• 한국정밀공학회지
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• 제28권7호
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• pp.834-850
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• 2011

In this paper, a novel tissue engineering scaffold design method based on triply periodic minimal surface (TPMS) is proposed. After generating the hexahedral elements for a 3D anatomical shape using the distance field algorithm, the unit cell libraries composed of triply periodic minimal surfaces are mapped into the subdivided hexahedral elements using the shape function widely used in the finite element method. In addition, a heterogeneous implicit solid representation method is introduced to design a 3D (Three-dimensional) bio-mimetic scaffold for tissue engineering from a sequence of computed tomography (CT) medical image data. CT image of a human spine bone is used as the case study for designing a 3D bio-mimetic scaffold model from CT image data.

• 대한지구과학교육학회지
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• 제8권3호
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• pp.387-398
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• 2015

The purposes of this study were to analyze the effect of a scaffold to help in understanding the principle of land and sea breeze through the convection current box experiment and to analyze the students' inference abilities and analogy abilities. For this purpose, the 60 elementary students who had not learned the principle of land and sea breeze were surveyed and analyzed. When using the scaffold to compare the movement of the incense smoke in the convection current box with that of the incense smoke on the outside of the convection current box, the rate of the students who correctly understood the principle of the land and sea breeze between the sea and the land was very low. The result shows that the scaffold used in this study do not help sufficiently in understanding the principle of the land and sea breeze through analogy and it is necessary to introduce a new scaffold for the elementary students to understand it.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 추계학술발표대회
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• pp.35.2-35.2
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• 2011

In this study, hyaluronic acid (HyA) - Gelatin (Gel) hydrogels were prepared at ratio of 15:85 with the goal of obtaining a high uniform porosity and porous biocompatibility scaffold for bone tissue engineering applications. In order to develop a proper scaffold for bone implant application, a HyA-Gel hydrogel loaded in sponge Biphasic Calcium Phosphate (BCP) was prepared. To assay the cytocompatibility and cell behavior on the HyA-Gel hydrogel and HyA-Gel/BCP scaffold, cell attachment and spreading of MSCs seeded on the scaffolds were studied. An invivo study was performed for HyA-Gel/BCP scaffolds after 1 and 3 months implantation. Our results provide a novel and simple method to obtain an adequate scaffold for osteoblast cells and indicate that HyA-Gel hydrogel and HyA-Gel/BCP scaffold could be a good candidate for bone tissue engineering scaffolds.

• 대한안전경영과학회지
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• 제18권2호
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• pp.37-46
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• 2016

Due to increased demand for remodeling and repair in construction market in recent year, the usage of horse scaffold is increasing in the indoor finish works. Injuries related horse scaffold are mainly caused by poor installation or of careless handling of scaffold. Approximately 300 workers are injuried at construction site every year, it is accounting for about 1.5% of the total construction sector and has increased on a year-to-year trends. But the main contents between national standards and speccifications related to the manufacture and usage of horse scaffolds are mutually inconsistent, In particular, the rules on occupational safety and health standards are the basis for the prevention of industrial injuries, there is no explicit application being made to the horse scaffold commonly used on construction sites. The purpose of this study was to analye the manufacture and usage situations in order to reduce construction injuries that occur at the horse scaffolds. It will be utilized the results of the analysis as the basis data for unifying the major domestic standards and specifications associated with the manufacture and usage of horse scaffold.

• 멤브레인
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• 제25권1호
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• pp.48-59
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• 2015

