The authors would like to gratefully thank Steffen Lippert, Khalid Aliyev, Korinna J&#246;hrens and Katharina Struecker for their help during this project.

Animals were kept at the Facility for Experimental Medicine (FEM, Charit&#233;, Berlin, Germany), and all experimental protocols were reviewed and approved by the State Office of Health and Local Affairs (LAGeSo, Berlin, Germany; Reg. No. O 0365/11).
1. Liver Harvesting
<ol>
	<li>Pre-surgical Preparation
	<ol>
		<li>Use a cork plate for fixation. Put a medical drape on the plate. Using four needles, fix an inhalation mask on the cork plate for intraoperative inhalation narcosis.</li>
	</ol>
...

<ol>
	<li>Struecker, B., Raschzok, N., Sauer, I. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Liver+support+strategies:+cutting-edge+technologies.">Liver support strategies: cutting-edge technologies.</a> Nat Rev Gastroenterol Hepatol. 11, 166-176 (2014).</li><li>Crapo, P. M., Gilbert, T. W., Badylak, S. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+overview+of+tissue+and+whole+organ+decellularization+processes.">An overview of tissue and whole organ decellularization processes.</a> Biomaterials. 32, 3233-3243 (2011).</li><li>Wang, X., 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=Decellularized+liver+scaffolds+effectively+support+the+proliferation+and+differentiation+of+mouse+fetal+hepatic+progenitors.">Decellularized liver scaffolds effectively support the proliferation and differentiation of mouse fetal hepatic progenitors.</a> J Biomed Mater Res A. , (2013).</li><li>Uygun, B. E., 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=Organ+reengineering+through+development+of+a+transplantable+recellularized+liver+graft+using+decellularized+liver+matrix.">Organ reengineering through development of a transplantable recellularized liver graft using decellularized liver matrix.</a> Nat Med. 16, 814-820 (2010).</li><li>Shupe, T., Williams, M., Brown, A., Willenberg, B., Petersen, B. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Method+for+the+decellularization+of+intact+rat+liver.">Method for the decellularization of intact rat liver.</a> Organogenesis. 6, 134-136 (2010).</li><li>Bao, J., 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=Construction+of+a+portal+implantable+functional+tissue-engineered+liver+using+perfusion-decellularized+matrix+and+hepatocytes+in+rats.">Construction of a portal implantable functional tissue-engineered liver using perfusion-decellularized matrix and hepatocytes in rats.</a> Cell transplantation. 20, 753-766 (2011).</li><li>Baptista, P. 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=The+use+of+whole+organ+decellularization+for+the+generation+of+a+vascularized+liver+organoid.">The use of whole organ decellularization for the generation of a vascularized liver organoid.</a> Hepatology. 53, 604-617 (2011).</li><li>Soto-Gutierrez, A., Wertheim, J. A., Ott, H. C., Gilbert, T. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Perspectives+on+whole-organ+assembly:+moving+toward+transplantation+on+demand.">Perspectives on whole-organ assembly: moving toward transplantation on demand.</a> J Clin Invest. 122, 3817-3823 (2012).</li><li>Soto-Gutierrez, A., 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=A+whole-organ+regenerative+medicine+approach+for+liver+replacement.">A whole-organ regenerative medicine approach for liver replacement.</a> Tissue engineering. Part C, Methods. 17, 677-686 (2011).</li><li>De Kock, J., 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=Simple+and+quick+method+for+whole-liver+decellularization:+a+novel+in+vitro+three-dimensional+bioengineering+tool.">Simple and quick method for whole-liver decellularization: a novel in vitro three-dimensional bioengineering tool.</a> Archives of toxicology. 85, 607-612 (2011).</li><li>Park, K. M., Woo, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systemic+decellularization+for+multi-organ+scaffolds+in+rats.">Systemic decellularization for multi-organ scaffolds in rats.</a> Transplantation proceedings. 44, 1151-1154 (2012).</li><li>Shirakigawa, N., Ijima, H., Takei, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Decellularized+liver+as+a+practical+scaffold+with+a+vascular+network+template+for+liver+tissue+engineering.">Decellularized liver as a practical scaffold with a vascular network template for liver tissue engineering.</a> J Biosci Bioeng. , (2012).</li><li>Ren, 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=Evaluation+of+two+decellularization+methods+in+the+development+of+a+whole-organ+decellularized+rat+liver+scaffold.">Evaluation of two decellularization methods in the development of a whole-organ decellularized rat liver scaffold.</a> Liver Int. 33, 448-458 (2013).</li><li>Struecker, B., 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=Improved+rat+liver+decellularization+by+arterial+perfusion+under+oscillating+pressure+conditions.">Improved rat liver decellularization by arterial perfusion under oscillating pressure conditions.</a> J Tissue Eng Regen Med. , (2014).</li><li>Struecker, B., 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=Porcine+Liver+Decellularization+Under+Oscillating+Pressure+Conditions:+A+Technical+Refinement+to+Improve+the+Homogeneity+of+the+Decellularization+Process.">Porcine Liver Decellularization Under Oscillating Pressure Conditions: A Technical Refinement to Improve the Homogeneity of the Decellularization Process.</a> Tissue engineering. Part C, Methods. , (2014).</li></ol>

