Antioxidant Activity of Dopamine-Modified Hydrogels Containing Cross-linked Hyaluronic Acid

Geun-Chang Ryu,Jeong Hee Hwang,Cheol-Woo Lee 대한시과학회 2018 대한시과학회지 Vol.20 No.4

목적: 이 연구에서는 도파민이 적용된 히알루론산 가교 하이드로겔을 제조하고 항산화 활성을 조사하였다. 방법: 먼저 히알루론산과 p(HEMA)로 구성된 상호침투고분자구조로 후처리 한 p(HEMA) 기반 하이드로겔을 제조하였다. 다음으로 아마이드 결합반응을 통해 도파민이 적용된 항산화 하이드로겔을 제조하였다. 항산화 활성의 평가는 ABTS 와 DDPH 라디칼 소거능 방법을 사용하였다. 결과: 도파민이 적용된 하이드로겔은 유의한 항산화 활성을 나타내었다. 히알루론산의 가교는 하이드로겔 표면의 습윤성을 개선시킨 반면에 도파민이 적용된 하이드로겔은 대조군과 비교하여 유의한 차이를 나타내지 못했다. 도파민이 적용된 하이드로겔은 높은 광투율을 나타내었다. (>88%) 결론: 도파민이 결합된 히알루론산의 가교에 기초한 항산화 하이드로겔의 개발이 안의료 및 생물의학 재질 개발에 도움을 줄 수 있을 것으로 사료된다. Purpose : : In this study, we made dopamine-functionalized hydrogels containing a cross-linked hyaluronic acid (HA) network and investigated their antioxidant activities. Methods : In the first step, we made poly hydroxyethyl methacrylate(p(HEMA))-based hydrogels post-modified with an interpenetrating polymer network(IPN) structure composed of HA polymers and a p(HEMA) network. The subsequent functionalization with dopamine via an amide coupling reaction resulted in the antioxidant hydrogels. Their antioxidant activities were evaluated using 2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging assays. Results : The dopamine-modified hydrogels exhibited significant antioxidant activities, when compared to unmodified control. The presence of the HA–IPN structure improved the surface wettability of the hydrogel while dopamine-conjugated IPN hydrogel did not demonstrate the significant difference compared to hydrogel control. Dopamine-modified hydrogels exhibited high transmittance (>88%). Conclusion : The results demonstrate that the development of antioxidant hydrogels based on dopamine-conjugated HA–IPN structures may help develop ophthalmic and biomedical materials.

Synthesizing of Blue-light Blocking Polymeric Materials and Manufacturing Contact Lenses

Geun-Chang Ryu,Cheol-Woo Lee,Eun-Sun Seo 대한시과학회 2020 대한시과학회지 Vol.22 No.4

목적 : 청색광을 차단하는 고분자를 합성하였고, 이를 하이드로겔 콘택트렌즈에 적용시켰다. 제조된 콘택트렌 즈의 함수율과 청색광차단 기능을 청색광차단 고분자의 첨가량에 따라 분석하고자 한다. 방법 : Polyethyleneimine(PEI에 친핵성 치환 반응을 통해 청색광 흡수기능의 반응성 염료 (Procion Yellow MX8G)와 결합시켰고, 이를 하이드로겔 콘택트렌즈에 적용시켰다. 콘택트렌즈의 청색광차단 특성은 UV-vis spectrophotometer를 이용하여 확인하였다. 결과 : 청색광 흡수기능의 반응성 염료가 성공적으로 PEI에 결합되었다. 청색광차단 고분자는 콘택트렌즈에 적 용되었으며, UV-vis spectra 분석을 통해 우수한 청색광차단 기능을 보임을 확인하였다. 추가적으로, 3일의 세 척과정 후에 청색광 흡수 염료는 더 이상 콘택트렌즈로부터 용출되지 않았다. 결론 : 본 연구에서는 청색광차단 고분자를 포함하는 하이드로겔 콘택트렌즈의 제조와 분석을 수행하였다. 하 이드로겔 콘택트렌즈는 450~700 nm 사이의 파장에서 90% 이상의 광투과율과 우수한 함수율을 보여주었다. 특 히, 첨가된 청색광차단 고분자의 양이 증가할수록, 380~450 nm 사이의 청색광 파장에서 차단 세기가 의미 있게 증가함을 확인하였다. 청색광차단 콘택트렌즈의 제조는 안의료용 디바이스 개발에 큰 역할을 할 것으로 기대된다. Purpose : Blue-light blocking polymers were synthesized and interpenetrated into the hydrogel contact lenses. The water contents and blue-light blocking properties of the resultant contact lenses with varying amounts of the blue-light blocking polymers were investigated and compared to that of the unmodified control. Methods : Polyethyleneimine (PEI) was covalently conjugated with blue-light adsorbing reactive dyes (Procion Yellow MX8G) via a nucleophilic substitution reaction and incorporated into the hydrogel contact lenses. The blue-light blocking properties of the hydrogel lenses were investigated using UV-vis spectrophotometry. Results : The blue-light adsorbing reactive dyes were successfully conjugated to the PEI and well incorporated into the hydrogel contact lenses. The resultant contact lenses exhibited good blue-light blocking properties according to the results of the UV-vis spectra investigation. Furthermore, we confirmed that the blue-light adsorbing dyes were not eluted from the contact lenses after extensive washings for 3 days. Conclusion : This report describes the synthesis and characterization of a series of hydrogel contact lenses containing blue-light blocking polymers. The hydrogel contact lenses showed good water contents and a transmittance of over 90% in the range of 450~700 nm. In particular, the blue-light blocking properties at the range of 380~450 nm were enhanced significantly as the increment in the amount of incorporated blue-light blocking polymers. The preparation of blue-light-blocking contact lenses may offer a new opportunity for the development of biomedical ophthalmic devices.

