Fluorescein

Fluorescein Based Fluorescence Sensors for the Selective Sensing of Various Analytes

J Fluoresc 2021 Sep;31(5):1251-1276.34255257 10.1007/s10895-021-02770-9

Fluorescein molecules are extensively used to develop fluorescent probes for various analytes due to their excellent photophysical properties and the spirocyclic structure. The main structural modification of Fluorescein occurs at the carboxyl group where different groups can be easily introduced to produce the spirolactam structure which is non-fluorescent. The spirolactam ring opening accounts for the fluorescence and the dual sensing of analytes using fluorescent sensors is still a topic of high interest. There is an increase in the number of dual sensors developed in the past five years and quite a good number of Fluorescein derivatives were also reported based on reversible mechanisms. This review analyses environmentally and biologically important cations such as Cu2+, Hg2+, Fe3+, Pd2+, Zn2+, Cd2+, and Mg2+; anions (F-, OCl-) and small molecules (thiols, CO and H2S). Structural modifications, binding mechanisms, different strategies and a comparative study for selected cations, anions and molecules are outlined in the article.

Ophthalmic Fluorescein Angiography

Methods Mol Biol 2023;2560:153-160.36481893 10.1007/978-1-0716-2651-1_15

Following its implementation in the 1960s, Fluorescein angiography (FA) has become a widely used and reliable tool in the diagnosis of retinal and choroidal disorders. FA is an imaging modality utilized to examine the circulation of the retina and choroid. Here, we describe the process of obtaining fundus images with sodium Fluorescein dye as a contrast agent. Using this methodology, ophthalmologists may examine the retinal and choroidal vasculature to diagnose a wide scope of retinal and choroidal diseases.

Generalized pseudopsoriasis due to Fluorescein injection

J Fr Ophtalmol 2021 Jun;44(6):922-923.33838945 10.1016/j.jfo.2020.10.008

Safety of sodium Fluorescein for in vivo study of skin

Skin Res Technol 2006 Aug;12(3):155-61.16827689 10.1111/j.0909-752X.2006.00147.x

Background/purpose: Epicutaneous labeling or intradermal injection of the fluorescent sodium Fluorescein is being used increasingly to investigate skin conditions in vivo when using non-invasive devices such as confocal scanning laser microscopy. Sodium Fluorescein was used intravenously for decades for the examination of the vasculature of the ocular fundus (Fluorescein angiography) and as eye drops for diagnosis of corneal erosions. The objective of this article is to systematically review the literature on Fluorescein and conclude its safety in cutaneous research to support research planning and evaluations by ethics committees. Methods: A number of databases and the literature about safety and toxicity of Fluorescein in animal and human studies were searched and analyzed. Results: Side effects or adverse events reported in the literature were related to intravenous bolus injection. Transient nausea and vomiting may occur. Other adverse events such as vasovagal reaction, cardiac or respiratory effects and anaphylaxes are extremely rare but may be fatal. Intradermal injection may cause mild itch or pain; systemic adverse event was reported. Epicutaneous labeling is associated with no reported problem. A typical local dose is several magnitudes of order smaller than a typical intravenous dose. Conclusion: Fluorescein has been used for many years in medicine for diagnostic purposes and is widely safe, albeit intravenous bolus injection may cause serious adverse reactions. In the literature, we could not trace reports of local or systemic side effects of topical sodium Fluorescein except itch and pain on intradermal injection, however, dependent on the Fluorescein preparation used. Local dermal application of Fluorescein for in vivo study of skin may be considered widely safe.

Fluorescein clearance kinetics in blood and bile indicates hepatic ischemia-reperfusion injury in rats

Am J Physiol Gastrointest Liver Physiol 2022 Aug 1;323(2):G126-G133.35700191 10.1152/ajpgi.00038.2022

Quantitative measurement of the degree of hepatic ischemia-reperfusion injury (IRI) is crucial for developing therapeutic strategies for its treatment. We hypothesized that clearance of fluorescent dye through bile metabolism may reflect the degree of hepatic IRI. In this study, we investigated sodium Fluorescein clearance kinetics in blood and bile for quantifying the degree of hepatic IRI. Warm ischemia times (WITs) of 0, 30, or 60 min followed by 1 h or 4 h of reperfusion, were applied to the median and lateral lobes of the liver in Sprague-Dawley rats. Subsequently, 2 mg/kg of sodium Fluorescein was injected intravenously, and blood and bile samples were collected over 60 min to measure fluorescence intensities. The bile-to-plasma fluorescence ratios demonstrated an inverse correlation with WIT and were distinctly lower in the 60-min WIT group than in the control or 30-min WIT groups. Bile-to-plasma fluorescence ratios displayed superior discriminability for short versus long WITs when measured 1 h after reperfusion versus 4 h. We conclude that the bile-to-blood ratio of fluorescence after sodium Fluorescein injection has the potential to enable the quantification of hepatic IRI severity.NEW & NOTEWORTHY Previous attempts to use fluorophore clearance to test liver function have relied on a single source of data. However, the kinetics of substrate processing via bile metabolism include decreasing levels in blood and increasing levels in bile. Thus, we analyzed data from blood and bile to better reflect Fluorescein clearance kinetics.