• Title/Summary/Keyword: biomaterials

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Biomaterials-assisted spheroid engineering for regenerative therapy

  • Lee, Na-Hyun;Bayaraa, Oyunchimeg;Zechu, Zhou;Kim, Hye Sung
    • BMB Reports
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    • v.54 no.7
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    • pp.356-367
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    • 2021
  • Cell-based therapy is a promising approach in the field of regenerative medicine. As cells are formed into spheroids, their survival, functions, and engraftment in the transplanted site are significantly improved compared to single cell transplantation. To improve the therapeutic effect of cell spheroids even further, various biomaterials (e.g., nano- or microparticles, fibers, and hydrogels) have been developed for spheroid engineering. These biomaterials not only can control the overall spheroid formation (e.g., size, shape, aggregation speed, and degree of compaction), but also can regulate cell-to-cell and cell-to-matrix interactions in spheroids. Therefore, cell spheroids in synergy with biomaterials have recently emerged for cell-based regenerative therapy. Biomaterials-assisted spheroid engineering has been extensively studied for regeneration of bone or/and cartilage defects, critical limb ischemia, and myocardial infarction. Furthermore, it has been expanded to pancreas islets and hair follicle transplantation. This paper comprehensively reviews biomaterials-assisted spheroid engineering for regenerative therapy.

Chromium(VI) Adsorption Behavior of Silk Sericin Beads

  • Kwak, Hyo Won;Yang, Ye Sol;Kim, Moo Kon;Lee, Jeong Yun;Yun, Haesung;Kim, Min Hwa;Lee, Ki Hoon
    • International Journal of Industrial Entomology
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    • v.26 no.1
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    • pp.47-53
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    • 2013
  • Silk sericin (SS) has been fabricated into beads using a 1 M LiCl/DMSO solvent and utilized as a heavy metal adsorbent. Among the various heavy metals, we targeted Cr(VI) for adsorption using SS beads and found that its adsorption depended on the coagulant used for the fabrication of the SS beads. When methanol was used as a coagulant, the beads had a better adsorption capacity than when ethanol was used except at pH 1. The adsorption behavior of Cr(VI) on the SS beads followed the BET isotherm. The maximum adsorption capacity was 33.76 mg/g at pH 2. The adsorption of Cr(VI) was confirmed by FT-IR and EDS analyses. Finally, the desorption was carried out using NaOH solution, and it was found that 73.19% of the adsorbed Cr(VI) could be detached.

Overexpression of Arabidopsis Homogentisate Phytyltransferase or Tocopherol Cyclase Elevates Vitamin E Content by Increasing γ-tocopherol Level in Lettuce (Lactuca sativa L.)

  • Lee, Koeun;Lee, Sa Mi;Park, Sang-Ryoung;Jung, Jinwook;Moon, Joon-Kwan;Cheong, Jong-Joo;Kim, Minkyun
    • Molecules and Cells
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    • v.24 no.2
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    • pp.301-306
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    • 2007
  • Tocopherols, essential components of the human diet, are synthesized exclusively by photosynthetic organisms. To increase tocopherol content by increasing total flux to the tocopherol biosynthetic pathway, genes encoding Arabidopsis homogentisate phytyltransferase (HPT/V-TE2) and tocopherol cyclase (TC/VTE1) were constitutively overexpressed in lettuce (Lactuca sativa L.). Total tocopherol content of the transgenic plants overexpressing either of the genes was increased by more than 2-fold mainly due to an increase in ${\gamma}$-tocopherol. However, chlorophyll content in the HPT/VTE2 and TC/VTE1 transgenic lines decreased by up to 20% and increased by up to 35%, respectively (P < 0.01). These results demonstrate that manipulation of the tocopherol biosynthetic pathway can increase or decrease chlorophyll content depending on the gene introduced.