순수용매와 혼합용매를 사용한 상전이를 통하여 poly(L-lactic acid) (PLLA) 스캐폴드 막을 제조하였다. 순수용매로서 chloroform과 1,4-dioxane을 사용하였으며, 이들 순수용매를 혼합하여 혼합용매를 제조하였다. 스캐폴드 막의 모폴로지, 기계적 특성 그리고, 물질전달 특성을 각각 SEM, 인장강도실험 및 당 확산실험을 통하여 측정, 평가하였다. 순수 chloroform 용매를 사용한 용액으로부터는 격벽-공극 구조(solid-wall pore structure)의 스캐폴드 막이 제조되었다. 반면, 순수 1,4-dioxane 용매를 사용한 용액으로부터는 나노섬유 구조의 스캐폴드 막이 제조되었다. 혼합용매의 경우 용매 내의 조성이 변화하면서 다양한 구조의 스캐폴드 막이 제조되었다. 혼합용매 내 1,4-dioxane 함량이 20% 이하인 경우에는 격벽-공극 구조의 스캐폴드 막이 제조되었으며, 1,4-dioxane 함량이 20%인 경우에는 최대직경 $100{\mu}m$의 거대공극을 갖는 구조를 보였다. 1,4-dioxane 함량이 25% 이상인 구간에서는 나노섬유 구조의 스캐폴드 막이 제조되었다. 이 구간에서는 혼합용매 내 1,4 dioxane 함량이 변화함에 따라 나노섬유의 직경이 함께 변화하였다. 나노섬유의 최소직경은 15 nm 가량이었으며, 혼합용매 내의 1,4-dioxane 함량이 80 wt%일 때에 얻어졌다. 이상의 결과를 통하여 용매의 조성은 스캐폴드 막의 구조를 결정짓는 중요한 요소가 된다는 결론을 얻을 수 있었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권6호
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• pp.384-390
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• 2012

Purpose: The purpose of this study is to examine in vivo osteogenesis of cultured human periosteal-derived cells and polydioxanone/pluronic F127 scaffold. Methods: Two one-year-old miniature pigs were used in this study. $2{\times}10^6$ periosteal-derived cells in 1 mL medium were seeded by dropping the cell suspension into the polydioxanone/pluronic F127 scaffold. These cell-scaffold constructs were cultured in osteogenic Dulbecco's modified Eagle's medium for 7 days. Under general anesthesia with azaperone and tiletamine-zolazepam, the mandibular body and ramus of the pigs were exposed. Three bony defects were created. Polydioxanone/pluronic F127 scaffold with periosteal-derived cells and the scaffold only were implanted into each defect. Another defect was left empty. Twelve weeks after implantation, the animals were sacrificed. Results: New bone formation was clearly observed in the polydioxanone/pluronic F127 scaffold with periosteal-derived cells. Newly generated bone was also observed in the scaffold without periosteal-derived osteoblasts and empty defect, but was mostly limited to the periphery. Conclusion: These results suggest that cultured human periosteal-derived cells have good osteogenic capacity in a polydioxanone/pluronic F127 scaffold, which provides a proper environment for the osteoblastic differentiation of these cells.

• 폴리머
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• 제32권3호
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• pp.199-205
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• 2008

단백질 및 펩타이드의 서방형 약물전달체로서 소장점막하조직(SIS)으로 개질된 PLGA 담체를 제조하고자 하였으며, SIS/PLGA 담체는 용매 캐스팅/염 추출법에 의해 준비된 PLGA 담체에 SIS 용액을 첨가하여 단순 함침방법으로 제조하였다. 본 실험에서 사용된 돼지의 소장 점막층에서 유래된 SIS는 면역거부반응이 적어 생체재료로 널리 사용되고 있다. 제조된 PLGA 및 SIS/PLGA 담체를 SEM을 통한 표면 및 내부 관찰결과 두 담체 모두 열린 다공구조를 이루며, 특히 SIS/PLGA 담체는 PLGA 담체의 다공 내부에 SIS가 침투되어 작은 네트워크를 형성하고 있음을 확인하였다. 또한 단백질의 방출경향을 확인하기 위하여 형광이 결합된 소 혈청 알부민(FITC-BSA)을 PLGA 및 SIS/PLGA 담체에 담지시킨 후, 형광광도계를 통해 이들의 방출거동을 확인하였다. PLGA 담체와 비교할 때 SIS/PLGA 담체에서의 BSA의 방출은 초기방출량이 적고 지속적으로 일정량이 방출되는 거동을 확인할 수 있었으며 함량별 BSA 농도에 따른 SIS/PLGA 담체에서의 방출은 BSA의 양이 증가할수록 빠르고 많은 양이 방출되는 경향성 있는 방출패턴을 보임을 확인하였다. 결론적으로 PLGA 담체에 침투한 SIS 젤이 BSA의 급격한 초기방출을 억제하며, SIS로 개질된 PLGA 담체는 방출조절이 가능한 약물전달체로서 매우 유용할 것으로 사료된다.

