Analysis for Osteoarthritis of the Ankle Joint in a Mouse Model of Chronic Ankle Instability

Sung-Hyun Lee 忠南大學校 大學院 2022 국내박사

발목 염좌는 스포츠 및 신체 활동 중에 경험하는 가장 흔한 정형외과적 병태 생리이며 종종 만성 발목 불안정성을 초래한다. 이 연구의 목적은 수술용 만성 발목 불안정성 마우스 모델에서 발목 관절의 골관절염 변화를 평가하는 것이다. Ankle sprains are the most common orthopedic pathology experienced during sports and physical activity and often result in chronic ankle instability (CAI). The purpose of this study was to assess osteoarthritic changes in the ankle joint in a surgical CAI mouse model.

기능기화 된 탄소나노튜브 개질전극에서 몇 가지 생체 화합물의 전극 촉매 산화 반응에 대한 연구

정혜란 전북대학교 일반대학원 2014 국내석사

The electrochemical oxidations of biological compounds such as ascorbic acid, catechol, dopamine, and uric acid were measured employing a bare glassy carbon electrode (GC) and carbon nanotube-modified glassy carbon electrodes. In this study, carboxylic groups or amino groups were introduced on single-walled carbon nanotubes (SWNT) to prepare carboxylic group-functionalized SWNTs (SWNT-COOH) or amino group-functionalized SWNTs (SWNT-CONH(CH2)2NH2). The functionalizations were confirmed by FT-IR and XPS analyses indicating the groups at both ends and on the sidewalls of the SWNTs. The functionalized SWNTs were then coated on the GC surfaces using a cross-linker, and two different SWNT-modified electrodes were prepared. Under the pH range within pH 3 ~ pH 11, cyclic voltammetric measurements were performed for the electrocatalytic oxidation reactions of the biological compounds, and comparisons to the bare GC electrode were made. Increasing the pH up to 8, enhancements of the oxidation currents of the electroactive biological compounds at the SWNT-COOH-modified electrode and the SWNT-CONH(CH2)2NH2-modified electrode were obtained. In solutions of higher pH range than 8, decreased oxidation currents of the biological compounds at the SWNT-COOH-modified electrode were observed while increases of the currents at the SWNT-CONH(CH2)2NH2-modified electrode were resulted. In overall, the electrode modified with amino group-functionalized SWNTs showed enhanced catalytic activities for the electro-oxidations of the biological compounds.

Comparative Study of Achilles Tendon Healing Outcomes after Open Tenotomy versus Percutaneous Tenotomy : : An Experimental Study in Rat=

