title: Molecular histopathology using gold nanorods and optical coherence tomography.
abstract: OBJECTIVE
  To examine the novel application of a commercially available optical coherence tomography (OCT) system toward molecular histopathology using gold nanorod (GNR) linked antibodies as a functionalized contrast agent to evaluate ocular surface squamous neoplasia (OSSN).
  
  
  METHODS
  GNRs were synthesized and covalently attached to anti-glucose transporter-1 (GLUT-1) antibodies via carbodiimide chemistry. Three specimens from each of three distinct categories of human conjunctival tissue were selected for analysis, including conjunctiva without epithelial atypia (controls); conjunctival intraepithelial neoplasia, carcinoma in situ (CIS); and conjunctival squamous cell carcinoma (SCC). Tissue sections were incubated initially with GNR tagged anti-GLUT-1 antibodies and then with a fluorescent-tagged secondary antibody. Immunofluorescence and OCT imaging of the tissue was performed and the results were correlated to the light microscopic findings on traditional hemotoxyin and eosin stained sections.
  
  
  RESULTS
  No binding of the functionalized GNRs was observed within the epithelium of three normal conjunctiva controls. While immunofluorescence disclosed variable binding of the functionalized GNRs to atypical epithelial cells in all six cases of OSSN, the enhancement of the OCT signal in three cases of CIS was insufficient to distinguish these specimens from normal controls. In two of three cases of SCC, binding of functionalized GNRs was sufficient to produce an increased scattering effect on OCT in areas correlating to atypical epithelial cells which stained intensely on immunofluorescence imaging. Binding of functionalized GNRs was sufficient to produce an increased scattering effect on OCT in areas correlating to regions of erythrocytes and hemorrhage which stained intensely on immunofluorescence imaging within all nine tested samples.
  
  
  CONCLUSIONS
  We have demonstrated the use of OCT for molecular histopathology using functionalized gold nanorods in the setting of OSSN. Our results suggest a threshold concentration of functionalized GNRs within tissue is required to achieve a detectable enhancement in scattering of the OCT signal.
authors: Department of Ophthalmology, University of Miami-Bascom Palmer Eye Institute, Miami, FL 33136, USA. sprabhulkar@med.miami.edu
authors: Shradha
authors: S
authors: Prabhulkar
authors: Jared
authors: J
authors: Matthews
authors: Siddarth
authors: S
authors: Rawal
authors: Richard M
authors: RM
authors: Awdeh
mesh_terms: D000953:Antigens, Protozoan / Q000276:immunology / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D002278:Carcinoma in Situ / Q000378:metabolism / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology*; D003228:Conjunctiva / Q000166:cytology / Q000378:metabolism; D003230:Conjunctival Neoplasms / Q000378:metabolism / Q000473:pathology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D051272:Glucose Transporter Type 1 / Q000276:immunology / Q000378:metabolism; D006046:Gold; D006651:Histocytochemistry / Q000379:methods; D006801:Humans; D066298:In Vitro Techniques; D043942:Nanotubes; D015800:Protozoan Proteins / Q000276:immunology / Q000378:metabolism; D012542:Scattering, Radiation; D014015:Tissue Banks; D041623:Tomography, Optical Coherence / Q000379:methods*
chemical_list: D000953:Antigens, Protozoan; D015415:Biomarkers; D051272:Glucose Transporter Type 1; D015800:Protozoan Proteins; C495677:SLC2A1 protein, human; C043323:immobilization antigens; D006046:Gold