• 대한기계학회논문집B
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• 제37권3호
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• pp.249-257
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• 2013

쾌속조형기술을 이용한 3차원 형상의 인공지지체가 조직공학 적용을 위해 개발되고 제작되었다. 본 연구에서는 폴리머 적층 시스템을 이용한 스캐폴드 제작에 있어 시린지 노즐 부분에 노즐 가이드를 장착하여 폴리머 적층 폭과 높이 실험을 수행하였다. 이 때 인공지지체 제작을 위한 생체재료로 폴리카프로락톤이 사용되었다. 폴리머 적층 공정 조건으로는 600 kPa의 공압과 $125^{\circ}C$의 온도가 이용되었다. 성공적인 와셔 인공지지체 제작을 통해 폴리머 적층 시스템에 적용된 노즐 가이드의 성능이 검증되었다. 결론적으로, 향상된 폴리머 적층 시스템을 이용함으로써 복잡한 형상의 조직공학용 3 차원 인공지지체를 제작할 수 있을 것으로 기대된다.

• Structural Engineering and Mechanics
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• 제10권1호
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• pp.53-66
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• 2000

This paper proposes a simple numerical model for use in a finite analysis (FEA) of scaffold-shoring systems. The structural model consists of a single set of multiple-story scaffolds with constraints in the out-of-plane direction at every connection joint between stories. Although this model has only two dimensions (termed the 2-D model), it is derived from the analysis of a complete scaffold-shoring system and represents the structural behavior of a complete three-dimensional system. Experimental testing of scaffolds up to three stories in height conducted in the laboratory, along with an outdoor test of a five-story scaffold system, were used to validate the 2-D model. Both failure modes and critical loads were compared. In the comparison of failure modes, the computational results agree very well with the test results. However, in the comparison of critical loads, computational results were consistently somewhat greater than test results. The decreasing trends of critical loads with number of stories in both the test and simulation results were similar. After investigations to explain the differences between the computationally and experimentally determined critical loads, it was recommended that the 2-D model be used as the numerical model in subsequent analysis. In addition, the computational critical loads were calibrated and revised in accordance with the experimental critical loads, and the revised critical loads were then used as load-carrying capacities for scaffold-shoring systems for any number of stories. Finally, a simple procedure is suggested for determining load-carrying capacities of scaffold-shoring systems of heights other than those considered in this study.

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.707-714
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• 2004

How to improve the cell culture method on scaffolds is important in the tissue engineering fileld. In this study, we optimized seeding and culture methods to vascular smooth muscle cells (VSMCs) on biodegradable polymer scaffold. The primary culture of VSMCs obtained from canine external jugular vein was accomplished by applying the explant-derived method. The primary cultured VSMCs were seeded into scaffolds and then cultured by using various different methods; static or dynamic seeding, static or dynamic culture. The difference in proliferative response of VSMCs was analyzed with an alamar blue assay. Cell-polymer construct was examined by histochemical method and scanning electron microscopy. Mesh type scaffold ($10 \times 10 \times0.4 mm$) was made of polyglycolic acid (PGA) suture thread. The PGA mesh type scaffold was 45% in porosity, and 0.03 g in weight. The primary cultured VSMCs were confirmed with immunohistochemical staining using monoclonal anti-$\alpha$-smooth muscle actin. The density and distribution of proliferated VSMCs within the scaffold and cellular adherence on the surface of the scaffold showed better results in the static seeding condition than in the dynamic condition. Under the same condition of seeding method as the static condition, the dynamic culture condition showed enhanced proliferation rates of the VSMCs when compared to the static culture condition. In conclusion, to improve the VSMCs proliferation in vitro, static seeding is better than the dynamic condition. In the culture condition, however, culture under the dynamic status is better than the static condition. This was a pilot study to manufacture artificial vascular vessel by tissue engineering.