• Title/Summary/Keyword: Molecular weight profile

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Development of Drug-Loaded PLGA Microparticles with Different Release Patterns for Prolonged Drug Delivery

  • Choi, Yeon-Soon;Joo, Jae-Ryang;Hong, Areum;Park, Jong-Sang
    • Bulletin of the Korean Chemical Society
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    • v.32 no.3
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    • pp.867-872
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    • 2011
  • For the prolonged delivery and sustained release rates of low molecular weight drugs, poly(lactic-co-glycolic acid) (PLGA) microparticles containing the drug SKL-2020 have been investigated. On increasing polyvinyl alcohol (PVA) concentration (from 0.2% to 5%), the size of microparticles decreased (from $48.02{\mu}m$ to $10.63{\mu}m$) and more uniform size distribution was noticeable due to the powerful emulsifying ability of PVA. A higher drug loading (from 5% to 20%) caused a larger concentration gradient between 2 phases at the polymer precipitation step; this resulted in decreased encapsulation efficiency (from 34.19% to 25.67%) and a greater initial burst (from 61.71% to 70.05%). SKL-2020-loaded PLGA microparticles prepared with different fabrication conditions exhibited unique release patterns of SKL-2020. High PVA concentration and high drug loading led to an initial burst effect by rapid drug diffusion through the polymer matrix. Since PLGA microparticles enabled the slow release of SKL-2020 over 1 week in vitro and in vivo, more convenient and comfortable treatment could be facilitated with less frequent administration. It is feasible to design a release profile by mixing microparticles that were prepared with different fabrication conditions. By this method, the initial burst could be repressed properly and drug release rate could decrease.

Physical, chemical composition and umami compound of dried immature and mature roes of skipjack tuna (Katsuwonus pelamis)

  • Phetchthumrongchai, Thithi;Chuchird, Niti;Roytrakul, Sittiruk;Chintong, Sutasinee;Klaypradit, Wanwimol
    • Fisheries and Aquatic Sciences
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    • v.25 no.7
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    • pp.390-402
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    • 2022
  • In this study we investigate physical and chemical characteristics of immature and mature skipjack tuna (Katsuwonus pelamis) roes in fresh and dried forms. Fresh roes were studied for histological structure and also dried by three methods: hot air drying (HD), vacuum drying (VD) and freeze drying (FD). The obtained roe powders were analysed for proximate composition, color value, fatty acid composition, amino acid profile, equivalent umami concentration (EUC) and protein pattern. Unyolked oocytes were more common in immature roes, while fully yolked oocytes were more common in mature roes. All dried tuna roes contained high content of protein and lipid (69.31%-70.55% and 11.14%-16.02%, respectively). The powders obtained by FD provided the highest lightness value (L*). The main fatty acid found in all roe powders was docosahexaenoic acid (DHA) (23.49%-27.02%). Glutamic acid, leucine, and aspartic acid were the three most abundant amino acids found in the powders (13.58-14.61, 8.06-8.42, and 7.81-8.39 g/100 g of protein, respectively). The mature roe powder obtained from HD provided the highest EUC value (73.09 g monosodium glutamate/100 g of samples). The protein band at molecular weight of 97 kDa (vitelline) represented the major protein. Therefore, dried tuna roe could be a functional ingredient source of protein and lipid rich in DHA and it also has potential to be used as taste enhancer with umami compound.

The Effects of Rotational Correlation Time of Paramagnetic Contrast Agents on Relaxation Enhancement: Partial Binding to Macromolecules (거대분자에 부분적으로 결합한 상자성 자기공명 조영제의 회전속도가 이완증강에 미치는 영향)

