title: A microfluidic magnetic bead impact generator for physical stimulation of osteoblast cell.
abstract: We developed a novel microfluidic cell culture device in which magnetic beads repetitively collide with osteoblast cells, MC3T3-E1, owing to attractive forces generated by pulsed electromagnetic fields and consequently the cells were physically stimulated by bead impacts. Our device consists of an on-chip microelectromagnet and a microfluidic channel which were fabricated by a microelectromechanical system technique. The impact forces and stresses acting on a cell were numerically analyzed and experimentally generated with different sizes of bead (4.5, 7.6 and 8.4 mum) and at various pulse frequencies (60 Hz, 1 kHz and 1 MHz). Cells were synchronized at each specific phase of the cell cycle before stimulation in order to determine the most susceptible phase against bead impacts. The cells were stimulated with different sizes of bead at various pulse frequencies for 1 min at G1, S and G2 phases, respectively, and then counted immediately after one doubling time. The growth rate of cells was highly accelerated when they were stimulated with 4.5 mum beads at G1 phase and a pulse frequency of 1 MHz. Almost all of the cells were viable after stimulation, indicating that our cell stimulator did not cause any cellular damage and is suitable for use in new physical stimulus modalities.
authors.affiliation: Laboratory of Biochip Technology, School of Mechanical Engineering Yonsei University, Seoul, South Korea.
authors.forename: Suk-Heung
authors.initials: SH
authors.lastname: Song
authors.forename: Jeongheon
authors.initials: J
authors.lastname: Choi
authors.forename: Hyo-Il
authors.initials: HI
authors.lastname: Jung
mesh_terms: D016475:3T3 Cells / Q000166:cytology / Q000502:physiology; D000818:Animals; D002452:Cell Count; D018929:Cell Culture Techniques / Q000379:methods; D002453:Cell Cycle; D002455:Cell Division; D002470:Cell Survival; D004261:DNA Replication; D004574:Electromagnetic Fields; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007700:Kinetics; D008280:Magnetics; D051379:Mice; D044085:Microfluidics; D018625:Microscopy, Atomic Force; D010006:Osteoblasts / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D010812:Physical Stimulation / Q000295:instrumentation / Q000379:methods*