title: Visualization of melanoma tumor with lectin-conjugated rare-earth doped fluoride nanocrystals.
abstract: OBJECTIVE
  To develop specific fluorescent markers for melanoma tumor visualization, which would provide high selectivity and reversible binding pattern, by the use of carbohydrate-recognizing proteins, lectins, combined with the physical ability for imaging deep in the living tissues by utilizing red and near infrared fluorescent properties of specific rare-earth doped nanocrystals (NC).
  
  
  METHODS
  B10F16 melanoma cells were inoculated to C57BL/6 mice for inducing experimental melanoma tumor. Tumors were removed and analyzed by lectin-histochemistry using LABA, PFA, PNA, HPA, SNA, GNA, and NPL lectins and stained with hematoxylin and eosin. NPL lectin was conjugated to fluorescent NaGdF4:Eu(3+)-COOH nanoparticles (5 nm) via zero length cross-linking reaction, and the conjugates were purified from unbound substances and then used for further visualization of histological samples. Fluorescent microscopy was used to visualize NPL-NaGdF4:Eu(3+) with the fluorescent emission at 600-720 nm range.
  
  
  RESULTS
  NPL lectin selectively recognized regions of undifferentiated melanoblasts surrounding neoangiogenic foci inside melanoma tumor, PNA lectin recognized differentiated melanoblasts, and LCA and WGA were bound to tumor stroma regions. NPL-NaGdF4:Eu(3+) conjugated NC were efficiently detecting newly formed regions of melanoma tumor, confirmed by fluorescent microscopy in visible and near infrared mode. These conjugates possessed high photostability and were compatible with convenient xylene-based mounting systems and preserved intensive fluorescent signal at samples storage for at least 6 months.
  
  
  CONCLUSIONS
  NPL lectin-NaGdF4:Eu(3+) conjugated NC permitted distinct identification of contours of the melanoma tissue on histological sections using red excitation at 590-610 nm and near infrared emission of 700-720 nm. These data are of potential practical significance for development of glycans-conjugated nanoparticles to be used for in vivo visualization of melanoma tumor.
authors.forename: Tetiana
authors.initials: T
authors.lastname: Dumych
authors.forename: Maxym
authors.initials: M
authors.lastname: Lutsyk
authors.forename: Mateusz
authors.initials: M
authors.lastname: Banski
authors.forename: Antonina
authors.initials: A
authors.lastname: Yashchenko
authors.forename: Bartlomiej
authors.initials: B
authors.lastname: Sojka
authors.forename: Rostyslav
authors.initials: R
authors.lastname: Horbay
authors.forename: Alexander
authors.initials: A
authors.lastname: Lutsyk
authors.forename: Rostyslav
authors.initials: R
authors.lastname: Stoika
authors.forename: Jan
authors.initials: J
authors.lastname: Misiewicz
authors.forename: Artur
authors.initials: A
authors.lastname: Podhorodecki
authors.affiliation: Rostyslav Bilyy, Drahomnanov Str. 14/16, 79005, Lviv, Ukraine, r.bilyy@gmail.com.
authors.forename: Rostyslav
authors.initials: R
authors.lastname: Bilyy
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000378:metabolism*; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000378:metabolism*; D005456:Fluorescent Dyes; D006651:Histocytochemistry; D006801:Humans; D037102:Lectins / Q000378:metabolism*; D008546:Melanoma, Experimental / Q000378:metabolism* / Q000473:pathology; D008674:Metals, Rare Earth; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence / Q000379:methods*; D053758:Nanoparticles; D009363:Neoplasm Proteins / Q000378:metabolism*; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology
chemical_list: D000951:Antigens, Neoplasm; D015295:Antigens, Tumor-Associated, Carbohydrate; D005456:Fluorescent Dyes; D037102:Lectins; D008674:Metals, Rare Earth; D009363:Neoplasm Proteins