Although the presented technique for rat liver harvesting and decellularization is easily reproducible, there are certain critical steps to consider:
During preparation for liver harvesting, it is important to avoid severe bleeding because it will activate blood coagulation and may lead to blood clot formation within the liver. In our opinion, it is advantageous to incise the abdominal aorta directly before cannulation of the portal vein to avoid blood inflow via the hepatic artery during perf...

Decellularization and recellularization may enable the generation of functional, transplantable organs in vitro 1. By removing cells and antigenic material (e.g., DNA, alpha-Gal epitopes) from an organ, the non- or less-immunogenic extracellular matrix (ECM) can be obtained. This matrix conserves the three-dimensional microanatomy of an organ and can serve as the ideal biomatrix for repopulation with cells of a different, possibly xenogeneic origin 2. Thus, a decellularized rat liver matrix could be repopulated with human liver cells. This humanized micro-liver could serve as an ex vivo model for research on diseases (e.g., inborn metabolic diseases, viral diseases or malignancies) or for preclinical pharmaceutical testing 3.
Several different protocols for rat liver perfusion decellularization have already been published 4-13. In all protocols, decellularization was achieved by perfusion of alkaline ionic or non-ionic detergents via the cannulated portal vein. To the best of our knowledge, we were the first group to report rat liver decellularization by selective perfusion via the portal vein and/or the rat hepatic artery 14. Enabling the selective perfusion of the different vascular systems in the liver may enable better decellularization results and, furthermore, may play an important role in cellular repopulation.
In the study detailed here, livers were perfused in a custom-made proprietary perfusion device, enabling perfusion under oscillating pressure conditions. These pressure conditions mimic the physiologic respiratory-dependent perfusion of the liver: in situ, the liver hangs under the copula of the diaphragm, whose movement during respiration has a direct impact on liver perfusion. Inspiration specifically leads to lowering of the diaphragm and squeezing of the liver, optimizing hepato-venous outflow, whereas expiration leads to elevation of the liver and lowering of the intraabdominal pressure to optimize portal-venous inflow 15.
Our aim was to evaluate whether oscillating pressure conditions have an impact on the homogeneity of rat liver perfusion decellularization by mimicking intraabdominal conditions ex vivo. The homogeneity of the decellularization process may be an underestimated factor in perfusion decellularization. All known agents used for liver decellularization cause alterations to the ECM. Cells in poorly perfused areas remain within the ECM, whereas other areas are already completely decellularized. To dissolve the remaining cells, the perfusion duration or pressure must be elevated, causing more alterations to the well-perfused areas. Thus, detergents for decellularization should be distributed homogenously within the organ.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>Self built arterial cannula</td>
		</tr>
		<tr>
			<td>&#160;Portex Non Sterile Polyethene Tubing</td>
			<td>SIMS Portex</td>
			<td>REF 800/110/100</td>
			<td>0,28mm ID 0,61mm OD</td>
		</tr>
		<tr>
			<td>&#160;Portex Non Sterile Polyethene Tubing</td>
			<td>SIMS Portex</td>
			<td>REF 800/110/200</td>
			<td>0,58mm ID 0,96m OD</td>
		</tr>
		<tr>
			<td>Venodrop Safe butterfly catheter</td>
			<td>Fresenius Kabi</td>
			<td>3275851</td>
			<td>21 G</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>portal vein cannula</td>
		</tr>
		<tr>
			<td>Periphereal Venous Catheter</td>
