[show abstract][hide abstract] ABSTRACT: Berberis koreana has been known as enthopharmacologically valuable plant in Korea, China and Japan. This plant has been reported to display numerous pharmacological activities such as anti-oxidative, neuroprotective, and anti-cancer effects. Although the pharmacological potentials have been demonstrated, anti-inflammatory effect of this plant has not been fully elucidated yet. To evaluate its anti-inflammatory activity, macrophages activated by lipopolysaccharide (LPS) were employed and the production of inflammatory mediators was explored in terms of understanding its molecular inhibitory mechanism. Hot water extract from B. koreana (Bk-HWE) was able to suppress the production of NO and TNF-α production and up-regulation of surface levels of costimulatory molecules such as CD80 and CD86. The anti-inflammatory effect of Bk-HWE seemed to be due to the inhibition of MAPK activation and c-fos translocation, according to immunoblotting analysis. In addition, Bk-HWE strongly suppressed the cell-cell adhesion events induced by functional activation of adhesion molecules such as CD29 and CD43. Therefore, our results suggest that Bk-HWE can be applied as an anti-inflammatory herbal medicine. To prove this assumption, further in vivo efficacy test will be continued in the following project.
Journal of Medicinal Plants Research. 04/2010; 4:745-752.
[show abstract][hide abstract] ABSTRACT: The monoolein (MO) cubic phases containing water soluble extract (WSE) from Berberis koreana (Korean barberry) were prepared by hydrating the molten MO with aqueous solutions of WSE (0.5, 1.0, and 1.5%). The phase
transition temperature of cubic phase containing WSE (∼70°C) was almost the same as that of WSE-free MO cubic phase that indicates
that WSE was immobilized in the water channels of the cubic phase and did not affect its structure. The release of WSE from
the cubic phase fits the first order process. The cubosomes were obtained by micronizing the cubic phase in a sonicator using
Pluronic F127 as a dispersant. The cubosomes were stable in size at the ethanol concentration ≲16%. When compared with WSE
solution in phosphate-buffered saline (10 mM, pH 7.4), in vitro skin permeation of WSE in the cubosomes was enhanced by about
[show abstract][hide abstract] ABSTRACT: Cordyceps sinensis, one of the well-known fungi used in traditional Chinese medicine, is recognized to play a role in the metabolic process of inflammation and immunity. The purpose of this study was to evaluate the effects of water extracts of C. sinensis on the immune function of mesenteric lymph node (MLN) lymphocytes in C57Bl/6N mice. C. sinensis-treated mice were administered the respective extract by oral gavage for 4 weeks. Immunoglobulin E concentrations in serum and MLN lymphocytes were significantly lower in C. sinensis-treated mice than in control mice. In contrast, the immunoglobulin A concentration from the C. sinensis group was higher than that in control mice. C. sinensis increased the proportion of CD4(+) and CD8(+) T cells in MLN lymphocytes. C. sinensis significantly decreased interleukin-4 and interleukin-10 cytokine concentrations. Therefore, water extracts of C. sinensis modulate immune parameters through regulation of immunoglobulin production resulting from decreased T-lymphocyte helper 2 cytokine secretion and reduce cytokine secretion in MLN lymphocytes.
Journal of medicinal food 01/2009; 11(4):784-8. · 1.39 Impact Factor
[show abstract][hide abstract] ABSTRACT: Berberis koreana extract (BE) has a strong neuroprotective effect after ischemic stroke in gerbils, which is associated with the inhibition of the N-methyl-d-aspartate receptor. The present study examined the antiinflammatory mechanism of BE after ischemic damage in vitro and in vivo. The BE used contained on average 7.39 +/- 0.78 mg/g of berberine. In PC12 cells with inflammation, prostaglandin E2 (PGE2) production was significantly reduced by BE. About 75% of pyramidal cells in the hippocampal CA1 region of gerbils exposed to 5 min of transient ischemia were protected from ischemic damage by BE. Cyclooxygenase-2 (COX-2) immunoreactivity and its protein level in the CA1 region of vehicle-treated animals exposed to an ischemic insult increased with time post-ischemia, whereas no such changes were observed in BE-treated animals exposed to ischemia. PGE2 production in BE-treated ischemic animals was significantly lower than that observed in vehicle-treated ischemic animals. Summarizing, the potent neuroprotective effect of BE was found to be due to the inhibitions of COX-2 expression and PGE2 production and its antiinflammatory activity.