  • 장용민
    • Investigative Magnetic Resonance Imaging
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    • v.3 no.2
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    • pp.159-166
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    • 1999
  • Purpose : To evaluate the effect of rotational correlation time (${\tau}_R$) and the possible related changes of other parameters, ${\tau}_M,{\;}{\tau}_S,{\;}and{\;}(\tau}_V$ of gadolinium (Gd) chelate on T1 relaxation enhancement in two pool model. Materials and Methods : The NMRD (Nuclear Magnetic Relaxation Dispersion) profiles were simulated from 0.02 MHz to 800 MHz proton Larmor frequency for different values of rotational correlation times based on Solomon-Bloembergen equation for inner-sphere relaxation enhancement. To include both unbound pool (pool A) and bound pool (pool B), the relaxivity was divided by contribution from unbound pool and bound pool. The rotational correlation time for pool A was fixed at the value of 0.1 ns, which is a typical value for low molecular weight complexes such as Gd-DTPA in solution and ${\tau}_R$ for pool B was changed from 0.1 ns to 20 ns to allow the slower rotation by binding to macromolecule. The fractional factor of was also adjusted from 0 to 1.0 to simulate different binding ratios to macromolecule. Since the binding of Gd-chelate to macromolecule cab alter the electronic environment of Gd ion and also the degree of bulk water access to hydration site of Gd-chelate, the effects of these parameters were also included. Results : The result shows that low field profiles, ranged from 0.02 to 40 MHz, and dominated by contribution from bound pool, which is bound to macromolecule regardless of binding ratios. In addition, as more Gd-chelate bound to macromolecule, sharp increase of relaxivity at higher field occurs. The NMRD profiles for different values of ${\tau}_S$ show the enormous increase of low field profile whereas relaxivity at high field is not affected by ${\tau}_S$. On the other hand, the change in ${\tau}$V does not affect low field profile but strongly in fluences on both inflection fie이 and the maximum relaxivity value. The results shows a fluences on both inflection field and the maximum relaxivity value. The results shows a parabolic dependence of relaxivity on ${\tau}_M$. Conclusion : Binding of Gd-chelate to a macromolecule causes slower rotational tumbling of Gd-chelate and would result in relaxation enhancement, especially in clinical imaging field. However, binding to macromolecule can change water enchange rate (${\tau}_M$) and electronic relaxation ($T_le$) vis structural deformation of electron environment and the access of bulk water to hydration site of metal-chelate. The clinical utilities of Gd-chelate bound to macromolecule are the less dose requirement, the tissue specificity, and the better perfusion and intravascular agents.

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Synthesis and Micellar Characterization of CBABC Type PLGA-PEO-PPO-PEO-PLGA Pentablock Copolymers

  • Seong, Haseob;Cho, Eun-Bum;Oh, Joongseok;Chang, Taihyun
    • Bulletin of the Korean Chemical Society
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    • v.35 no.8
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    • pp.2342-2348
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    • 2014
  • Poly(lactic-co-glycolic acid) (PLGA) were grafted to both ends of Pluronic$^{(R)}$ F68 ($(EO)_{75}(PO)_{30}(EO)_{75}$) triblock copolymer to produce poly{(lactic acid)$_m$-co-(glycolic acid)$_n$}-b-poly(ethylene oxide)$_{75}$-b-poly(propylene oxide)$_{30}$-b-poly(ethylene oxide)$_{75}$-b-poly{(lactic acid)$_m$-co-(glycolic acid)$_n$} (PLGA-F68-PLGA) pentablock copolymers. Molecular weights of PLGA blocks were controlled and five kinds of pentablock copolymers with different PLGA block lengths were synthesized using in-situ ring-opening polymerization of D,L-lactide and glycolide with tin(II) 2-ethylhexanoate ($Sn(Oct)_2$) catalyst. PLGA-F68-PLGA pentablock copolymers were characterized by $^1H$- and $^{13}C$-NMR, GPC, and TGA. The numbers (2m, 2n) of repeating units for lactic acid and glycolic acid inside PLGA segments were obtained as (48, 17), (90, 23), (125, 40), (180, 59), and (246, 64), with $^1H$-NMR measurement. From NMR data, the resultant molecular weights were determined in the range of 12,700-29,700, which were similar to those obtained from GPC. Polydispersity index was increased in the range of 1.32-1.91 as the content of PLGA blocks increased. TG and DTG thermograms showed discrete degradation traces for PLGA and F68 blocks, which indicate the weight fractions of PLGA blocks in pentablock copolymers can be calculated by TG profile and it is possible to remove PLGA block selectively. Hydrodynamic radius and radius of gyration of pentablock copolymer micelle were obtained in the range of 46-68 nm and 31-49 nm, respectively, in very dilute (i.e. 0.005 wt %) aqueous solution of THF:$H_2O$ = 10:90 by volume at $25^{\circ}C$.

