• 제목/요약/키워드: Bioactive material

검색결과 240건 처리시간 0.019초

Design Optimization of Dental Implants Using Finite Element Analysis for Injecting Bioactive Materials

  • Lee, Kang-Soo;Lee, Yong-Keun
    • 한국재료학회지
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    • 제22권6호
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    • pp.292-297
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    • 2012
  • In order to improve osseointegration of dental implants with bone we studied an implant with holes inside its body to deliver bioactive materials based on a proposed patent. Bioactive materials can be selectively applied through holes to a patient according to diagnosis and the integration progress. After the bioactive material is applied, bone can grow into the holes to increase implant bonding and also enhance surface integration. In order to improve the concept and study the effect of bioactive material injection on implant integration, design optimization and integration research were undertaken utilizing the finite element method. A 2-dimensional simulation study showed that when bone grew into the holes after the bioactive material was injected, stress vertically distributed in the upper part of the implant was relieved and mild stress appeared at the opening of the injection holes. This confirmed the effect of the bioactive material and the contribution of the injection holes, but the maximum stress increased ten-fold at the opening. In order to reduce the maximum stress, the size, location, and the number of holes were varied and the effects were studied. When bioactive materials formed an interface layer between the implant and the mandible and four holes were filled with cortical and cancellous bones all the stress concentrated opposite to the loading side without holes disappeared. The stresses at the four outlets of the holes was mildly elevated but the maximum stress value was ten-fold greater compared to the case without the bioactive material.

Induction of caspase-dependent apoptosis in melanoma cells by the synthetic compound (E)-1-(3,4-dihydroxyphenethyl)-3-styrylurea

  • Kim, Ji-Hae;Jang, Young-Oh;Kim, Beom-Tae;Hwang, Ki-Jun;Lee, Jeong-Chae
    • BMB Reports
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    • 제42권12호
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    • pp.806-811
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    • 2009
  • Recently, various phenolic acid phenethyl ureas (PAPUs) have been synthesized from phenolic acids by Curtius rearrangement for the development of more effective anti-oxidants. In this study, we examined the anti-tumor activity and cellular mechanism of the synthetic compound (E)-1-(3,4-dihydroxyphenethyl)-3-styrylurea (PAPU1) using melanoma B16/F10 and M-3 cells. Results showed that PAPU1 inhibited the cell proliferation and viability, but did not induce cytotoxic effects on primary cultured fibroblasts. PAPU1 induced apoptotic cell death rather than necrosis in melanoma cells, a result clearly proven by the shift of cells into sub-$G_1$ phase of the cell cycle and by the substantial increase in cells positively stained with TUNEL or Annexin V. Collectively, this study revealed that PAPU1 induced apoptosis in a caspase-dependent manner, suggesting a potential role as a cancer chemopreventive agent for melanoma cells.

Mycoflora and Enzymatic Characterization of Fungal Isolates in Commercial Meju, Starter for a Korean Traditional Fermented Soybean Product

  • Baek, Jin-Ho;So, Kum-Kang;Ko, Yo-Han;Kim, Jung-Mi;Kim, Dae-Hyuk
    • Mycobiology
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    • 제42권3호
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    • pp.291-295
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    • 2014
  • Mycoflora was assessed in the commercial meju from four well-separated geographic origins. A total of 112 fungal isolates were identified by phenotypic characteristics and molecular taxonomy using sequencing the internal transcribed spacer of the rDNA and revealed 19 species from 13 genera. Enzymatic characteristics of protease and amylase, and mycotoxin production were analyzed.

Design optimization of the outlet holes for bone crystal growing with bioactive materials in dental implants: Part II. number and shapes

  • Lee, Kangsoo;Kim, Geug Tae;Lee, Yong Keun
    • 한국결정성장학회지
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    • 제23권2호
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    • pp.76-80
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    • 2013
  • For further improvement of osseo-integration of bone crystal with a dental implant, a design optimization study is carried out for various holes inside its body to deliver bioactive materials and the effect of bioactive material injection on the bone crystal growing. When bioactive material is absorbed, the bone crystal can grow into holes, which would increase the strength of implant bonding as well as a surface integration. The stress concentrations near the uppermost outlet holes were reduced with increasing the number of outlet holes. A design improvement in the uppermost outlet was shown to be effective in reducing the stress concentration. For design parameters under consideration in this study, total area of outlet of 6.38 $mm^2$ and maximum stress of 1.114 MPa, which corresponds to type 6-C. It is due to the minimization of maximum stress and total area of outlet. The design of the outlet facing down was more effective in reducing the maximum stress value compared with a horizontal symmetry.