Phytotherapy Research 08/2008; 22(11):1527-32. · 2.07 Impact Factor
[show abstract][hide abstract] ABSTRACT: Myb genes are a family of transcription factors and have been implicated in the control of the proliferation and differentiation of normal and transformed cells. c-Myb is the best characterized member of the myb family. In the present study, we investigated age-dependent changes of c-myb immunoreactivity, its protein and mRNA level in the hippocampus proper (CA1-3 regions) at various age stages in gerbils. In the postnatal month 1 (PM 1) group, c-myb immunoreactivity was detected in non-pyramidal neurons of the strata oriens and radiatum as well as in pyramidal neurons of the stratum pyramidale. At PM 3, c-myb immunoreactivity and its protein level were similar to those at PM 1. Thereafter, c-myb immunoreactivity and its protein level were increased with time. In the PM 24 group, c-myb immunoreactivity, its protein and mRNA levels were highest. These results suggest that the significant increase of c-myb immunoreactivity, protein and mRNA levels in the aged hippocampus may be associated with neuronal aging.
Neurochemical Research 06/2007; 32(6):1091-7. · 2.13 Impact Factor
[show abstract][hide abstract] ABSTRACT: The present study examined ischemia-related changes in tyrosine kinase A (trkA) immunoreactivity and its protein content in the dentate gyrus after 5 min of transient forebrain ischemia in gerbils. One day after ischemic insult, cresyl violet-positive polymorphic cells showed ischemic degeneration. The ischemia-induced changes in trkA immunoreactivity were found in the polymorphic layer (PL) and granule cell layer (GCL) of the dentate gyrus. In the sham-operated group, trkA immunoreactivity in the dentate gyrus was very weak. From 30 min after ischemia, trkA immunoreactivity was increased in the dentate gyrus and peaked in the dentate gyrus at 12 h after ischemia-reperfusion. Thereafter, trkA immunoreactivity was decreased time-dependently after ischemia-reperfusion. Four days after ischemic insult, trkA immunoreactivity was similar to that of the sham-operated group. In addition, it was found that ischemia-related changes in trkA protein content were similar to the immunohistochemical changes. These results suggest that the chronological changes of trkA in the dentate gyrus after transient forebrain ischemia may be associated with ischemic damage in polymorphic cells of the dentate gyrus.
International Journal of Neuroscience 09/2006; 116(8):975-89. · 1.22 Impact Factor
[show abstract][hide abstract] ABSTRACT: In the present study, we studied the neuroprotective effects of berberry extract (BE) against ischemic damage and the temporal and spatial alterations of N-methyl-D-aspartate receptor type 1 (NR1) and NR2A/2B immunoreactivities in the gerbil hippocampal CA1 region after transient ischemia to examine anti-ischemic effects and its role in transient forebrain ischemia. In the vehicle-treated group, the percentage of cresyl violet positive pyramidal cells in the CA1 region was about 11.4% compared to the sham-operated group 4 d after ischemic insult. BE showed neuroprotective effects against ischemic damage after ischemia-reperfusion. In the BE-treated groups, about 60-75% of CA1 pyramidal cells were stained with cresyl violet 4 d after ischemic insult. We observed the percentage of berberine (7.45+0.85 mg/g in BE) by HPLC, which is active ingredient of BE. NR1 immunoreactivity in the stratum pyramidale of the CA1 region in the vehicle-treated group was significantly increased at 30 min after transient forebrain ischemia, while at this time the NR1 immunoreactivity in the BE-treated groups was significantly low compared to the vehicle-treated group. The pattern of NR2A/B immunoreactivity in the stratum pyramidale of the BE-treated group and its protein levels were similar to that in the vehicle-treated group after ischemic insult. These results suggest that BE has potent neuroprotective effects against ischemic damage via the reduction of NR1 activity.
