• Journal of fish pathology
• /
• v.17 no.1
• /
• pp.11-20
• /
• 2004

The present study compared purification methods of hen egg yolk immunoglobulin (IgY) from the hen immunized with Edwardsiella tarda. The purification of anti-E. tarda IgY was performed by four different methods, polyethylene glycol (PEG), chloroform polyethylene glycol (Chloroform-PEG), ammonium sulfate and purification kit. Purified IgY had heavy chain of 64 kDa and light chain of 27 kDa size. IgY purified from the hen immunized with E. tarda showed higher ELISA values and agglutination titers than those with IgY purified from the non-immunized hen as a negative control. In addition, purified IgY recognized similar E. tarda proteins to those with anti-E. tarda rabbit serum by western blotting. Purified IgY had an agglutination titer of 1:512 by PEG method and ammonium sulfate method, and 1:128 by chloroform-PEG method and purification kit. Moreover, PEG method was the most rapid method among the four different IgY purification methods. These results indicate that PEG method is effective purification method maintaining biological activity of the IgY.

• Applied Chemistry for Engineering
• /
• v.7 no.1
• /
• pp.59-66
• /
• 1996

Novel chitosan beads containing a series of bisamino-terminated polyethylene glycol (Bisamino-PEG, $Jeffamine^{(R)}ED$ series) have been prepared via capillary extrusion method using an alkaline solution. The results of swelling kinetics of chitosan beads showed that as the chain length of PEG in chitosan beads increased, the swelling process of the beads proceeded slowly. In order to study the releasing kinetics quantitatively, fluorescamine was coupled to the pendant amino groups and the releasing processes were followed by UV spectra. The results revealed that the releasing process was retarded in the order of $Jeffamine^{(R)}ED$-600 < $Jeffamine^{(R)}ED$-900 < $Jeffamine^{(R)}ED$-2001 as the chain length of PEG was increased. The slow release of PEG from the beads is considered to be governed by the chain length of PEG and interpolymeric hydrogen bonding between PEG and the chitosan molecule.

• Journal of Radiopharmaceuticals and Molecular Probes
• /
• v.5 no.2
• /
• pp.89-100
• /
• 2019

In our previous studies, we developed a ¹⁸F-labeled TSPO-binding ligand, named [¹⁸F]CB251, which has been proved to be a promising TSPO-binding PET radiotracer for the detection and monitoring of TSPO expression in pathological diseases. (Ki = 0.27 nM for TSPO, 1.96% ID/g of tumor uptake at 1h post-injection) Based on these results, we utilized 6,8-dichloro-2-phenylimidazo[1,2-a]pyridineacetamide analogs, CB185 (1) as a targeting moiety for the selective delivery of probes and anticancer molecules to TSPO-overexpressed tissues. In this study, we designed CB185 derivatives contains different PEG chains (n = 1, 3 and 5) and fluorescence dye (Cy5) to identify the necessary space between a TSPO-binding ligand and an anticancer agent. Three CB185 derivatives (11a-c) which contains Cy5 and PEG chain, were synthesized and the effect of PEG additive on their TSPO-binding affinities were evaluated using in vitro assays. The binding affinity for compounds 11a-c was lower than that of PK11195 (Ki = 3.2 nM), but still characterized by nanomolar binding affinity for TSPO (Ki = 46.5 nM for 11a, 51.0 nM for 11b, and 388.5 nM for 11c). These results showed that the conjugates are characterized by a moderate binding affinity toward TSPO except for compound 11c, which PEG chain consist of five PEG monomers. Our finding might add useful information to decide the appropriate PET chain length for developing new TSPO-targeting drug carriers.

• Macromolecular Research
• /
• v.14 no.1
• /
• pp.73-80
• /
• 2006

Sulfonated poly(ethylene glycol) (PEG-$SO_{3}$) grafted polyrotaxanes (PRx-PEG-$SO_{3}$) were prepared in order to utilize the unique properties of PEG-$SO_{3}$ and the supramolecular structure of PRx, in which PEG-$SO_{3}$ grafted $\alpha$-cyclodextrins ($\alpha$-CDs) were threaded onto PEG segments in a PEG-b-poly(propylene glycol) (PPG)-b-PEG triblock copolymer (Pluronic) chain capped with bulky end groups. Some of the PRx-PEG-$SO_{3}$ demonstrated a higher anticoagulant activity in case of PRx-PEG-$SO_{3}$ (P 105), and compared with the control they showed a lower fibrinogen adsorption in PRx-PEG-$SO_{3}$ (F68) and a higher binding affinity with fibroblast growth factor. The obtained results suggested that polyrotaxane incorporated with PEG-$SO_{3}$ may be applicable to the surface modification of clinically used polymers, especially for blood/cell compatible medical devices.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.25 no.1
• /
• pp.107-119
• /
• 1999

3 Kinds of PEG-hEGF conjugate, PEG5-hEGF, PEG5-hEGF, PEG10-hEGF, were synthesized. Major fractions containing 2 chains of PEG were separated by preparative GPC. Molecular weight was estimated by GPC-MALLS, TOF-Mass and SDS-PAGE, and the data were well corresponding to calculated one. The cell proliferation effect of the conjugates was evaluated, Indicating that the conjugate bound to longer chain PEG exhibits lower activity. Selective modification of hEGF and activity preservation of PEG-hEGF conjugate are undergoing.

