• Title/Summary/Keyword: Reconstitution

Search Result 139, Processing Time 0.032 seconds

Preparation and Reconstitution of Core-shell Type Nanoparticles of Poly(ε -caprolactone)/Poly(ethyleneglycol)/Poly(ε -caprolactone) Triblock Copolymers

  • Jeong, Young-Il;Ryu, Jae-Gon;Kim, Young-Hoon;Kim, Sung-Ho
    • Bulletin of the Korean Chemical Society
    • /
    • v.23 no.6
    • /
    • pp.872-879
    • /
    • 2002
  • One of the improtant characteristics of core-shell type nanoparticles is the long-term storage and reuse as an aqueous injection solution when required. For this reason, reconstruction of lyophilized core-shell type nanoparticles is considered to be essential . BAB type triblock copolymers differ from AB type diblock copolymers, which contain the A block as a hydrophilic part and the B block as a hydrophobic part. by not being easily redistributed into phosphate-buffered saline (PBS, pH 7.4, 0.1 M). Therefore, lyophilized core-shell type nanoparticles of CEC triblock copolymer were reconstituted using a somication process with a bar-type sonicator in combination with a freezing-thawing process. Soncation for 30s only resuspended CEC nanoparticles in PBS; their particle size distribution showed a monomodal pattern with narrow size distribution. The bimodal size distribution pattern and the aggregates were reduced by further sonication for 120 s but these nanoparticles showed a wide size distribution. The initial burst of drug release was increased by reconstitution process. The reconstitution of CEC core-shell type nanoparticles by freezing-thawing resulted in trimodal distribution pattern and formed aggregates, although freezing-thawing process was easier than sonication . Drug release form CEC nanoparticles prepared by freezing-thawing was slower than from the original dialysis solution. Although core-shell typenanoparticles of CEC triblock copolymers were not easily performed. Cytotoxicity testing of core-shell type nanoparticles of CEC-2 triblock copolymers containing clonazepam (CNZ) was performed using L929 cells. Cytotoxicity of CNZ was decreased by incorporation into nanoparticles.

Characterization and Evaluation of Freeze-dried Liposomes Loaded with Ascorbyl Palmitate Enabling Anti-aging Therapy of the Skin

  • Lee, Sang-Kil;Lee, Jae-Hwi;Choi, Young-Wook
    • Bulletin of the Korean Chemical Society
    • /
    • v.28 no.1
    • /
    • pp.99-102
    • /
    • 2007
  • To prepare freeze-dried ascorbyl palmitate (AsP)-containing liposome which can protect the drug from moisture attack and be used instantly by mixing with water for anti-aging and skin whitening therapy, AsP was encapsulated into liposomes and freeze-dried with trehalose. The freeze-dried liposome formulations were characterized by measuring water contents, particle size, time required for complete reconstitution. With the freeze-dried liposomes, we performed the stability test under accelerated conditions, skin permeation and localization test. The measurement of the time to perfect reconstitution showed that the freeze-dried liposomes can be changed to their initial state rapidly and short term stability test of AsP in reconstituted liposomes under accelerated conditions confirmed that the stability of AsP was considerably enhanced as compared to freshly prepared liposomes. The skin permeation and localization properties of AsP in reconstituted liposomes were not significantly different, indicating that the liposomal structures were maintained before and after freezedrying. In conclusion, the freeze-drying method provided a possible way to overcome the instability issue of AsP induced by the moisture and reproduced similar skin permeation and localization properties as shown by freshly prepared liposomes.

Recombinant Human L-ferritin from Saccharomyces cerevisiae: Molecular Characterization and Synthesis of Iron Oxide Nanoparticles (효모에서 생산한 재조합 human L-ferritin의 생화학적 특성 및 나노입자의 철산화물 합성)