미백제 선발을 위한 In Vitro 측정법의 신뢰도 (Reliability of In Vitro Assay for Initial Depigmenting Agent Screening)

  • 호앙구엔;민은엔;라련화;이향복;신정현;김은기
    • 대한화장품학회지
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    • 제34권3호
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    • pp.183-188
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    • 2008
  • 미백제를 선발하기 위해 주로 사용하는 현재의 방법은 in vitro 타이로시네이즈 활성 및 항산화능을 측정하는 것이다. 이 결과에 기초하여 다음 단계인 멜라노사이트에서의 멜라닌 생성량을 측정한다. 세포 내의 멜라닌 생성량 측정 법은 시간, 인력 및 숙련도가 요구된다. 따라서 초기 선발 방법의 신뢰성이 중요하다. 200개 중국시료 중 측정범위 내에서 세포독성이 없는 34개를 대상으로 세포 내 멜라닌량, 타이로시네이즈 활성, 항산화능의 상관관계를 조사하였다. 조사결과 직선의 상판관계를 확인할 수 없었다. 이 결과는 현재 선발방법의 한계 및 새로운 방법이 필요함을 보여주었다.

Design optimization of the outlet holes for bone crystal growing with bioactive materials in dental implants: Part I. cross-sectional area

  • Lee, Yong Keun;Lee, Kangsoo
    • 한국결정성장학회지
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    • 제23권2호
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    • pp.67-75
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    • 2013
  • In order to improve osseo-integration of a dental implant with bone crystal we studied an implant with holes inside its body to deliver bioactive materials based on a proposed patent. After bioactive material is absorbed, bone crystal can grow into holes to increase implant bonding in addition to surface integration. The larger cross section area of outlet holes showed the less values of the maximum stress, and the stress concentrations near the uppermost outlet holes were also reduced with an increasing number of outlet holes. The conclusion, that the uppermost outlet design improvement was most effective to reduce the stress concentration and improve the growth rate of bone crystal, could be drawn. After the design optimizations, Type 6-C had provided the best results in this study. The overall shape optimization studies on the shape, location, number, and so on, of the outlet holes, should be carried out further.

AMPK Activators from Natural Products: A Patent Review

  • Uddin, Mohammad Nasir;Sharma, Govinda;Choi, Hong Seok;Lim, Seong-Il;Oh, Won Keun
    • Natural Product Sciences
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    • 제19권1호
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    • pp.1-7
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    • 2013
  • AMP-activated protein kinase (AMPK) is a major cellular energy sensor and master regulator of metabolic homeostasis. On activation, this cellular fuel sensing enzyme induces a series of metabolic changes to balance energy consumption via multiple downstream signaling pathways controlling nutrient uptake and energy metabolism. This pivotal role of AMPK has led to the development of numerous AMPK activators which might be used as novel drug candidates in the treatment of AMPK related disorders, diabetes, obesity, and other metabolic diseases. Consequently, a number of patents have been published on AMPK activators from natural products and other sources. This review covers the patented AMPK activators from natural products and their therapeutic potential in treatment or prevention of metabolic diseases including diabetes and obesity.

Antimicrobial and Antitumor Photodynamic Effects of Phleichrome from the Phytopathogenic Fungus Cladosporium Phlei

  • So, Kum-Kang;Chun, Jeesun;Kim, Dae-Hyuk
    • Mycobiology
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    • 제46권4호
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    • pp.448-451
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    • 2018
  • Fungal perylenequinones have photodynamic activity and are promising photosensitizers for photodynamic therapy (PDT). Here, we investigated the bactericidal and antitumor activities of phleichrome from the fungal perylenequinone family in vitro. Photodynamic bactericidal activity of phleichrome was analyzed by agar-well diffusion method under dark and illuminated conditions. The photodynamic antitumor activity of phleichrome was analyzed in MCF-7, HeLa, SW480, and HepG2 human cancer cell lines using in vitro cytotoxicity assays. Photodynamic bactericidal activities against Gram-negative and Gram-positive bacteria were species-specific. Antitumor activity against all tumor cell lines increased under the illuminated condition. Depending on the results of the analyses, Phleichrome has potential for further drug development related to its antibacterial and antitumor activities.