title: Three-dimensional (3D) printing of mouse primary hepatocytes to generate 3D hepatic structure.
abstract: OBJECTIVE
  The major problem in producing artificial livers is that primary hepatocytes cannot be cultured for many days. Recently, 3-dimensional (3D) printing technology draws attention and this technology regarded as a useful tool for current cell biology. By using the 3D bio-printing, these problems can be resolved.
  
  
  METHODS
  To generate 3D bio-printed structures (25 mm × 25 mm), cells-alginate constructs were fabricated by 3D bio-printing system. Mouse primary hepatocytes were isolated from the livers of 6-8 weeks old mice by a 2-step collagenase method. Samples of 4 × 107hepatocytes with 80%-90% viability were printed with 3% alginate solution, and cultured with well-defined culture medium for primary hepatocytes. To confirm functional ability of hepatocytes cultured on 3D alginate scaffold, we conducted quantitative real-time polymerase chain reaction and immunofluorescence with hepatic marker genes.
  
  
  RESULTS
  Isolated primary hepatocytes were printed with alginate. The 3D printed hepatocytes remained alive for 14 days. Gene expression levels ofAlbumin,HNF-4αandFoxa3were gradually increased in the 3D structures. Immunofluorescence analysis showed that the primary hepatocytes produced hepatic-specific proteins over the same period of time.
  
  
  CONCLUSIONS
  Our research indicates that 3D bio-printing technique can be used for long-term culture of primary hepatocytes. It can therefore be used for drug screening and as a potential method of producing artificial livers.
authors.affiliation: Department of Surgery, Hanyang University College of Medicine, Seoul, Korea.; Department of Translational Medicine, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, Korea.; HY Indang Center of Regenerative Medicine and Stem Cell Research, Hanyang University, Seoul, Korea.
authors.forename: Yohan
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Surgery, Hanyang University College of Medicine, Seoul, Korea.; Department of Translational Medicine, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, Korea.; HY Indang Center of Regenerative Medicine and Stem Cell Research, Hanyang University, Seoul, Korea.
authors.forename: Kyojin
authors.initials: K
authors.lastname: Kang
authors.affiliation: Department of Surgery, Hanyang University College of Medicine, Seoul, Korea.; HY Indang Center of Regenerative Medicine and Stem Cell Research, Hanyang University, Seoul, Korea.
authors.forename: Jaemin
authors.initials: J
authors.lastname: Jeong
authors.affiliation: Department of Pathology, Hanyang University College of Medicine, Seoul, Korea.
authors.forename: Seung Sam
authors.initials: SS
authors.lastname: Paik
authors.affiliation: Department of Pathology, Hanyang University College of Medicine, Seoul, Korea.
authors.forename: Ji Sook
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Nature-Inspired Nanoconvergence Systems, Korea Institute of Machinery and Materials, Daejeon, Korea.
authors.forename: Su A
authors.initials: SA
authors.lastname: Park
authors.affiliation: Department of Nature-Inspired Nanoconvergence Systems, Korea Institute of Machinery and Materials, Daejeon, Korea.
authors.forename: Wan Doo
authors.initials: WD
authors.lastname: Kim
authors.affiliation: Department of Nature-Inspired Nanoconvergence Systems, Korea Institute of Machinery and Materials, Daejeon, Korea.
authors.forename: Jisun
authors.initials: J
authors.lastname: Park
authors.affiliation: Department of Surgery, Hanyang University College of Medicine, Seoul, Korea.; Department of Translational Medicine, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul, Korea.; HY Indang Center of Regenerative Medicine and Stem Cell Research, Hanyang University, Seoul, Korea.
authors.forename: Dongho
authors.initials: D
authors.lastname: Choi
keywords: Culture; Hepatocytes; Maintenance; Three-dimensional printing