• Journal of Chest Surgery
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• 제43권1호
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• pp.1-10
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• 2010

Background: Bioprosthetic materials have been made using glutaraldehyde fixation of porcine or bovine pericardium during cardiovascular surgery. But these bioprostheses have the problems of calcification and mechanical failure. We determined changes in tensile strength and elasticity of pericardium after glutaraldehyde, solvent, decellularization and detoxification. Material and Method: Tissues were allocated to four groups: glutaraldehyde with and without solvent, decellularization, and detoxification. We studied tensile strength and strain on tissues. We measured the tensile strength of fresh pericardium stretched in six directions (with 5 mm width), and % strain, which we calculated from the breaking point when we pulled the pericardium in two directions. Result: Tensile strength was reduced when we used the usual concentrated glutaraldehyde fixation (n=83, $MPa=11.47{\pm}5.40$, p=0.006), but there was no change when we used solvent. Elasticity was increased after glutaraldehyde fixation (n=83, strain $(%)=24.55{\pm}9.81$, p=0.00), but there was no change after solvent. After decellularization of pericardium, the tensile strength was generally reduced. The decrease in tensile strength after concentrated glutaraldehyde fixation for a long time was significantly greater less than after concentrated solvent (p=0.01, p=0.00). After detoxification, the differences in strength and strain were not significant. Conclusion: After glutaraldehyde treatment of pericardium there is no loss in tensile strength (even though we did the glutaraldehyde, solvent and detoxification treatments LOGIC IS UNCLEAR). Also, these treatments had a tendency to increase elasticity. Although post-treatment decellularization led to a significant loss in strength, this effect could be attenuated using a low concentration of solvent or hypertonic solution.

• Journal of Chest Surgery
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• 제42권2호
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• pp.165-174
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• 2009

Background: With the advances of cardiac surgery, the demand for an artificial prosthesis has increased, and this has led to the development and utilization of diverse alternative materials. We conducted this research to improve an artificial prosthesis by examining the changes of the physical qualities, the pressure related tensile strength, the change in elasticity and the thermostability of a xenograft valve (porcine) and pericardium (bovine, porcine) based on the type of fixation liquid we used. Material and Method: The xenograft valves and pericardium were assigned into three groups: the untreated group, the fixed with glutaraldehyde (GA) group and the glutaraldehyde with GA+solvent such as ethanol etc. group. The surgeons carried out each group's physical activities. Each group's uniaxial tension and elasticity was measured and compared. Thermostability testing was conducted and compared between the bovine and porcine pericardium fixed with GA group and the GA+solvent group. Result: On the physical activity test in the surgeon's hand, no significant difference between the groups was sensed on palpation. For suture and tension, the GA+solvent group was slightly firmer than the low GA concentration group. In general, the circumferential uniaxial tension and elasticity of the porcine aortic and pulmonary valves were better in the fixed groups than that in the untreated group. There was no significant difference between the GA and GA+solvent groups (p>0.05). Bovine and porcine pericardium also showed no significant difference between the GA group and the GA+solvent group (p>0.05). When comparing between the groups for each experiment, the elasticity tended to be stronger in most of the higher GA concentration group (porcine pulmonary valve, porcine pericardium). On the thermostability testing of the bovine and porcine pericardium, the GA group and the G+solvent group both had a sudden shrinking point at $80^{\circ}C$ that showed no difference (bovine pericardium: p=0.057, porcine pericardium: p=0.227). Conclusion: When fixing xenograft prosthetic devices with GA, adding a solvent did not cause a loss in pressure-tension, tension-elasticity and thermostability. In addition, more functional solvents or cleansers should be developed for developing better xenografts.

