Preparation of Thermo-Responsive and Injectable Hydrogels Based on Hyaluronic Acid and Poly(N-isopropylacrylamide) and Their Drug Release Behaviors

Ha Dong In,Lee Sang Bong,Chong Moo Sang,Lee Young Moo,Kim So Yeon,Park Young Hoon The Polymer Society of Korea 2006 Macromolecular Research Vol.14 No.1

Copolymers composed of hyaluronic acid (HA) and poly(N-isopropylacrylamide) (PNIPAAm) were prepared to create temperature-sensitive injectable gels for use in controlled drug delivery applications. Semi-telechelic PNIPAAm, with amino groups at the end of each main chain, was synthesized by radical polymerization using 2-aminoethanethiol hydrochloride (AESH) as the chain transfer agent, and was then grafted onto the carboxyl groups of HA using carbodiimide chemistry. The result of the thermo-optical analysis revealed that the phase transition of the PNIPAAm-grafted HA solution occurred at around 30$\∼$33$^{circ}C$. As the graft yield of PNIPAAm onto the HA backbone increased, the HA-g-PNIPAAm copolymer solution exhibited sharper phase transition. The short chain PNIPAAm-grafted HA ($M_{w}$=6,100) showed a narrower temperature range for optical turbidity changes than the long chain PNIPAAm-grafted HA ($M_{w}$=13,100). PNIPAAm-grafted HA exhibited an increase in viscosity above 35$^{circ}C$, thus allowing the gels to maintain their shape for 24 h after in vivo administration. From the in vitro riboflavin release study, the HA-g-PNIPAAm gel showed a more sustained release behavior when the grafting yield of PNIPAAm onto the HA backbone was increased. In addition, BSA released from the PNIPAAm-g-HA gels showed a maximum concentration in the blood 12 h after being injected into the dorsal surface of a rabbit, followed by a sustained release profile after 60 h.

전자선 조사에 의한 국내산 신선돈육의 이화학적 특성 변화

이무하 서울대학교 농업개발연구소 1999 농업생명과학연구 Vol.3 No.-

This study was carried out to examine the effects of electron-beam irradiation on the shelf life of pork loins. The pork loins were aerobically packed by polyethylene films and exposed to an absorbed dose of 0, 05, 1 and 2kGy of electron-beam irradiation at ambient temperature. The irradiated samples were stored together with the nonirradiated samples at 4±2℃. Nonirradiated pork loin began to putrefy after 10 days, while 2kGy irradiated one showed 106 CFU/cm2 after 12 days at 4℃. As the irradiation dose increased, effects of the treatments increased in total plate count, lactic acid bacteria and psychrotrophs. TBA values were apt to increase as the storage period and the irradiation dose increased. VBN value of nonirradiated pork loin was increased rapidly after 7days and that of irradiated treatments increased slowly during the storage period. Redness(a value) and yellowness(b value) of 2kGy irradiated treatment were lower than those of other treatments as the storage period increased. pH value of nonirradiated pork loin showed the increase slow during the storage period. The results of triangle test showed that the degrees of difference were significant between 0.5kGy irradiated treatments and 1kGy irradiated treatments(P 〈0.05) in the cooked pork loin. In the fresh pork loin, degrees of difference were significant between nonirradiated treatment and 0.5kGy irradiated treatment(P 〈0.05) and between nonirradiated treatment and 1kGy irradiated treatment(P〈0.01). In the descriptive analysis with scaling for fresh and cooked pork loin, it was observed that the nonirradiated pork loin scored higher in acceptability than the irradiated. In the fresh pork loin, off-flavor was detected more in 2kGy irradiated treatment than in others.

한우 및 수입산 쇠고기 냉장 목심 부위의 물리ㆍ화학적, 미생물학적 및 관능적 품질 특성

이무하 서울대학교 농업개발연구소 2000 농업생명과학연구 Vol.4 No.-

This study was carried out to compare qualities of Han-woo chuck rolls with those of the imported beef(American and Australian). The beef chuck rolls were aerobically packed by polyethylene films and were stored at 2℃. Han-woo chuck rolls were higher in crude fat but lower in moisture than others. The three treatments were significantly different in crude fat(P < 0.001), crude protein(P < 0.01) and moisture(P <0.001). Both total plate count and psychrotrophs were highest in Australian beef chuck rolls whereas lowest in Han-woo chuck rolls. VBN values of American beef chuck rolls were higher than those of others. Han-woo chuck rolls showed the highest value in water-holding capacity(P <0.05), whereas the lowest value in shear force(P <0.001). Lightness(L*value) and yellowness(b*value) were higher in American beef chuck rolls than in others. In the descriptive analysis with scaling for cooked beef loin, Australian beef chuck rolls were evaluated better in total acceptability.

