VIABILITY AND PROTEIN SECRETION FROM HUMAN HEPATOMA (HEPG2) CELLS ENCAPSULATED IN 400-MU-M POLYACRYLATE MICROCAPSULES BY SUBMERGED NOZZLE LIQUID JET EXTRUSION

An interfacial precipitation process to encapsulate mammalian cells in hydroxyethyl methacrylate-methyl methacrylate (HEMA-MMA) microcapsule s of similar to 750 in mu m diameter was previously described. It was not possible to produce smaller capsules due to low shearing force. A new droplet generation scheme was developed by suspending the cell and polymer co-extrusion nozzle in a uniform co-axial fluid jet which ena bled the production of 300 to 600-mu m diameter capsules. HepG2 hepato ma cells in 400-mu m-diameter HEMA-MMA capsules were able to retain th eir metabolic activity during and after the encapsulation process. The in vitro secretion of plasma proteins alpha(1)-acid glycoprotein, alp ha(1)-antitrypsin, and fibrinogen by the encapsulated cells was retain ed. The encapsulated cells secreted less fibrinogen (340 kD) relative to alpha(1)-acid glycoprotein (42 kD), indicating the sieving effect ( but not absolute cut-off) of the HEMA-MMA membrane. (C) 1994 John Wile y and Sons, Inc.