Changes in Visual Function According to the Addition of Center-near Designed Multifocals and Utilization as Contact Lenses for Fatigue

Chae-Youn Seo,Geun-Chang Ryu 대한시과학회 2018 대한시과학회지 Vol.20 No.1

목적: 본 연구에서는 단초점 콘택트렌즈와 3가지 가입도의 중심부 근용 동시보기 디자인의 멀티포컬 콘 택트렌즈를 착용한 후 근거리에서 조절을 유도하여 콘택트렌즈 타입에 따른 시기능의 변화를 비교하고, 피 로감소용 기능성 콘택트렌즈로서 멀티포컬 콘택트렌즈의 처방에 대한 활용도를 알아보고자 하였다. 방법: 본 연구의 취지를 이해하고 목적과 방법에 동의한 20-30대 성인 남녀 20명(40안, 26.63±4.36세) 을 대상으로 하였다. 평균 구면 굴절력은 –3.38±2.57 D이며, 평균 원주 굴절력은 –0.46±0.31 D, 평균 등 가구면 굴절력은 -3.61±2.64 D였다. 대상자들은 총 4회 방문하였고 매 방문시 단초점 콘택트렌즈, 멀티포 컬 콘택트렌즈 LOW, MID, HIGH를 각각 착용하였고, 조절 부담을 유도하기 위해 40 cm에서 1시간 동안 휴 대폰(4.7 inches)으로 자막이 있는 영상을 시청하였다. 영상을 시청한 후 MEM과 원근 대비시력 100%와 10%, 선명시역, 조절근점, 폭주근점, 조절용이성, 입체시 검사를 실시하였고, 온라인 설문지를 통해 자각적 만족도를 평가하였다. 결과: 멀티포컬 콘택트렌즈의 가입도가 증가함에 따라 MEM은 증가하였고 조절근접은 감소하였다 (p<0.05). 원근거리 대비시력과 선명시역, 폭주근점, 입체시, 조절용이성은 4 종류의 렌즈에서 유의한 차이 가 없는 것으로 나타났다(p>0.05). 단초점 콘텍트렌즈를 착용했을 때 원거리 시력에 대한 만족도가 가장 높 은 것으로 조사되었다. 결론: 멀티포컬 콘택트렌즈의 가입도가 증가하면서 MEM은 증가하고 조절근점은 짧아졌음을 확인하였 다. 멀티포컬 콘택트렌즈를 기능성 콘택트렌즈로 처방하기 위해서는 더 오랜 기간 착용한 후 시기능의 변화 를 추적할 필요성이 있을 것으로 사료된다. Purpose: To compare changes in visual function according to single vision and additions of center-near simultaneous vision multifocal contact lenses and investigate the use as a functional contact lens for fatigue. Methods: Twenty young adult subjects(40 eyes, 26.63±4.36 years) participated in this study. Mean spherical refractive errors were–3.38±2.57 D, mean cylinderical errors were–0.46±0.31 D and mean spherical equivalent errors were -3.61±2.64 D. Subjects visited four times and wore single vision, multifocal LOW, MID, and HIGH addition lenses for each visit. They were asked to watch a video with subtitles on a cell phone (4.7 inches) at 40 cm for 60 minutes in order to induce accommodation. After that, MEM, distance and near contrast visual acuity (100% and 10%), near range of clear vision, near point of accommodation, near point of convergence, accommodative facility and stereoacuity were measured and subjective satisfaction was evaluated. Results: As the addition increased, MEM tended to increase and near point of accommodation decreased(p<0.05). On the other hand, with four types of contact lenses, statistically significant differences were not found for distance and near contrast visual acuity, near range of clear vision, near point of convergence, accommodative facility and stereoacuity(p>0.05). Satisfaction with distance vision showed the highest score in single vision contact lenses. Conclusion: As the addition increases, an increase in MEM and a decrease in near point of accommodation are verified. However, differences in the other tests were mostly not significant. Therefore, in order to use the multifocal contact lenses as functional contact lenses, it may be necessary to trance changes in visual function after wearing for a longer period of time.