浸透水에 의한 모래層의 破壞에 관한 硏究

權武男,李相昊,柳泰夏 慶北大學校 1991 論文集 Vol.51 No.-

In order to investigate seepage failure of sand layer and analyze the effect of the loaded filter constructed on the top of the layer, small scale laboratory tests were carried out on 6 kinds of grain sized sand layers with and without loaded filter of variations of thickness. The results obtained are as follows; 1. The relationship between critical velocity and critical gradient had positive correlation and appears to be linear equation regardless of grain size of the sand. 2. The critical velocity had a trend to increase linearly as grain size of the sand get to be bigger. And the critical velocity in the effective size of 10mm appeared to be about 15 times of that of the 0.2㎜ effective size. 3. The critical velocity was increased according to increase the thickness of loaded filter. And the critical velocity in the 8㎝ thick of loaded filter showed to be 2 times as comparison to the case of no loaded filter. In virtue of the conclusion above, the seepage force can fail sand layer seriously but the stability of sand layers will be able to improve remarkably by construction of loaded filter on the top of the sand layer.

속잎이 노랗고 뿌리혹병에 저항성인 배추 계통‘원교20034호’육성

박수형,장하영,서명훈,박민영,윤무경,이정수 忠北大學校 農業科學硏究所 2015 農業科學硏究 Vol.31 No.2

貧血症과 赤血球過多症에 있어서 血淸 Erythropoietin 活性度에 關한 硏究

尹起英,李夏白,朴鍾茂 한양대학교 의과대학 1985 한양의대 학술지 Vol.5 No.2

Erythropoietin (Ep) is a glycoprotein hormone of mostly renal origin that stimulates red cell production in response to tissue hypoxia. Serum Ep activities provide important clinical clues in making the differential diagnosis of some types of anemia and polycythemia. The study was performed in order to evaluate the diagnostic value of serum Ep activities in 29 normal subjects, 43 anemic patients and 15 secondary polycythemia patients and to find out the relationship between hemoglobin concentration and serum Ep activities in these patients using the Enzyme Immunoassay with Second International Preparation for Ep. The results obtained were as follows: 1. Ep activities in sera from 29 normal subjects among children ranged from 11 to 72 mU/ml, with a mean of 37.10±16.54 mU/ml. There was no significant difference between the serum Ep activities in male and female subjects (p>0.05). 2. Ep activities in sera from 22 patients with iron deficiency anemia ranged from 48 to 400 mU/ml, with a mean of 153.5 mU/ml which was about 4 times higher than normal value. Ep activities in sera from 18 anemic patients with acute infection ranged from 35 to 290 mU/ml, with a mean of 134.05 mU/ml which was about 3.5 times higher than normal value. Ep activities in sera from 3 patients with aplastic anemic ranged from 620 to 840 mU/ml, with a mean of 720 mU/ml which was about 20 times higher than normal value. 3. Ep activities in sera from 15 patients with secondary polycythemia ranged from 12 to 140 mU/ml. In 10 of 15 patients, the mean Ep activities was 87.50 ± 25.60 mU/ml, which was about 2 times higher than normal value. In 5 of 15 patients, Ep activities were within normal range as a mean of 35.80 ± 17.23 mU/ml. In summary, a significant negative correlation was found between the hemoglobin concentration and the logarithm of the serum Ep activities in 43 patients with anemia (r=0.73, Y=3.6766-0.1802x) and Ep activities in patients with aplastic anemia was higher than those in patients with iron deficiency anemia at comparable hemoglobin concentration. From the above results, it was concluded that serum Ep activities in anemic patients are not only inversely related to the hemoglobin concentration but also to the activity of the erythroid bone marrow. While no significant correlation was found between hemoglobin concentration, hematocrit percentages and Ep activities in 15 patients with secondary polycythemia (r=0.18, 0.39 respectively).

대장암종에서 암관련 유전자들의 Promoter Methylation과 암종 발생 및 진행과의 관게에 대한 연구

정동준,이정은,민영기,조성우,백무준,양승하,김의한,김창진 순천향대학교 교수학습개발센터 2004 Journal of Soonchunhyang Medical Science Vol.10 No.3

