• Textile Coloration and Finishing
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• v.33 no.4
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• pp.338-347
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• 2021

In the case of occlusive dressings currently used in dressings for burn treatment, it is impossible to confirm the replacement time, so replacement is delayed, resulting in additional infection. To solve this problem, liposomes capable of bacterial sensing were prepared using 5(6)-Carboxyfluorescein, Phosphatidylcholine, 1,2-Dipalmitoyl-sn-glycero-3-phosphocholine, Cholesterol, and 10,12-Tricosadiynoic acid. In this study, evaluation of changes in drug encapsulation rate in liposomes according to changes in three types of phosphatidylcholine phospholipids during liposome production, high-performance phosphatidylcholine phospholipids selected through vesicle size analysis, low and high temperature stability evaluation, bacterial sensitization ability evaluation, animals cell responses were assessed.

• Applied Microscopy
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• v.26 no.4
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• pp.465-477
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• 1996

The influence of dehydrocholic acid, cholesterol and phosphstidylcholie to the fine structure of vacuolar apparatus was investigated to better understand the mechanism of intracellular transport of bile constituents in the hepatocytes of rats. The cis Golgi cisterns faced toward the bile canaliculi both in normal and experimental groups. In the hepatocytes from the rats of experimental groups, the primary organic solutes in bile influence the Gogi apparatus, ER and lysosome in the way of increase, cisternal dilation or budding to form the vacuoles. In the dehydrocholic acid group, the cis Golgi cisterns appeared to be sacculated and showed buds, which were probably separated to be vacuoles. Some of the vacuoles appeared to be fused to the bile canaliculi. In the cholesterol and phosphatidylcholine groups, the Golgi cisterns appeared to be dilated and lysosomes were increased in the vicinity of bile canaliculi. The cis Golgi cisterns showing linear saccular fashions were occasonally observed. The increase of lysosomes were more predominant in the cholesterol group. The evidence suggests that dehydrocholic acid is mainly transported through the ER and cis Golgi cisterns, and cholesterol and phosphatidylcholine are mainly transported through the ER and lysosomes via the trans Golgi cisterns, but the cholesterols are frequently transported via the lysosomes.

• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.117-124
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• 1994

Phospholamban is the regulator of $Ca^{2+}-ATPase$ in cardiac sarcoplasmic reticulum(SR). The mechanism of regulation appears to involve inhibition by dephosphorylated phospholamban. Phosphorylation of phospholamban relieves this inhibition. Recently, there has been a report that the cytoplasmic domain (amino acids 1-25) of phospholamban is insufficient to inhibit the $Ca^{2+}$ pump. To explore the domains of phospholamban responsible for $Ca^{2+}-ATPase$ inhibitory activity, we examined the effect of a synthetic phospholamban peptide consisting of amino acid residues 1-25 on $Ca^{2+}$ uptake by reconstituted skeletal SR $Ca^{2+}-ATPase$. The $Ca^{2+}-ATPase$ of skeletal SR was purified and reconstituted in proteoliposomes containing phosphatidylcholine (PC) or phosphatidylcholine: phosphatidylserine (PC:PS). Inclusion of a phospholamban peptide in PC proteoliposomes was associated with significant inhibition of the initial rates of $Ca^{2+}$ uptake at pCa 6.0, and phosphorylation of this peptide by the catalytic subunit of cAMP-dependent protein kinase reversed the inhibitory effect on the $Ca^{2+}$ pump. Similar effects of phospholamban peptide were also observed using PC:PS proteoliposomes. Based on these results, we could conclude that the cytoplasmic domain of phospholamban, containing the phosphorylation sites, by itself is sufficient to inhibit the $Ca^{2+}$ pump of SR.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.522-527
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• 2015

We applied a displacement current measurement technique for the study of L-${\alpha}$-dilauryl phosphatidylcholine (DLPC) monolayer. Displacement current was generated at the DLPC monolayer on the water surface, while induced by compression and expansion of the monolayer. Generation of Maxwell displacement current (MDC) was observed when surface areas per DLPC molecule were approximately $200{\AA}^2$ and $40{\AA}^2$. We investigated MDC for monolayer compression cycles, and found that MDC reached the maximum at the molecular area, which was measured right before surface pressure began to increase during compression cycles. The monolayer surface morphology of Langmuir-Blodgett (LB) films was characterized using atomic force microscope (AFM). As a result, we measured the result from the microscopic properties shown in the AFM images of LB films that molecules in the monolayer were in good orientations and the thickness of the monolayer ranged from 5 to 10 nm.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.578-589
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• 2003

