著者は、骨軟骨プラグのラッピング過程で彼らの助けのためにUMCユトレヒトでの開発力学グループから氏のJeroenファンデンベルク氏Matthijs Wassinkに感謝の意を表したいと思います。この作品は、オランダの関節炎財団からの助成金によってサポートされていました。

注：ここで紹介するプロトコルは、最近の研究論文6、8、9の実験と計算手順から採用されています。プロトコルは、 図1に示されています。 死体の材料はユトレヒト大学の獣医学部の許可を得て収集しました。 1.サンプルおよびバス製造<ol><li>クールリン酸緩衝生理食塩水（PBS）を噴霧しながら過熱とその後の軟骨損傷を防止するために、カスタムメイドのドリルビット（ 図1）を用いて、死体ウマ大腿骨顆から円筒状の骨軟骨プラグ（8.5ミリメートルの直径）をドリル。 </li><li>オーバーレイ浴の横方向の拡散を最小限に抑えるためにプラスチック収縮スリーブと骨軟骨プラグを熱収縮。 <ol><li>目の軟骨と骨軟骨プラグをマウント電子のトップ当初、プラスチックシュリンクスリーブの内側とそれに熱風を吹き付けてください。熱関連の損傷を防ぐために、軟骨の表面に濡れた綿片を追加します。 </li></ol></li><li>別料金（ 例えば、650μL、420 mMの、イオキサグレート、分子量（Mw）= 1,269 Daの、電荷= -1）および中性（650μL、420ミリモル、イオジキサノール、MW = 1,550 Da）での溶質の有限浴を準備します。 </li><li>注射器を用いて軟骨の表面上に作製有限浴をロードし、RT（ 図2A）での実験中に蒸発を防ぐためにラップされたサンプル上にコルク栓を配置します。ニュートラル溶質輸送を研究するために、イオジキサノール槽を配置し、軟骨表面に負に帯電した溶質輸送場所のイオキサグレートバスを研究します。 </li></ol> 2.画像​​撮影・画像処理<ol><li>マイクロCTの電動ステージに取り付けられた特注ホルダにコルク栓を用いて単離し包まれたサンプルを置きます。置きトン彼は、造影剤溶液で覆われた軟骨表面が上を向いているように、試料。 </li><li>マイクロCT（40×40×40μmの3のボクセルサイズ、2分のスキャン時間、90キロボルトの管電圧及び180μAの管電流）軟骨、軟骨下プレートからなる視野を使用してスキャンし、finite-平衡状態（48時間）までのいくつかの時点で浴（ 図2A）に到達します。濃度値が時間とともに変化していない時に平衡状態が達成されます。 </li><li>メーカーのソフトウェアを使用して、関心領域（ROI）（ 例えば、分析）の位置決めを容易にするために、最初の画像に基づいて、異なる時点で3D画像を登録します。 </li><li>変換した3Dは、メーカーのソフトウェアを使用して、それらを処理する前に、2Dタグイメージファイル形式（TIFF）スタックにマイクロCT画像を再構成します。 </li><li>グローバルセグメント（ImageJの&gt;調整&gt;閾値）軟骨下骨と上から軟骨ソフトウェアのバスタブに横たわっ。 </li><li>前のステップで生成された軟骨のマスクを用いて（ImageJの&gt;&gt;測定分析）異なる時点での軟骨の平均グレー値を得ます。 </li><li>軟骨における初期浴濃度と初期の造影剤濃度を与えられ、溶質の実際の濃度を平均グレー値を変換するために、線形較正曲線を使用します。以前のデータは、グレー値が造影剤の濃度と線形関係を維持することをサポートします。 </li><li>実験の時点対溶質濃度をプロットします。 </li></ol> 3.計算モデル注：この問題に拡散実験境界条件に準拠し、（z軸に沿って）1Dに起こると仮定されます。したがって、ジオメトリが任意に作成することができます。 <ol><li>有限風呂に基づく軟骨マルチゾーンモデルを構築する：1）軟骨表面的なゾーンから成ります<html> （全軟骨厚さの20％）、中間ゾーン（全軟骨厚さの50％）と深いゾーン（全軟骨厚さの30％）12とFEBio 13、14（ 図2Bの2）有限浴）。 </li><li> FEBioでの軟骨および浴の異なるゾーンの機械的および物理的特性を割り当てます。ヤング率（10 MPa）を上層浴によって及ぼされる浸透圧に抵抗し、従って、過度の変形から軟骨を保護するのに十分高いと仮定しました。 <ol><li> 10 -3 mmでの透水率を使用して4 / Nsとシミュレーション8浴の0使用実際の溶質の拡散係数のポアソン比、9。 </li></ol></li><li>メッシュを生成する（8ノードトリリニアの六面体エレメント）との境界（ 図2B）の近くに絞り込みますクラス= &quot;外部参照&quot;&gt; 8、9。 </li><li>二相性-溶質モデル<ol><li>バスとそれに対応する有効圧力に初期溶質濃度を適用します。 9有効圧力、15の説明を見てください。 </li><li>異なる軟骨ゾーンにおいて所定の拡散係数に応じて時間曲線に対する溶質濃度を得るために過渡モードでモデルを実行します。 </li></ol></li><li>多相モデル 注：お風呂と組織との間の電気的な変動にはバスタブと組織の両方に2価の対イオンを加えることによって回避することができます。 <ol><li>定常状態モデルの場合：その所望の値にFCDを増加させながら、軟骨および上層浴中で同じ有効流体圧力および濃度を使用します。 </li><li>過渡モデルの場合：十分に高い浴中の溶質の拡散係数を維持することによって、よく攪拌有限風呂を作成します。注射します浴中に浴 - 空気界面からの溶質は、所望の濃度値に到達します。 </li><li>過渡：前のステップにおける所定の溶質濃度の境界条件を除去し、その実際の拡散係数に有限浴の拡散係数を元に戻します。 </li><li>異なる軟骨ゾーンに適用FirstClassディレクトリサービスと拡散係数に基づいて溶質濃度 - 時間曲線を得るために、モデルを実行します。 </li></ol></li><li> FEBio、MATLABインターフェイス<ol><li>自動的FEBioプロット濃度-時間曲線（FEBio-MATLABインタフェース）8、9でシミュレーションを実行するためにMATLABコードを開発。 </li><li> FEBio-MATLABインターフェイスを使用して、軟骨ゾーンの拡散係数とFirstClassディレクトリサービスを変更します。 FEBioでモデルを実行し、溶質濃度-時間曲線8,9を抽出します。 </li><li>実験で得られた溶質濃度 - 時間曲線の比較データおよび平均二乗誤差最小のルートに基づいて、異なる軟骨ゾーンで拡散係数とFirstClassディレクトリサービスのセットを得る（RMSE）8、9。 </li></ol></li></ol><img alt="図1" class="xfigimg" src="/files/ftp_upload/54984/54984fig1.jpg" /> 図1： 実験セットアップ。 A）カスタムメイドのドリルビットを使用してサンプル抽出手順。 B）マイクロCTイメージング手順は、拡散プロセスを監視します。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54984/54984fig1large.jpg" target="_blank">この図の拡大版をご覧になるにはこちらをクリックしてください。</a> <img alt="図2" class="xfigimg" src="/files/ftp_upload/54984/54984fig2.jpg" /> 図2： 回路図。A）実験計画。有限浴、表層、中間及び軟骨と関連メッシュの深い領域からなるB）マルチゾーン計算モデル。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54984/54984fig2large.jpg" target="_blank">この図の拡大版をご覧になるにはこちらをクリックしてください。</a>

