title: Single-Crystalline, Nanoporous Gallium Nitride Films With Fine Tuning of Pore Size for Stem Cell Engineering.
abstract: Single-crystalline nanoporous gallium nitride (GaN) thin films were fabricated with the pore size readily tunable in 20-100 nm. Uniform adhesion and spreading of human mesenchymal stem cells (hMSCs) seeded on these thin films peak on the surface with pore size of 30 nm. Substantial cell elongation emerges as pore size increases to ∼80 nm. The osteogenic differentiation of hMSCs occurs preferentially on the films with 30 nm sized nanopores, which is correlated with the optimum condition for cell spreading, which suggests that adhesion, spreading, and stem cell differentiation are interlinked and might be coregulated by nanotopography.
authors.affiliation: Biomedical Engineering, Yale University , Malone Center Room / space 103C , 55 Prospect Street , New Haven, CT 06511 e-mail:  han.lin@yale.edu.
authors.forename: Lin
authors.initials: L
authors.lastname: Han
authors.affiliation: Anesthesiology, Yale School of Medicine, Biomedical Engineering, Yale University , Room 314 , 10 Amistad Street , New Haven, CT 06510 e-mail:  jzjzhou@gmail.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Mechanical Engineering, University of Michigan , 2664 GGB (George G. Brown Laboratory) , 2350 Hayward , Ann Arbor, MI 48109-2125 e-mail:  ybsun@umich.edu.
authors.forename: Yubing
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Electrical Engineering, Yale University , 15 Prospect Street , New Haven, CT 06511 e-mail:  yuzhang18@gmail.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Electrical Engineering, Yale University , Becton 517 , 15 Prospect Street , New Haven, CT 06511 e-mail:  jung.han@yale.edu.
authors.forename: Jung
authors.initials: J
authors.lastname: Han
authors.affiliation: Mem. ASME Mechanical Engineering, Biomedical Engineering, University of Michigan , 2664 GGB (George G. Brown Laboratory) , 2350 Hayward , Ann Arbor, MI 48109-2125 e-mail:  jphu@umich.edu.
authors.forename: Jianping
authors.initials: J
authors.lastname: Fu
authors.affiliation: Biomedical Engineering, Yale University , Malone 213 , 55 Prospect Street , New Haven, CT 06511 e-mail:  rong.fan@yale.edu.
authors.forename: Rong
authors.initials: R
authors.lastname: Fan