건성안의 분포와 진단 방법에 대한 연구

유근창(Geun Chang Ryu),박현주(Hyun Ju Park),김재민(Jae Min Kim),이승아(Seung A Lee),나명석(Myung Suk Ra) 한국안광학회 2000 한국안광학회지 Vol.5 No.2

To investigate the distribution of dry eye and to accept diagnosis methods of dry eye in ophthalmic shop, this study was performed on 81 persons ( male : 49, female : 32 ) . 1. We divided two group for diagnosing dry eye by dry eye screening questionnaire : one was dry eye symptom group ( 49.3% ) and the other was non - dry eye symptom group ( 50.7 % ) . 2. Non - invasive break - up time ( NIBUT) which was measured by using Tear scope R ( Killer. co)was longer than invasive break-up time(IBUT). 3. A blink rate in dry eye symptom group(10%) was measured lesser than 10 cycle/min, in non - dry eye symptom group(14.9%). 4. In shirmer test there were lesser than lOmm/5min in dry eye symptom group(67.5%), in non-dry eye symptom group(39%). 5. Cornea and conjunctival staining by rose bengal represented Mild 25%, medium 36.25%, extreme 38.75% in dry eye symptom group. Non-dry eye symptom group was showed Mild 19.51%, medium 14.63%, extreme 12.19%. 6. These results showed that the patient showed dry eye symptom in 3 items of eye examination was 22.5%, 4 items 25%. 5 items 30%. 6 items 15%.

한국인의 양안 시기능 이상에 관한 고찰

유근창(Geun Chang Ryu),박현주(Hyun Ju Park),성정섭(Jeong Sub Seong),김재민(Jae Min Kim) 한국안광학회 2000 한국안광학회지 Vol.5 No.1

To describe the prevalence of binocular anomalies in adult Koreans. Patients included were 19 to 40 years of age, 41 males and 60 females and living in Kwang-Ju Korea. Refractive correction was estimated objectively with an autorefractometer and subjectively refined without cycloplegia. Myopia was defined as a refractive error less than -0.50 diopters hyperopia was defined as a refractive error greater than +0.50 diopters. 101 no strabismic patients who had a refractive error and a near lateral phoria(46%) and an AC/A(accommodative convergence / accommodation) anomaly ( 50.4 % ) . The prevalence of a near vergence anomaly ( 52.5 % ) was higher than a near divergence anomaly ( 55.5% ) . The prevalence of a positive relative accommodation ( PRA ) anomaly (61.4%) was higher than a negative relative accommodation(NRA) anomaly(54.5%). According to Morgan`s analysis method, patients with vergence anomaly(21.7%) were seen slightly less frequently than those with accommodative interaction anomaly(29.7%). 34.6% of patients had both vergence anomaly and accommodative interaction anomaly. These results indicate that full prescription for a refractive corrections should be considered as these can improve binocular visual function for ametropia.