<ol>
	<li>Arkill, K. P., Winlove, C. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solute+transport+in+the+deep+and+calcified+zones+of+articular+cartilage.">Solute transport in the deep and calcified zones of articular cartilage.</a> Osteoarthritis Cartilage. 16 (6), 708-714 (2008).</li><li>Chin, H. C., Moeini, M., Quinn, T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solute+transport+across+the+articular+surface+of+injured+cartilage.">Solute transport across the articular surface of injured cartilage.</a> Arch Biochem Biophys. 535 (2), 241-247 (2013).</li><li>Leddy, H. A., Guilak, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Site-specific+effects+of+compression+on+macromolecular+diffusion+in+articular+cartilage.">Site-specific effects of compression on macromolecular diffusion in articular cartilage.</a> Biophys J. 95 (10), 4890-4895 (2008).</li><li>Leddy, H. A., Guilak, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Site-Specific+Molecular+Diffusion+in+Articular+Cartilage+Measured+using+Fluorescence+Recovery+after+Photobleaching.">Site-Specific Molecular Diffusion in Articular Cartilage Measured using Fluorescence Recovery after Photobleaching.</a> Annals of Biomedical Engineering. 31 (7), 753-760 (2003).</li><li>Gu, W. Y., Yao, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+hydration+and+fixed+charge+density+on+fluid+transport+in+charged+hydrated+soft+tissues.">Effects of hydration and fixed charge density on fluid transport in charged hydrated soft tissues.</a> Ann Biomed Eng. 31 (10), 1162-1170 (2003).</li><li>Pouran, B., Arbabi, V., Zadpoor, A. A., Weinans, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolated+effects+of+external+bath+osmolality,+solute+concentration,+and+electrical+charge+on+solute+transport+across+articular+cartilage.">Isolated effects of external bath osmolality, solute concentration, and electrical charge on solute transport across articular cartilage.</a> Medical Engineering and Physics. 38 (12), 1399-1407 (2016).</li><li>Kulmala, K. A. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffusion+coefficients+of+articular+cartilage+for+different+CT+and+MRI+contrast+agents.">Diffusion coefficients of articular cartilage for different CT and MRI contrast agents.</a> Medical Engineering &amp; Physics. 32 (8), 878-882 (2010).</li><li>Arbabi, V., Pouran, B., Weinans, H., Zadpoor, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transport+of+Neutral+Solute+Across+Articular+Cartilage:+The+Role+of+Zonal+Diffusivities.">Transport of Neutral Solute Across Articular Cartilage: The Role of Zonal Diffusivities.</a> Journal of Biomechanical Engineering. 137 (7), 071001-071001 (2015).</li><li>Arbabi, V., Pouran, B., Weinans, H., Zadpoor, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiphasic+modeling+of+charged+solute+transport+across+articular+cartilage:+Application+of+multi-zone+finite-bath+model.">Multiphasic modeling of charged solute transport across articular cartilage: Application of multi-zone finite-bath model.</a> J Biomech. 49 (9), 1510-1517 (2016).</li><li>Arbabi, V., Pouran, B., Weinans, H., Zadpoor, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combined+artificial+neural+networks+for+robust+estimation+of+the+diffusion+coefficients+across+cartilage.">Combined artificial neural networks for robust estimation of the diffusion coefficients across cartilage.</a> , (2016).</li><li>Arbabi, V., Pouran, B., Weinans, H., Zadpoor, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combined+inverse-forward+artificial+neural+networks+for+fast+and+accurate+estimation+of+the+diffusion+coefficients+of+cartilage+based+on+multi-physics+models.">Combined inverse-forward artificial neural networks for fast and accurate estimation of the diffusion coefficients of cartilage based on multi-physics models.</a> Journal of Biomechanics. , (2016).</li><li>Sophia Fox, A. J., Bedi, A., Rodeo, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Basic+Science+of+Articular+Cartilage:+Structure,+Composition,+and+Function.">The Basic Science of Articular Cartilage: Structure, Composition, and Function.</a> Sports Health. 1 (6), 461-468 (2009).</li><li>Ateshian, G., Weiss, J., Holzapfel, G. A., Kuhl, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ch.+17.">Ch. 17.</a> Computer Models in Biomechanics. , 231-249 (2013).</li><li>Ateshian, G. A., Maas, S., Weiss, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiphasic+Finite+Element+Framework+for+Modeling+Hydrated+Mixtures+With+Multiple+Neutral+and+Charged+Solutes.">Multiphasic Finite Element Framework for Modeling Hydrated Mixtures With Multiple Neutral and Charged Solutes.</a> Journal of Biomechanical Engineering. 135 (11), 111001-111001 (2013).</li><li>Arbabi, V., Pouran, B., Weinans, H., Zadpoor, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transport+of+neutral+solute+across+articular+cartilage+and+subchondral+plate.">Transport of neutral solute across articular cartilage and subchondral plate.</a> , (2016).</li><li>Pouran, B., Arbabi, V., Weinans, H., Zadpoor, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+multiphysics+models+to+efficient+design+of+experiments+of+solute+transport+across+articular+cartilage.">Application of multiphysics models to efficient design of experiments of solute transport across articular cartilage.