  • Kim, Kyung-Suk
    • KSBB Journal
    • /
    • v.26 no.2
    • /
    • pp.119-125
    • /
    • 2011
  • In the synthesis of nanoparticles, much attention has been paid to regulating the particle size. There has been a possible evident that using the central cavity (core) of the protein ferritin has a greatly significant influence on it because the core can generate the nanometer-sized mineral particles of variable metal ions. In this report, recombinant human L-ferritins produced from Saccharomyces cerevisiae were purified and their molecular properties were characterized. The cDNA for human ferritin L chain was also expressed in another host such as Escherichia coli, and the properties of recombinant L-ferritins were compared. From isoelectric focusing experiment, the L-ferritin from the recombinant yeast showed no indication of N-glycosylation. Some post-translational modifications other than N-glycosylation were speculated in the L-ferritins from yeast. A difference was made in the L-ferritins in their iron uptake rates and the initial rate of the L-ferritin from yeast was slightly increased. The reconstitution yield and size distribution of the core minerals were analyzed in the L-ferritins by transmission electron microscopy. The L-ferritin from yeast with higher reconstitution yield (54.5%) showed slightly larger sizes (mean 6.92 nm) with narrower size distribution than the L-ferritin from E. coli. It is, in conclusion, speculated that L-ferritin from yeast is relatively superior to the other, in view of the size of nanoparticle and its relative homogeneity.

Immune Reconstitution Inflammatory Syndrome-Like Reaction During the Treatment of Pneumocystis jirovecii Pneumonia in an Infant With Severe Combined Immunodeficiency

  • Ching-Yu Lin;Sung-Min Lim;Soo-Yeon Kim;Seung-Min Hahn;Jong-Gyun Ahn;Ji-Man Kang
    • Pediatric Infection and Vaccine
    • /
    • v.31 no.1
    • /
    • pp.130-135
    • /
    • 2024
  • The effectiveness of corticosteroids in preventing immune reconstitution inflammatory syndrome in non-human immunodeficiency viruses Pneumocystis carinii pneumonia (PCP) patients, such as severe combined immunodeficiency (SCID) patients, is controversial. We experienced a paradoxical reaction during severe PCP treatment in a SCID infant, which responded well to adjuvant corticosteroids.

Porosome: the Universal Molecular Machinery for Cell Secretion

  • Jena, Bhanu P.
    • Molecules and Cells
    • /
    • v.26 no.6
    • /
    • pp.517-529
    • /
    • 2008
  • Porosomes are supramolecular, lipoprotein structures at the cell plasma membrane, where membrane-bound secretory vesicles transiently dock and fuse to release inravesicular contents to the outside during cell secretion. The mouth of the porosome opening to the outside, range in size from 150 nm in diameter in acinar cells of the exocrine pancreas, to 12 nm in neurons, which dilates during cell secretion, returning to its resting size following completion of the process. In the past decade, the composition of the porosome, its structure and dynamics at nm resolution and in real time, and its functional reconstitution into artificial lipid membrane, have all been elucidated. In this mini review, the discovery of the porosome, its structure, function, isolation, chemistry, and reconstitution into lipid membrane, the molecular mechanism of secretory vesicle swelling and fusion at the base of porosomes, and how this new information provides a paradigm shift in our understanding of cell secretion, is discussed.

The Methodology in Historical Demography at the Cambridge Group (역사 인구학 방법론의 현황)

  • 이흥탁
    • Korea journal of population studies
    • /
    • v.12 no.2
    • /
    • pp.56-68
    • /
    • 1989
  • The methodology in historical demography comprises the three core areas the family reconstitution method at the Institut National d' Ftudes Demographiques(I.N.E.D), the back projection at the Cambridge Group for the History of PopuJation and Social Struc-ture(HPSS). and the household-pattern analysis at the Cambridge Group and at the California Institute of Technology. The paper presents an outline of the family reconstitu-tion method and discusses the problems, both theoretical and methodological, arising from the problematic back projection vis-a-vis the usual inverse projection developed by Ronald D. Lee at Berkeley. Recent developments in the tield of the generalized inverse projection method designed 10 supplement the defects in the back projection and the inverse projection are presented. and for ease of explanation of the parish register data for the family reconstitution form (FRE). pre-modern Korean household register data are presented along with the parish register data of England and Wales that constitute the backbone of historical demography in pre-modern Europe. Possibilities of exploring the household pattern analysis method based on the Laslett-Hammel classification scheme for the mid-eighteenth-century Korean household register data are suggested.

  • PDF

Dual-Chamber Technology: Safe and Convenient Drug Delivery for Lyophilized Biologics

  • Moore, John
    • Journal of mucopolysaccharidosis and rare diseases
    • /
    • v.1 no.1
    • /
    • pp.28-30
    • /
    • 2015
  • Biologics present a challenge to both the manufacturer and end user. They must usually be formulated as parenterals. However, they are often unstable in liquid form, due to their complex structure and composition. In that case, they must be manufactured using highly specialized processes, such as lyophilization (freeze-drying). Lyophilization nearly eliminates stability issues. Reducing a compound's sensitivity to temperature prolongs its shelf life. However, reconstitution can be cumbersome, involving multiple steps that increase the potential for error. Dual-chamber technology provides an effective alternative, combining a lyophilized drug and diluent in a closed system and enabling reconstitution in a few simple steps.

