title: Microfabricated silicon nitride membranes for hepatocyte sandwich culture.
abstract: We have developed a hepatocyte sandwich culture with improved mass transport properties based on ultra-thin microfabricated porous silicon nitride (Si(3)N(4)) membranes. The dimensions and uniformity of the membrane pores can be configurable, which confers more control over the mass transport. Instead of collagen gels used in conventional sandwich culture, we utilized galactose ligands immobilized on the Si(3)N(4) membranes to support hepatocyte attachment and function in the sandwich culture. Diffusion studies using FITC-dextrans confirmed that mass transport of the microfabricated Si(3)N(4) membrane based sandwich was significantly better than conventional collagen gel sandwich and can be configured by varying the porosity of the Si(3)N(4) membrane. Hepatocytes cultured in the microfabricated Si(3)N(4) membrane based sandwich culture exhibited earlier apical repolarization and biliary excretion, improved differentiated functions and enhanced drug sensitivity compared to hepatocytes cultured in a collagen gel sandwich. The Si(3)N(4) membrane based sandwich culture allows for a systematic optimization of the mass transport properties of hepatocyte culture by changing the pore size and inter-pore distance. This will enable more effective drug testing applications where optimal mass transport is required for hepatocyte function maintenance and drug accessibility.
authors.affiliation: Institute of Bioengineering and Nanotechnology, A*STAR, The Nanos #04-01, 31 Biopolis Way, Singapore 138669, Singapore.
authors.forename: Shufang
authors.initials: S
authors.lastname: Zhang
authors.forename: Lei
authors.initials: L
authors.lastname: Xia
authors.forename: Chiang Huen
authors.initials: CH
authors.lastname: Kang
authors.forename: Guangfa
authors.initials: G
authors.lastname: Xiao
authors.forename: Siew Min
authors.initials: SM
authors.lastname: Ong
authors.forename: Yi Chin
authors.initials: YC
authors.lastname: Toh
authors.forename: Hwa Liang
authors.initials: HL
authors.lastname: Leo
authors.forename: Danny
authors.initials: D
authors.lastname: van Noort
authors.forename: Shyi Herng
authors.initials: SH
authors.lastname: Kan
authors.forename: Hui Huan
authors.initials: HH
authors.lastname: Tang
authors.forename: Hanry
authors.initials: H
authors.lastname: Yu
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D001692:Biological Transport; D018929:Cell Culture Techniques / Q000379:methods*; D016764:Cell Polarity; D048430:Cell Shape; D002478:Cells, Cultured; D005690:Galactose / Q000378:metabolism; D022781:Hepatocytes / Q000166:cytology* / Q000378:metabolism; D008297:Male; D008422:Materials Testing; D008567:Membranes, Artificial; D016062:Porosity; D051381:Rats; D017208:Rats, Wistar; D017655:Silicon Compounds / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D008567:Membranes, Artificial; D017655:Silicon Compounds; C032734:silicon nitride; D005690:Galactose