</a> Comput Biol Med. 78, 91-96 (2016).</li><li>Hosseini, S. M., Wu, Y., Ito, K., Donkelaar, C. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+importance+of+superficial+collagen+fibrils+for+the+function+of+articular+cartilage.">The importance of superficial collagen fibrils for the function of articular cartilage.</a> Biomechanics and Modeling in Mechanobiology. 13 (1), 41-51 (2013).</li><li>Alexopoulos, L. G., Williams, G. M., Upton, M. L., Setton, L. A., Guilak, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Osteoarthritic+changes+in+the+biphasic+mechanical+properties+of+the+chondrocyte+pericellular+matrix+in+articular+cartilage.">Osteoarthritic changes in the biphasic mechanical properties of the chondrocyte pericellular matrix in articular cartilage.</a> Journal of Biomechanics. 38 (3), 509-517 (2005).</li><li>Felson, D. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Osteoarthritis:+new+insights.+Part+1:+the+disease+and+its+risk+factors.">Osteoarthritis: new insights. Part 1: the disease and its risk factors.</a> Ann Intern Med. 133 (8), 635-646 (2000).</li><li>Kokkonen, H. T., Jurvelin, J. S., Tiitu, V., Toyras, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+mechanical+injury+of+articular+cartilage+using+contrast+enhanced+computed+tomography.">Detection of mechanical injury of articular cartilage using contrast enhanced computed tomography.</a> Osteoarthritis Cartilage. 19 (3), 295-301 (2011).</li><li>Raya, J. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffusion-tensor+imaging+of+human+articular+cartilage+specimens+with+early+signs+of+cartilage+damage.">Diffusion-tensor imaging of human articular cartilage specimens with early signs of cartilage damage.</a> Radiology. 266 (3), 831-841 (2013).</li><li>Tavakoli Nia, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aggrecan+Nanoscale+Solid-Fluid+Interactions+Are+a+Primary+Determinant+of+Cartilage+Dynamic+Mechanical+Properties.">Aggrecan Nanoscale Solid-Fluid Interactions Are a Primary Determinant of Cartilage Dynamic Mechanical Properties.</a> ACS Nano. 9 (3), 2614-2625 (2015).</li><li>Arbabi, V., Campoli, G., Weinans, H., Zadpoor, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Estimation+of+cartilage+properties+using+indentation+tests,+finite+element+models,+and+artificial+neural+networks.">Estimation of cartilage properties using indentation tests, finite element models, and artificial neural networks.</a> , (2014).</li><li>Arbabi, V., Pouran, B., Campoli, G., Weinans, H., Zadpoor, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+the+mechanical+and+physical+properties+of+cartilage+by+coupling+poroelastic-based+finite+element+models+of+indentation+with+artificial+neural+networks.">Determination of the mechanical and physical properties of cartilage by coupling poroelastic-based finite element models of indentation with artificial neural networks.</a> Journal of Biomechanics. 49 (5), 631-637 (2016).</li><li>Kokkonen, H. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Computed+tomography+detects+changes+in+contrast+agent+diffusion+after+collagen+cross-linking+typical+to+natural+aging+of+articular+cartilage.">Computed tomography detects changes in contrast agent diffusion after collagen cross-linking typical to natural aging of articular cartilage.</a> Osteoarthritis and Cartilage. 19 (10), 1190-1198 (2011).</li><li>Decker, S. G., Moeini, M., Chin, H. C., Rosenzweig, D. H., Quinn, T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adsorption+and+Distribution+of+Fluorescent+Solutes+near+the+Articular+Surface+of+Mechanically+Injured+Cartilage.">Adsorption and Distribution of Fluorescent Solutes near the Articular Surface of Mechanically Injured Cartilage.</a> Biophysical Journal. 105 (10), 2427-2436 (2013).</li><li>Silvast, T. S., Jurvelin, S. J., Tiitu, V., Quinn, T. M., Töyräs, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bath+Concentration+of+Anionic+Contrast+Agents+Does+Not+Affect+Their+Diffusion+and+Distribution+in+Articular+cartilage+In+Vitro.">Bath Concentration of Anionic Contrast Agents Does Not Affect Their Diffusion and Distribution in Articular cartilage In Vitro.</a> Cartilage. 4 (1), 42-51 (2013).</li><li>Silvast, T. S., Jurvelin, J. S., Lammi, M. J., T&#246;yr&#228;s, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=pQCT+study+on+diffusion+and+equilibrium+distribution+of+iodinated+anionic+contrast+agent+in+human+articular+cartilage+-+associations+to+matrix+composition+and+integrity.">pQCT study on diffusion and equilibrium distribution of iodinated anionic contrast agent in human articular cartilage - associations to matrix composition and integrity.</a> Osteoarthritis and Cartilage. 17 (1), 26-32 (2009).</li><li>Pouran, B., Arbabi, V., Villamar, J., Weinans, H., Zadpoor, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contrast+agent's+transport+across+healthy+articular+cartilage+under+various+bath+conditions.">Contrast agent's transport across healthy articular cartilage under various bath conditions.</a> , (2015).</li><li>Arbabi, V., Pouran, B., Weinans, H., Zadpoor, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+a+biphasic-solute+model+in+predicting+diffusive+properties+of+osteochondral+interface.">Application of a biphasic-solute model in predicting diffusive properties of osteochondral interface.</a> , (2016).</li></ol>

