• Title/Summary/Keyword: encapsulation

Search Result 807, Processing Time 0.03 seconds

Effect of Nonlamellar-Prone Lipids on Protein Encapsulation in Liposomes

  • Ahn, Tae-Ho;Chi, Youn-Tae;Yun, Chul-Ho
    • Macromolecular Research
    • /
    • v.17 no.12
    • /
    • pp.956-962
    • /
    • 2009
  • We investigated the effect of two nonlamellar-prone lipids, phosphatidylethanolamine (PE) and dioleoylglycerol (DOG), on the efficiency of protein encapsulation in liposomes. When the phosphatidylcholine (PC) matrix was replaced with PE or DOG during liposome formulation, the amounts of glutathione S-transferase and bovine serum albumin entrapped in the vesicles increased with increasing PE or DOG concentration. The presence of PE and DOG synergistically affected protein entrapment. These results suggest that protein encapsulation can be enhanced by the presence of nonlamellar lipids and/or lipid-induced membrane properties.

Preparation and Characterization of Vesicles Using Octasubstituted Cyclotetraphosphazene

  • Shin, Young-Jae;Park, Chul-Soon;Lee, Chun-Il;Shin, Jae-Sup
    • Bulletin of the Korean Chemical Society
    • /
    • v.29 no.10
    • /
    • pp.2005-2008
    • /
    • 2008
  • A cyclotetraphosphazene derivative with eight chains was synthesized from octachlorocyclotetraphosphazene. The vesicles were prepared using the cyclotetraphosphazene derivative and cholesterol. The resulting vesicles were characterized by TEM and measurements of their encapsulation efficiency. The stability of the vesicles was enhanced with the addition of dihexadecylphosphate. The size and the encapsulation efficiency of the vesicles changed according to the amount of cholesterol added. The size and the encapsulation efficiency of the vesicle were lowest when the mole ratio (cholesterol: the cyclophosphazene derivative) was 0.9.

A multi Step Cure Process to Prevent Residual Bubbles in LED Encapsulation Silicone Resin (LED Encapsulation 실리콘의 기포잔류방지를 위한 Step 경화공정 연구)

  • Song, M.J.;Kim, H.K.;Yoon, G.S.;Kim, K.H.
    • Transactions of Materials Processing
    • /
    • v.21 no.2
    • /
    • pp.101-106
    • /
    • 2012
  • Generally, rapid cure reaction of LED encapsulation silicone resin causes serious defects in cured resin products such as warpage, residual bubbles, and reduced wettablility. In order to prevent residual bubbles in silicone resin, the step cure process was examined in the present paper. Three kinds of step cure processes were applied, and bubble-free phenomenon was observed. Most of the bubbles were removed under $70^{\circ}C$, the minimum temperature for activating cure reaction. In addition, degree of cure(DOC) and temperature distribution were predicted by using FEM analysis of heat transfer. It was concluded that maintaining cure temperature which provide a DOC under 0.5~0.6 effectively reduces residual bubbles.

A Study on a Knowledge-Based Design System for Chip Encapsulation (반도체 칩의 캡슐화 성형을 위한 지식형 설계시스템에 관한 연구)

  • 허용정;한세진
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.15 no.2
    • /
    • pp.99-106
    • /
    • 1998
  • In this paper, we have constructed an expert system for semiconductor chip encapsulation which combines a knowledge-based system with CAE software. The knowledge-base module includes heuristic and pre analysis knowledge for evaluation and redesign. Evaluation of the initial design and generation of redesign recommendations can be developed from the rules as applied to a given chip package. The CAE programs can be used for simulating the filling and packing stage of encapsulation process. The expert system is a new tool which enables package design or process conditions with high yields and high productivity.

  • PDF

Highly Efficient Encapsulation of Anionic Small Molecules in Asymmetric Liposome Particles

  • Lee, Myung Kyu
    • Applied Science and Convergence Technology
    • /
    • v.24 no.6
    • /
    • pp.284-288
    • /
    • 2015
  • Anionic small molecules are hard to penetrate the cell membranes because of their negative charges. Encapsulation of small molecules into liposome particles can provide target specific delivery of them. In our previous study, siRNA could be efficiently encapsulated into liposome particles using an asymmetric preparation method of liposomes. In this study, the same method was applied for encapsulation of small anionic fluorescent chemicals such as calcein and indocyanine green (ICG). More than 90% fluorescent chemicals were encapsulated in the asymmetric liposome particles (ALPs). No intracellular fluorescent signal was observed in the tumor cells treated with the unmodified calcein/ALPs and ICG/ALPs, whereas the surface modification with a cell-penetrating polyarginine peptide (R8 or R12) allows cellular uptake of the ALPs. The results demonstrate that the ALPs encapsulating small anionic drugs will be useful for target-specific delivery after modification of target-specific ligands.