[show abstract][hide abstract] ABSTRACT: In the present study, we observed ischemia-related changes in Rip recognizing the promyelinating and myelinating oligodendrocytes in the hippocampus proper after 5 min of transient forebrain ischemia in gerbils. Rip immunoreactivity was significantly altered in the hippocampal CA1 region but not in the CA2/3 region after ischemic insult. In the sham-operated group, Rip immunoreactivity was shown in the cell bodies and processes of oligodendrocytes in all layers of the hippocampus proper. From 15 min to 2 days after ischemic insult, Rip immunoreactivity was similar to that of sham-operated group. Three days after ischemic insult, Rip-immunoreactive processes were tangled in the stratum oriens of the CA1 region, and Rip protein level decreased from this time after ischemia. Thereafter, Rip immunoreactivity was decreased time dependently in the CA1 region. Seven days after ischemic insult, Rip-immunoreactive processes were tangled and densely detected in the stratum oriens adjacent to the stratum pyramidale. In brief, these results indicate that the significant decrease of Rip immunoreactivity in processes in the stratum oriens of the hippocampal CA1 region occurs at late time after ischemia, and this decrease in Rip immunoreactivity may be associated with delayed neuronal death of CA1 pyramidal cells.
Brain Research 03/2006; 1073-1074:491-6. · 2.88 Impact Factor
[show abstract][hide abstract] ABSTRACT: The graft copolymer (APN) of alginate and poly(N-isopropylacrylamide) (PNIPAM) were synthesized and APN beads were prepared by dropping the aqueous solution of the copolymer into an aqueous solution of Ca(2+) solution. Alginate chains were employed to play a role in forming beads by electrostatic interactions with a multivalent ion, Ca(2+). Grafted PNIPAM segments were adopted to act as a valve for the pores of the beads, since they exhibit the properties of thermal contraction and expansion. The percent of release of blue dextran from APN beads was higher at 40 degrees C than at 25 degrees C. The difference in the release between two temperatures became more distinguishable when the content of PNIPAM in APN beads is higher. Below lower critical solution temperature (LCST), the expanded PNIPAM would close the pores of the beads, resulting in a lower release rate. Above LCST, the thermally contracted polymer would open the pores, resulting in a higher release rate. The percent of release from APN beads were investigated when the temperature of the release medium is altered. The release rate was relatively low at 25 degrees C. The temperature, however, changed up to 40 degrees C, a marked increase in the release rate was observed. These trends were found to be reproducible when the temperature was repeatedly altered between 25 and 40 degrees C. As a result, a stepwise response to the temperature alteration was obtained.
[show abstract][hide abstract] ABSTRACT: Although galanin (GAL) protects hippocampal neurons from ischemic damage, no study has examined ischemia-related changes in endogenous GAL in the hippocampal dentate gyrus. We investigated the chronological changes of GAL, well-known as the potassium channel opener, expression in the dentate gyrus at various times after 5 min of transient forebrain ischemia in gerbils. A few GAL-immunoreactive (IR) neurons were found in the polymorphic layer of the sham-operated group. Three hours after ischemia-reperfusion, the pattern of GAL immunoreactivity was similar to that of the sham-operated group and the number of GAL-IR neurons and immunoreactivity were highest 12 h after ischemic insult. At this time, GAL-IR neurons in the polymorphic layer showed strong GAL immunoreactivity. Thereafter, GAL-IR neurons and immunoreactivity significantly decreased in the dentate hilar region. Four days after ischemic insult, GAL-IR neurons were not detectable. In addition, the results of a Western blot study showed a pattern of GAL expression similar to the immunohistochemical changes. GAL protein content also was highest 12 h after ischemia. In conclusion, the increased expression of endogenous GAL in the dentate gyrus after ischemia is related to response to the ischemic damage.
[show abstract][hide abstract] ABSTRACT: Grape seed extract (GSE) possess cardioprotective abilities by functioning as in vivo antioxidants and by virtue of their ability to directly scavenge ROS including hydroxyl and peroxyl radicals. In the present study, we investigated the neuroprotective effects of grape seed extract (GSE) in the gerbil hippocampus after 5 min transient forebrain ischemia. Neuronal cell density in GSE-treated ischemic animals was significantly increased as compared with vehicle-treated ischemic animals 4 days after ischemic insult. In the GSE-treated groups, about 60% of pyramidal cells of the sham-operated group were stained with cresyl violet 4 days after ischemic insult. In this study, we found that GSE had neuroprotective effects on neuronal injury by inhibiting DNA damage in the CA1 region after ischemia. In vehicle-treated groups, 8-hydroxy-2'-deoxyguanosine (8-OHdG) immunoreactivity was significantly changed time-dependently, whereas the immunoreactivity in the GSE-treated group was similar to the sham-operated group. In addition, we confirmed that astrocytes and microglia did not show significant activation in the CA1 region 4 days after ischemia-reperfusion, because many CA1 pyramidal cells were not damaged. Therefore, these results suggest that GSE can protect ischemic neuronal damage by inhibiting DNA damage after transient forebrain ischemia.
