Nanofabrication for micropatterned cell arrays by combining electron beam-irradiated polymer grafting and localized laser ablation

J Biomed Mater Res A. 2003 Dec 15;67(4):1065-71. doi: 10.1002/jbm.a.10078.

Abstract

Most methods reported for cell-surface patterning are generally based on photolithography and use of silicon or glass substrates with processing analogous to semiconductor manufacturing. Herein, we report a novel method to prepare patterned plastic surfaces to achieve cell arrays by combining homogeneous polymer grafting by electron beam irradiation and localized laser ablation of the grafted polymer. Poly(N-isopropylacrylamide) (PIPAAm) was covalently grafted to surfaces of tissue culture-grade polystyrene dishes. Subsequent ultraviolet ArF excimer laser exposure to limited square areas (sides of 30 or 50 microm) produced patterned ablative photodecomposition of only the surface region (approximately 100-nm depth). Three-dimensional surface profiles showed that these ablated surfaces were as smooth and flat as the original tissue culture-grade polystyrene surfaces. Time-of-flight secondary ion mass spectrometry analysis revealed that the ablated domains exposed basal polystyrene and were surrounded with PIPAAm-grafted chemistry. Before cell seeding, fibronectin was adsorbed selectively onto ablated domains at 20 degrees C, a condition in which the non-ablated grafted PIPAAm matrix remains highly hydrated. Hepatocytes seeded specifically adhered onto the ablated domains adsorbed with fibronectin. Because PIPAAm, inhibits cell adhesion and migration even at 37 degrees C when the grafted density is > 3 microg/cm2, all the cells were confined within the ablated domains. A 100-cell domain array was achieved by this method. This surface modification technique can be utilized for fabrication of cell-based biosensors as well as tissue-engineered constructs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acrylic Resins / chemistry*
  • Animals
  • Biocompatible Materials / chemistry
  • Cell Culture Techniques / instrumentation*
  • Cell Culture Techniques / methods
  • Cells, Cultured
  • Fibronectins / chemistry
  • Hepatocytes / cytology
  • Hepatocytes / metabolism
  • Lasers*
  • Nanotechnology*
  • Rats
  • Surface Properties

Substances

  • Acrylic Resins
  • Biocompatible Materials
  • Fibronectins
  • poly-N-isopropylacrylamide