An Analysis of Tendencies of Studies on Herbal Acupuncture - Focusing on domestic theses since 2001 about anti-inflammation, pain relief and anti-obesity effects, including safety- (약침(藥鍼)의 연구 동향에 대한 분석 - 항염(抗炎) ${\cdot}$ 진통(鎭痛) ${\cdot}$ 비만(肥滿) 및 안전성(安全性)에 관한 연구를 중심으로 -)

  • Kang, Jun-Hyuk;Heo, Dong-Seok;Yoon, Il-Ji;Oh, Min-Seok
    • The Journal of Korean Medicine
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    • v.28 no.2 s.70
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    • pp.93-113
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    • 2007
  • Objective : To research Trends of studies about anti-inflammation and pain relief, obesity, and safety of herbal acupuncture therapy by analyzing domestic theses, published since 2001, about herbal acupuncture therapy. Methods : Domestic theses, published since 2001, mentioning anti-inflammation or pain relief, obesity, or safety of herbal acupuncture therapy were reviewed and analyzed. These theses were then classified by university, year, and subject. Results : The following results were obtained in this study. 1. Among published theses related to anti-inflammation effects of herbal-acupuncture, studies about arthritis comprised the most part, 52. In theses relating to causes of arthritis, 16 were about adjuvant, which was the most, followed by Type II collagen, LPS and carrageenan. Blood test, reactions of inflammation and revelation of cytokine and immune cellswere methods for evaluating anti-inflammation effect. The tendency of experimental methods was to focus on molecular biologic method. 2. In theses related to pain relief, many clinical attempts with herbal injection were carried out, and Carthami Flos and Scolopendrawere used most. Observing reduction of pain inducing factor and checking behavioral change were methods for evaluating pain relief. 3. In theses related to obesity, research focused on effects in association with spots on the body suitable for acupuncture. There were also attempts comparing effectiveness between single injections and complex injections. Astraball Radix, Angelica Gigantis Radix, Coicis Semen and Taeumjowetang were used. Evaluation of anti-obesity effects were by weight loss, food efficiency, blood lipid profile and evaluation of liver function. 4. In theses related to safety of herbal-acupuncture, Herba Chelidonii Chaenonelis Fructus, Clematis Florida Thunb, Corydalidis Tuber, Paeoniae Radix, and Carthami Flos which marked 2 theses each were most studied. Methods of evaluating safety were mostly by observing liver and kidney functions based on blood test, and by applying herbal injections to clinical treatment. Conclusion : Herbal acupuncture is being used in various ways associating with its anti-inflammation, pain relief and anti-obesity effect. Studies on efficacy and mechanism of herbal acupuncture are being conducted even at the molecular biology level.

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The Relationships between Plasma Insulin-like Growth Factor (IGF)-1 and IGF-Binding Proteins (IGFBPs) to Growth Pattern, and Characteristics of Plasma IGFBPs in Steers

  • Lee, H.G.;Hidari, H.;Kang, S.K.;Hong, Z.S.;Xu, C.X.;Kim, S.H.;Seo, K.S.;Yoon, D.H.;Choi, Y.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.11
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    • pp.1575-1581
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    • 2005
  • This study was conducted to determine the characteristics of IGFBPs in plasma of steers, and to profile the relationship between growth and plasma IGF-1 and IGFBPs with aging in Holstein steers. Four blots of IGFBP at molecular weights of 38-43, 34, 29-32 and 24 kDa bands were detected by western ligand blot assay using $^{125}I-IGF-1$. On the basis of immunoblotting with anti-bovine IGFBP-2 and -3 antiserums, we observed the band for IGFBP-2 at approximately 34 kDa, and the IGFBP-3 band was detected at 38-43 kDa and 34 kDa in adult steers and calves. The IGFBP-3 antiserum used on the blots exhibited significant cross-reactivity with 34 kDa IGFBP-2. Furthermore, the 38-43 kDa IGFBP-3 bands were reduced to a 36 kDa band after deglycosylation, whereas the 34 kDa IGFBP-2 was intact. The plasma IGF-1, IGFBP-3 and other IGFBPs showed stability throughout a whole day. The change in live weight was found to be positively correlated to the plasma IGF-1 concentration (r = 0.6801, n = 64, p<0.05) and plasma IGFBP-3 (r = 0.6321, n = 64, p<0.05), while inversely correlated to plasma IGFBP-2 (r = -0.2919, n = 64, p<0.05). Furthermore, plasma IGF-1 was positively correlated to plasma IGFBP-3 (r = 0.6191, p<0.001), but was not correlated to plasma IGFBP-2. The portion of IGFBP-2 for total IGFBPs in calves was higher than in adult steers (p<0.05) and was decreased with growth, whereas that of IGFBP-3 was increased with increased live weight (p<0.05). The ratio IGFBP-3 for IGFBP-2 (BP-3/BP-2) was increased with growing of liveweight. Therefore, the changes in plasma IGF-1 level with increased liveweight may be related to the changes in plasma IGFBP-3 level and IGFBP-2 may give an important role in anabolic action of IGF-1 with the growth of body during calfhood in Holstein steers.