The colorectal corcinoma is one of the most common malignant tumor in Korea and its carcinogenic mechanism has not been elucidated exactly yet. So far, the most common carcinogenic mechanism has been known to be multiple genetic changes. But, the CpG island hypermethylation has been revealed to be one of the most important carcinogenic mechanism second to the genetic changes. The epigenetic changes characteristically imprint and transfer to the next generation without changes of nucleotide sequences. When the CpG island of promoter or 5'- exon 1 of a specific gene is methylated by DNA methyltrasferases (DNMTs), the gene expression is inhibited. Carcinogenic mechansisms by promoter methylation has been well known, but the progression of the cancer has not been elucidated yet. The molecular researches on the carcinogenic mechanisms largely depended on the tumor tissue containing various components of cell, due to difficulties in harvesting pure homogeneous tumor cells. Promoter methylatonof the cancer related genes as APc, hMLH2, p16, DAP-K and MGMT in 50 cases of sporadic colorectal carcinoma was studied. The pure normal colorectal epithelial cells, and cancer cells from superficial and deep invasive portion were harvested respectively by laser captured microdissection(LCM), and DNA was extracted from them. The promoter methylation was studied by methylation specific poymerase reaction (MSP) after bisulfite modification of the DNA and the expression of the genes by immunohistochemistry. The results suggests that promoter methylation of the cancer related genes are closely related with the colorectal carcinogenesis and it occurrs from early phase of carcinogenesis, progressing constantly to the late stage. And the promoter methylation of normal epithelial cells increased by age. The p15, known to be the genes related to hematologic malignancy, was closely related to the colorectal carcinoma as well.

돼지에서 정맥, 근육 그리고 경구 투여시의 enrofloxacin의 약물동태학

윤효인,김무열,박승춘,조준형,박병권,이내경,노상석,장범수,신광순,조명행 충남대학교 수의과대학 동물의과학연구소 1996 動物醫科學硏究誌 Vol.4 No.-

In order to characterize pharmacokinetic profiles according to route of a new enrofloxacin salt form (Enrotil®), it was given to 4 healthy pigs via oral (p.o.), intramuscular (i.m.) or intravenous (i.v.) administrations at a dose rate of 5 ㎎/㎏ body weight. Enrofloxacin (ENFX) in serum was detected by bioassay using E. coli BE1186 as a test organism. The biological elimination half-lives (t_1/2(β)) of ENFX were 6.76±0.99 h (i.v.), 7.16±2.30 h (i.m.) and 11.45±3.90 h (p.o.), Volume of distribution (Vd) of enrofloxacin was 2.20±0.31 L/㎏ (i.v.), 2.52±0.60 L/㎏ (i.m.) and 1.88±0.33 L/㎏ (i.m.). Mean residence time (MRT) was 8.77±1.26 h after i.v. injection and the maximal concentration time (Tmax) following p.o. and i.m. administration was 0.76±0.09 h and 0.60±0.12 h, indicating a rapid absorption from these routes. Bioavailibility (F) was calculated as 64.1% for p.o. administration and 59.71% for i.m. injections. In summary, the newly formulated enrofloxacin salt form has shown a high water solubility, rapid absorption and large tissue distribution, suggesting a potential antibacterials for oral application on a large scale in veterinary sectors.

Fosfomycin의 항균효과 및 capillary electrophoresis에 의한 측정법에 관한 연구

윤효인,박승춘,이규승,권진욱,조준형,신광순,김무열,허강준,조명행 충남대학교 수의과대학 동물의과학연구소 1996 動物醫科學硏究誌 Vol.4 No.-

Fosfomycin, a low molecular antibiotic, is to be easily synthesized, therefore to be possibly used in veterinary sectors due to econimic reasons. In this study, we determined the antibacterial activities of fosfomycin against some domestic animal-origin pathogens, and its combined effects with some important antibacterials available. We also compared detection methods of fosfomycin from various measuring instruments. The results obtained through this experiment were as follows: 1. Antibacterial activities of fosfomycin against the pathogens used in this experiment were appeared fairly low. We found the antobacterial activities depanded on the kinds of media and the addition of some material thereins, which suggests the importance of appropriate medium so as to judge the antibacterial activity of fosfomycin. 2. Fosfomycin showed varying antibacterial effects in combination with other antibacterials, which should be taken into consideration when combining other antobacterials especially in the clinical settings. Of the combined antivacterials, fosfomycin had synergistic effects in combination with amoxicillin but antagonistic effects with oxytetracyline. 3. Conventional detection methods using HPLC, GC and spectrophotometer were not appropriate to measure fosfomycin. Capillary electrophoresis by the way of the indirect ultraviolet detection method was good enough to detect fosfomycin in the range of expected concentration in tissues, with the limit of quantitation (LOQ) of 1.25 ㎍/㎖. We recommend the eletrophoresis method could be used to detect fosfomycin, thereby being able to set the optimal dosage for animals and providing the measures in relation with the residual concentration in the meat.

백서에서 수술 후 복부 유착방지용 재료들의 효능평가

심희수(Hee Soo Shim),이영우(Young Woo Lee1),이영무(Young Moo Lee),오영하(Young Ha Oh),권성원(Sung Won Kwon),김진홍(Jin Hong Kim),손승국(Seung Kook Sohn) 대한외과학회 2002 Annals of Surgical Treatment and Research(ASRT) Vol.63 No.3