著者は、開示することは何もありません。

私たちは、関節軟骨全体で中性および充電溶質の拡散を研究するために、有限要素モデリング手法と組み合わせて実験プロトコルを提示しました。私たちの最近の研究によると、提案されたモデルは、正確に関節軟骨8、9の異なるゾーン間ニュートラル（二相性-溶質）の両方の輸送と負に帯電した（多相）溶質を記述することができます。広く、関節軟骨が機能OA進行21、22、23、24中にこのような負に荷電したGAG巨大分子としての重要な成分の損失ならびにコラーゲン線維を介して制限されるようになると考えられています。本研究で提案された技術を使用して、1は、潜在的に関節軟骨の健全性を調べることができます。ニュートラル溶質の輸送は、OA primarに増補することができます<html> ILYが低いため、溶質の間の相互作用と同様のGAG及びコラーゲンの。一方、負に帯電した溶質の輸送ことによりOAの進行のレベルのいくつかの指標を与え、プロテオグリカンの固定電荷の濃度に関する情報を取得助けることができます。 以前の研究によると、有限浴概念の出現に基づいて開発された二相性-溶質および多相モデルは、関節軟骨の帯状の特性の正確な推定を提供することができたことにより、プラットフォームとしての役割を果たすことができました。造影剤の大浴場、すなわち可能なビーム硬化アーチファクト、及び軟骨7、関節ために単一の拡散係数を割り当てる、20、25、26、27、28、に関連する制限小娘=「外部参照」&gt; 29、30は、現在の研究を発展させる動機を運転しました。将来のOAの研究では、私たちの開発したモデルは、潜在的に早期OA診断用のアプリケーションを見つけるかもしれません。 実験と計算シミュレーションの両方で必要ないくつかの重要なステップがあります。実験中の軟骨の整合性を維持するためには、その後の酵素の活動を防ぐために、プロテアーゼ阻害剤の十分な量を加えることが必要となります。以上の実験のために一つのサンプルを用いた場合には、平衡化後に貫通溶質のためのウォッシュアウト時間は約48時間でした。ウォッシュアウトの効率は、マイクロCTを使用してチェックする必要があります。馬軟骨を採用し、当社のセットを使用する場合は、無限の風呂に上層のバスと同等の最小体積は、軟骨の量の5倍と計算されました。また、拡散の有限要素モデリングを行うためには、実際の溶質拡散coefficを適用することが重要ですそれからの偏差以来浴中のientは転帰に影響を与える可能性があります。 基礎となる有限要素モデルでは、溶質サイズ効果は実装されていなかったので、勉強することができませんでした。私たちの提案する有限浴モデル、すなわち、より適切な関節の関節に拡散プロセスを理解し、いくつかの利点を提供し、ビームハードニングアーチファクトを減らします。実験と計算モデルを組み合わせた提案手法は、正に帯電した造影剤が適用される場合、軟骨の拡散属性を精査できます。お風呂での実際の溶質拡散係数の知識はそれを大幅に関節軟骨間で得られた拡散係数の精度に影響を与える可能性があるとして、非常に重要であると考えられます。これは、実験浴の拡散係数を求めるか、または容易に使用文献値のいずれかを必要とするであろう。 結論として、私たちは実験からなる一般的なプロトコルを提案し、計算関節軟骨全体に充電し、非荷電溶質の輸送を調査します。プロトコルを使用し、一方は正常拡散係数と異なる軟骨層に固定された荷電密度を得ることができます。

<html>分子輸送は、関節の関節の恒常性に重要な役割を果たしている関節ための治療薬の配達軟骨と軟骨造影イメージング1、2、3。このような軟骨の統合と完全性、溶質の電荷およびサイズならびに軟骨と接触している浴の重量オスモル濃度および濃度のような因子は、トランスポートレート4、5、6に影響を及ぼし得ます。各ゾーンは、異なる濃度および主要細胞外マトリックス分子の配向から成るので、中性または荷電のいずれかの溶質の輸送は、関節軟骨のゾーン間で異なることができる、すなわち、プロテオグリカン（PG類）及びコラーゲンII型1、7、8、9、小娘= &quot;外部参照&quot;&gt; 10、11。より重要なことに、帯電した溶質の輸送は、関節軟骨8,9を横切って増加、細胞外マトリックス内の負の固定電荷を含むプロテオグリカンの濃度に大きく依存することができます。それらのパラメータ、特に固定電荷密度（FCD）、変形性関節症（OA）は、それによって軟骨を横切る拡散を研究することの重要性を意味する、進行するにつれて、軟骨を横断コラーゲン原線維と含水量変化の向きが変化を受けることができます。 今回の研究では、プロトコルは6、8、9を正確拡散の有限浴モデルに中性および充電溶質を使用して、さまざまな境界条件の下で拡散を調査するために提案され、以前に確立された実験と計算研究に基づきます。 T彼は、方法は、軟骨および高度な二相性-溶質および多相有限要素モデルでサポートされている有限浴を含むシステムのマイクロコンピュータ断層撮影（マイクロCT）で構成されている提案しました。これらのモデルは、関節軟骨の種々のゾーンを横切って中性と荷電分子ならびにFirstClassディレクトリサービスの拡散係数を得ることができます。これらのモデルを使用して、1は、軟骨および有限風呂を重ねる間の相互作用を調査するために使用することができ、拡散中性及び荷電した分子の挙動をよりよく理解を得ることができます。

<table border="0" cellpadding="0" cellspacing="0" width="688">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Hexabrix</td>
			<td style="width:149px;">Guerbet</td>
			<td style="width:123px;">15HX005D</td>
			<td style="width:201px;">Negatively charged contrast agent</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Visipaque</td>
			<td style="width:149px;">GE healthcare</td>
			<td align="right" style="width:123px;">12570511</td>
			<td>Nuetral contrast agent</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">PBS</td>
			<td style="width:149px;">Life technologies</td>
			<td align="right" style="width:123px;">10010023</td>
			<td>Medium</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">micro-CT</td>
			<td style="width:149px;">Perkin Elmer</td>
			<td style="width:123px;"></td>
			<td>Monitoring diffusion</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Freezing-point osmometer</td>
			<td style="width:149px;">Advanced instruments</td>
			<td style="width:123px;"></td>
			<td>Measuring solution osmolality</td>
		</tr>
	</tbody>
</table>

an experimental and finite element protocol to investigate the transport of neutral and charged solutes across articular cartilage