Life Sciences 10/2004; 75(16):1989-2001. · 2.56 Impact Factor
[show abstract][hide abstract] ABSTRACT: Monoolein (MO) cubic phases were prepared by hydrating MO using distilled water or 12wt.% H(2)O(2) solution so that the content of aqueous phase in the cubic phase is 30wt.%. The thermal transition of the isotropic cubic phase to reversed hexagonal phase was observed on a polarizing photomicroscope and the transition temperature was found to be around 65 degrees C on a differential scanning calorimeter (DSC). Small-angle X-ray scattering (SAXS) patterns indicated the cubic phases had diamond surfaces. The cubic phase released H(2)O(2) into an aqueous phase in a saturation manner so that approx. 50% of total loaded H(2)O(2) release in the first 10 h and thereafter relatively slow was observed over 40 h. The cubic phase was stable at 45 degrees C for 56 days before it broke down into an oily phase and an aqueous phase in 70 days. According to (1)H NMR spectrum, glycerol moiety and -CH(2)=CH(2)- of the oily phase were detected less in number than those of intact MO. Therefore, the hydrolysis and the oxidation of MO would be responsible for the breakdown of the cubic phase. The tensile adhesive forces of the cubic phases were higher than a skin-adhesive patch prepared using polyacrylate. The cubic phase containing H(2)O(2) could be used as a topical disinfected gel for a wounded skin.
[show abstract][hide abstract] ABSTRACT: An amino acid surfactant, monosodium N-stearoyl-L-glutamate (MSSG), was assumed to associate with higher alcohols (HAs) in 1:1 molar ratio in an aqueous phase, and the packing parameters of the 1/1 MSSG/HA associates, Pa, were calculated by molecular dynamics (MD). Pa is defined as At1(l(t1)+l(t2))/a(h)l(t1), where At1 stands for the cross-sectional area of the MSSG tail, l(t1) for the length of the MSSG tail, l(t2) for the length of the HA tail, and a(h) for the area of the MSSG head group. The Pa value increased from 0.83 to 1.02 as the HA tail length (l(t2)) increased from C14 to C22. Associates of HAs having longer tails with MSSG are likely to fit better into bilayers because Pa is closer to 1 when l(t2) is longer. In the graphical results of the MD simulation for the association, however, a steric hindrance was found between the head groups of MSSG/HA when l(t2) was > or = C19. Based on this result, HA was classified into short-chain HA (SCHA, l(t2) < C19) and long-chain HA (LCHA, l(t2) > or = C19), and several possible packing units, composed of compositional combinations of MSSG, SCHA, and LCHA, were proposed. The packing unit is a building block which could constitute bilayers, and it is composed of variable compositional combinations of MSSG/HA. Assuming that SCHA associates with MSSG, the packing parameter, Punit, was calculated in a water box by MD for each packing unit. Punit is the packing parameter of a packing unit and it is defined as Vu/l(u)a(u), where Vu is the tail volume of the packing unit, l(u) is the chain length, and a(u) is the head area. For the calculation, stearyl alcohol (C18-OH, SA) was chosen as a SCHA and behenyl alcohol (C22-OH, BA) as a LCHA. When the compositional ratio MSSG:SCHA:LCHA was 1:1:1, Punit was around 1. The packing unit having Punit of around 1 formed a colloidally stable suspension for 30 days and its aggregate was a lamellar structure. However, the other packing units, for which Punit deviates significantly from 1, precipitated out in their suspensions and showed no evidence of a lamellar structure. According to the graphical MD simulations for the compositional MSSG/SCHA/LCHA associations in bilayers, vertical steric hindrance was found between LCHAs when Punit deviated significantly from 1. The steric hindrance would prevent the packing units from forming a stable bilayer and induce precipitation in the suspensions. Therefore, a proper combinational ratio of MSSG:LCHA:SCHA would play a major role in forming a lamellar structure.