송재황 忠南大學校 大學院 2021 국내박사

Background: The optimal treatment of Achilles tendon ruptures (ATR) remains controversial. Due to limitations of conventional open repair regarding its complication including wound breakdown or healing complications, numerous minimally invasive repair techniques have been developed and several clinical studies reported their favorable results. However, there was no experimental comparative study of spontaneous Achilles tendon healing outcomes between two different incision methods itself. Hypothesis/Purpose: Achilles tendon healing of rat between open tenotomy (OT) and percutaneous tenotomy (PT) may have different results regarding functional, biomechanical, and histological investigation. Here, we evaluated whether OT and PT of Achilles tendon have different outcomes in rats with ATR. Study Design: Controlled laboratory study. Methods: The right Achilles tendons of 42 Sprague–Dawley rats were transected. The animals were divided into 2 groups according to surgical technique: the OT and the microscopy-assisted PT. After 1, 2, and 4 weeks, Achilles functional index (AFI) for functional study, cross sectional area (CSA), load to failure, and stiffness for biomechanical investigation, and modified Bonar score for histologic evaluation were performed. Results: PT group showed superior AFI than OT group at 1 week (P = .009). CSA of the PT group was significantly larger than the OT group at 4 weeks (P = .008). Comparison to native tendon, load to failure of the PT group yielded comparable result at 2 weeks (P = .264) and that of the OT group showed comparable result at 4 weeks (P = .396). There was no significant difference in stiffness between the two groups at all time points. The histologic score of the PT group was significantly superior than the OT group at 1 week (P = .049) and 2 weeks (P = .014). Overall, Achilles tendon healing in the PT group showed earlier restoration and superior functional, biomechanical, histological results compared with OT group. Conclusions: Functional, biomechanical, histological properties of the tendon healing was significantly affected by incision methods. Minimal incision showed more rapid, favorable tendon healing than open incision. Clinical Relevance: As the PT showed more rapid and favorable tendon healing than the OT in the present study, surgeon may consider the minimally invasive repair as a good treatment option for ATR under the assumption of adequate repair. Keywords: Achilles tendon; tendon healing; rat; open tenotomy; percutaneous tenotomy; open repair; minimally invasive repair; microscopic What is known about the subject?: Several studies have advocated minimally invasive repair reporting diverse advantages including lower infection and wound breakdown rates. However, scientific quality of papers comparing open to minimally invasive repair is heterogeneous, with most articles mainly reporting clinical outcomes, without structured, experimental methods to evaluate the effectiveness of the technique. What this study adds to existing knowledge?: The present study is the first in vivo comparative study of spontaneous Achilles tendon healing outcomes between OT and PT which was performed by well demonstrated animal experimental methods including functional, biomechanical and histologic evaluation. The present study might suggest a novel reference from a new angle about the advantage of minimal approach for the treatment of ATR over its previously well-known strengths. 서론: 아킬레스건 파열은 스포츠 인구의 증가와 함께 그 빈도가 증가하고 있다. 하지만 아직까지 급성 아킬레스건 파열에 대한 최선의 치료에 대해서는 정해진 바가 없다. 고식적인 개방적 봉합술은 아킬레스건 파열단을 육안으로 직접 확인하며 봉합할 수 있는 장점이 있지만 큰 절개로 인한 감염, 유착, 피부 괴사 등의 합병증이 술식의 제한점으로 남아있다. 이러한 단점을 보완하기 위하여 여러 최소 침습적 소절개 술식이 개발, 연구되었고 이들의 임상적, 기능적 결과는 우수한 것으로 보고되었다. 하지만 지금까지 동물 실험을 통하여 아킬레스건의 고식적 개방적 절개술과 소절개술에 대한 비교 연구는 보고된 적이 없었다. 이에 저자들은 개방적 절개술과 경피적 절개술이 rat의 파열된 아킬레스건의 자연 치유 과정에 어떠한 영향을 미치는지 알아보고자 하였다. 가설: 저자들은 개방적 절개술과 경피적 절개술이 rat의 파열된 아킬레스건의 치유에 있어서 다른 기능적, 생역학적, 조직학적 결과를 보일 것으로 예상했다. 재료 및 방법: 42마리의 Sprague Dawley rat (8주령)을 두 군으로 나누어 우측에 대한 아킬레스건 절단술을 시행하였고 한 군 (21족)은 개방적 절개술 (개방군)을, 한 군 (21족)은 현미경적 경피적 절개술(소절개군)을 시행하였다. 수술 후 1, 2, 4주차에 기능적 검사로 Achilles functional index (AFI)를 조사하였고 안락사를 진행 후 생역학적 검사로 cross sectional area(CSA), load to failure와 stiffness를 측정하였으며, 조직학적 검사로는 Hematoxylin-eosin, Masson trichrome, Alcian blue 염색을 통한 modified Bonar score를 측정하였다. 결과: 기능적 검사 결과에서 수술 후 1주차에 소절개군이 개방군에 비해 AFI score가 유의하게 높았다. 생역학적 검사 결과에서 수술 후 4주차에 소절개군이 개방군에 비해 CSA가 유의하게 증가되어 있었고 전체 실험 기간 동안 소절개군이 대조군에 비해 CSA가 컸다. 전체 실험 기간 동안 소절개군과 개방군의 load to failure와 stiffness는 유의한 차이가 없었다. 그러나 load to failure를 대조군과 비교하였을 때, 소절개군은 수술 후 2주차에 비슷한 결과를 보였고 개방군은 4주차에 비슷한 결과를 보였다. 조직학적 검사 결과 1, 2주차에 소절개군이 개방군에 비하여 modified Bonar score가 유의하게 우수한 것으로 확인되었다. 결론: 실험 결과 소절개군이 개방군에 비하여 조기에 기능적, 생역학적, 조직학적 결과가 우수한 것으로 확인되었다. 본 연구에서는 소절개에서 봉합술을 시행하기가 불가하였다는 제한점이 있지만 절개 방법 자체가 아킬레스건의 치유 과정에 영향을 줄 수 있는 것을 확인하였고 소절개가 조기 자연 치유 과정에서 우월한 절개 방법임을 확인하였다. 추후 rat 아킬레스건을 이용한 다른 힘줄 실험에서도 현미경적 소절개 방식이 보존적 치료 또는 최소 침습 방식의 한 실험 모델이 될 수 있을 거라 사료된다