			<td>BD</td>
			<td>393224</td>
			<td>BD Venflon Pro 20G</td>
		</tr>
		<tr>
			<td>three-way stopcock</td>
			<td>smiths medical</td>
			<td>888-101RE</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>surgery</td>
		</tr>
		<tr>
			<td>Cotton Sticks</td>
			<td>Hecht-Assistent</td>
			<td>4302</td>
			<td></td>
		</tr>
		<tr>
			<td>Cotton Pads&#160;</td>
			<td>Shaoxing Zhengde Surgical dressing</td>
			<td>13H118-03</td>
			<td></td>
		</tr>
		<tr>
			<td>Gauze Bandage</td>
			<td>Hubei Haige&#160; Medical Instruments</td>
			<td>14388</td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;Ringer Solution</td>
			<td>Fresenius Kabi</td>
			<td>13 HKP022</td>
			<td>1000ml</td>
		</tr>
		<tr>
			<td>10ml Syringe</td>
			<td>Braun</td>
			<td>4606108V</td>
			<td>10ml/ Luer Solo</td>
		</tr>
		<tr>
			<td>5ml Syringe</td>
			<td>Braun</td>
			<td>4606061V</td>
			<td>5ml /Luer Solo</td>
		</tr>
		<tr>
			<td>Suture (Silk 6/0)</td>
			<td>Resorba</td>
			<td>H1F</td>
			<td>LOT 105001.81</td>
		</tr>
		<tr>
			<td>medical drape</td>
			<td>Shaoxing Zhengde Surgical dressing</td>
			<td>D0613011</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>surgical instruments</td>
		</tr>
		<tr>
			<td>needle holder</td>
			<td>Geuder</td>
			<td>17570</td>
			<td></td>
		</tr>
		<tr>
			<td>micro-forceps</td>
			<td>Inox-Electronic</td>
			<td>91150-20</td>
			<td></td>
		</tr>
		<tr>
			<td>micro-scissors</td>
			<td>Martin</td>
			<td>11-740-11</td>
			<td></td>
		</tr>
		<tr>
			<td>micro-forceps</td>
			<td>S&#38;T&#160;</td>
			<td>112314</td>
			<td></td>
		</tr>
		<tr>
			<td>Clamp</td>
			<td>Aesculap</td>
			<td>BH111R</td>
			<td></td>
		</tr>
		<tr>
			<td>scissors</td>
			<td>F S T&#160;</td>
			<td>14501-14</td>
			<td></td>
		</tr>
		<tr>
			<td>surgical forceps</td>
			<td>Aesculap</td>
			<td>BD 557</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>Decellularisation</td>
		</tr>
		<tr>
			<td>Respirator</td>
			<td>Resmed</td>
			<td>14.24.11.0004</td>
			<td>SmartAIR ST</td>
		</tr>
		<tr>
			<td>Perfusion Device</td>
			<td>Charite, medical engineering laboratory</td>
			<td>custome-made device</td>
			<td>decellularisation device</td>
		</tr>
		<tr>
			<td>peristaltic pump ismatec reglo ICC</td>
			<td>IDEX</td>
			<td>ISM4408&#160;</td>
			<td>4-channel</td>
		</tr>
		<tr>
			<td>heidelberger extension 75 cm&#160;</td>
			<td>Fresenius Kabi</td>
			<td>2873</td>
			<td>75 cm</td>
		</tr>
		<tr>
			<td>MS/CA pump-segment</td>
			<td>IDEX</td>
			<td>IS 3510&#160;</td>
			<td>MS/CA/click&#39;n&#39;go/POM-C</td>
		</tr>
		<tr>
			<td>CA 2-stopper tube</td>
			<td>Pharmed</td>
			<td>BPT NSF-51</td>
			<td></td>
		</tr>
		<tr>
			<td>bubble trap&#160;</td>
			<td></td>
			<td>custome-made item</td>
			<td></td>
		</tr>
		<tr>
			<td>Luer Lock hose connector</td>
			<td>Neolab</td>
			<td>No. 02-1887</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>Detergents</td>
		</tr>
		<tr>
			<td>SDS pellets</td>
			<td>Carl Roth&#160;</td>
			<td>CN30.4&#160;</td>
			<td>2,5 kg</td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Carl Roth&#160;</td>
			<td>3051.1&#160;</td>
			<td>10l</td>
		</tr>
		<tr>
			<td>PBS&#160;</td>
			<td>Gibco</td>
			<td>14190-094</td>
			<td>DPBS</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>staining</td>
		</tr>
		<tr>
			<td>Eosin 1%</td>
			<td>Morphisto</td>
			<td>10177</td>
			<td></td>
		</tr>
		<tr>
			<td>Mayer hematoxylin</td>
			<td>AppliChem</td>
			<td>A4840</td>
			<td></td>
		</tr>
		<tr>
			<td>gomori staining</td>
			<td>Morphisto</td>
			<td>11104</td>
			<td></td>
		</tr>
		<tr>
			<td>AlcainBlue-PAS staining</td>
			<td>Morphisto</td>
			<td>11388</td>
			<td></td>
		</tr>
		<tr>
			<td>Direct Red 80&#160;</td>
			<td>Sigma Aldrich</td>
			<td>365548</td>
			<td></td>
		</tr>
	</tbody>
</table>