The fuzzy rat that expresses hypersecretion of sebum and hyperplastic sebaceous glands is a genetic mutant for the study of many pharmacological aspects especially human acne. Through this model, we examined the effects of several phospholipids on the secretion of sebum after topical application. The phospholipid derivatives were phosphatidylcholine (PC), hydrogenated phosphatidylcholine (HPC), phosphati dylserine (PS) and hydrogenated phosphatidylserine(HPS). All agents were dissolved into the vehicle (1, 3-Butanediol, ethanol and water) at 0.5％ weight volume and applied on the dorsal area of the fuzzy rat. To observe histological changes, the skin biopsies were stained with Oil Red O and the size and morphology of sebaceous gland was observed under microscope. Topical treatment with PC and/or HPC showed a marked decrease in sebum excretion. Especially hydrogenated PC (HPC) appeared to have more predominant sebosuppressive function than any other treatment. The other agents such as PS and HPS showed a marginal effect on sebum secretion. With the sebosuppressive activity, HPC and PC seem to have a good potential application on acne treatment. In order to obtain more insights into possible mechanisms behind the above observations, effects of each phospholipid on the expression of peroxisome proliferator-activated receptor (PPAR) genes were investigated. Recently, it has been demonstrated that expression and activation of PPAR subtypes appear to modulate the accumulation of cytoplasmic fat droplets that characterizes the sebocyte differentiation(1). It was also previously suggested that PPAR${\gamma}$ antagonist would seem possible to interfere sebum production without side effects (2). In this study we examined the diverse effects of the tested phospholipids on the expression of several PPAR genes based on reverse transcription-polymerase chain reaction (RT-PCR) from the topically treated skin of fuzzy rats. The results and possible implications are discussed.

• Nutritional Sciences
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• v.6 no.1
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• pp.20-24
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• 2003

The effect of a-tocopherol on the formation and accumulation of phospholipid hydroperoxides, especially of phosphatidylcholine hydroperoxides, in the tissues of 2, 2 -azobis Hydrochloride (AAPH) - dosed rats was investigated. In a-tocopherol supplemented rats, the activities of glutathione peroxidase, catalase and superoxide dismutase were significantly inhibited, compared with the AAPH group. AAPH treatment led to oxidation of phospholipids in the liver, lungs, brain, plasma and red blood cells (RBC), resulting in a notable increase in phosphatidylcholine hydroperoxide (PCOOH). All tissues of the rats given an $\alpha$-tocopherol supplement showed an attenuation of the stimulating effect of AAPH, leading to low levels of formation of PCOOH. Also, the rats injected with AAPH and a-tocopherol showed relatively normal-appearing hepatocytes, except for a little loss of the granules. With regards to the morphological appearance of the liver, it was observed that oral intakes of a -tocopherol resulted in an antioxidant defense against attacks of peroxyl radicals. Thus, we suggest that a-tocopherol is potentially helpful in protecting membrane phospholipids against oxidative damage in vivo.

• Journal of the Korean Applied Science and Technology
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• v.29 no.2
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• pp.295-301
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• 2012

The collagen-liposomes were prepared with hydrogenated phosphatidylcholine and by solvent injection method for maximum protection and stable absorption of collagen into the body. Cholesterol was added to phosphatidylcholine to increase the stability of liposome membrane. The mixture was dissolved in ethanol and propylene glycol and PBS Buffer was used to Stabilize ions. The properties collagen-liposome were analyzed by DLS, SEM and POM.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.373-377
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• 2007

No phosphatidylcholine (PC) was detected in the membrane of Rhodobacter sphaeroides pmtA mutant (PmtAl) lacking phosphatidylethanolamine (PE) N-methyltransferase, whereas PE in the mutant was increased up to the mole % comparable to the combined level of PE and PC of wild type. Neither the fatty acid composition nor the fluidity of membrane was altered by pmtA mutation. Consistently, aerobic and photoheterotrophic growth of PmtAl were not different from wild type. However, PmtAl showed an extended lag phase (15 h) after the growth transition from aerobic to photoheterotrophic conditions, indicating the PC requirement for the efficient formation of intracytoplasmic membrane (ICM). Interestingly, the B800-850 complex of PmtAl was decreased more than twofold in comparison with wild type, whereas the level of the B875 complex comprising the fixed photosynthetic unit was not changed. Since puc expression is not affected by pmtA mutation, PC appears to be required for the proper formation of the B800-850 complex in the ICM of R. sphaeroides.

• Archives of Pharmacal Research
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• v.11 no.3
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• pp.181-184
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• 1988

The effect of clover saponin on the phase transition of liposomal lipid bilayers of dimyristoyl phosphatidylcholine was investigated with differential scanning calorimetry. The thermograms of the liposomal bilayers incorporated with the clover saponin were obtained, and the enthalpy changes and the sizes of cooperative unit of the transition were calculated. The results showed that incorporation of the clover saponin into the liposomal bilayers effectively reduced the transition temperature at which the transition from solid state to liquid-crystalline state occurs, and broadened the thermogram peaks. It also reduced the size of cooperative unit of the transition. These results indicate that the clover saponin might have significant effect on the fluidity of biological membranes.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2143-2147
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• 2013

Matrix assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is a very effective method for lipid mass fingerprinting. However, MALDI MS suffered from spectral complexities, differential ionization efficiencies, and poor reproducibility when analyzing complex lipid mixtures without prior separation steps. Here, we aimed to find optimal MALDI sample preparation methods which enable selective or class-wide mass fingerprinting of two totally different lipid classes. In order to achieve this, various matrices with additives were tested against the mixture of phosphatidylcholine (PC) and cerebrosides (Cers) which are abundant in animal brain tissues and also of great interests in disease biology. Our results showed that, from complex lipid mixtures, 2,4,6-trihydroxyacetophenone (THAP) with $NaNO_3$ was a useful MALDI matrix for the class-wide fingerprinting of PC and Cers. In contrast, THAP efficiently generated PC-focused profiles and graphene oxide (GO) with $NaNO_3$ provided Cer-only profiles with reduced spectral complexity.