Chromosome images Reconstitution and Feature Parameter Extraction (염색체 영상의 재구성과 특징 파라메타 추출)

  • Chang, Y.H.;Lee, K.S.;Lee, Y.J.;Jun, K.R.;Eom, S.H.
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1996 no.05
    • /
    • pp.103-107
    • /
    • 1996
  • In this paper, We propose an algorithm for reconstitution of chromosome images to extract its morphological feature parameters. It is reconstituted from 460 chromosome images using the 32 direction line algorithm. We extract three morphological feature parameters such as centromeric index, relative length ratio, and relative area ratio. The experiment results show that our method is batter than that of other researchers comparing with the error of feature parameters.

  • PDF

Paradoxical Cryptococcal Meningitis Immune Reconstitution Inflammatory Syndrome in a Patient with Human Immunodeficiency Virus Infection: Matching Clinical Findings with MRI Findings (인간면역결핍바이러스 감염환자에서 역설적 크립토코쿠스 수막염 면역재구성 염증증후군: 임상 소견들과 자기공명영상 소견들의 대조)

  • Moon, Sungjun;Hahm, Myong Hun
    • Journal of the Korean Society of Radiology
    • /
    • v.79 no.6
    • /
    • pp.359-364
    • /
    • 2018
  • There are two forms of cryptococcal meningitis immune reconstitution inflammatory syndrome (CM-IRIS): paradoxical CM-IRIS and unmasking CM-IRIS. It is important to distinguish paradoxical CM-IRIS and CM relapse because mortality of CM-IRIS is higher than that of CM without IRIS, and paradoxical CM-IRIS and CM relapse requires different treatment. We report a case of paradoxical CM-IRIS that well matches the clinical findings with MR findings during three years follow-up of a HIV infected patient and new MRI finding is also introduced to help distinguish them.

Improvement of Somatic Cell Nuclear Transfer Technology for the Production of Disease Model Mouse: I. Optimization of Oocyte Enucleation and Reconstruction (질환모델마우스 생산을 위한 체세포핵이식방법 개선; I. 탈핵 및 재조합난자 생산기법 최적화)

  • Jun, S. H.;Shim, H. S.;Chung, H. M.;Lee, B. C.;Lee, E. S.;Ko, J. J.;Shin, T.;Park, C.;Hwang, W. S.;Cha, K. Y.;Lim, J. M.
    • Journal of Embryo Transfer
    • /
    • v.15 no.3
    • /
    • pp.247-253
    • /
    • 2000
  • This study was undertaken to optimize enucleation and reconstitution methods for the production of cloned mice by somatic cell nuclear transfer Outbred ICR mouse oocytes at the metapahse- II stage were retrieved from female mice superovulated by PMSG and hCG. In Experiment 1, oocytes were enucleated in medium supplemented with cytochalasin B (CCB) of 3 levels (0, 7.5 or 15 $\mu\textrm{g}$/mL), and higher rate of encleation was obtained at 7.5 and 15 $\mu\textrm{g}$/mL than at $\mu\textrm{g}$/mL. In Experiment 2, oocytes enucleated in 7.5 $\mu\textrm{g}$/mL CCB-containing medium were reconstituted with different types of somatic cell by following methods; 1) cumulus cells by direct cell injection, 2) cumulus cells by electric fusion (1.25 kV/cm, 2 pulses for each 70 $mutextrm{s}$) or 3) STO cells by the electrofusion. Electrofusion of STO cells with enucleated oocytes yielded the greatest (P<0.05) rate of reconstitution without lysis (76%) than any other combinations. Although significant decrease in the rate of somatic cell introduction was found, the electrofusion of cumulus cells yielded better rate of reconstitution than direct injection (0 vs. 18%). In Experiment 3, the duration of electric stimulation for the fusion was changed to either 50 $mutextrm{s}$ or 90 $mutextrm{s}$, but no significant improvement of reconstitution efficacy was obtained. In conclusion, this study showed that ICR mouse oocytes could be used for the production of reconstituted oocytes and a fusion method of 1.25 KV/cm with 2 pulses using 570 cell was the optimal.

  • PDF