Construction of Novel Bifunctional Chimeric Proteins Possessing Antitumor and Thrombolytic Activities

  • Hui, Jing;Dai, Youjin;Bian, Yuanyuan;Li, Hui;Cui, Xiaojin;Yu, Xiaojie;You, Song;Hu, Fengqing
    • Journal of Microbiology and Biotechnology
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    • v.22 no.7
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    • pp.894-901
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    • 2012
  • Based on their respective antitumor and thrombolytic activities, the superantigen staphylococcal enterotoxin C2 (SEC2) and staphylokinase (Sak) were chosen for the construction of the novel chimeric proteins Sak-linker-SEC2 and SEC2-linker-Sak using a linker composed of nine Ala residues. Both chimeric proteins possessed nearly the same PBMC proliferation stimulating activity and antitumor activity as SEC2 and thrombolytic activity as Sak. Neither the SEC2 or Sak component of each chimeric protein affected the activity of the other component. The results presented in this study provide a possible strategy to prevent and cure tumor thrombus.

Inhibitory Effect of Cirsium japonicum Root or Flower Extract on Hepatic Stellate Cells Activation (엉겅퀴 뿌리 및 꽃 추출물의 간 성상세포 활성 억제 효과)

  • Kim, Sang-Jun;Kim, Seon-Young;Kim, Ji-Ae;Park, In-Sun;Yu, Kang-Yeol;Chung, Chang-Ho;Shim, Jae-Suk;Jang, Seon-Il;Jeong, Seung-Il
    • Korean Journal of Pharmacognosy
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    • v.43 no.1
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    • pp.27-31
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    • 2012
  • This study was designed to elucidate the effects of Cirsium japonicum (CJ) extracts on hepatic stellate cells (HSCs, LX-2 cells) proliferation, which is induced by platelet-derived growth factor (PDGF) or transforming growth factor-${\beta}$ (TGF-${\beta}$). The content of total phenol, flavonoid, and silymarin derivatives was more higher in CJ-flower than in CJ-root. Consistent with these results, the LX-2 cells growth inhibition was more effective in CJ-flower extract than in CJ-root extract, the complete growth inhibition concentration was $1{\mu}g/mL$ and $50{\mu}g/mL$, respectively. These results suggest that extracts from CJ-flower can be potentially used as therapeutic substances for the regulatioin of HSCs activation.

Recent updates for biomaterials used in total hip arthroplasty

  • Hu, Chang Yong;Yoon, Taek-Rim
    • Biomaterials Research
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    • v.22 no.4
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    • pp.259-270
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    • 2018
  • Background: Total hip arthroplasty (THA) is probably one of the most successful surgical interventions performed in medicine. Through the revolution of hip arthroplasty by principles of low friction arthroplasty was introduced by Sir John Charnley in 1960s. Thereafter, new bearing materials, fixation methods, and new designs has been improved. The main concern regarding failure of THA has been the biological response to particulate polyethylene debris generated by conventional metal on polyethylene bearing surfaces leading to osteolysis and aseptic loosening of the prosthesis. To resolve these problems, the materials of the modern THA were developed since then. Methods: A literature search strategy was conducted using various search terms in PUBMED. The highest quality articles that met the inclusion criteria and best answered the topics of focus of this review were selected. Key search terms included 'total hip arthroplasty', 'biomaterials', 'stainless steel', 'cobalt-chromium', 'titanium', 'polyethylene', and 'ceramic'. Results: The initial search retrieved 6921 articles. Thirty-two articles were selected and used in the review. Conclusion: This article introduces biomaterials used in THA and discusses various bearing materials in currentclinical use in THA as well as the newer biomaterials which may even further decrease wear and improve THA survivorship.

Fundamental Biotribological Characteristics between Biomaterials and Small Intestine (생체내 미소의료기기에 대한 Biotribology 기초연구)

  • 김영태;권은영;정효일;김대은
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.1361-1364
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    • 2004
  • There is a need for fundamental understanding of biotribological characteristics of various biomaterials sliding against biological materials in order to develop a moving mechanism of medical microsystems having high energy efficiency. A special experimental equipment was designed and built to study the frictional behavior of various biomaterials sliding against a small intestine specimen of a pig. Friction experiments for six biomaterials were performed. Particularly, the effects of load and speed on frictional behavior were investigated. The results of this work will aid in the development of the actuator for a self-propelling micro-endoscope.

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