Low Temperature Encapsulation-Layer Fabrication of Organic-Inorganic Hybrid Thin Film by Atomic Layer Deposition-Molecular Layer Deposition

  • Kim, Se-Jun;Kim, Hong-Beom;Seong, Myeong-Mo
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2013.02a
    • /
    • pp.274-274
    • /
    • 2013
  • We fabricate encapsulation-layer of OLED panel from organic-inorganic hybrid thin film by atomic layer deposition (ALD) molecular layer deposition (MLD) using Al2O3 as ALD process and Adipoyl Chloride (AC) and 1,4-Butanediamine as MLD process. Ellipsometry was employed to verify self-limiting reaction of MLD. Linear relationship between number of cycle and thickness was obtained. By such investigation, we found that desirable organic thin film fabrication is possible by MLD surface reaction in monolayer scale. Purging was carried out after dosing of each precursor to eliminate physically adsorbed precursor with surface. We also confirmed roughness of the organic thin film by atomic force microscopy (AFM). We deposit AC and 1,4-Butanediamine at $70^{\circ}C$ and investigated surface roughness as a function of increasing thickness of organic thin film. We confirmed precursor's functional group by IR spectrum. We calculated WVTR of organic-inorganic hybrid super-lattice epitaxial layer using Ca test. WVTR indicates super-lattice film can be possibly use as encapsulation in flexible devices.

  • PDF

Effects of Chalcogenide Glasses Thin Film Encapsulation Layer on Lifetime of Organic Light Emitting Diodes

  • Fanghui, Zhang;Jianfei, Xi
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2009.10a
    • /
    • pp.839-842
    • /
    • 2009
  • In this paper, chalcogenide glasses material(Se, Te, Sb) is firstly used as encapsulation layer of OLEDs under high vacuum of $10^{-4}$Pa. In the experiments, properties of OLEDs encapsulated by Se, Te, Sb thin film is compared with that of device encapsulated by traditional method. It is found that Se, Te, Sb film can extend lifetime of devices to 1.4, 2, 1.3 times respectively. Chalcogenide glasses film as encapsulation layer has little effect on some characteristics of device. The research indicated that OLEDs can be well protected upon applying Se, Te, Sb film as encapsulation layer. It is clear that it can prolong the lifetime obviously.

  • PDF

Effect of Liposomal Encapsulation of Astaxanthin from Haematococcus pluvialis on Stabilities for Cosmeceuticals (Haematococcus pluvialis 유래 아스타잔틴의 리포좀 캡슐화가 코스메슈티컬 소재로서의 안정성에 미치는 영향)

  • Lee, Chung-Hyun;Kim, Dong-Myung;Byun, Sang-Yo
    • KSBB Journal
    • /
    • v.26 no.5
    • /
    • pp.381-385
    • /
    • 2011
  • Studies were made to improve the stability of astaxanthin which has application limitations caused by light and thermal stability problems in spite of its strong anti-oxidant property. Astaxanthin was extracted from Haematococcus pluvialis with supercritical carbon dioxide. Liposomal encapsulation of astaxanthin to improve the stability was made with high pressure homogenizer. The narrow size distribution was observed with astaxanthin liposomes. Tests on light and thermal stabilities resulted that the liposormal encapsulation improved the stability of astaxanthin for cosmeceutical purposes.

Reliability Evaluation of Atomic layer Deposited Polymer / Al2O3 Multilayer Film for Encapsulation and Barrier of OLEDs in High Humidity and Temperature Environments (OLED Barrier와 Encapsulation을 위한 원자층 증착 Polymer / Al2O3 다층 필름의 온습도 신뢰도 평가 분석)

  • Lee, Sayah;Song, Yoon Seog;Kim, Hyun;Ryu, Sang Ouk
    • Journal of the Semiconductor & Display Technology
    • /
    • v.16 no.4
    • /
    • pp.1-4
    • /
    • 2017
  • Encapsulation of organic based devices is essential issue due to easy deterioration of organic material by water vapor. Atomic layer deposition (ALD) is a promising solution because of its low temperature deposition and quality of the deposited film. Moisture permeation has a mechanism to pass through defects, Thin Film Encapsulation using inorganic / organic / inorganic hybrid film has been used as promising technology. $Al_2O_3$ / Polymer / $Al_2O_3$ multilayer film has shown excellent environmental protection characteristics despite of thin thicknesses of the films.

  • PDF

Reduction of Wire Sweep during Chip Encapsulation by Runner Balancing and Ram Control (반도체 칩 캡슐화 공정에 있어서 와이어 스윕(wire sweep) 최소화에 관한 연구)

  • Han, S.;Huh, Y.J.
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.13 no.12
    • /
    • pp.13-21
    • /
    • 1996
  • In this paper, methods to reduce wire sweep during the chip-encapsulation process have been studide. Two methods have been tried for this purpose, namely runner balancing and ram velocity control. Runner balancing has been achieved automatically by using a computer program. Ram-velocity control has been achieved using empirical rules and results from a flow simulation of the encapsulation process. A mold which has 12 cavities for chip has been used as a case study. The simulation results show that the wire sweep obtained from the optimal process condition is about 1/5 of that from initial, unoptimized condition.

  • PDF