• Title/Summary/Keyword: surface immobilization

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Strategies in Protein Immobilization on a Gold Surface

  • Park, Jeho;Kim, Moonil
    • Applied Science and Convergence Technology
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    • v.24 no.1
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    • pp.1-8
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    • 2015
  • Protein immobilization on a gold surface plays an important role in the usefulness of biosensors that utilize gold-coated surfaces such as surface plasmon resonance (SPR), quartz crystal microbalance (QCM), etc. For developing high performance biosensors, it is necessarily required that immobilized proteins must remain biologically active. Loss of protein activity and maintenance of its stability on transducer surfaces is directly associated with the choice of immobilization methods, affecting protein-protein interactions. During the past decade, a variety of strategies have been extensively developed for the effective immobilization of proteins in terms of the orientation, density, and stability of immobilized proteins on analytical devices operating on different principles. In this review, recent advances and novel strategies in protein immobilization technologies developed for biosensors are briefly discussed, thereby providing an useful information for the selection of appropriate immobilization approach.

Immobilization of Lysozyme from Hen Egg by Crosslinking Method onto Chitosan Non-woven (키토산 섬유를 담체로 이용한 라이소자임 효소의 고정화)

  • Lee, So Hee
    • Textile Coloration and Finishing
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    • v.30 no.4
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    • pp.264-274
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    • 2018
  • Immobilization of lysozyme on chitosan non-woven using glutaraldehyde(GA) was investigated. For this, 100 % chitosan non-woven was prepared as novel support for the enzyme immobilization. In addition, free lysozyme activity was examined depending on various pH and temperature by measuring time. Moreover, the optimum immobilization conditions depending on various pH, temperature, immobilization time and lysozyme concentration was evaluated. In addition, thermal stability and storage stability of immobilized lysozyme were measured. The characteristics of immobilized lysozyme was examined by FT-IR, surface morphology, and MTT assay. The results are follows: the optimal immobilization of lysozyme were pH 7.0, $25^{\circ}C$, lysozyme concentration 1.5 mg/ml, immobilization time 240 min. The immobilized lysozyme showed higher thermal stability than the free trypsin. The immobilized lysozyme activity was retained 80 % of its initial activity at $4^{\circ}C$ over 30 days of storage. The lysozyme was immobilized effectively on chitosan non-woven by observation of surface morphology.

A comprehensive review of techniques for biofunctionalization of titanium

  • Hanawa, Takao
    • Journal of Periodontal and Implant Science
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    • v.41 no.6
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    • pp.263-272
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    • 2011
  • A number of surface modification techniques using immobilization of biofunctional molecules of Titanium (Ti) for dental implants as well as surface properties of Ti and Ti alloys have been developed. The method using passive surface oxide film on titanium takes advantage of the fact that the surface film on Ti consists mainly of amorphous or low-crystalline and nonstoichiometric $TiO_2$. In another method, the reconstruction of passive films, calcium phosphate naturally forms on Ti and its alloys, which is characteristic of Ti. A third method uses the surface active hydroxyl group. The oxide surface immediately reacts with water molecules and hydroxyl groups are formed. The hydroxyl groups dissociate in aqueous solutions and show acidic and basic properties. Several additional methods are also possible, including surface modification techniques, immobilization of poly(ethylene glycol), and immobilization of biomolecules such as bone morphogenetic protein, peptide, collagen, hydrogel, and gelatin.

Skin Hydration Status and Skin Surface pH According to the Body Parts of the Aged with Immobilization (기동장애 노인의 신체 부위별 피부수분 상태와 피부표면 산성도)

  • Han, Ae-Kyung;Won, Jong-Soon;Kim, Ok-Soo
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.17 no.3
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    • pp.314-323
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    • 2010
  • Purpose: This study was performed to identify skin hydration status and skin surface pH according to the body parts of the aged with immobilization. Methods: The subjects were 101 aged patients in a hospital and a institution for the elderly in Seoul. Data for skin hydration and skin surface pH were collected using corneo-meter and skin pH-meter. The body parts of measurement were 10 parts; face, forearm, back of the hand, flank, upper abdomen, leg, back of the foot, heel, scapular, and sacrum. The data were analyzed by SPSS/WIN 12.0 program. Results: Skin hydration status were relatively low especially on lower extremity and back of body, and skin surface pH of scapular and sacrum were high. There was significant negative correlation between skin hydration status and skin surface pH on the 6 body parts. Conclusion: Skin hydration status and skin surface pH, especially on scapular, sacrum, and lower extremity need to be considered as important control factors for increasing skin health status of the aged with immobilization.

