Semiautomatic macroencapsulation of large numbers of porcine hepatocytes by coextrusion with a solution of AN69 polymer

We have previously demonstrated that allogenic and xenogenic hepatocytes ma croencapsulated manually in AN-69 polymer and transplanted intra-peritoneal ly in rats remained viable for several weeks. However, this manual techniqu e is inadequate to encapsulate several billions of hepatocytes which would be required to correct hepatic failure in big animals or humans. In the pre sent study, we developed an original semiautomatic device in which isolated pig hepatocytes and the polymer solution containing 6% poly(acrylonitrile- sodium methallylsulfonate), 91% dimethylsulfoxide and 3% 0.9% NaCl solution were coextruded through a double-lumen spinneret. The extruded minitube (i nner diameter: 1.8 mm, wall thickness: 0.07-0.1 mm) containing the encapsul ated hepatocytes fell and coiled up in a 0.9% NaCl solution at 4 degrees C and was cut down in 4 m units containing about 120 million hepatocytes. Thi s process allowed to encapsulate 50 million hepatocytes by minute with a pr eserved immediate cell viability (92 +/- 5%). To test prolonged cell viabil ity after coextrusion, the minitubes were implanted intraperitoneally in ra ts. Three and seven days after implantation, they were explanted and analyz ed. Cells were Viable and well-preserved. Therefore, the semiautomatic devi ce appears able to efficiently macroencapsulate in a limited time several b illions of porcine hepatocytes which remain viable after transplantation in xenogenic conditions. (C) 2000 Elsevier Science Ltd. All rights reserved.