• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1697-1699
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• 2008

The purpose of tissue engineering is to repair or replace damaged tissues or organs by a combination of cells, scaffold, suitable biochemical and physio-chemical factors. Among the three components, the biodegradable scaffold plays an important role in cell attachment and migration. In this study, we designed 3D porous scaffold by Rapid Prototyping (RP) system and fabricated layer-by-layer 3D structure using Polycarprolactone (PCL) - one of the most flexible biodegradable polymer. Furthermore, the physical and mechanical properties of the scaffolds were evaluated by changing the pore size and the strand diameter of the scaffold. We changed nozzle diameter (strand diameter) and strand to strand distance (pore size) to find the effect on the mechanical property of the scaffold. And the surface morphology, inner structure and storage modulus of PCL scaffold were analyzed with SEM, Micro-CT and DMA.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.179-179
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• 2006

PLGA/HA composite scaffold fabricated by GF/PL method showed enhanced mechanical property, hydrophilicity and osteoconductivity compared with the SC/PL scaffolds, and this enhancement was most likely due to a higher extent of exposure of HA particles to the scaffold surface. The biodegradable polymer/bioceramic composite scaffolds fabricated by the GF/PL method could enhance bone regeneration efficacy for the treatment of bone defects compared with conventional composite scaffolds.

• 대한의용생체공학회:의공학회지
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• 제36권6호
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• pp.251-263
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• 2015

Scaffolds play a crucial role in the tissue engineering. Biodegradable polymers with great processing flexibility and biocompatability are predominant scaffolding materials. New developments in biodegradable polymers and their nanocomposites for the tissue engineering are discussed. Recent development in the scaffold designs that mimic nano and micro features of the extracellular matrix (ECM) of bones, cartilages, and vascular vessels are presented as well.

• 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.

• KSBB Journal
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• 제19권3호
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• pp.210-214
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• 2004

본 연구에서는 생분해성 고분자 담체인 PGA 담체에 부착된 간세포의 이식을 통해서 이식된 간세포가 괴사하지 않고 남아 있으며 간 조직 구조의 일종인 담세관 유사구조를 확인하였다. 조직공학적인 간세포 이식 방법의 개발은 간 질환에 새로운 치료방법 개발의 가능성을 열어줄 수 있다.

• 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.

• 한국기계가공학회지
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• 제13권3호
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• pp.35-41
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• 2014

Poly(g-glutamic acid) (g-PGA) is a very promising biodegradable polymer that is produced by microorganism of Bacillus subtilis. Because g-PGA is water-soluble, anionic, biodegradable, and even edible, its potential applications have been studied from an industrial standpoint. In this study, we fabricated porous g-PGA foams by means of a freeze-solvent extraction method for tissue-engineering applications. Porous g-PGA foams were chemically cross-linked using a hexamethylene diisocyanate solution. An aqueous basic solution was used to neutralize g-PGA foam for cell culturing. During an in vitro cell culture study, it was observed that primary rabbit ear chondrocytes were well at tached and spread over the surface oft hree-dimensional cross-linkedg-PGA foam. From these results, it is concluded that cross-linkedg-PGA foam is aprom is in gmaterial for tissue-engineering applications, especially those pertaining to the regeneration of human cartilage.

• 한국정밀공학회지
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• 제29권1호
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• pp.33-40
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• 2012

The scaffold serves as 3D substrate for the cells adhesion and mechanical support for the newly grown tissue by maintaining the 3D structure for the regeneration of tissue and organ. In this paper, we proposed integrated scaffold fabrication system using multi-axis rapid prototyping (RP) technology. It can fabricate various types of scaffolds: arbitrary sculptured shape, primitive shape, and tube shape scaffolds by layered dispensing biocompatible/ biodegradable polymer strands in designated patterns. In order to fabricate the 3D scaffold, we need to generate the plotting path way for the scaffold fabrication system. We design a data processing program - scaffold plotting software, which can convert the 3D STL file, primitive and tube model images into the NC code for the system. Finally, we fabricated the customized 3D scaffolds with high accuracy using the plotting software and the fabrication system.

• International Journal of Precision Engineering and Manufacturing
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• 제9권2호
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• pp.81-83
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• 2008

The Rapid Prototyping (RP) technology has advanced in many application areas. In this research, two different types, cylinder and scaffold, of implantable Drug Delivery System (DDS) were fabricated using Nano Composite Deposition System (NCDS), one of the RP systems. The anti-cancer drug (5-fluorouracil, 5-FU), biodegradable polymer (PLGA(85: 15)), and bio ceramic (Hydroxyapatite, HA) were used to form drug-polymer composite material. Both types of DDS were evaluated in vivo environment for two weeks. For evaluation, the cumulative drug release and shape stability were measured. Test results showed that the scaffold DDS provide higher cumulative drug release and has better stability than cylinder DDS.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1265-1270
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• 2007

Conventional methods for fabricating three-dimensional (3-D) scaffolds have substantial limitations. In this paper, we present 3-D scaffolds that can be made repeatedly with the same dimensions using a microstereolithography system. This system allows the fabrication of a pre-designed internal structure, such as pore size and porosity, by stacking photopolymerized materials. The scaffolds must be manufactured in a material that is biocompatible and biodegradable. In this regard, we synthesized liquid photocurable biodegradable TMC/TMP, followed by acrylation at terminal ends. And also, solidification properties of TMC/TMP polymer are to be obtained through experiments. Cell adhesion to scaffolds significantly affects tissue regeneration. As a typical example, we seeded chondrocytes on two types of 3-D scaffold and compared the adhesion results. Based on these results, the scaffold geometry is one of the most important factors in chondrocyte adhesion. These 3-D scaffolds could be key factors for studying cell behavior in complex environments and eventually lead to the optimum design of scaffolds for the regeneration of various tissues, such as cartilage and bone.