<html>変形性関節症（OA）は、関節軟骨および軟骨下骨の変性に関連している衰弱性疾患です。これは驚異的な化学的分解、 すなわちプロテオグリカン損失及びコラーゲン原線維破壊を経験するように関節軟骨の変性が実質的にその荷重支持機能を損ないます。 OA中に化学的損傷のメカニズムを調査するための一つの有望な方法は、外部の溶質に軟骨標本を公開し、分子の拡散を監視することです。健康な軟骨と比較して異なる拡散特性を作成する関節軟骨を横切って移動しながら、軟骨損傷（ すなわち、濃度及び本質的な巨大分子の構成）の程度は、外部溶質の衝突エネルギー損失と関連しています。本研究では、いくつかのステップで構成され、以前に開発された実験マイクロ-Cに基づいてされているプロトコルを導入します14px; &quot;&gt; omputed T omography（マイクロCT）及び有限要素モデリング第二相、溶質および拡散係数を得るために、多相有限要素モデルを適用することにより、続いてマイクロCTを使用して記録されて充電され、非荷電ヨウ素化分子の輸送。軟骨ゾーン間で電荷密度を修正しました。

ここで提供される代表的な結果は、以前の研究論文6、8、9、16から採用されています。 OAは、関節軟骨は有意な変化最も重要なGAGの損失、及びコラーゲン線維の損傷17、18、19を受けます。これらの変更は、関節軟骨20、21を介して溶質の拡散挙動に影響を与える可能性があります。我々は、マイクロCTを用いて死体ウマ骨軟骨プラグでは、軸2ヨウ素化造影剤の拡散、 すなわちイオジキサノール（電荷= 0）、イオキサグレート（電荷= -1）を研究しました。中性溶質（イオジキサノール）、二相性-溶質モデルと荷電ソルの拡散プロセスを定量化します<html> TE（イオキサグレート）多相モデルは、軟骨の帯状構造を考えFEBioに開発されました。二相性-溶質および多相モデルは、関節軟骨を横断イオジキサノール及びイオキサグレートの拡散（ 図3）を予測することができました。これらのモデルは9、8つの異なる軟骨ゾーンに取得イオジキサノール（二相性-溶質）と拡散係数の拡散係数、ならびにFCD（イオキサグレート）を可能にしました。 <img alt="図3" class="xfigimg" src="/files/ftp_upload/54984/54984fig3.jpg" /> 図3： 計算的データ曲線嵌合。実験データ及び実験データ（シンボル対B）の破線の多相モデルフィット（））8,9対破線A）マルチゾーン二相性-溶質（）。：//ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54984/54984fig3large.jpg」ターゲット= 『_空白』&gt;この図の拡大版をご覧になるにはこちらをクリックしてください。

Watch this Scientific Journal Video about An Experimental and Finite Element Protocol to Investigate the Transport of Neutral and Charged Solutes across Articular Cartilage at JoVE.com

An Experimental and Finite Element Protocol to Investigate the Transport of Neutral and Charged Solutes across Articular Cartilage

我々は最近開発された実験と数値解析法を用いて関節軟骨全体に充電し、非荷電分子の輸送を調査するためのプロトコルを提案します。

実験および有限要素議定書は、関節軟骨全体で中性および荷電溶質の輸送を調査します

Osteoarthritis (OA) is a debilitating disease that is associated with degeneration of articular cartilage and subchondral bone. Degeneration of articular ...

an-experimental-finite-element-protocol-to-investigate-transport

Nanyang Technological University

Research

JoVE Journal

Bioengineering

6.2K ビュー.  Delft University of Technology (TU Delft). 我々は最近開発された実験と数値解析法を用いて関節軟骨全体に充電し、非荷電分子の輸送を調査するためのプロトコルを提案します。 

ビデオ: An Experimental and Finite Element Protocol to Investigate the Transport of Neutral and Charged Solutes across Articular Cartilage

Patterned Photostimulation with Digital Micromirror Devices to Investigate Dendritic Integration Across Branch Points

Light is a versatile and precise means to control neuronal excitability. The recent introduction of light sensitive effectors such as channel-rhodopsin and caged neurotransmitters have led to interests in developing better means to control patterns of light in space and time that are useful for experimental neuroscience. One conventional strategy, employed in confocal and 2-photon microscopy, is to focus light to a diffraction limited spot and then scan that single spot sequentially over the region of interest. This approach becomes problematic if large areas have to be stimulated within a brief time window, a problem more applicable to photostimulation than for imaging. An alternate strategy is to project the complete spatial pattern on the target with the aid of a digital micromirror device (DMD). The DMD approach is appealing because the hardware components are relatively inexpensive and is supported by commercial interests. Because such a system is not available for upright microscopes, we will discuss the critical issues in the construction and operations of such a DMD system. Even though we will be primarily describing the construction of the system for UV photolysis, the modifications for building the much simpler visible light system for optogenetic experiments will also be provided. The UV photolysis system was used to carryout experiments to study a fundamental question in neuroscience, how are spatially distributed inputs integrated across distal dendritic branch points. The results suggest that integration can be non-linear across branch points and the supralinearity is largely mediated by NMDA receptors.

Digital micromirror devices (DMD) can generate complex patterns in time and space with which to control neuronal excitability. Issues relevant to the design, construction, and operation of DMD systems are discussed. Such a system enabled the demonstration of non-linear integration across distal dendritic branch points.

分岐点間での樹の統合を調査するためにデジタルマイクロミラーデバイスと模様の光刺激

Light is a versatile and precise means to control neuronal excitability. The recent introduction of light sensitive effectors such as channel-rhodopsin ...

