title: Preparation and characterization of chitosan porous microcarriers for hepatocyte culture.
abstract: BACKGROUND
  The bioartificial liver (BAL) is considered a possible alternative method for treating liver failure. The core of the BAL system is culturing liver cells in vitro with high density and activity. Microcarrier culture is a mode of high-density culture. We set out to prepare a novel porous microcarrier to improve the activity of liver cells in vitro.
  
  
  METHODS
  Chitosan was used to prepare a novel porous spherical microcarrier with interconnected structure. The chitosan porous microcarriers (CPMs) were modified with gelatin to improve their biocompatibility. CPMs were co-cultured with liver cells, HL-7702 (L-02), to evaluate their effect on cell culture.
  
  
  RESULTS
  The average size of the CPMs was about 400 μm in diameter and their apertures were less than 30 μm. The pores of the microcarrier were interconnected. After fixation by sodium tripolyphosphate, the structure of the first freeze-dried CPMs was stable. To further improve the biocompatibility, the surface of CPMs was modified with gelatin through chemical crosslinking (GM-CPMs). Comparing the proliferation curves of L-02 cells cultured on simple CPMs, GM-CPMs and tissue culture polystyrene (TCPS, a mode of planar cell culture), the proliferation rates were similar in the first 5 days and the cells proliferated until day 8 in culture with microcarriers. The OD value of liver cells cultured on GM-CPMs was 1.97-fold higher than that on TCPS culture at day 8. Levels of urea and albumin in supernatants of cells cultured on GM-CPMs increased steadily for 8 days, and were clearly higher than those of cells cultured on TCPS (P<0.05).
  
  
  CONCLUSIONS
  The novel CPMs were promising microcarriers for hepatocyte culture and the GM-CPM seemed better. Porous microcarrier culture was beneficial for hepatocyte function and activity.
authors.affiliation: Center of Organ Transplantation, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.
authors.forename: Xu-Bo
authors.initials: XB
authors.lastname: Wu
authors.forename: Cheng-Hong
authors.initials: CH
authors.lastname: Peng
authors.forename: Fang
authors.initials: F
authors.lastname: Huang
authors.forename: Jie
authors.initials: J
authors.lastname: Kuang
authors.forename: Song-Lin
authors.initials: SL
authors.lastname: Yu
authors.forename: Ya-Dong
authors.initials: YD
authors.lastname: Dong
authors.forename: Bao-San
authors.initials: BS
authors.lastname: Han
mesh_terms: D000418:Albumins / Q000378:metabolism; D018929:Cell Culture Techniques; D002460:Cell Line; D049109:Cell Proliferation; D048430:Cell Shape; D048271:Chitosan / Q000737:chemistry*; D005780:Gelatin / Q000737:chemistry; D022781:Hepatocytes / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D019164:Liver, Artificial; D010316:Particle Size; D016062:Porosity; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*; D014508:Urea / Q000378:metabolism
chemical_list: D000418:Albumins; D014508:Urea; D005780:Gelatin; D048271:Chitosan