The Relationships between UCP-1 Polymorphism and the Degree of Obesity or Plasma Lipid Profile in Prepubertal Children (소아에서의 UCP-1 다형성과 비만도 및 혈액 지질수치와의 관련성에 관한 연구)

  • Oh, Hyun-Hee;Shin, Eun-Jung;Lee, Myoung-Sook
    • Journal of Nutrition and Health
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    • v.41 no.8
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    • pp.767-775
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    • 2008
  • Uncoupling protein-1 (UCP-1) plays a major role in thermogenesis at brown adipose tissues and has been implicated in the pathogenesis of obesity and metabolic disorders. The purpose of this study was to estimate the effects of A-3826G polymorphism in 117 Korean prepubertal children aged 8-11 years olds. Anthropometry by bioelectrical impedance analysis method, plasma lipid profiles by auto-biochemical analyzer and UCP-1 genotyping by PCR-RFLP were done. The frequencies of UCP-1 genotypes were AA; 17.7%, AG; 57.8%, GG; 26.6%. The frequencies of each G allele (55.5%) was similar to Japanese's (49%) and higher than Caucacian's (25%). No correlation UCP-1 polymorphism and BMI (kg/$m^2$) or the degree of obesity described by the relative percentiles of the standard weight according to height in prepubertal children. However, plasma total- and LDL-cholesterol were significantly increased in G allele when sex, age and weight were adjusted. Our results suggested that G allele of UCP-1 gene was stronger risk factors in hyperLDLcholesterolemia than A allele. This impact might be progressed as the precaution against the revalence of obesity based-metabolic disease.

Phylogenetic and expression analysis of the angiopoietin-like gene family and their role in lipid metabolism in pigs

  • Zibin Zheng;Wentao Lyu;Qihua Hong;Hua Yang;Ying Li;Shengjun Zhao;Ying Ren;Yingping Xiao
    • Animal Bioscience
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    • v.36 no.10
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    • pp.1517-1529
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    • 2023
  • Objective: The objective of this study was to investigate the phylogenetic and expression analysis of the angiopoietin-like (ANGPTL) gene family and their role in lipid metabolism in pigs. Methods: In this study, the amino acid sequence analysis, phylogenetic analysis, and chromosome adjacent gene analysis were performed to identify the ANGPTL gene family in pigs. According to the body weight data from 60 Jinhua pigs, different tissues of 6 pigs with average body weight were used to determine the expression profile of ANGPTL1-8. The ileum, subcutaneous fat, and liver of 8 pigs with distinct fatness were selected to analyze the gene expression of ANGPTL3, ANGPTL4, and ANGPTL8. Results: The sequence length of ANGPTLs in pigs was between 1,186 and 1,991 bp, and the pig ANGPTL family members shared common features with human homologous genes, including the high similarity of the amino acid sequence and chromosome flanking genes. Amino acid sequence analysis showed that ANGPTL1-7 had a highly conserved domain except for ANGPTL8. Phylogenetic analysis showed that each ANGPTL homologous gene shared a common origin. Quantitative reverse-transcription polymerase chain reaction analysis showed that ANGPTL family members had different expression patterns in different tissues. ANGPTL3 and ANGPTL8 were mainly expressed in the liver, while ANGPTL4 was expressed in many other tissues, such as the intestine and subcutaneous fat. The expression levels of ANGPTL3 in the liver and ANGPTL4 in the liver, intestine and subcutaneous fat of Jinhua pigs with low propensity for adipogenesis were significantly higher than those of high propensity for adipogenesis. Conclusion: These results increase our knowledge about the biological role of the ANGPTL family in this important economic species, it will also help to better understand the role of ANGPTL3, ANGPTL4, and ANGPTL8 in lipid metabolism of pigs, and provide innovative ideas for developing strategies to improve meat quality of pigs.

