title: Microtransponders, the miniature RFID electronic chips, as platforms for cell growth in cytotoxicity assays.
abstract: BACKGROUND
  An electronic radio frequency (RF) microchip, the microtransponder (MTP), has been developed as a platform for assays in the fields of genomics and proteomics. Upon activation by light, each MTP provides a unique RF identification (ID) signal that matches a chip to the specific biological material attached to it. The MTP is powered by a photocell and has an antenna that transmits the signal. The aim of the present study was to explore utility of MTPs as a platform for cell growth in cytotoxicity assays.
  
  
  METHODS
  The MCF-7, MCF-116, A549, or T-24 cells growing on MTPs placed in petri dishes or slide chambers were cultured untreated or exposed to antitumor drugs topotecan, mitoxantrone, or onconase for up to 4 days. Their attachment to- and growth on- MTPs was assessed by fluorescence microscopy and laser scanning cytometry (LSC) and compared with growth on the dish surface in the MTP neighborhood. The MTPs were fixed in ethanol, stained with propidium iodide (PI), and interrogated in flow in the instrument capable to rapidly (up to 103 MTPs/s) identify their ID signal and measure fluorescence.
  
  
  RESULTS
  The cells plated on MTPs exhibited similar attachment properties to those plated in culture dishes. When measured by LSC, they had similar mitotic activity, growth rate, and cell cycle distributions as the cells adhering to the culture dish in the neighborhood of MTPs. The fluorescence intensity of MTPs provided information about the cell number per MTP, which made it possible to assess cell growth rate and monitor the cytostatic/cytotoxic effects of the tested drugs.
  
  
  CONCLUSIONS
  The MTP-based system holds promise for the multiplexed cell assays in which numerous different cell lines can be screened for their growth rate or sensitivity while exposed to particular agents in the same vessel. Other advantages of the system are the rapidity of the screening and a very large number of ID codes. Because many cell lines/types can be assayed in a single dish, the system also offers cost savings on tissue culture reagents.
authors.affiliation: PharmaSeq, Inc., Monmouth Jct., New Jersey 08852, USA. mandecki@pharmaseq.com
authors.forename: Wlodek
authors.initials: W
authors.lastname: Mandecki
authors.forename: Barbara
authors.initials: B
authors.lastname: Ardelt
authors.forename: Thomas
authors.initials: T
authors.lastname: Coradetti
authors.forename: Hanan
authors.initials: H
authors.lastname: Davidowitz
authors.forename: James A
authors.initials: JA
authors.lastname: AFlint
authors.forename: Zhili
authors.initials: Z
authors.lastname: Huang
authors.forename: Wesley M
authors.initials: WM
authors.lastname: MKopacka
authors.forename: Xin
authors.initials: X
authors.lastname: Lin
authors.forename: Zhuying
authors.initials: Z
authors.lastname: Wang
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Darzynkiewicz
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000473:pathology; D002295:Carcinoma, Transitional Cell / Q000473:pathology; D018929:Cell Culture Techniques / Q000379:methods; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D003363:Cost Control; D004354:Drug Screening Assays, Antitumor / Q000191:economics / Q000295:instrumentation* / Q000379:methods; D004581:Electronics / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D056656:Lab-On-A-Chip Devices; D047569:Laser Scanning Cytometry / Q000295:instrumentation* / Q000379:methods; D008175:Lung Neoplasms / Q000473:pathology; D046208:Microchip Analytical Procedures / Q000379:methods; D008856:Microscopy, Fluorescence; D008942:Mitoxantrone / Q000494:pharmacology; D011846:Radio Waves; D012260:Ribonucleases / Q000494:pharmacology; D019772:Topotecan / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D019772:Topotecan; D008942:Mitoxantrone; D012260:Ribonucleases; C058703:ranpirnase