Polymer materials for enzyme immobilization and their application in bioreactors

  • Fang, Yan;Huang, Xiao-Jun;Chen, Peng-Cheng;Xu, Zhi-Kang
    • BMB Reports
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    • v.44 no.2
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    • pp.87-95
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    • 2011
  • Enzymatic catalysis has been pursued extensively in a wide range of important chemical processes for their unparalleled selectivity and mild reaction conditions. However, enzymes are usually costly and easy to inactivate in their free forms. Immobilization is the key to optimizing the in-service performance of an enzyme in industrial processes, particularly in the field of non-aqueous phase catalysis. Since the immobilization process for enzymes will inevitably result in some loss of activity, improving the activity retention of the immobilized enzyme is critical. To some extent, the performance of an immobilized enzyme is mainly governed by the supports used for immobilization, thus it is important to fully understand the properties of supporting materials and immobilization processes. In recent years, there has been growing concern in using polymeric materials as supports for their good mechanical and easily adjustable properties. Furthermore, a great many work has been done in order to improve the activity retention and stabilities of immobilized enzymes. Some introduce a spacer arm onto the support surface to improve the enzyme mobility. The support surface is also modified towards biocompatibility to reduce non-biospecific interactions between the enzyme and support. Besides, natural materials can be used directly as supporting materials owning to their inert and biocompatible properties. This review is focused on recent advances in using polymeric materials as hosts for lipase immobilization by two different methods, surface attachment and encapsulation. Polymeric materials of different forms, such as particles, membranes and nanofibers, are discussed in detail. The prospective applications of immobilized enzymes, especially the enzyme-immobilized membrane bioreactors (EMBR) are also discussed.

Enhancement of Microbial Immobilization on the Surface of a Reticulated PU-g-PAAc Foam prepared through Graft Copolymerization induced by Atmosoheric Pressure Plasma Treatment (대기압 플라즈마 유도 그라프트 공중합으로 합성된 망상형 PU-g-PAAc 폼의 미생물 고정화능 향상)

  • Myung Sung Woon;Jang Yung Mi;Nam Ki Chun;Choi Ho Suk;Cho Dae Chul
    • KSBB Journal
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    • v.19 no.5
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    • pp.399-405
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    • 2004
  • A reticulated PU-g-PAAc foam was modified through the surface treatment of PU foam by one atmospheric pressure plasma. The synthesized PU-g-PAAc foam was prepared for the purpose of immobilizing microbial organisms. We also attempted different plasma treatment methods including simple plasma treatment, plasma induced grafting and plasma induced grafting followed by plasma re-treatment. The effect of grafting on equilibrium water content (EWC) of PU forms was examined by swelling measurements. Adhesion test was performed to investigate the effect of different plasma treatment methods on the improvement of microbial immobilization. Two foams modified by plasma induced grafting and plasma re-treatment after grafting showed 2.7 and 3.0 fold higher microbial immobilization than unmodified one, respectively. Meanwhile, simple plasma treatment showed a little enhancement. FT-IR analysis of each sample verified the contribution of surface functional groups on the enhancement of microbial immobilization. SEM observation confirmed microbial adherence.

Optimization of the Condition of Immobilized Photobacterium phosphoreum with Strontium Alginate (Strontium Alginate를 담체로 한 Photobacterium phosphoreum 고정화 조건의 최적화)

  • 이홍주;김현숙;정계훈;이은수;전억한
    • Microbiology and Biotechnology Letters
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    • v.27 no.2
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    • pp.136-144
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    • 1999
  • Since the condition of immobilization must be optimized, it is very important to know whether and on how conditions bacterial cells retain their metabolic activity during immobilization process. A bioluminescence intensity had the maximum value when cell concentrations were between 1.0 and 1.2 measured at O.D660. The strontium alginate was used as an immobilization matrix and two independent factors for immobilization of Photobacterium phosphoreum with strontium alginate were optimized with the response surface methodology(RSM) considering degree of bioluminescence. As a result, the optimum concentration for immobilization was found to be 2.4%(w/w) for sodium alginate and 0.31M for strontium chloride, respectively. A dilution was carried out with 2.5%(w/v) NaCl solution that is an optimum environmental condition for growth of P. phosphoreum. Under the such condition of immobilization, hardness could be predicted as 4.66$\times$104N/$m^2$ and it took different time according to the volume of matrix to be immobilized completely.

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Surface Modification Studies by Atomic Force Microscopy for Ar-Plasma Treated Polyethylene

  • Seo, Eun-Deock
    • Macromolecular Research
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    • v.10 no.5
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    • pp.291-295
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    • 2002
  • Atomic force microscopy(AFM) was used to study the polyethylene(PE) surfaces grafted and immobilized with acrylic acid by Ar plasma treatment. The topographical images and parameters including RMS roughness and Rp-v value provided an appropriate means to characterize the surfaces. The plasma grafting and immobilization method were a useful tool for the preparation of surfaces with carboxyl group. However, the plasma immobilization method turned out to have a limitation to use as a means of preparation of PE surface with specific functionalities, due to ablation effect during the Ar plasma treatment process.

Nano-Scale Immobilization of Antibody for the Construction of Immunosensor

  • Cho, Il-Hoon;Paek, Se-Hwan
    • 한국생물공학회:학술대회논문집
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    • 2003.10a
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    • pp.701-705
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    • 2003
  • Performance of an immunosensor can usually be assessed in terms of its analytical sensitivity and specificity. Sensitivity, i.e., the detection limit of analyte, is particularly determined by the amount of analyte molecules bound to the capture antibody immobilized onto a solid surface. In order to increase the binding complexes, we have investigated an immobilization method of antibody allowing for a molecular arrangement of the protein on a selective surface of a nano-patterned solid substrate. This has not been accomplished only by a surface treatment with a chemical, but also by fragmentation of immunoglobulin. Such approach would offer a protocol of antibody immobilization for the construction of nano-immunosensor and eventually improve the sensitivity of detection.

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