• Polymer(Korea)
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• v.25 no.6
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• pp.893-901
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• 2001

We developed the nerve growth factor (NGF) loaded poly (L - lactide) (PLA) scaffolds by means of emulsion freeze drying method to the possibility for the application of the nerve regeneration of spinal cord disease and the degeneration in Alzheimer's disease. The release amount of NGF from NGF loaded PLA scaffold were analyzed over a 4 week period in vitro at phosphate buffered saline (PBS), pH 7.4, at $37^{\circ}C$. It can be observed the open cell pore structure of porous scaffolds and can be easily controlled the pore structure by the controlling of formulation factors resulting in the controlling of the release rate and the release period. The stability of NGF during the preparation of PLA scaffold was evaluated by comparing the released amounts of total NGF, assayed NGF enzyme - linked immunosorbent assay (ELISA). Released NGF has been found to enhance the neurite sprouting and outgrowth from pheochromocytoma (PC-12) cells. These results suggest that the released NGF from NGF loaded PLA scaffold such as conduit type can be very useful for the nerve regeneration in the neural tissue engineering area.

• Archives of Plastic Surgery
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• v.35 no.2
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• pp.127-133
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• 2008

Purpose: The purpose of this study is to evaluate the remodeling process of the various skin substitutes in 4th and 6th weeks following the transplantation when transplanted onto nude mice. Methods: Three types of artificial skin substitutes, such as PLGA scaffold with keratinocyte sheets(group 1), acellular human dermis($Surederm^{(TM)}$) and keratinocyte sheet(group 2), bioengineered skin($Neoderm^{(TM)}$)(group 3), were applied to the wound on nude mice. All mice were killed in 2, 4 weeks and/or 6 weeks after grafting and tissue samples were harvested from the back of mice. The changes in wound size, degree of angiogenesis, formation of basement membrane and epidermis, density of collagen fibers and neural restoration were examined. Results: There was no significant changes in wound size among the three groups. However, the size of wound decreased in the non-substituted group due to contracture. Degree of angiogenesis and systhesis of collagen or neurofilaments were mostly increased in bioengineered skin($Neoderm^{(TM)}$)(group 3), followed by acellular human dermis($Surederm^{(TM)}$) and keratinocyte sheet(group 2), PLGA scaffold with keratinocyte sheets (group 1). However, group 3 and group 2 showed similar thickness of basement membrane and epidermis. Conclusion: We found that degree of angiogenesis, formation of basement membrane and skin appendages, density of collagen fibers and neurofilaments can be the categories to evaluate the success of artificial skin substitution in early stages.

• Prospectives of Industrial Chemistry
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• v.22 no.6
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• pp.26-40
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• 2019

고령화 사회에 접어들면서 신경, 정신질환으로 인한 사회경제적 부담이 늘어나고 있다. 이를 해결하기 위해서는 관련된 신경 회로를 직접적으로 자극하거나 그곳에서 일어나는 일을 실시간으로 감지할 수 있는 장비의 개발이 필수적이다. 하지만 이를 위한 수많은 공학적 도구의 개발에도 불구하고, 뛰어난 공간적/시간적 분해능, 세포형의 선택성, 장시간 안정성을 보유한 신경 인터페이스의 개발은 아직까지도 연구가 필요한 분야이다. 특히 신경전달 원리를 모두 이용하고자 하는 다기능 인터페이스의 개발은 최근 많은 연구자들의 관심 주제이고, 유연성을 가지는 인터페이스 개발 또한 안정성뿐만 아니라 신경 신호의 수명을 좌우하는 중요한 요소이기에 그 중요성을 인정받고 있다. 이를 해결하기 위한 여러 가지 과학적 시도 중에서도, 열 인장 공정으로 제작되는 섬유 형태의 장비는 그 통합적 기능을 수행하는 한 가지 방법으로써 많은 관심을 받고 있다. 이 기술은 다양한 기하학적 구조, 기능적 요소 등을 통합하는데 매우 유리하며, 또한 기존 반도체 공정으로 다루기 어려운 유연성 물질로 마이크로 스케일의 인터페이스를 제작하는 데에 매우 효과적이다. 본 기고문에서는 먼저 현재까지 개발되고 있는 다기능 유연 신경 인터페이스의 연구동향을 소개하고, 특히 그 중에서도 최근에 주목받고 있는 광섬유 기반의 인터페이스 개발에 대해 이야기하고자 한다.

• Journal of Computational Design and Engineering
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• v.1 no.3
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• pp.194-201
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• 2014

Optimization of design is an important step in obtaining tissue engineering scaffolds with appropriate shapes and inner micro-structures. Different shapes and sizes of scaffolds are modeled using UGS NX 6.0 software with variable pore sizes. The quality issue we are concerned is the scaffold porosity, which is mainly caused by the fabrication inaccuracies. Bone scaffolds are usually characterized using a scanning electron microscope, but this study presents a new automated inspection and classification technique. Due to many numbers and size variations for the pores, the manual inspection of the fabricated scaffolds tends to be error-prone and costly. Manual inspection also raises the chance of contamination. Thus, non-contact, precise inspection is preferred. In this study, the critical dimensions are automatically measured by the vision camera. The measured data are analyzed to classify the quality characteristics. The automated inspection and classification techniques developed in this study are expected to improve the quality of the fabricated scaffolds and reduce the overall cost of manufacturing.