Functionalities of Squid Liver Hydrolysates (오징어 간 가수분해물의 기능성)

  • Lee, Su-Seon;Park, Si-Hyang;Park, Joo-Dong;Konno, Kunihiko;Choi, Yeung Joon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.12
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    • pp.1677-1685
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    • 2012
  • The autolysate and hydrolysate of a common squid liver, Todarodes pacificus, were prepared. Autolysis (liver ratio, pH, temperature) and Protamex-treated hydrolysis (pH, temperature, ratio of protease to liver) conditions were optimized by response surface methodology using central composite design for under 1 hr of hydrolysis time. The desirability profile indicated that maximum DH could be achieved at a squid liver of 93.5%, pH 6.4, and $47^{\circ}C$ in autolysis, while that of Protamex-treated hydrolysis did at a Protamex-to-squid liver level of 0.33%, pH 6.0, and $55^{\circ}C$. Three amino acids, proline, cysteine, and methionine, were not detected in the total amino acid composition of the Protamex-treated hydrolysate, while they were detected in the free amino acid composition. Cadmium was $8.32{\pm}0.03$ mg/100 g-powder for raw, $3.56{\pm}0.02$ mg/100 g-powder for the autolysate, and $13.26{\pm}0.04$ mg/100 g powder for the Protamex-treated hydrolysate. The major molecular weight ranged from 1.0 to 1.5 kDa for the autolysate and from 210 to 470 Da for the Protamex-treated hydrolysate. Food functionalities of the autolysate, such as surface hydrolphobicity, emulsion activity index, emulsion stability, water, and fat adsorption, were similar to the Protamex-treated hydrolysate. Both the autolysate and Protamex-hydrolysate showed high inhibitory activities on the angiotensin-I converting enzyme. Cell toxicity against the HepG2 cell line was not detected in the autolysate or the Protamex-treated hydrolysate by 200 ${\mu}g/mL$.

Stabilization of Membrane Proteins by Benzyladenine during Wheat Leaf Senescence (노쇠중인 밀잎에서 Benzyladenine에 의한 막단백질의 안정화)

  • 진창덕
    • Journal of Plant Biology
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    • v.35 no.2
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    • pp.117-123
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    • 1992
  • The effect of benzyladenine (BA) on lipid peroxidation and compositions of total insoluble proteins and chloroplast thylakoid protein from wheat primary leaves during senescence in the dark was studied. BA ($10^{-5}\;M$) treatment prevented conspicuously the loss of chlorophyll content and soluble and insoluble leaf protein contents in senescing wheat leaf segments during 4-day dark incubation. Under the BA treatment, especially, the level of insoluble protein was highly maintained than that of soluble protein. Also, the increase of malondialdehyde (MDA: the peroxidation product of membrane lipids) content was inhibited in the BA treated leaves. Three major polypeptide bands in quantity corresponding to 57, 26 and 12 KD molecular weight were clearly resolved with other minor bands by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) in the insoluble protein fraction. The insoluble protein profiles of the control leaves showed a remarkable decrease in the intensity of the 57 and 12 KD band except for 26 KD band in the 72 h dark incubation. This loss during dark incubation was reduced by BA treatment. More than 20 polypeptides were resolved in the chloroplast thylakoid membrane fraction with the most prominent bands which are 59 and 57 KD ($\alpha\;and\;\beta$ subunit of coupling factor: CF) and 26 KD (apoprotein of LHCP). The changes in thylakoid protein profile during 72 h dark incubation showed the rapid degradation in control, but this degradation was prevented in quantity by BA treatment. The above results suggested that BA would inhibit the peroxidation of membrane lipids, thereby preventing the loss of membrane proteins which led to the maintenance of the membrane integrity including chloroplast thylakoid.

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