title: Detecting a secreted gastric cancer biomarker molecule by targeted nanoparticles for real-time diagnostics.
abstract: OBJECTIVE
  A real time detection of gastric cancer-associated biomarker molecules in the lumen of the stomach could assist in early detection of this multi-step malignancy.
  
  
  METHODS
  Employing α1-antitrypsin precursor (A1AT) as a secreted biomarker model, a platform with immunoassay capabilities, comprising sensing and detecting compartments was developed. It was made of a microarray-type functionalized glass, containing a high density of amine groups. Trypsin, the capturing moiety, was immobilized to the glass surface with the aid of a PEG-based spacer mixture, identified as being crucial for both capturing and detecting properties. The detecting compartment contained near infrared fluorescently labeled nanoparticles conjugated to A1AT-specific antibodies, aimed at generating an optical signal, detectable by a conventional endoscope or a video capsule.
  
  
  RESULTS
  The specific recognition reaction between the captured A1AT and the immuno-nanoparticles generated a profound fluorescence with a signal to noise ratio (SNR) of 12-32, in a biomarker-concentration dependent manner. Moreover, the optical recognition signal was intense enough to be detected by a video capsule simulator (with optical detection capabilities of a video capsule) with a SNR of 6-20.
  
  
  CONCLUSIONS
  This platform could serve as a real time diagnostic kit for early detection of a secreted biomarker of gastric cancer.
authors.affiliation: Faculty of Medicine, the School of Pharmacy Institute for Drug Research, The Hebrew University of Jerusalem, P.O.Box 12065, Jerusalem, 91120, Israel.
authors.forename: Elena
authors.initials: E
authors.lastname: Khazanov
authors.forename: Eylon
authors.initials: E
authors.lastname: Yavin
authors.forename: Amit
authors.initials: A
authors.lastname: Pascal
authors.forename: Aviram
authors.initials: A
authors.lastname: Nissan
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Kohl
authors.forename: Meike
authors.initials: M
authors.lastname: Reimann-Zawadzki
authors.forename: Abraham
authors.initials: A
authors.lastname: Rubinstein
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000032:analysis*; D018938:Caco-2 Cells; D005453:Fluorescence; D005898:Glass / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000379:methods; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D059629:Signal-To-Noise Ratio; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D014357:Trypsin / Q000737:chemistry; D014407:Tumor Cells, Cultured; D000515:alpha 1-Antitrypsin / Q000032:analysis*
chemical_list: D014408:Biomarkers, Tumor; D000515:alpha 1-Antitrypsin; D011092:Polyethylene Glycols; D014357:Trypsin