生物工学

Determination of the Transport Rate of Xenobiotics and Nanomaterials Across the Placenta using the ex vivo Human Placental Perfusion Model

Decades ago the human placenta was thought to be an impenetrable barrier between mother and unborn child. However, the discovery of thalidomide-induced birth defects and many later studies afterwards proved the opposite. Today several harmful xenobiotics like nicotine, heroin, methadone or drugs as well as environmental pollutants were described to overcome this barrier. With the growing use of nanotechnology, the placenta is likely to come into contact with novel nanoparticles either accidentally through exposure or intentionally in the case of potential nanomedical applications. Data from animal experiments cannot be extrapolated to humans because the placenta is the most species-specific mammalian organ 1. Therefore, the ex vivo dual recirculating human placental perfusion, developed by Panigel et al. in 1967 2 and continuously modified by Schneider et al. in 1972 3, can serve as an excellent model to study the transfer of xenobiotics or particles.
Here, we focus on the ex vivo dual recirculating human placental perfusion protocol and its further development to acquire reproducible results.
The placentae were obtained after informed consent of the mothers from uncomplicated term pregnancies undergoing caesarean delivery. The fetal and maternal vessels of an intact cotyledon were cannulated and perfused at least for five hours. As a model particle fluorescently labelled polystyrene particles with sizes of 80 and 500 nm in diameter were added to the maternal circuit. The 80 nm particles were able to cross the placental barrier and provide a perfect example for a substance which is transferred across the placenta to the fetus while the 500 nm particles were retained in the placental tissue or maternal circuit. The ex vivo human placental perfusion model is one of few models providing reliable information about the transport behavior of xenobiotics at an important tissue barrier which delivers predictive and clinical relevant data.

Determination of the Transport Rate of Xenobiotics and Nanomaterials Across the Placenta using the ex vivo Human Placental Perfusion Model

The ex vivo dual recirculating human placental perfusion model can be used to investigate the transfer of xenobiotics and nanoparticles across the human placenta. In this video protocol we describe the equipment and techniques required for a successful execution of a placenta perfusion.

使用プラ​​センタアクロス異物およびナノ材料の輸送速度の決定<em&gt; ex vivoで</em&gt;ヒト胎盤灌流モデル

Decades ago the human placenta was thought to be an impenetrable barrier between mother and unborn child. However, the discovery of thalidomide-induced ...

Models and Methods to Evaluate Transport of Drug Delivery Systems Across Cellular Barriers

Sub-micrometer carriers (nanocarriers; NCs) enhance efficacy of drugs by improving solubility, stability, circulation time, targeting, and release. Additionally, traversing cellular barriers in the body is crucial for both oral delivery of therapeutic NCs into the circulation and transport from the blood into tissues, where intervention is needed. NC transport across cellular barriers is achieved by: (i) the paracellular route, via transient disruption of the junctions that interlock adjacent cells, or (ii) the transcellular route, where materials are internalized by endocytosis, transported across the cell body, and secreted at the opposite cell surface (transyctosis). Delivery across cellular barriers can be facilitated by coupling therapeutics or their carriers with targeting agents that bind specifically to cell-surface markers involved in transport. Here, we provide methods to measure the extent and mechanism of NC transport across a model cell barrier, which consists of a monolayer of gastrointestinal (GI) epithelial cells grown on a porous membrane located in a transwell insert. Formation of a permeability barrier is confirmed by measuring transepithelial electrical resistance (TEER), transepithelial transport of a control substance, and immunostaining of tight junctions. As an example, ~200&#160;nm polymer NCs are used, which carry a therapeutic cargo and are coated with an antibody that targets a cell-surface determinant. The antibody or therapeutic cargo is labeled with 125I for radioisotope tracing and labeled NCs are added to the upper chamber over the cell monolayer for varying periods of time. NCs associated to the cells and/or transported to the underlying chamber can be detected. Measurement of free 125I allows subtraction of the degraded fraction. The paracellular route is assessed by determining potential changes caused by NC transport to the barrier parameters described above. Transcellular transport is determined by addressing the effect of modulating endocytosis and transcytosis pathways.

Many therapeutic applications require safe and efficient transport of drug carriers and their cargoes across cellular barriers in the body. This article describes an adaptation of established methods to evaluate the rate and mechanism of transport of drug nanocarriers (NCs) across cellular barriers, such as the gastrointestinal (GI) epithelium.

携帯の障壁を通過する薬物送達システムの輸送を評価するためのモデルと方法

Sub-micrometer carriers (nanocarriers; NCs) enhance efficacy of drugs by improving solubility, stability, circulation time, targeting, and release. ...

Human Cartilage Tissue Fabrication Using Three-dimensional Inkjet Printing Technology

Bioprinting, which is based on thermal inkjet printing, is one of the most attractive enabling technologies in the field of tissue engineering and regenerative medicine. With digital control&#160;cells, scaffolds, and growth factors can be precisely deposited to the desired two-dimensional (2D) and three-dimensional (3D) locations rapidly. Therefore, this technology is an ideal approach to fabricate tissues mimicking their native anatomic structures. In order to engineer cartilage with native zonal organization, extracellular matrix composition (ECM), and mechanical properties, we developed a bioprinting platform using a commercial inkjet printer with simultaneous photopolymerization capable for 3D cartilage tissue engineering. Human chondrocytes suspended in poly(ethylene glycol) diacrylate (PEGDA) were printed for 3D neocartilage construction via layer-by-layer assembly. The printed cells were fixed at their original deposited positions, supported by the surrounding scaffold in simultaneous photopolymerization. The mechanical properties of the printed tissue were similar to the native cartilage. Compared to conventional tissue fabrication, which requires longer UV exposure, the viability of the printed cells with simultaneous photopolymerization was significantly higher. Printed neocartilage demonstrated excellent glycosaminoglycan (GAG) and collagen type II production, which was consistent with gene expression. Therefore, this platform is ideal for accurate cell distribution and arrangement for anatomic tissue engineering.

The methods described in this paper show how to convert a commercial inkjet printer into a bioprinter with simultaneous UV polymerization. The printer is capable of constructing 3D tissue structure with cells and biomaterials. The study demonstrated here constructed a 3D neocartilage.