• Macromolecular Research
• /
• v.12 no.4
• /
• pp.342-351
• /
• 2004

Poly(ethylene glycol) (PEG1K) and sulfonated PEG (PEG1K-SO$_3$) methacrylate (MA) copolymers have been prepared and characterized. The structures of the synthesized copolymers were confirmed by $^1$H and $^{13}$ C NMR spectroscopy and elemental analysis. The bulk characteristics of the copolymers were evaluated by viscosity and thermal analysis. The surface properties of the copolymers were investigated using dynamic contact angle measurements and electron spectroscopy for chemical analysis. The hydrophilicity of the surfaces modified with PEG1KMA or PEG1K-SO$_3$MA increased, possibly as a result of the orientation of the hydrophilic PEG1KMA/PEG1K-SO$_3$MA chains into the water phase. Platelets adhered less to the surfaces of the copolymers than they did to a polyurethane control. In addition, adhesion of platelets to the copolymer surfaces decreased upon increasing the chain density of PEG1KMA and sulfonated PEG1KMA in the copolymers. Both bacterial adhesion and protein adsorption were significantly reduced on the copolymer surfaces and their levels differ depending on the kind of surface or media.

• Macromolecular Research
• /
• v.16 no.7
• /
• pp.609-613
• /
• 2008

Poly($\varepsilon$-caprolactone)-poly(ethylene glycol)-poly($\varepsilon$-caprolactone) (PCL-PEG-PCL) multiblock copolymers at various hydrophobic-hydrophilic ratios were successfully synthesized by the chain extension of triblock copolymers through isocyanate (hexamethylene diisocyanate). Biodegradable films were prepared from the resulting multiblock copolymers using the casting method. The mechanical properties of the films were improved by chain extension of the triblock copolymers, whereas the films prepared by the triblock copolymers were weak and brittle. Atomic force microscopy (AFM) of the multiblock copolymer film showed that the hydrophilic PEG had segregated on the film surface. This is consistent with the observed contact angle of the films.

• Clean Technology
• /
• v.17 no.3
• /
• pp.244-249
• /
• 2011

We synthesized low molecular-weight polymers bearing hydrophobic and hydrophilic parts in a chain through $CO_2$/propylene oxide copolymerization. When hydrophilic poly (ethylene glycol) bearing -OH group (s) at the end group (s) was added as a chain transfer agent in the $CO_2$/propylene oxide copolymerization catalyzed by a highly active catalyst, block polymers were formed. If poly (ethylene glycol) (PEG) bearing -OH group only at an end was fed, PEG-block-PPC diblock copolymer was obtained. When PEG bearing -OH group at both ends was fed, PPC-block-PEG-block-PPC triblock copolymer was obtained. We confirmed formation of block copolymers by $^1H$-NMR spectroscopy and GPC studies.

• Journal of the Korean Chemical Society
• /
• v.36 no.6
• /
• pp.947-954
• /
• 1992

Polyethylene glycol (PEG) grafted poly (γ-benzyl L-glutamate) (PBLG) was synthesized by the substitution reaction of PBLG and PEG having primary amino groups at both ends. PEG-g-PBLG films containing hydroxyl group were also prepared by the substitution reaction of PEG-g-PBLG film and ethanolamine (EA). Adhesion of platelets and activation of plasma proteins on the copolypeptide films were studied. The results showed that platelets are less adhered and activated on the PEG-g-PBLG than on other polypeptides and plasma recalcification time (PRT) on the PEG-g-PBLG was longer than that on other polypeptides. These results were consistent with those of blood clotting time and thrombus formation on the polypeptides. As a results, PEG-g-PBLG surfaces showed better blood compatibility than PBLG or PEG-g-PBLG-EA surfaces.

• Applied Biological Chemistry
• /
• v.36 no.6
• /
• pp.557-561
• /
• 1993

The neomycin phosphotransferase II gene (nptII) was introduced into geranium (Pelargonium zonale hybrids) protoplast by using PEG or electroporation method. The presence of the introduced DNA in the protoplast and the expressions of the gene in the transformed cells were examined. The presence of the nptII DNA in the protoplasts were detected by polymerase chain reaction. The expressions of nptII gene in the transformed cells were confirmed by the nptII assay.