caa a22 4500 605479380 CHVBK 20210128100410.0 cr unu---uuuuu 210128e20150201xx s 000 0 eng 10.1007/s10544-014-9922-9 doi (NATIONALLICENCE)springer-10.1007/s10544-014-9922-9 Balancing oxygen diffusion and convection in spiral microfluidics to mimic radial biological gradients [Elektronische Daten] [Zidong Li, Di Hu, Zhengtuo Zhao, Mengyang Zhou, Rui Liu, Joe Lo] Biological gradients are more than linear, one-dimensional phenomena—they often manifest radial geometries superimposed over tissue features and in turn, elicit a spatial response. In wound healing, injury to tissue produces a hypoxic gradient towards the center of the wound, and wound cells respond to this by secreting growth hormones to promote healing. Despite this spatial element in tissue hypoxia, most in vitro hypoxia techniques rely on linear, diffusion-based gradients of limited dimensions. To demonstrate a large area, radial hypoxia gradient, a concentric spiral microfluidics was devised to balance oxygen diffusion against nitrogen convection. The devices were fabricated using only a simple robotic cutter and soft lithography. With these spirals, spatial gradients of 3-15% oxygen were delivered to fibroblast cells seeded across a gas-permeable membrane to modulate VEGF secretions. This technique opens the door for more studies on hypoxic gradients in wound healing and a number of tissue oxygen applications. Springer Science+Business Media New York, 2015 Microfluidic nationallicence Spatial gradient nationallicence Oxygen nationallicence Hypoxia nationallicence Diffusion nationallicence Convection nationallicence Fibroblast nationallicence VEGF secretion nationallicence Li Zidong Bioengineering Program, Department of Mechanical Engineering, University of Michigan, HPEC 1332, 4901 Evergreen Rd., 48128, Dearborn, MI, USA aut Hu Di Bioengineering Program, Department of Mechanical Engineering, University of Michigan, HPEC 1332, 4901 Evergreen Rd., 48128, Dearborn, MI, USA aut Zhao Zhengtuo Bioengineering Program, Department of Mechanical Engineering, University of Michigan, HPEC 1332, 4901 Evergreen Rd., 48128, Dearborn, MI, USA aut Zhou Mengyang Bioengineering Program, Department of Mechanical Engineering, University of Michigan, HPEC 1332, 4901 Evergreen Rd., 48128, Dearborn, MI, USA aut Liu Rui Bioengineering Program, Department of Mechanical Engineering, University of Michigan, HPEC 1332, 4901 Evergreen Rd., 48128, Dearborn, MI, USA aut Lo Joe Bioengineering Program, Department of Mechanical Engineering, University of Michigan, HPEC 1332, 4901 Evergreen Rd., 48128, Dearborn, MI, USA aut Biomedical Microdevices Springer US; http://www.springer-ny.com 17/1(2015-02-01), 1-9 1387-2176 17:1<1 2015 17 10544 https://doi.org/10.1007/s10544-014-9922-9 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10544-014-9922-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Li Zidong Bioengineering Program, Department of Mechanical Engineering, University of Michigan, HPEC 1332, 4901 Evergreen Rd., 48128, Dearborn, MI, USA aut NATIONALLICENCE 700 1- Hu Di Bioengineering Program, Department of Mechanical Engineering, University of Michigan, HPEC 1332, 4901 Evergreen Rd., 48128, Dearborn, MI, USA aut NATIONALLICENCE 700 1- Zhao Zhengtuo Bioengineering Program, Department of Mechanical Engineering, University of Michigan, HPEC 1332, 4901 Evergreen Rd., 48128, Dearborn, MI, USA aut NATIONALLICENCE 700 1- Zhou Mengyang Bioengineering Program, Department of Mechanical Engineering, University of Michigan, HPEC 1332, 4901 Evergreen Rd., 48128, Dearborn, MI, USA aut NATIONALLICENCE 700 1- Liu Rui Bioengineering Program, Department of Mechanical Engineering, University of Michigan, HPEC 1332, 4901 Evergreen Rd., 48128, Dearborn, MI, USA aut NATIONALLICENCE 700 1- Lo Joe Bioengineering Program, Department of Mechanical Engineering, University of Michigan, HPEC 1332, 4901 Evergreen Rd., 48128, Dearborn, MI, USA aut NATIONALLICENCE 773 0- Biomedical Microdevices Springer US; http://www.springer-ny.com 17/1(2015-02-01), 1-9 1387-2176 17:1<1 2015 17 10544