三次元インクジェット印刷技術を用いて、ヒト軟骨組織の作製

Bioprinting, which is based on thermal inkjet printing, is one of the most attractive enabling technologies in the field of tissue engineering and ...

A Coupled Experiment-finite Element Modeling Methodology for Assessing High Strain Rate Mechanical Response of Soft Biomaterials

This study offers a combined experimental and finite element (FE) simulation approach for examining the mechanical behavior of soft biomaterials (e.g. brain, liver, tendon, fat, etc.) when exposed to high strain rates. This study utilized a Split-Hopkinson Pressure Bar (SHPB) to generate strain rates of 100-1,500 sec-1. The SHPB employed a striker bar consisting of a viscoelastic material (polycarbonate). A sample of the biomaterial was obtained shortly postmortem and prepared for SHPB testing. The specimen was interposed between the incident and transmitted bars, and the pneumatic components of the SHPB were activated to drive the striker bar toward the incident bar. The resulting impact generated a compressive stress wave (i.e. incident wave) that traveled through the incident bar. When the compressive stress wave reached the end of the incident bar, a portion continued forward through the sample and transmitted bar (i.e. transmitted wave) while another portion reversed through the incident bar as a tensile wave (i.e. reflected wave). These waves were measured using strain gages mounted on the incident and transmitted bars. The true stress-strain behavior of the sample was determined from equations based on wave propagation and dynamic force equilibrium. The experimental stress-strain response was three dimensional in nature because the specimen bulged. As such, the hydrostatic stress (first invariant) was used to generate the stress-strain response. In order to extract the uniaxial (one-dimensional) mechanical response of the tissue, an iterative coupled optimization was performed using experimental results and Finite Element Analysis (FEA), which contained an Internal State Variable (ISV) material model used for the tissue. The ISV material model used in the FE simulations of the experimental setup was iteratively calibrated (i.e. optimized) to the experimental data such that the experiment and FEA strain gage values and first invariant of stresses were in good agreement.

The current study prescribes a coupled experiment-finite element simulation methodology to obtain the uniaxial dynamic mechanical response of soft biomaterials (brain, liver, tendon, fat, etc.). The multiaxial experimental results that arose because of specimen bulging obtained from Split-Hopkinson Pressure Bar testing were rendered to a uniaxial true stress-strain behavior when simulated through iterative optimization of the finite element analysis of the biomaterial.

ソフトバイオマテリアルの高ひずみ速度機械的応答を評価するための結合実験、有限要素モデリング手法

This study offers a combined experimental and finite element (FE) simulation approach for examining the mechanical behavior of soft biomaterials (e.g. ...

3D Hydrogel Scaffolds for Articular Chondrocyte Culture and Cartilage Generation

Human articular cartilage is highly susceptible to damage and has limited self-repair and regeneration potential. Cell-based strategies to engineer cartilage tissue offer a promising solution to repair articular cartilage. To select the optimal cell source for tissue repair, it is important to develop an appropriate culture platform to systematically examine the biological and biomechanical differences in the tissue-engineered cartilage by different cell sources. Here we applied a three-dimensional (3D) biomimetic hydrogel culture platform to systematically examine cartilage regeneration potential of juvenile, adult, and osteoarthritic (OA) chondrocytes. The 3D biomimetic hydrogel consisted of synthetic component poly(ethylene glycol) and bioactive component chondroitin sulfate, which provides a physiologically relevant microenvironment for in vitro culture of chondrocytes. In addition, the scaffold may be potentially used for cell delivery for cartilage repair in vivo. Cartilage tissue engineered in the scaffold can be evaluated using quantitative gene expression, immunofluorescence staining, biochemical assays, and mechanical testing. Utilizing these outcomes, we were able to characterize the differential regenerative potential of chondrocytes of varying age, both at the gene expression level and in the biochemical and biomechanical properties of the engineered cartilage tissue. The 3D culture model could be applied to investigate the molecular and functional differences among chondrocytes and progenitor cells from different stages of normal or aberrant development.

Cartilage repair represents an unmet medical challenge and cell-based approaches to engineer human articular cartilage are a promising solution. Here, we describe three-dimensional (3D) biomimetic hydrogels as an ideal tool for the expansion and maturation of human articular chondrocytes.

関節軟骨細胞培養軟骨の生成のための3Dハイドロゲルの足場

Human articular cartilage is highly susceptible to damage and has limited self-repair and regeneration potential. Cell-based strategies to engineer ...

An Experimental Protocol for Assessing the Performance of New Ultrasound Probes Based on CMUT Technology in Application to Brain Imaging

The possibility to perform an early and repeatable assessment of imaging performance is fundamental in the design and development process of new ultrasound (US) probes. Particularly, a more realistic analysis with application-specific imaging targets can be extremely valuable to assess the expected performance of US probes in their potential clinical field of application.
The experimental protocol presented in this work was purposely designed to provide an application-specific assessment procedure for newly-developed US probe prototypes based on Capacitive Micromachined Ultrasonic Transducer (CMUT) technology in relation to brain imaging.
The protocol combines the use of a bovine brain fixed in formalin as the imaging target, which ensures both realism and repeatability of the described procedures, and of neuronavigation techniques borrowed from neurosurgery. The US probe is in fact connected to a motion tracking system which acquires position data and enables the superposition of US images to reference Magnetic Resonance (MR) images of the brain. This provides a means for human experts to perform a visual qualitative assessment of the US probe imaging performance and to compare acquisitions made with different probes. Moreover, the protocol relies on the use of a complete and open research and development system for US image acquisition, i.e. the Ultrasound Advanced Open Platform (ULA-OP) scanner.
The manuscript describes in detail the instruments and procedures involved in the protocol, in particular for&#160;the calibration, image acquisition and registration of US and MR images. The obtained results prove the effectiveness of the overall protocol presented, which is entirely open (within the limits of the instrumentation involved), repeatable, and covers the entire set of acquisition and processing activities for US images.

