시스템사고를 통한 학교 민원 분석: 한나 아렌트의 ‘악의 평범성’을 중심으로

박수아,신은영 한국시스템다이내믹스학회 2024 한국시스템다이내믹스 연구 Vol.25 No.1

The purpose of this paper is to analyze school complaints through systems thinking. In particular, as a result of examining the four subjects of parents, administrators, teachers, and government, focusing on Hannah Arendt’s ‘banality of evil’, it was possible to analyze the process by which evil (the teacher’s extreme choice) arises from the ordinary intentions of each subject. Specifically, parents were found to have ‘failure to consider the method and attitude of expressing demands’ (thoughtlessness) in ‘the process of exercising their children’s right to education’ (non-evil intentions). It was discovered that administrators ‘avoid fundamental solutions’ (thoughtlessness) due to lack of interest in recurring problems ‘in the process of exercising school management and management rights’ (non-evil intentions). In the process of exercising students’ right to education (non-evil intentions), teachers were found to be ‘avoiding fundamental solutions’ (thoughtlessness) due to their lack of interest in recurring problems due to the teaching culture of disinterest and indifference. Lastly, the government was able to discover ‘indifference to school complaints’ (thoughtlessness) in the ‘process of guaranteeing schools’ autonomy’ (non-evil intentions). Based on these results, research implications and future research directions for improving school complaints were presented.

골 대체물 개발을 위한 열처리한 돼지 해면골의 골형성에 대한 평가

박수아,신정욱,양영일,박기동,김영곤,조인희,이진우 한국생체재료학회 2002 생체재료학회지 Vol.6 No.3

The purpose of this study is to investigate the potential of tissue engineered heat-treated porcine trabecular bones as a bone substitute through three dimensional culture system with bone marrow stromal cells (BMSCs). Structural characteristics, mechanical stiffness and chemical composition were investigated. BMSCs were dynamically seeded into the block and cultured by either static or dynamic culturing condition. The cell-seeded bone blocks were examined histologically starting from 3 days up to 21 days after culture. The effects of seeding and culturing conditions on the tissue generation were examined. The effect of the collagen coating on the cell adhesion at initial stage was also investigated. The heat-treated porcine bone block was found to be hydroxyapatite (HA)-based material. It had high porosity (pore size: 300-500 m) and had similar strength to the human trabecular bones (Young’s modulus=346.33 MPa). Observation by scanning electron microscopy (SEM), H&E staining and transmission electron microscopy (TEM) revealed bony tissue regeneration such as the cell adhesion, the formation of osteoids, and generation of lamellar bone and woven bone. The result showed that the dynamic culture was superior to static culture. Although there was no significant effect of the collagen coating on the cell activities, the attachment was improved in collagen coated bone blocks. Based on all the results obtained from this study, we could conclude this heat-treated porcine trabecular bone had the potential of the xenograft for bone regeneration.

Fabrication using a plotting system and in vitro characterization of porous PCL scaffolds

박수아,이준희,이수희,김완두 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.5

Fabrication of Hydrogel Scaffolds Using Rapid Prototyping for Soft Tissue Engineering

박수아,이수희,김완두 한국고분자학회 2011 Macromolecular Research Vol.19 No.7

Three-dimensional (3-D) scaffolds require an interconnected structure with controllable and reproducible porosity to guide cell growth and tissue regeneration for tissue engineering and regenerative medicine. In this study,a cell-plotting system was developed using a solid freeform fabrication (SFF) technique and fabricated hydrogel scaffolds with an interconnected pore structure using various hydrogels such as agarose, Pluronic^® F127, and alginate. The plotting process was characterized using discharge data and the thicknesses of the hydrogel lines. Alginate was plotted under a range of pressures, with optimal plotting at 120 and 220 kPa for 2% and 4% alginate, respectively. The 4% alginate hydrogel was more stable in the plotting process than the 2% alginate. Cells seeded in the hydrogel showed good cell viability in a preliminary in vitro test. 3-D hydrogel scaffolds were produced successfully for soft tissue engineering applications.

Fabrication of Biomimetic PCL Scaffold Using Rapid Prototyping for Bone Tissue Engineering

박수아,이정복,김양은,김지은,이준희,신정욱,권일근,김완두 한국고분자학회 2014 Macromolecular Research Vol.22 No.8

We report the fabrication of a porous three-dimensional (3D) scaffold using a 3D plotting system, withapplications in bone tissue engineering. Biomimetic surface coatings of hydroxyapatite were formed using concentratedsimulated body fluid (SBF). The mineralized scaffold had a uniform interconnected porous structure. The apatitethat was formed on the surface of the scaffold was characterized by using energy dispersive spectroscopy (EDS), Xraypowder diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The biological properties of thescaffold were evaluated using WST-1 assays of alkaline phosphatase (ALP) activity and gene expression of D1 mousemesenchymal stem cells. The results show that the biomimetic scaffolds exhibited good apatite-forming properties,with favorable cell proliferation and differentiation for bone formation. Therefore, these biomimetic scaffolds withhydroxyapatite coatings have potential applications in bone regeneration.

