• BMB Reports
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• v.44 no.2
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• pp.77-86
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• 2011

Over the years, nanostructures have been developed to enable to support enzyme usability to obtain highly selective and efficient biocatalysts for catalyzing processes under various conditions. This review summarizes recent developments in the nanostructures for enzyme supporters, typically those formed with various inorganic materials. To improve enzyme attachment, the surface of nanomaterials is properly modified to express specific functional groups. Various materials and nanostructures can be applied to improve both enzyme activity and stability. The merits of the incorporation of enzymes in inorganic nanomaterials and unprecedented opportunities for enhanced enzyme properties are discussed. Finally, the limitations encountered with nanomaterial-based enzyme immobilization are discussed together with the future prospects of such systems.

• Food Science and Biotechnology
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• v.14 no.3
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• pp.317-322
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• 2005

A simple and convenient method of immobilizing dextransucrase via an affinity interaction is described, along with the use of this system to synthesize leucrose. Dextransucrase was produced in sucrose-free medium by fermenting a constitutive mutant of Leuconostoc mesenteroides NRRL B-512F and was separated using an ultrafiltration membrane. The purified enzyme was free of dextran polymer, which previously was always found with the sucrose-induced enzyme. Therefore, it was possible to immobilize the enzyme on dextran-based resins using an affinity interaction. Sephadex G-200 was the best resin for immobilizing the dextransucrase and gave a fast flow rate through the packed column. The immobilized dextransucrase retained more than 80% of its specific activity after immobilization ($K_m\;=\;18.1\;mM$ and $k_{cat}\;=\;450\;sec^{-1}$ vs. 13.1 mM and $640\;sec^{-1}$, respectively, for the free enzyme). The immobilized dextransucrase showed improved stability over a pH range of 4.0 to 6.5 and at moderately high temperatures over $40^{\circ}C$. When immobilized dextransucrase was used to synthesize leucrose via the transfer reaction with sucrose and fructose, about 74% of the sucrose was converted into leucrose after one day, and the half-life of the enzyme activity was 15 days. Regeneration of the resin by supplementation with dextransucrase enabled the recovery of the initial activity of the system, but both the reaction and the flow rate were lower, probably owing to the accumulation of dextran inside the resin.

• Macromolecular Research
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• v.17 no.5
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• pp.346-351
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• 2009

$TiCl(O-i-Pr)_3/SiO_2$ and $Ti(O-i-Pr)_4/SiO_2$ were prepared by immobilizing chlorotitanium (IV) isopropoxide ($TiCl(O-i-Pr)_3$) and titanium (IV) isopropoxide ($Ti(O-i-Pr)_4$), to pretreated silica. The effect of the polymerization reaction conditions on the catalytic activity and characteristics of the resulting PLA were investigated. The catalytic conversion, molecular weight and polydispersity index (PDI) of the PLA produced on the titanium alkoxide supported catalysts increased proportionally with the reaction temperature. When the PLA was synthesized in bulk polymerization, the PLA produced with the supported catalysts had higher molecular weight than those with homogeneous catalysts. The melting temperature of the polymer produced with silica supported alkoxide catalysts was approximately $170-180^{\circ}C$.

• Molecular & Cellular Toxicology
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• v.4 no.2
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• pp.100-105
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• 2008

Biochips are a powerful emerging technology for biomedical, environmental applications. Especially, making use of bioseonors in the evaluation of toxicity becomes increasingly important. For biosensor as a toxicity detection, biomolecules like antibodies or aptamers have been developed to specifically capture the toxic target molecules. In addition, the development of optimal chip materials capable of maintaining the activity of embedded biomolecules such as proteins or aptamers has proven challenging. Here, using sol-gel materials, new chip material, whose ability for immobilizing the embedded aptamers and maintaining the ability of embedded aptamers is optimal, was searched. We used sol-gel formulation screening methods previously developed and found the best formulation which shows high sensitive and specific interactions of aptamers. This study results will support the technological advancement for diagnosis and environmental sensor.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.4
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• pp.227-232
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• 2003

A self-assembled monolayer of protein G was fabricated to develop an immunosensor based on surface plasmon resonance (SPR), thereby improving the performance of the antibodybased biosensor through immobilizing the antibody molecules (lgG). As such, 11-mercaptoundecanoic acid (11-MUA) was adsorbed on a gold (Au) support, while the non-reactive hydrophilic surface was changed through substituting the carboxylic acid group (-COOH) in the 11-MUA molecule using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrocholide (EDAC). The formation of the self-assembled protein G layer on the Au substrate and binding of the antibody and antigen were investigated using SPR spectroscopy, while the surface topographies of the fabricated thin films were analyzed using atomic force microscopy (AFM). A fabricated monoclonal antibody (Mab) layer was applied for detecting E. coli O157:H7. As a result, a linear relationship was achieved between the pathogen concentration and the SPR angle shift, plus the detection limit was enhanced up to 10$^2$ CFU/mL.

