Both exogenous fluorophores (AF647 and AF350) tested showed similar results even though the fluorophores are on the opposite ends of the visible spectrum. Selleck Fulvestrant The AF647-WGA probe was used to initially test the feasibility of cancer detection as there is negligible tissue autofluorescence in the far-red and near-infrared spectrums [23], providing a measure of confidence that the fluorescence obtained was from the binding of the lectin to glycoconjugates. Additionally, near infrared wavelengths can penetrate further
into the tissue [33]. However, since we are imaging the probe on the superficial tissue surface, light propagation into the tissue is not a concern and did not seem to enhance the SNRs in this experiment. The disadvantage of utilizing near‐infrared fluorophores is the fact that a camera and narrow bandpass filtering is needed since visualization is outside of the visible spectrum, and near‐infrared fluorophores exhibit small stokes shifts. Previous work of ours detailed the use of AF647-WGA Stem Cell Compound Library purchase for oral cancer detection; however, the data is not shown in this manuscript (besides the single patient comparison of AF350-WGA and AF647-WGA) since this paper focused on developing a clinically useful tool without the need for complex filters and cameras. As such,
most of the presented data was with AF350-WGA, which allowed for fluorophore emission easily visible to the naked eye. Furthermore, as the AF350 is in the UV spectrum, there is more energy per photon which yields a larger stokes shift for UV fluorophores; a larger stokes shift is advantageous to allow for easier discrimination of excited and emitted light. Combined, these features make the AF350-WGA more suitable for
clinical use as additional equipment is not required. Previously, researchers have examined intrinsic fluorescent molecules and tissue reflectance properties to differentiate between normal and cancerous tissue. For example, commercially available devices (VELscope, ViziLite, etc.) have been developed to analyze tissue autofluorescence for cancerous tissue. However, these devices were identified as ineffective adjuncts to current white light head and neck exams as well as Carnitine palmitoyltransferase II histological methods as they lack adequate specificity and sensitivity to accurately diagnose oral cancer [34] and [35]. Similar conclusions were seen in our data which showed suggestive differences in autofluorescence between normal and cancerous tissue at 365nm (P = .098). Another group demonstrated that fluorescently labeled glucose preferentially localized in cancerous tissue due to increased metabolic activity. This approach was favorable and lead to a SNR of 3.7 [36]; however, this is lower than the SNR reported in this manuscript (5.88).