Polyethylene glycol 35 000 peg

Following complete hepatectomy, the rat liver was placed on NMP. Ex-vivo NMP with Sprague Dawley rats was performed with a nonoxygen carrier, sterilized perfusate consisting of 950 mL of William’s E media (Sigma-Aldrich), 20 g of bovine serum albumin (Sigma-Aldrich), 20 g of polyethylene glycol 35,000(PEG) (Sigma-Aldrich), 20 mg of dexamethasone (Sigma-Aldrich), 2 mL of heparin, 1 mL of regular insulin, 10 mL penicillin-streptomycin (Thermo Fisher Scientific), 10 mL of antibiotic-antimycotic (anti-anti) (Sigma-Aldrich), and 2.2 g of sodium bicarbonate to obtain a pH of 7.4. 500 mL perfusate was circulated at 37°C at 25–30 mL/min through an oxygenator with 95% O₂ and 5% CO₂ for a PV intrahepatic inflow pressure of less than 12 mmHg. The perfusate was changed at 12 hours to limit bacterial growth due to potential contamination.
Perfusate entered the PV and exited freely from the supra-hepatic vena cava (SHVC) and IVC. The perfusion circuit consisted of a perfusion chamber, two Masterflex peristaltic pumps (Cole Parmer, Vernon Hill, IL), a membrane oxygenator (Radnoti), a heat exchanger (Radnoti), and a bubble trap (Radnoti). Liver temperature was regulated by a water bath (Lauda, Brinkmann, Westbury, NY) and constantly monitored (Fig. 1). During the 24-hour perfusion, perfusion pH was maintained at 7.35–7.45 with the supplementation of sodium bicarbonate as necessary^{19 (link)}.