procedure for decellularization of rat livers in an oscillating-pressure perfusion device

Decellularization and recellularization of parenchymal organs may enable the generation of functional organs in vitro, and several protocols for rodent liver decellularization have already been published. We aimed to improve the decellularization process by construction of a proprietary perfusion device enabling selective perfusion via the portal vein and/or the hepatic artery. Furthermore, we sought to perform perfusion under oscillating surrounding pressure conditions to improve the homogeneity of decellularization. The homogeneity of perfusion decellularization has been an underestimated factor to date. During decellularization, areas within the organ that are poorly perfused may still contain cells, whereas the extracellular matrix (ECM) in well-perfused areas may already be affected by alkaline detergents. Oscillating pressure changes can mimic the intraabdominal pressure changes that occur during respiration to optimize microperfusion inside the liver. In the study presented here, decellularized rat liver matrices were analyzed by histological staining, DNA content analysis and corrosion casting. Perfusion via the hepatic artery showed more homogenous results than portal venous perfusion did. The application of oscillating pressure conditions improved the effectiveness of perfusion decellularization. Livers perfused via the hepatic artery and under oscillating pressure conditions showed the best results. The presented techniques for liver harvesting, cannulation and perfusion using our proprietary device enable sophisticated perfusion set-ups to improve decellularization and recellularization experiments in rat livers.

The homogeneity and thus the effectiveness of different decellularization protocols were evaluated by macroscopic observation, histological analysis, and analysis of the remaining DNA content within decellularized liver matrices. Furthermore, corrosion casting was performed to visualize the intact microanatomy of livers after decellularization.
Macroscopy
During decellularization, livers become lucent, indicating the removal of cellular content. Livers perfused via ...

Watch this Scientific Journal Video about Procedure for Decellularization of Rat Livers in an Oscillating-pressure Perfusion Device at JoVE.com

Procedure for Decellularization of Rat Livers in an Oscillating-pressure Perfusion Device

The presented techniques for liver harvesting, cannulation and perfusion using our proprietary device enable sophisticated perfusion set-ups to improve decellularization and recellularization experiments in rat livers.

Decellularization and recellularization of parenchymal organs may enable the generation of functional organs in vitro, and several protocols for rodent ...

procedure-for-decellularization-rat-livers-an-oscillating-pressure

Research

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Bioengineering

10.2K 조회수.  Charité – Universitätsmedizin Berlin. The presented techniques for liver harvesting, cannulation and perfusion using our proprietary device enable sophisticated perfusion set-ups to improve decellularization and recellularization experiments in rat livers.