콘택트렌즈 착용에 따른 사용자 실태조사

유근창(Geun Chang Ryu),김인숙(In Suk Kim) 한국안광학회 2002 한국안광학회지 Vol.7 No.1

전기자동차용 공진식 무선충전기의 전력전송거리에 따른 효율 및 출력의 변화에 관한 연구

허창근(Chang Geun Heo),이호영(Ho Yeong Lee),류재호(Jae Ho Ryu),박관수(Gwan Soo Park) 대한전기학회 2016 대한전기학회 학술대회 논문집 Vol.2016 No.3

구강궤양 환자의 타액내 면역글로블린 A 의 농도

유근춘(Geun Chun Ryu),윤창륙(Chang Lyuk Yoon) 조선대학교 구강생물학연구소 1994 Oral Biology Research (Oral Biol Res) Vol.18 No.1

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LC,Acute : PO-29 ; Effect of balloon-occluded retrograde transvenous obliteration on liver function

( Kwang Duck Ryu ),( Jeong Heo ),( Hyun Young Woo ),( Dong Uk Kim ),( Gwang Ha Kim ),( Geun Am Song ),( Mong Cho ),( Ki Tae Yoon ),( Chang Won Kim ) 대한간학회 2012 춘·추계 학술대회 (KASL) Vol.2012 No.1

Background: Balloon-occluded retrograde transvenous obliteration (BRTO) is one of the therapeutic methods for the treatments of gastric varices with splenorenal shunt. BRTO is a very useful treatment in terms of bleeding control. However there are few reports that evaluated about influence of liver function after BRTO procedures. Methods: From August 2004 to September 2011 at Pusan National University Hospital, we retrospectively reviewed the medical records of patients with liver cirrhosis, who were performed the BRTO procedures to treat their gastric varices or gastric variceal bleeding. The improvement of liver function was defined reduction of Child-Pugh (CP) score. CP class checked at before BRTO, 3month and 6month after. Results: Total 81 patients were analyzed. At baseline, 40.7% was CP class A, 53.1% CP class B, 4.9% CP class C. CP class data at 3 months was available in 57 patients and at 6 months in 42 patients. At 3 month, CP class was improved in 17.3% (14/81), not changed in 49.4% (40/81) and worsened in 3.7% (3/81). At 6 month, CP class was improved in 16.0% (13/81), not changed in 27.2% (22/81) and worsened in 6.2% (5/81). In multivate analysis, independent predictor associated with improvement of liver dysfunction was only CP class at baseline (p=0.005). Patient with improvement at 3 months was CP class A in 0, CP class B in 13 and CP class C in 1. Patient with improvement at 6 months was CP class A in 1, CP class in 11 and CP class C in 1. Rebleeding after BRTO occurred in 6 patients and all of them had baseline CP class B (p=0.044) Conclusion: Liver dysfunction was not significantly worsened in cases of liver cirrhosis after BRTO procedures. Liver function might be improved in some patients after BRTO.

LC, Acute : PO-29 ; Effect of balloon-occluded retrograde transvenous obliteration on liver function

( Kwang Duck Ryu ),( Jeong Heo ),( Hyun Young Woo ),( Dong Uk Kim ),( Gwang Ha Kim ),( Geun Am Song ),( Mong Cho ),( Ki Tae Yoon ),( Chang Won Kim ) 대한간학회 2012 춘·추계 학술대회 (KASL) Vol.2012 No.-

Background: Balloon-occluded retrograde transvenous obliteration (BRTO) is one of the therapeutic methods for the treatments of gastric varices with splenorenal shunt. BRTO is a very useful treatment in terms of bleeding control. However there are few reports that evaluated about influence of liver function after BRTO procedures. Methods: From August 2004 to September 2011 at Pusan National University Hospital, we retrospectively reviewed the medical records of patients with liver cirrhosis, who were performed the BRTO procedures to treat their gastric varices or gastric variceal bleeding. The improvement of liver function was defined reduction of Child-Pugh (CP) score. CP class checked at before BRTO, 3month and 6month after. Results: Total 81 patients were analyzed. At baseline, 40.7% was CP class A, 53.1% CP class B, 4.9% CP class C. CP class data at 3 months was available in 57 patients and at 6 months in 42 patients. At 3 month, CP class was improved in 17.3% (14/81), not changed in 49.4% (40/81) and worsened in 3.7% (3/81). At 6 month, CP class was improved in 16.0% (13/81), not changed in 27.2% (22/81) and worsened in 6.2% (5/81). In multivate analysis, independent predictor associated with improvement of liver dysfunction was only CP class at baseline (p=0.005). Patient with improvement at 3 months was CP class A in 0, CP class B in 13 and CP class C in 1. Patient with improvement at 6 months was CP class A in 1, CP class in 11 and CP class C in 1. Rebleeding after BRTO occurred in 6 patients and all of them had baseline CP class B (p=0.044) Conclusion: Liver dysfunction was not significantly worsened in cases of liver cirrhosis after BRTO procedures. Liver function might be improved in some patients after BRTO.