Expression of liver-specific functions by rat hepatocytes seeded in treated poly( lactic-co-glycolic) acid biodegradable foams

Techniques of liver replacement would benefit patients awaiting donor liver s and may be a substitute for transplantation in patients whose livers can regenerate. Poly(lactic-co-glycolic acid) (PLGA) copolymers are biodegradab le and have been shown to be useful as scaffolds for seeding and culturing various types of cells. In this study, foam disks were prepared from PLGA ( lactic-to-glycolic mole ratio of 85:15) by lyophilization of benzene (5% w/ v) solutions. These disks were then used as scaffolds for rat hepatocyte cu lture. Foams were coated with either a type I collagen gel (0.1% w/v), coat ed with gelatin (5% w/v), or treated with oxygen plasma (25 W, 90 s) to mod ify their surface chemistry and wettability. The disks were then seeded wit h rat hepatocytes (10(6)/mL) and cultured for a period of 2 weeks. All surf ace treatments resulted in increased hydrophilicity, the greatest being obt ained by collagen treatment (contact angle, < 10<degrees>), and a minimal d ecrease in void fraction (5%). DNA content after a 2-week culture period in creased proportionally with the wettability of the treated foam surface. Ur ea synthesis in untreated foams averaged 15.3 +/- 62.3 mug/h/ mg DNA, which was significantly higher than that for controls, whereas gelatin and colla gen treated foams exhibited urea synthetic rates below the control levels a t all times. The DNA content decreased significantly by about 50% between d ays 1 and 12. PLGA foams, treated and untreated, represent a promising scaf fold for scaling up hepatocyte cultures.