Catch and release cell sorting: electrochemical desorption of T-cells from antibody-modified microelectrodes

Colloids Surf B Biointerfaces. 2008 Jul 15;64(2):260-8. doi: 10.1016/j.colsurfb.2008.02.010. Epub 2008 Mar 10.

Abstract

The development of integrated microsystems capable of interrogation, characterization and sorting of mammalian cells is highly significant for further advancement of point-of-care diagnostics and drug discovery fields. The present study sought to design a novel strategy for releasing antibody-bound cells through electrochemical disruption of the underlying antibody (Ab) layer. A microsystem for selective capture and release of cells consisted of an array of individually addressable gold microelectrodes fabricated on a glass substrate. Poly(ethylene glycol) (PEG) hydrogel photolithography was employed to make the glass regions non-fouling, thus, ensuring selective localization of proteins and cells on the microelectrodes. The gold surfaces were decorated with anti-CD4 Ab molecules using standard alkanethiol self-assembly and carbodiimide coupling approaches. The Ab-functionalized electrodes selectively captured model T-lymphocytes (Molt-3 cells) expressing CD4 antigen while minimal cell adhesion was observed on PEG hydrogel-modified glass substrates. Importantly, application of a reductive potential (-1.2V vs. Ag/AgCl reference electrode) resulted in release of surface-bound T-cells from the electrode surface. Cyclic voltammetry and fluorescence microscopy were employed to verify that the detachment of captured T-cells was indeed due to the electrochemical disruption of the underlying alkanethiol-Ab layer. In the future, the cell sorting approach described here may be combined with microfluidic delivery to enable Ab-mediated capture of T-lymphocytes or other cell types followed by release of select cells for downstream gene expression studies or re-cultivation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Antibodies / chemistry
  • Antibodies / immunology*
  • Antigens, CD / analysis
  • Antigens, CD / immunology
  • CD4 Antigens / immunology
  • Cell Line, Tumor
  • Cell Separation / methods*
  • Electrochemistry
  • Glass / chemistry
  • Gold / chemistry
  • Humans
  • Hydrogels / chemistry
  • Immunophenotyping / methods
  • Leukemia / pathology
  • Microelectrodes
  • Microscopy, Fluorescence
  • Polyethylene Glycols / chemistry
  • Substrate Specificity
  • Surface Properties
  • T-Lymphocytes / cytology*
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / metabolism

Substances

  • Antibodies
  • Antigens, CD
  • CD4 Antigens
  • Hydrogels
  • Polyethylene Glycols
  • Gold