title: Micromolding of photocrosslinkable chitosan hydrogel for spheroid microarray and co-cultures.
abstract: Bioengineering approaches, such as co-cultures of multiple cell types, that aim to mimic the physiological microenvironment may be beneficial for optimizing cell function and for engineering tissues in vitro. This study describes a novel method for preparing a spheroid microarray on microfabricated hydrogels, alone or in co-cultures. Photocrosslinkable chitosan was synthesized and utilized for fabricating hydrogel microstructures through a micromolding process. The chitosan surface was initially cell repellent but became increasingly cell adhesive over time. By using this unique property of chitosan hydrogels, it was possible to generate patterned co-cultures of spheroids and support cells. In this scheme, cells were initially microarrayed within low shear stress regions of microwells. Human hepatoblastoma cells, Hep G2, seeded in these wells formed spheroids with controlled sizes and shapes and stably secreted albumin during the culture period. The change of cell adhesive properties in the chitosan surface facilitated the adhesion and growth of a second cell type, NIH-3T3 fibroblast, and therefore enabled co-cultures of hepatocyte spheroids and fibroblast monolayers. This co-culture system could be a useful platform for studying heterotypic cell-cell interactions, for drug screening, and for developing implantable bioartificial organs.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Junji
authors.initials: J
authors.lastname: Fukuda
authors.forename: Ali
authors.initials: A
authors.lastname: Khademhosseini
authors.forename: Yoon
authors.initials: Y
authors.lastname: Yeo
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Yang
authors.forename: Judy
authors.initials: J
authors.lastname: Yeh
authors.forename: George
authors.initials: G
authors.lastname: Eng
authors.forename: James
authors.initials: J
authors.lastname: Blumling
authors.forename: Chi-Fong
authors.initials: CF
authors.lastname: Wang
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Kohane
authors.forename: Robert
authors.initials: R
authors.lastname: Langer
mesh_terms: D000818:Animals; D032701:Biomimetics / Q000379:methods*; D002448:Cell Adhesion; D048271:Chitosan / Q000737:chemistry*; D018920:Coculture Techniques / Q000379:methods*; D005347:Fibroblasts / Q000166:cytology; D022781:Hepatocytes / Q000166:cytology; D006801:Humans; D020100:Hydrogels / Q000737:chemistry*; D051379:Mice; D046228:Microarray Analysis; D041681:NIH 3T3 Cells; D010777:Photochemistry; D018874:Spheroids, Cellular / Q000166:cytology; D014407:Tumor Cells, Cultured
chemical_list: D020100:Hydrogels; D048271:Chitosan