간섭적 효과를 회피하는 직접적 글루코즈 산화를 위한 다공성 금 양극 및 산소 환원을 위한 빌리루빈 옥시다제 음극에 관한 연구

조상은 전북대학교 대학원 2009 국내박사

본 연구는 PAA-PVI-[Os(dcl-bpy)2Cl]^(+/2+)와 BOD 효소가 전선연결된 BOD 음극에서의 촉매적 산소 환원반응의 비활성화를 초래하는 유레이트의 영향을 극복할 수 있는 새로운 전극수식법에 대하여 수행한 결과이다. BOD 음극과 수식층의 전하분위기를 조절하는 원리를 이용하여 양이온 분위기의 BOD 효소층 위에 음이온 유레이트와 전하반발력을 일으킬 수 있는 음이온막인 나피온을 도입하고자 하였다. 그 결과 나피온 코팅처리는 유레이트에 대한 차단은 효과적이었으나 음이온막인 나피온 자체로 인해 BOD 음극의 활성을 잃게 한다는 것을 확인하였다. 이를 보완하기 위하여 BOD 음극과 나피온막 사이에 양이온 분위기의 BOD 음극을 보호할 수 있도록 양이온 분위기의 양이온 중간막을 도입하였다. PAA-PVI가 적합한 후보 물질임을 확인하였으며, 이후 유레이트 영향을 최소화 하면서 최대의 산소 환원전류를 얻을 수 있는 PAA-PVI 층의 코팅부피를 결정하였다. 최종적으로 25 mg/mL PAA-PVI 15 μL와 1 wt% 나피온 6 μL 순으로 이중막 코팅처리한 BOD 음극을 사용하여 체내 조건과 유사한 pH 7.4, 0.15 M NaCl, 포스페이트 완충용액에서 유레이트의 부정적인 영향을 피한 성공적인 결과를 얻을 수 있었다. 한편 PAA-PVI/나피온-BOD 음극을 세룸에 적용할 경우 3시간 정도에 산소 환원 활성을 잃는 것을 확인하였으며, 이로 인하여 유레이트 이외에도 여러 방해물질의 존재 가능성을 제안하였다. 따라서 유레이트 이외에 세룸 구성 성분인 글루타티온, NADH, SCN^(-), Br^(-), 락테이트, 피루베이트, 하이드로부틸레이트, 아세토아세테이트, 타우린의 영향을 조사하였다. 그 결과 글루타티온, NADH, SCN^(-)이 추가적으로 BOD 음극의 비활성화를 초래하는 물질로 판명되었다. 이들 중 음이온인 NADH와 SCN^(-)은 PAA-PVI/나피온 이중막 코팅처리로 영향을 차단할 수 있었다. 하지만 중성인 글루타티온은 제안한 수식전극에서 50 %에 달하는 전류감소 현상을 야기시켰으며, 이는 글루타티온이 BOD 음극의 비활성에 책임이 있는 세룸 성분 중 하나임을 의심하게 한다. 현단계에서 PAA-PVI/나피온 수식 BOD 음극이 음이온 방해물질의 차단에 효과적임을 알 수 있었으며, 중성 방해물질의 손상 영향을 방지하기 위한 추가적인 연구가 이루어져야 할 것이다. The electrocatalytic glucose oxidation and oxygen reduction reactions have been studied extensively because of their potential applications to sensors and glucose-oxygen biofuel cells. For most results, enzyme electrodes were generally employed. Glucose oxidase or glucose dehydrogenase for the glucose anode, and laccase or bilirubin oxidase for the oxygen cathode have been used. The enzyme electrodes, however, have some disadvantages of a complicated fabrication and insufficient stability due to the instinct enzyme natures. Interfering effects of some electro-oxidizable biological components such as ascorbic acid, urate, and acet- aminophen should be also overcome. This dissertation includes the studies of the direct glucose oxidation at noN^(-)enzymetic porous gold electrodes in part I-1 through I-3 and an anioN^(-)excluding bi-layer protecting the wired-bilirubin oxidase cathode against anioic interfering species in part II. In part I-1, glucose oxidations avoiding the interfering effect of ascorbate at porous gold electrodes after amalgamation treatments were studied. The amalgamation treatment produced a highly porous structure at a gold electrode surface and catalytic effects of reducing overpotential and increasing oxidation currents were resulted. With these effects, a good selectivity for glucose oxidation against ascorbate, which is a common interfering species, could be obtained. With a gold electrode with a 60s amalgamation treatment, an optimal condition was determined and two glucose calibration curves at different potentials were made in a normal human glucose concentration range in the presence of 0.1 mM ascorbate. Sensitivities of 16 Acm^(-2)mM and 32 Acm^(-2)mM at -0.1 V and +0.25 V, respectively, were evaluated. In part I-2, EQCM studies were carried out during the glucose oxidations at a gold surface, on which gold nanoparticles were electrochemically deposited. In an open circuit potential condition, glucose was injected and mass change was detected by the QCM experiments. A spontaneous adsorption of glucose at the electrode surface with the gold nanoparticles attached was observed by the surface mass increase while no mass change was measured at a bare gold electrode. During the oxidation of the adsorbed glucose, the EQCM measurements indicated desorption of the product from the surface. As the surface became inactive, the glucose seemed not to adsorb on the surface any more. In part I-3, an effect of different size of gold nanoparticles in the direct glucose oxidation was investigated. Gold nanoparticles of 7.2, 17.3, and 30.7 nm diameters were prepared and characterized by size distribution analyzer, uv-vis spectroscopy, and FE-SEM. They were spontaneously adsorbed on the EPG surface, which was employed for the glucose oxidation. In the comparison of the glucose oxidation current vs. the microscopic surface area of the gold nanoparticles among different sizes, size effect was observed. As the size of the gold nanoparticles became smaller, higher glucose oxidation current was measured. In part II, studies regarding to the protecting bi-layer against biological components damaging the wired-BOD cathode for the electrocatalytic reduction of O₂ were carried out. The anioN^(-)excluding membrane, Nafion, can not be directly used because of its de-wiring effect in the electrostatic binding of the BOD enzymes with the redox polymer chains. An intermediate layer of cationic polyacrylamide-poly-N^(-)vinylimidazole between the BOD cathode and the anionic Nafion was introduced. With this bi-layer, the BOD in a phosphate buffer solution could be protected from the Nafion layer and influxes of anionic interfering species, such as urate, NADH, and SCN^(-), could be successfully prohibited. The bi-layer over-coated BOD cathode was also examined in a bovine serum, and its activity was still lost in a few hours, which suggests the existence of other damaging species in addition to the anionic interfering species.