• Journal of Biomedical Engineering Research
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• 제16권3호
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• pp.367-375
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• 1995

Ampicillin sodium (AMP-Na) was loaded Into fibrin glue (FG) in two different ways and was tried to achieve sustained release from FG. One was loading of AMP-Na in a simple mixing and the other was loading of bovine serum albumin (BSA) microspheres which contained ANP-Na. In case of simple mixing, the release control of AWP-Na from FG was tried by variation of FBNG concentration, but failed. However, the loading of BSA mlcrosphere containing ANP-Na into FG showed sustained re- lease of AMP-Na, especially when microsphere was crosslinked with glutaraldehyde (tO.9 : 33hr). The maximum adhesive strength of FG showed at concentration of FBWG and thrombin, 5.0 % and 25-50 NIHU/ml, respectively. The concentration of Factor Xlll (0-500 U/1g of FBNG) did not affect the adhesive strength of FG. The optimal incubation time was 60 min. The AMP-Na or BSA microsphere which was loaded into FG had no significant effect on the adhesive strength of FG.

• Journal of environmental and Sanitary engineering
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• 제11권3호
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• pp.13-19
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• 1996

Packed bed reactor containing immobilized microorganisms which degraded phenol without growth was used to remove phenol from the synthetic wastewater. The effects of temperature, retention time(reactor volume/flow rate) and phenol concentration on the removal efficiency of phenol were investigated. The effect of temperature in the range of 20-30$\circ $C was negligible while retention time and phenol concentration influenced the removal of phenol significantly. When retention time was in the range of 1-1.5 hour, the removal efficiency of phenol was affected not by phenol concentration but by retention time itself while it was influenced by phenol concentration above 1.5 hour of retention time. The beads after 720 hours operation were swelled by 40 % in diameter which could be prevented by crosslinking with glutaraldehyde at the expense of cell activity.

• Journal of Chest Surgery
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• 제41권2호
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• pp.170-176
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• 2008

Background: Bioprosthetic devices for treating cardiovascular diseases and defects may provide alternatives to autologous and homograft tissue. We evaluated the mechanical and physical conditions of a porcine pericardial bioprosthesis treated with Glutaraldehyde (GA), Ethanol, or Sodium dodecylsulfate (SDS) before implantation. Material and Method: 1) Thirty square-shaped pieces of porcine pericardium were fixed in 0.625%, 1.5% or 3% GA solution. 2) The tensile strength and thickness of these and other bioprosthesis, including fresh porcine pericardium, fresh human pericardium, and commercially produced heterografts, were measured. 3) The tensile strength and thickness of the six treated groups (GA-Ethanol, Ethanol-GA, SDS only, SDS-GA, Ethanol-SDS-GA and SDS-Ethanol-GA) were measured. Result: 1) Porcine pericardium fixed in 0.625% GA the thinnest and had the lowest tensile strength, with thickness and tensile strength increasing with the concentration of GA solution. The relationship between tensile strength and thickness of porcine pericardium increased at thicknesses greater than 0.1mm (correlation-coefficient 0.514, 0<0.001). 2) There were no differences in tensile strength or thickness between commercially-produced heterografts. 3) Treatment of GA, ethanol, or SDS minimally influenced thickness and tensile strength of porcine pericardium, except for SDS alone. Conclusion: Porcine pericardial bioprosthesis greater than 0.1 mm thick provide better handling and advantageous tensile strength. GA fixation did not cause physical or mechanical damage during anticalcification or decellularization treatment, but combining SDS-ethanol pre-treatment and GA fixation provided the best tensile strength and thickness.

• Proceedings of the KIEE Conference
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.490-492
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• 1987

Urea-Sensor was fabricated by immobilizing urease on ISFET's gate using BSA(bovine serum albumin) and glutaraldehyde, and its characteristics were examined. This sensor showed approximately linear characteristic in the urea concentration range of $3{\times}10^{-5}-10^{-9}$ (g/ml). Fast response time was obtained and minute amounts of expensive enzyme were used in comparison to general electrode type biosensors.