The development of new ultrasound (US) probes based on Capacitive Micromachined Ultrasonic Transducer (CMUT) technology requires an early realistic assessment of imaging capabilities. We describe a repeatable experimental protocol for US image acquisition and comparison with magnetic resonance images, using an ex vivo bovine brain as an imaging target.

脳イメージングへの応用による CMUT 技術に基づく新しい超音波プローブの性能を評価するための実験プロトコル

The possibility to perform an early and repeatable assessment of imaging performance is fundamental in the design and development process of new ...

Creating a Structurally Realistic Finite Element Geometric Model of a Cardiomyocyte to Study the Role of Cellular Architecture in Cardiomyocyte Systems Biology

With the advent of three-dimensional (3D) imaging technologies such as electron tomography, serial-block-face scanning electron microscopy and confocal microscopy, the scientific community has unprecedented access to large datasets at sub-micrometer resolution that characterize the architectural remodeling that accompanies changes in cardiomyocyte function in health and disease. However, these datasets have been under-utilized for&#160;investigating the role of cellular architecture remodeling in cardiomyocyte function. The purpose of this protocol is to outline how to create an accurate finite element model of a cardiomyocyte using high resolution electron microscopy and confocal microscopy images. A detailed and accurate model of cellular architecture has significant potential to provide new insights into cardiomyocyte biology, more than experiments alone can garner. The power of this method lies in its ability to computationally fuse information from two disparate imaging modalities of cardiomyocyte ultrastructure to develop one unified and detailed model of the cardiomyocyte. This protocol outlines steps to integrate electron tomography and confocal microscopy images of adult male Wistar (name for a specific breed of albino rat) rat cardiomyocytes to develop a half-sarcomere finite element model of the cardiomyocyte. The procedure generates a 3D finite element model that contains an accurate, high-resolution depiction (on the order of ~35 nm) of the distribution of mitochondria, myofibrils and ryanodine receptor clusters that release the necessary calcium for cardiomyocyte contraction from the sarcoplasmic reticular network (SR) into the myofibril and cytosolic compartment. The model generated here as an illustration does not incorporate details of the transverse-tubule architecture or the sarcoplasmic reticular network and is therefore a minimal model of the cardiomyocyte. Nevertheless, the model can already be applied in simulation-based investigations into the role of cell structure in calcium signaling and mitochondrial bioenergetics, which is illustrated and discussed using two case studies that are presented following the detailed protocol.

This protocol outlines a novel method to create a spatially detailed finite element model of the intracellular architecture of cardiomyocytes from electron microscopy and confocal microscopy images. The power of this spatially detailed model is demonstrated using case studies in calcium signaling and bioenergetics.

心筋細胞のシステム生物学における細胞構造の役割を研究する心筋細胞の構造的に現実的な有限要素の幾何学的なモデルを作成します。

With the advent of three-dimensional (3D) imaging technologies such as electron tomography, serial-block-face scanning electron microscopy and confocal ...

A Novel Surgical Technique As a Foundation for In Vivo Partial Liver Engineering in Rat

Organ engineering is a novel strategy to generate liver organ substitutes that can potentially be used in transplantation. Recently, in vivo liver engineering, including in vivo organ decellularization followed by repopulation, has emerged as a promising approach over ex vivo liver engineering. However, postoperative survival was not achieved. The aim of this study is to develop a novel surgical technique of in vivo selective liver lobe perfusion in rats as a prerequisite for in vivo liver engineering. We generate a circuit bypass only through the left lateral lobe. Then, the left lateral lobe is perfused with heparinized saline. The experiment is performed with 4 groups (n = 3 rats per group) based on different perfusion times of 20 min, 2 h, 3 h, and 4 h. Survival, as well as the macroscopically visible change of color and the histologically determined absence of blood cells in the portal triad and the sinusoids, is taken as an indicator for a successful model establishment. After selective perfusion of the left lateral lobe, we observe that the left lateral lobe, indeed, turned from red to faint yellow. In a histological assessment, no blood cells are visible in the branch of the portal vein, the central vein, and the sinusoids. The left lateral lobe turns red after reopening the blocked vessels. 12/12 rats survived the procedure for more than one week. We are the first to report a surgical model for in vivo single liver lobe perfusion with a long survival period of more than one week. In contrast to the previously published report, the most important advantage of the technique presented here is that perfusion of 70% of the liver is maintained throughout the whole procedure. The establishment of this technique provides a foundation for in vivo partial liver engineering in rats, including decellularization and recellularization.

A Novel Surgical Technique As a Foundation for In Vivo Partial Liver Engineering in Rat

We establish a novel surgical technique for an in vivo single liver lobe perfusion model in rat as a prerequisite for further studying in vivo partial liver engineering in the future.

ラットでの肝部分工学生体内での基盤として新しい手術手技

Organ engineering is a novel strategy to generate liver organ substitutes that can potentially be used in transplantation. Recently, in vivo liver ...

Fabrication of Decellularized Cartilage-derived Matrix Scaffolds

Osteochondral defects lack sufficient intrinsic repair capacity to regenerate functionally sound bone and cartilage tissue. To this extent, cartilage research has focused on the development of regenerative scaffolds. This article describes the development of scaffolds that are completely derived from natural cartilage extracellular matrix, coming from an equine donor. Potential applications of the scaffolds include producing allografts for cartilage repair, serving as a scaffold for osteochondral tissue engineering, and providing in vitro models to study tissue formation. By decellularizing the tissue, the donor cells are removed, but many of the natural bioactive cues are thought to be retained. The main advantage of using such a natural scaffold in comparison to a synthetically produced scaffold is that no further functionalization of polymers is required to drive osteochondral tissue regeneration. The cartilage-derived matrix scaffolds can be used for bone and cartilage tissue regeneration in both in vivo and in vitro settings.

Decellularized cartilage-derived scaffolds can be used as a scaffold to guide cartilage repair and as a means to regenerate osteochondral tissue. This paper describes the decellularization process in detail and provides suggestions to use these scaffolds in in vitro settings.

脱軟骨由来のマトリックス足場の作製

Osteochondral defects lack sufficient intrinsic repair capacity to regenerate functionally sound bone and cartilage tissue. To this extent, cartilage ...