전자전달 능력이 개선된 효소전극으로 구성하는 글루코즈-산소 바이오 연료전지에 관한 연구

송지선 전북대학교 대학원 2011 국내박사

Catalyzed oxygen reduction on bilirubin oxidase (BOD) cathode, and glucose oxidation (GOx) on glucose oxidase anode with improved electron conducting abilities were studied. A glucose-oxygen biofuel cell was also constructed with those two enzyme electrodes for better performances. In part I, BOD electrocatalyst wired by the redox polymer of polyacrylamide poly(N-vinylimidazole) coordinated to [Os(4,4’-dichloro-2,2’-bipyridine)₂Cl]^(+/2+) (PAA-PVI-[Os(dCl-bpy)₂Cl]^(+/2+)) over the single-walled carbon nanotube (SWNT) layer for O₂ reduction was studied. The SWNTs, whose surfaces were treated to introduce carboxylic functional groups (SWNT-COOH), were utilized. An enhancement of current density by about 50% in comparison to the same BOD cathode on a conventional GC surface was obtained. Systematic studies with different amounts of SWNTs, BOD wt %, and amount of catalyst were carried out to find an optimized condition for the catalytic reduction of O₂. In part II, conducting molecules instead of the wiring redox polymer were introduced in the BOD electrocatalyst film layer for better electron transferring for the electrocatalytic O₂ reduction. As one method, the conducting molecules were simply mixed with BOD enzymes and copolymer of polyacrylamide poly(N-vinylimidazole) (PAA-PVI). For another method, the conducting molecules were covalently bonded to the PAA-PVI polymer, which was then cross-linked to BOD enzyme molecules. BOD cathodes were prepared by coating the BOD electrocatalyst films on the electrode surfaces and then employed for the reduction of O₂. Enhanced current densities of O₂ reduction were measured in comparison to that with the electrode with the BOD film not including any conducting species. In part III, GOx wired by the redox polymer of polyacrylamide poly(N-vinylimidazole) coordinated to [Os(4,4’-dimethyl-2,2’-bipyridine)₂Cl]^(+/2+) (PAA-PVI-[Os(dme-bpy)₂Cl]^(+/2+)) mixed with SWNT-COOH was employed as the electrocatalyst for the glucose oxidation. The current density for the glucose oxidation with the wired GOx enzyme electrode mixed with SWNT-COOHs was measured twice as high as the current with the same electrode without containing the SWNT-COOHs. The electrode also showed the inhibition effect against chloride ions. In part IV, glucose-oxygen biofuel cell composed of glucose oxidase anode and bilirubin oxidase cathode was constructed. For both electrodes, enzyme catalysts were wired by redox polymers and mixed with SWNT-COOHs for better activities. Under air saturated 3 mM glucose solution in pH 7.4 potassium phosphate buffer with 0.15M NaCl at 37.5℃, the obtained power density of the proposed biofuel cell was as high as 104 ㎼/㎠ with a voltage of 0.26 V, which demonstrated improved performances than those of the reported results.