• Biomaterials and Biomechanics in Bioengineering
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• 제4권1호
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• pp.1-8
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• 2019

The aim of this study was to investigate the effect of total polymer concentration on the chemical structure, morphology of pores, porosity, swelling ratio, degradation of gelatin-poly (vinyl alcohol) (Gel-PVA) cryogel scaffolds. Porous cryogels were prepared with cryogelation technique by using glutaraldehyde as a crosslinker. Functional group composition of cryogels after crosslinking was investigated by Fourier Transform Infrared (FTIR). The morphology of cryogels was characterized via scanning electron microscopy (SEM) and porosity analysis. All of the cryogels had a porous structure with an average pore size between $45.58{\pm}14.28$ and $50.14{\pm}4.26{\mu}m$. The cryogels were biodegradable and started to degrade in 14 days. As the polymer concentration increased the swelling ratio, the porosity and the degradation rate decreased. Spongy and mechanically stable Gel-PVA cryogels, with tunable properties, can be potential candidates as scaffolds for tissue engineering applications.

• Journal of Pharmaceutical Investigation
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• 제41권5호
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• pp.279-288
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• 2011

The Dexamethasone (DEX) loaded chitosan microspheres were prepared by thermal denaturation and chemical cross-linking method using a dierent concentration of glutaraldehyde as chemical cross-linking agent. The prepared microspheres were evaluated for the percentage of Drug Loading (DL), Encapsulation Efficiency (EE) and surface morphology by Scanning Electron Microscopy (SEM). DL and EE were found to be maximum range of 10.0 to 10.79 % and 58.19 to 64.73 % respectively. The SEM Photographs of the resultant microspheres exhibited fairly smooth surfaces and predominantly spherical in appearance. In addition, Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) shown that there was no interaction between the drug and polymer. In vitro and in vivo release studies revealed that the release of dexamethasone was sustained and extended up to 63 days and effectively controlled by the extent of cross-linking agent. Non-clinical parameters such as paw volume, hematological parameters like Erythrocyte Sedimentation Rate (ESR), Paced Cell Volume (PCV), Total Leucocytes Count (TLC), Hemoglobin (Hb), Differential Cell Count (DCC) were investigated in Fruend's Complete Adjuvant (FCA) induced arthritic rats. Radiology and histopathological studies were also performed in order to evaluate the therapeutic efficacy of the DEX-loaded microspheres in extenuating the rat arthritic model.

• The Korean Journal of Mycology
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• 제11권3호
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• pp.109-114
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• 1983

${\beta}-Galactosidase$ activity of Aspergillus phoenicis was studied using ONPG and lactose as substrate. It increased monotonically during the exponential growth phase and dropped rapidly at the beginning of the stationary one. It exhibited high tolerable temperature and acidic optimal pH which provides certain advantages from the industrial view point. Enzyme of ${\beta}-galactosidase$ had more subsrate affinity for ONPG than for lactose and its apparent maximum activity was also higher with the former as substrate. Activity of this enzyme depended upon the conditions of immobilization. Optimum crosslinking reaction was occurred at pH 7.2 and 0. 35 vol. % of glutaraldehyde concentration.

• Microbiology and Biotechnology Letters
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• 제21권4호
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• pp.373-380
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• 1993

When the cells of yeast K35 were immobilized in Ca-alginate gel, cell concentration and viability decreased as alginate concentration increased. Considering the results, 2% (w/v) Ca-alginate concentration would be suitable. Among various concentrations of additives and cross-lin-king agent, the addition of 1.67% (w/v) of bentonite together with 0.33% (v/v) of glutaraldehyde (ABG bead) resulted in the highest ethanol production of 1.8%(w/v), using YPD medium containing 2% glucose. ABG bead seemed to be more resistant to phosphate ion than Ca-alginate bead. 0.33%(w/v) of phosphate was a proper concentration for the ethanol production by ABG bead. Scanning electron microscopic observation depicted that the immobilized cells on the bead surface were coated by alginate gel and that the cells in the internal bead were cross-linked with alginate matrix. When repeated-batch culture was performed with ABG bead for 40 days in a packed-bed reactor, ethanol concentration of about 90~110 g/l-gel was maintained. Cell viability was maintained around 70%, and outgrowing cell concentration was below 6.3% of total cell concentration. Consequently, the results showed that ABG head was a potential carrier for continuous production of ethanol compared to conventional Ca-alginate bead.