Journal of Colloid and Interface Science 05/2004; 273(2):596-603. · 3.17 Impact Factor
[show abstract][hide abstract] ABSTRACT: Parvalbumin (PV) is found in the olfactory system, including the main olfactory bulb, and is thought to be one of the neuroactive substances in olfaction. Changes in PV immunoreactivity in the olfactory system during aging have not been examined. We investigated such changes in the main olfactory bulb (MOB) of the rat at postnatal month 1 (PM 1), PM 3, PM 6, PM 12 and PM 24. PV-IR neurons were almost completely restricted to the external plexiform layer. At PM 1 there were only a few PV-IR neurons; at PM 3, the number of PV-IR neurons was at its greatest but they were not well developed morphologically. At PM 6, the number of PV-IR neurons was similar to that at PM 3 and they had satellite somata with well-developed processes with many varicosities. By PM 12 the number of neurons and processes had declined, and by PM 24, they had fallen even further and the remaining processes had lost most of their varicosities. We conclude that age-related degeneration of PV-IR neurons in the MOB may reduce calcium buffering and affect olfactory function in senile species.
Molecules and Cells 01/2004; 16(3):302-6. · 2.21 Impact Factor
[show abstract][hide abstract] ABSTRACT: In the current study, we show the anti-oxidative and hypocholesterol effects of aloe vera in the liver. Male specific pathogen-free (SPF) Fischer 344 rats were randomly assigned to one of four groups: Group A (control) was fed test chow without aloe supplementation; Group B was fed a diet containing a 1% (per weight basis) freeze-dried aloe filet; Group C was fed a diet containing a 1% (per weight basis) charcoal-processed, freeze-dried aloe filet; and Group D was fed a diet containing a charcoal-processed freeze-dried, whole leaf aloe (0.02% per weight basis) in the drinking water. Our results show that a life-long intake of aloe had superior anti-oxidative action against lipid peroxidation in vivo, as indicated by reduced levels of hepatic phosphatidylcholine hydroperoxide. Additional anti-oxidative action was evidenced by enhanced superoxide dismutase (SOD) and catalase activity in groups B and C. Furthermore, our study revealed that hepatic cholesterol significantly increased in the control group during aging in contrast to the aloe-supplemented groups, which showed approximately 30% lower cholesterol levels, thereby an effective hypocholesteremic efficacy. In this report, we suggest that life-long dietary aloe supplementation suppresses free radical-induced oxidative damage and age-related increases in hepatic cholesterol.
Journal of Nutritional Science and Vitaminology 09/2003; 49(4):292-6. · 0.99 Impact Factor
[show abstract][hide abstract] ABSTRACT: The effect on the IgE content induced by concanavalin A in spleen lymphocytes of the presence wogonin, ganhuangenin, wogonoside and 3,5,7,2',6'-pentahydroxyl flavanone was investigated. These flavonoid components markedly inhibited the histamine released from cells stimulated with the calcium ionophore, A23187. However, the magnitude of the inhibitory effect on the degree of lipid peroxidation by ConA of these components was in order of PHF>GHG>WG>WGS. Interestingly, WG, GHG and WGS, with a methoxyl group in the A and B rings, strongly inhibited histamine and IgE production, whereas PHF without a methoxyl group was much stronger than that for lipid peroxidation. We suggest that WG, GHG and WGS might block the pathway for the release of histamine, and that the IgE level in spleen lymphocytes is responsible for the lipid peroxidation.
Bioscience Biotechnology and Biochemistry 05/2003; 67(5):1126-9. · 1.27 Impact Factor
[show abstract][hide abstract] ABSTRACT: Angiogenesis is an essential step for many physiological and pathological processes. Tumor necrosis factor (TNF) superfamily cytokines are increasingly recognized as key modulators of angiogenesis. In this study, we tested whether TNF-related activation-induced cytokine (TRANCE), a new member of the TNF superfamily, possesses angiogenic activity in vitro and in vivo. TRANCE stimulated DNA synthesis, chemotactic motility, and capillary-like tube formation in primary cultured human umbilical vein endothelial cells (HUVECs). Both Matrigel plug assay in mice and chick chorioallantoic membrane assay revealed that TRANCE potently induced neovascularization in vivo. TRANCE had no effect on vascular endothelial growth factor (VEGF) expression in HUVECs and TRANCE-induced angiogenic activity was not suppressed by VEGF-neutralizing antibody, implying that TRANCE-induced angiogenesis may be the result of its direct action on endothelial cells. TRANCE evoked a time- and dose-dependent activation of the mitogen-activated protein kinases ERK1/2 and focal adhesion kinase p125(FAK) in HUVECs, which are closely linked to angiogenesis. These signaling events were blocked by the Src inhibitor PP1 or the phospholipase C (PLC) inhibitor. Furthermore, these inhibitors and the Ca(2+) chelator BAPTA-AM suppressed TRANCE-induced HUVEC migration. These results indicate that the angiogenic activity of TRANCE is mediated through the Src-PLC-Ca(2+) signaling cascade upon receptor engagement in endothelial cells, suggesting the role of TRANCE in neovessel formation under physiological and pathological conditions.