탄소나노튜브에 흡착된 구리 콤플렉스를 촉매로 하는 산소 환원반응 및 전기화학적 활성인 몇 가지 생체 화합물의 동시 결정에 관한 연구

신은정 전북대학교 대학원 2011 국내석사

In part I, oxygen reduction catalyzed by copper complexes adsorbed on single-walled carbon nanotube(SWNT) modified glassy carbon electrodes was studied. Complexes of Cu(II) with 1,10-phenanthroline, 5-chloro-1,10-phenanthroline, and 2,9-dimethyl-1,10-phenanthroline ligands were irreversibly adsorbed on SWNT electrode-modified glassy carbon electrode surfaces. Effects depending on various parameters such as adsorption time and amount of SWNT immobilized were examined. It was found that the slope of the Koutecky-Levich plot from rotating electrodes was parallel to that calculated for the four-electron reduction of O2 to water. The result demonstrated that the copper complexes adsorbed on the SWNT-modified electrodes showed superior catalytic effects for the four-electron reduction of O2 to water. In part II, a simultaneous determination of several electro-active biological compounds was studied. A mixture of ascorbic acid (AA), dopamine (DA), and uric acid (UA) was tested and their oxidation potentials are close to each other at conventional electrodes. It is not easy to observe each individual oxidation wave clearly separated. In this study, however, an EPG electrode, whose surface was simply roughened by 2000 SiC paper, was employed and three well separated individual waves were observed. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to obtain the calibration curves for each component. Detection limit, sensitivity, and dynamic concentration ranges were also determined.

탄소나노튜브가 포함된 산화환원 고분자 수식 전극에서 NADH의 전극촉매 산화반응에 대한 연구

신봉선 전북대학교 대학원 2010 국내석사

Nicotinamide adenine dinucleotide (NADH) is a cofactor in a glutamate oxidation reaction with glutamate dehydrogenase and its efficient oxidation with less overpotential is required. In oder to decrease overpotential used the redox polymer of a polyacryamide and poly (N-vinylimidazole) complexed with [Os(4,4'-dimethyl -2,2'-bipyridine)2Cl]+/2+. This redox polymer has more negative potential. Electrocatalytic oxidation of NADH was measured at an redox hydrogel electrode with carbon- nanotubes. The hydrogel film was prepared by coating a mixture of the redox polymer, carbon-nanotubes and poly (ethylene glycol) diglycidyl ether) cross-linker on a graphite electrode. Consequently, the oxidation potential of NADH was observed at 0.10 V. Effects depending on various parameters such as NADH concentration, scan rate, and catalyst amount were examined. The results suggest that the redox hydrogel electrode with carbon-nanotubes can be used in glutamic dehydrogenase based amperometric biosensors.

아민기로 치환된 탄소나노튜브의 이온교환 성질 및 효소전극 적용에 관한 연구

이현아 전북대학교 일반대학원 2015 국내석사

In this study, single-walled carbon nanotubes (SWNTs) were functionalized by attaching ethylenediamine on the sidewalls and the ends of the SWNTs to produce amine group-functionalized SWNTs (SWNT-CONH(CH2)2NH2). A mixture of SWNTCONH(CH2)2NH2 and poly (ethylene glycol) diglycidyl ether (PEGDGE) as a cross-linker was coated on the surface of a glassy carbon electrode and a carbon nanotube modified electrode (aminoSWNT/GC) was prepared. Anionic Fe(CN)63- ions were adsorbed on the surface of amino-SWNT/GC electrode in a solution at low pH and the electrochemical reactions of the adsorbed Fe(CN6)4/Fe(CN6)3- couples were measured. The amino groups were protonated in a low pH solution to bepositively charged and the amino-SWNT/GC electrode showed a new anion-exchange property. The SWNT-CONH(CH2)2NH2 was used in the construction bilirubin oxidase (BOD)cathode for the electrocatalytic reduction of oxygen. The SWNT-incorporated BOD cathode was prepared by dropping a mixture of BOD, PEGDGE and SWNT-CONH(CH2)2NH2 over the carbon cloth-attached glassy carbon surface. The prepared BOD electrode was employed for the oxygen reduction in an airsaturated pH 7.4, 0.04 M phosphate buffer with 0.15 M NaCl at 37.5 ℃. A clear current enhancement for oxygen reduction was observed with SWNT-incorporated BOD cathode in comparison to the BOD cathode without any SWNT incorporated.