Preparation of Sodium Alginate/Poly(ethylene oxide) Blend Nanofibers with Lecithin

박수아,박고은,김완두 한국고분자학회 2010 Macromolecular Research Vol.18 No.9

Tissue engineered scaffolds are necessary to serve as a bioengineered construct to guide cell growth and tissue regeneration. This study examined an electrospinning method as a simple technique for fabricating tissue engineered scaffolds. Electrospun nanofiber webs have a biocompatibility and high surface area. Therefore, they can be used in the biomedical applications. In this study, sodium alginate (SA) nanofibers were electrospun by blending with a biocompatible poly(ethylene oxide) (PEO) and lecithin. Alginate is a natural polymer extracted from marine brown algae and PEO is a synthetic polymer with non-toxicity and biocompatibility. Lecithin was used as a natural surfactant to fabricate the uniform nanofiber. The solution properties of SA/PEO blends were measured, including the viscosity and conductivity. The characteristics of the SA/PEO blend nanofiber were observed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). In addition, the water absorption ability of the SA/PEO nanofibers was evaluated. The SA/PEO blend nanofibers exhibited a good water absorption and structural morphology. The biocompatibility of the SA/PEO blend nanofibers was confirmed by cell culturing. These electrospun nanofibers showed the potential of wound dressing for exuding wounds.

Development of alginate nanofiber for wound dressing

박수아,박고은 한국고분자학회 2009 한국고분자학회 학술대회 연구논문 초록집 Vol.2009 No.4

플로팅 기법과 전기방사법을 이용한 이중 스케일의 인공지지체 제작

박수아,이준희,김완두 한국고분자학회 2009 한국고분자학회 학술대회 연구논문 초록집 Vol.2009 No.4

기계적 인장 자극에 의한 마이크로패턴화된 기질에서의 세포 배열

박수아,김인애,이용재,황영미,김동화,서승석,신정욱 한국생체재료학회 2006 생체재료학회지 Vol.10 No.2

Mechanical stimuli, such as pressure, tensile or biaxial stretching, fluid-induced shear stress, have been applied to cells to examine the responses of the cells. Also, cells elongate in the direction of the groove and migrate guided by the grooves. Cells are subjected to compression, tension, and shear in the body and undergo specific biochemical changes to respond and adapt to deformation. Cell deformation can be induced by mechanical forces such as cyclic stretch, fluid shear stress, and hydrostatic compressive pressure. Especially, fibroblasts in anterior cruciate ligament (ACL) are continuously stimulated from stretching environment and are aligned along the collagen fibers. This suggests that the mechanical forces change cellular responses such as morphological changes, protein synthesis, cell proliferation, and gene expression. In this study, human ligament fibroblasts (HLFs) were cultivated on micropatterned silicone substrates subjected to cyclic stretch, simulating ligament motion. The profile of silicone substrate was 10/50 and 20/50 μm in width (groove/ridge) and 3 μm in depth. Strain was applied over two days for 4 hours per day with a frequency of 0.5 Hz and its magnitude was set to be 8%. The purpose of this study was to evaluate ligament fibroblast alignment and cellular responses according to pattern size of microgrooved surface and stretching. Ligament fibroblasts in the microgrooved surface were elongated and aligned parallel to the microgrooves under no stretch. However, the formation of stress fibers and their orientation tend to be aligned perpendicular to the stretching direction. And, nuclei position on groove or ridge of micropatterned silicone substrate were located mainly on groove (>=62.5%). We suggest that the silicone microgrooves can be a useful tool to study the ligament fibroblasts under stretch. These results confirmed that for the regeneration of tissue in relation to tissue engineering the isolated and cultured cells or tissues should be cultivated under both appropriate biomechanical and morphological environments. However, further study is recommended to analyze the mechanism of the various cellular responses due to the mechanical stretching to evaluate the optimal mechanical condition for the control of the cellular responses in relation to tissue engineering.

조형가공기술을 이용한 인공지지체의 대기압 플라즈마 개질 효과

박수아,이수희,김완두,한인호,박종철 한국조직공학과 재생의학회 2011 조직공학과 재생의학 Vol.8 No.1s

Scaffolds have been fabricated using conventional techniques such as salt leaching, fiber bonding, phase separation, and gas expansion. However, their interconnected networks for cell ingrowth is not sufficient. Therefore,scaffold design necessitates the application of novel fabrication. Three dimensional (3D) polycaprolactone (PCL)scaffolds were prepared by the plotting system using solid freeform fabrication (SFF) of the rapid prototyping (RP)technique. Also, plasma treatment on the scaffold surface was used to increase the hydrophilicity for the enhancement of the initial cellular adhesion. Helium atmospheric pressure glow discharge (He-APGD) treatment was employed for the scaffold surface modification. The hydrophilized surface after He-APGD treatment could be wetted with culture media well. The scaffolds were supposed to enhance cell attachment. Morphology change and wettability was observed with scanning electron microscopy (SEM) and contact angle measurement system,respectively. Biological responses of osteoblast like cells (MG63) were evaluated with WST-1 and ALP activity assays. Cell morphology on the scaffold were observed using SEM and fluorescent microscopy. In this study, the He-APGD treated 3D PCL scaffolds showed good cellular responses and potential of this modified scaffolds for tissue engineering.