ◽  
Kinetics Analysis ◽  
Swelling Rate

In this study, we developed the porous alginate (AL) scaffolds with modified pores size and distributions to actively control tissue regeneration. An addition of 5 and 10% (v/v) butanol to AL solution was effective to control pores structures of AL scaffolds. Especially, increased amount of butanol induced that proportion of smaller pores (size of around 5~10 μm) on AL scaffolds increased. Using swelling kinetics analysis, we confirmed that micro pore modified AL scaffolds show faster swelling rate than pristine scaffolds. During in vitro study, the enhanced viability and proliferation of human dermal fibroblasts (HDFs) were observed by the pore size and distribution from micro pore modified AL scaffolds. However, AL scaffolds added 10 % butanol with excessive proportion of smaller pores induced the decreased viability of HDFs for 7 days. From our results, AL scaffolds with modified pores structures represent a potential implants to control biological in vitro and in vivo functions in a variety of tissue engineering.

scholarly journals In Vivo and In Vitro Elution of Analgesics from Multilayered Poly(D,L)-lactide-co-glycolide Nanofibers Incorporated Ureteral Stents

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Yi-Chia Lin ◽  
Kuo-Sheng Liu ◽  
Demei Lee ◽  
Min-Jhan Li ◽  
Shih-Jung Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Local Drug Delivery ◽  
Ureteral Stents ◽  
Water Contact ◽  
Elution Behavior ◽  
Behavior Characteristics ◽  
Contact Angle Analysis ◽  
Scanning Electron

We develop novel analgesic-eluting nanofiber-incorporated ureteral stents that offer sustained release of lidocaine and ketorolac for local drug delivery. Lidocaine and poly(D,L)-lactide-co-glycolide (PLGA) were dissolved in hexafluoroisopropanol and were electrospun into nonwoven nanofibers onto the surface of ureteral stents. This was followed by electrospinning of another layer of PLGA nanofibers containing ketorolac. Electrospun drug-loaded nanofibers were then characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, and water contact angle analysis. In addition, the elution behavior characteristics of the analgesics, both in vivo and in vitro, from the nanofiber-incorporated stents were evaluated. Experimental results indicate that the analgesic-eluting ureteral stents could liberate high strengths of analgesics in vitro and in vivo for at least 50 and 30 days, respectively. The analgesic-eluting nanofiber-incorporated ureteral stents are potentially applicable for alleviating the discomfort associated with stent implant.

scholarly journals Synthesis and evaluation of AlgNa-g-poly(QCL-co-HEMA) hydrogels for cartilage tissue engineering and controlled release of betamethasone.

2021 ◽  
Author(s):  
Jomarien García-Couce ◽  
Marioly Vernhes ◽  
Nancy Bada ◽  
Lissette Agüero ◽  
Oscar Valdés ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Tissue Engineering ◽  
Scanning Electron Microscopy ◽  
Controlled Release ◽  
Biomedical Applications ◽  
Release Kinetics ◽  
Cartilage Tissue Engineering ◽  
Cartilage Tissue ◽  
Scanning Electron

Hydrogels obtained from the combination of different polymers are an interesting strategy for the development of 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 different concentration of the components. The hydrogels were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and 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 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 up to 8 h. Human chondrocytes and fibroblasts were cultured on the hydrogels. The MTS assay shown that almost all hydrogels are cytocompatibles and an increase the proliferation in both cell types after one week of incubation was observed by 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.

scholarly journals Synthesis and evaluation of AlgNa-g-poly(QCL-co-HEMA) hydrogels for cartilage tissue engineering and controlled release of betamethasone.

2021 ◽  
Author(s):  
Jomarien García-Couce ◽  
Marioly Vernhes ◽  
Nancy Bada ◽  
Lissette Agüero ◽  
Oscar Valdés ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Tissue Engineering ◽  
Scanning Electron Microscopy ◽  
Controlled Release ◽  
Biomedical Applications ◽  
Release Kinetics ◽  
Cartilage Tissue Engineering ◽  
Cartilage Tissue ◽  
Scanning Electron

Hydrogels obtained from the combination of different polymers are an interesting strategy for the development of 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 different concentration of the components. The hydrogels were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and 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 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 up to 8 h. Human chondrocytes and fibroblasts were cultured on the hydrogels. The MTS assay shown that almost all hydrogels are cytocompatibles and an increase the proliferation in both cell types after one week of incubation was observed by 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.

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

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.

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

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.

The Mesothelial Cell as a Non-Thrombogenic Surface

1984 ◽  
Vol 52 (02) ◽  
pp. 102-104 ◽  
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.

Needleless electrospinning of PVP/PGS fibrous scaffolds for skin tissue engineering applications

2018 ◽  
Author(s):  
Antonios Keirouz ◽  
Giuseppino Fortunato ◽  
Anthony Callanan ◽  
Norbert Radacsi
Keyword(s):  
Tissue Engineering ◽  
Tensile Modulus ◽  
Dermal Fibroblasts ◽  
Skin Tissue ◽  
Skin Substitute ◽  
Electrospinning Technique ◽  
Skin Tissue Engineering ◽  
Needleless Electrospinning ◽  
High Concentrations

Scaffolds and implants used for tissue engineering need to be adapted for their mechanical properties with respect to their environment within the human body. Therefore, a novel composite for skin tissue engineering is presented by use of blends of Poly(vinylpyrrolidone) (PVP) and Poly(glycerol sebacate) (PGS) were fabricated via the needleless electrospinning technique. The formed PGS/PVP blends were morphologically, thermochemically and mechanically characterized. The morphology of the developed fibers related to the concentration of PGS, with high concentrations of PGS merging the fibers together plasticizing the scaffold. The tensile modulus appeared to be affected by the concentration of PGS within the blends, with an apparent decrease in the elastic modulus of the electrospun mats and an exponential increase of the elongation at break. Ultraviolet (UV) crosslinking of PGS/PVP significantly decreased and stabilized the wettability of the formed fiber mats, as indicated by contact angle measurements. In vitro examination showed good viability and proliferation of human dermal fibroblasts over the period of a week. The present findings provide important insights for tuning the elastic properties of electrospun material by incorporating this unique elastomer, as a promising future candidate for skin substitute constructs.

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