Journal of Biological Chemistry 04/2002; 277(9):6799-805. · 4.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: Two types of purified samples, water-soluble (sample A; M. W, 1.2×106 dalton) and water-insoluble (sample C; M. W., 1.0×106 dalton) samples, were obtained through consecutive separation processes from the culture broth of Ganoderma lucidia mycelium. It was found that both samples from the culture broth were very effective in inhibiting the growth of several human cancer cell lines, having a 93-85% growth inhibition on Hep3B, AGS and A549 with the least cytotoxicity on the normal human lung cell line, WRL68 of less than 25% the highest supplementation concentration of 1.0 mg/l. In general, the sample C showed greater inhibition of cancer cell growth than the sample A. The same trend was also observed in antimutagenicity using the Chinese hamster ovary cell line (CHO test) or Salmonella typhimurium (Ames test). The CHO test showed that sample C had higher antimutagenicity on mutagens 4NQO or MMNG than sample A (approximately 40% vs approximately 25%). The percentage of antimutagenicity from the Ames test was lower than that from the CHO test, possibly due to the difference in the sensitivity of mutagens. The water-insoluble sample greatly enhanced the growth of the human T cell line (H9) up to 1×105 with sample supplementation at 1.0 mg/l concentration from 4.3×104 without sample supplementation as well as improved the secretion level of both IL-6 and TNF-α up to 100 pg/ml from approximately 40 pg/ml without sample supplementation. The kinetics of response to the immune cell growth was illustrated by the response time obtained when the sample concentration was increased. The water-insoluble sample can be used for effectively treating cancer in that it accelerated apoptosis of human carcinoma cells up to 70% compared to less than 50% for the control. The sample also increased the differentiation ratio of HL-60 cells up to 58% after four days of cultivation, compared to 18% in the case of no sample supplementation. These results can be used in implying that the insoluble part of G. lucidium mycelium culture broth must be related to controlling signal transduction, resulting in the regulation of cancer cell growth.
Journal of Bioscience and Bioengineering 02/2001; · 1.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: Free radical metabolism can be altered by several interventions, including dietary restriction (DR) and exercise. Most of the previous work has focused on the liver and skeletal muscle. The following experiments were performed to determine whether long-term DR and chronic exercise affect free radical metabolism and change the status of the antioxidant defenses of the heart. Rats were subjected to DR and/or endurance exercise for 18.5 months and were sacrificed along with their ad lib fed and sedentary controls. Both DR and exercise decreased the malondialdehyde content of cardiac mitochondria, indicating a decrease in lipid peroxidation damage. The antioxidant enzymes in the cytosol, superoxide dismutase, selenium dependent glutathione peroxidase, and glutathione S-transferase were all increased by DR. Catalase activity was unaffected by DR but was increased by exercise. The following results demonstrate that long-term DR and exercise modulate the extent of free radical damage in the heart and enhance the antioxidant defense system.
Free Radical Biology and Medicine 02/1996; · 5.27 Impact Factor
[show abstract][hide abstract] ABSTRACT: Coumarin residues were conjugated to poly(vinyl alcohol) (PVA) by reacting epoxypropoxy coumarin (EPC) with the polymer. According to the peak areas on the 1H NMR spectrum, EPC was calculated to be conjugated to every 283 repeating units (vinyl alcohols). A cyclic photo-dimerization and dedimerization of EPC of PVA-EPC conjugate were observed under a cyclic irradiation of 365 nm and 254 nm. The salting-out of the conjugate significantly took a place in the range of 0–2.0M NaCl, and the phenomenon was observed at a lower concentration than that of unmodified PVA was. Oil-in-water emulsion was prepared as a template for the preparation of hollow microcapsules using chloroform as an oil phase and PVA-EPC as an emulsifier. The emulsion was stable for 24 hr in terms of droplet size. The wall surrounding droplets was built-up by the salting-out of PVA-EPC, and it was cross-linked by the irradiation of 365 nm. After chloroform was evaporated and salt was removed by a dialysis, hollow microcapsules were successfully obtained.
Korean Journal of Chemical Engineering 29(8). · 1.06 Impact Factor