Laser direct-write of single microbeads into spatially-ordered patterns

Biofabrication. 2012 Jun;4(2):025006. doi: 10.1088/1758-5082/4/2/025006. Epub 2012 May 4.

Abstract

Fabrication of heterogeneous microbead patterns on a bead-by-bead basis promotes new opportunities for sensors, lab-on-a-chip technology and cell-culturing systems within the context of customizable constructs. Laser direct-write (LDW) was utilized to target and deposit solid polystyrene and stem cell-laden alginate hydrogel beads into computer-programmed patterns. We successfully demonstrated single-bead printing resolution and fabricated spatially-ordered patterns of microbeads. The probability of successful microbead transfer from the ribbon surface increased from 0 to 80% with decreasing diameter of 600 to 45 µm, respectively. Direct-written microbeads retained spatial pattern registry, even after 10 min of ultrasonication treatment. SEM imaging confirmed immobilization of microbeads. Viability of cells encapsulated in transferred hydrogel microbeads achieved 37 ± 11% immediately after the transfer process, whereas randomly-patterned pipetted control beads achieved a viability of 51 ± 25%. Individual placement of >10 µm diameter microbeads onto planar surfaces has previously been unattainable. We have demonstrated LDW as a valuable tool for the patterning of single, micrometer-diameter beads into spatially-ordered patterns.

MeSH terms

  • Adsorption
  • Alginates / chemistry
  • Animals
  • Biotechnology / methods*
  • Cell Adhesion
  • Cell Culture Techniques / methods*
  • Cell Survival
  • Embryonic Stem Cells / cytology
  • Glucuronic Acid / chemistry
  • Hexuronic Acids / chemistry
  • Hydrogel, Polyethylene Glycol Dimethacrylate / chemistry
  • Lasers*
  • Mice
  • Microscopy, Phase-Contrast
  • Microspheres*
  • Particle Size
  • Polystyrenes / chemistry

Substances

  • Alginates
  • Hexuronic Acids
  • Polystyrenes
  • Hydrogel, Polyethylene Glycol Dimethacrylate
  • Glucuronic Acid