• KSBB Journal
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• v.6 no.4
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• pp.403-406
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• 1991

Lactic acid production yield was examined for commercial use by immobilizing Rhizopus oryzae with radiation induced polymer. The supporting material was synthesized by the low temperature radiation polymerization method, in which the microorganism was entrapped physically by contacting together in culture broth shaking for 24 hours. Support polymers with 5∼10vol-% monomers were able to increase their catalytic activities, consuming 65g/1 of glucose, producing 56g/1 of lactic acid, thus yielding 88% of product in general. But in free culture, the microorganism consumed almost all carbon sources and produced lactic acid only 60% even after 96 hours. The yield of the experiment under discussion was significantly high compared with conventional immobilization procedure.

• Membrane Journal
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• v.27 no.4
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• pp.328-335
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• 2017

Fabricating photocatalytic composite membrane with a mesoporous and tailored morphological structure would have significant implication for environmental remediation. In this study, we reported hybrid $TiO_2$ immobilized photocatalytic membrane and its application for the treatment of dye solution. Photocatalytic film with high porosity and homogeneity was fabricated by graft copolymer as polymer template. Hybridization of membrane filtration with photocatalysis was successfully achieved by photocatalytic membrane reactor developed. Result showed that membrane permeability was significantly reduced after immobilizing the $TiO_2$ film on bare $Al_2O_3$ support. The membrane characterization indicated that well organized $TiO_2$ film was successfully formed on $Al_2O_3$ support. Benefiting from the controlled morphology of $TiO_2$ film, the composite membrane exhibited almost complete degradation of organic dye within 5 h of filtration under UV illumination. Langmuir-Hinshelwood model explained degradation of organic dye. First-order rate constant was approximately six times with $TiO_2$ immobilized composite ceramic membrane, higher than the one with the bare $Al_2O_3$ support (0.0081 vs. $0.0013min^{-1}$).

• Journal of Periodontal and Implant Science
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• v.29 no.3
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• pp.693-703
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• 1999

Since they were introduced by Ward in 1923, periodontal dressing have been routinely used following the periodontal surgery to avoid pain, infection, desensitizing teeth, inhibiting food impaction of the surgical areas, and immobilizing injured areas. Recently, however, the value of periodontal dressings and their effects on periodontal wound healing have been questioned, several authors have been reported that the use of dressing has little influence on healing following periodontal surgical procedures. In addition, there is evidence that when good flap adaptation is achieved, the use of a periodontal dressing does not add to patient comfort nor promote healing. The purpose of this study was to evaluate patient postoperative pain experience and discomfort with and without the use of periodontal dressing following periodontal surgery. Twenty-eight patients, 11 male and 17 female. were selected for this study; The age range was 31 to 56, with an average of 40.2years. Patient selection was based on existence of two bilateral sites presenting similar periodontal involvement, as determined by clinical and radiographic assessment, and requiring comparable bilateral surgical procedures. Using a splitmouth dressing. one site received a periodontal dressing while the other site did not. Pain assessment was made according to a horizontal, rating scale(0-10). After at least a two-week period, the second surgical precedure was performed using the alternate postoperative treatment. At the conclusion of the trial, a self-administered questionnaire on postoperative experience was administered, and were asked of their preference of either, dressed or undressed. The results were as follows: 1. A similar trend for mean pain and discomfort scores as assessed by patients both dressed and salinetreated procedures was evident during 7-day postsurgical period. 2. Statistical analysis of differences between the dressed side and salinetreated side with respect to pain, discomfort and patient's experiences revealed that both treatment sides behaved similarly at any postoperative day(P>0.05). 3. Considering the patient's preference, on the basis of pain and discomfort experienced, 43% preferred the saline-mouthwash and 32% preferred the dressing, 25% showing no preference for either the dressing or the saline-mouthwash. There is evidence to support the use of a periodontal dressing in retention of an apically positioned flap by preventing coronal displacement, or its use to provide additional support to stabilize a free gingival graft. However, there will always be a use for periodontal dressing although routine use of dressings may decrease because of better surgical techniques and the use of antibacterial mouth rinses.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.8
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• pp.663-672
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• 2009

In this studies, the adsorption test using Chlorella pyrenoidosa was conducted to examine the effect of Pb adsorption according to various immobilized methods such as Ca-alginate, K-carrageenan, and Polyacrylamide. From the results, the duration to need to reach adsorption equilibrium was delayed according to the immobilization. And, the higher adsorption capacity of immobilized Chlorella pyrenoidosa was represented in the higher concentration of Pb, the smaller amount of immobilizing agent, and the higher pH of solution. The maximum adsorption capacity of Pb was shown in the adsorption test using Chlorella pyrenoidosa immobilized with Ca-alginate even though it was sensitive pH. The adsorption results properly represented with Freundlich isotherm equations. And, pseudo second-order chemisorption kinetic rate equation was applicable to all the biosorption data over the entire time range. The FT-IR analysis showed that the mechanism involved in biosorption of Pb by Chlorella pyrenoidosa was mainly attributed to Pb binding of carbo-acid and amide group. Adsorbed Pb on immobilized Chlorella prenoidosa was easily desorbed in the higher concentration of desorbents(NTA, HCl, EDTA, $H_2SO_4,\;Na_2CO_3$). Among the several desorbents, NTA showed the maximum desoption capacities of Pb from Chlorella pyrenoidosa immobilized with Ca-alginate and K-carrageenan and EDTA was the most effective in Chlorella pyrenoidosa immobilized with polyacrylamide. The desoprtion efficiency in the optimum condition was 90.0, 83.0, and 80.0%, respectively.