Acid-induced degradation of widely used NIR dye DiR causes hypsochromic shift in fluorescence properties

European Journal of Pharmaceutical Sciences : Official Journal of the European Federation for Pharmaceutical Sciences
Markus RiehlKarsten Mäder

Abstract

DiR (1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbocyanine iodide) is one of the most widely used near-infrared dyes for in-vivo imaging due to its favorable optical properties. So far, chemical stability has been taken for granted by most investigators. However, in a recently published imaging study, we found that DiR can exert a hypsochromic shift in fluorescence in-vivo, potentially induced by low pH. This behavior may disturb kinetic measurements and the readout of additional markers fluorescing at lower wavelengths. The present in-vitro experiments were conducted to verify the findings from our in-vivo study and to elucidate the changes of the optical properties of DiR. For this purpose, DiR was incubated in a pH range from pH 2 to neutral pH over 42 days. Fluorescence and absorption measurements as well as mass spectrometry analytics (MS) were conducted to monitor the degradation process of DiR. The protonation effect on DiR optical behavior was estimated using in-silico modelling. For the most acidic sample, a distinct decrease in DIR-fluorescence was noted and several degradation products could be analyzed via MS, confirming the initial hypothesis. Ultimately, scientists should be aware of the possibility of acid-in...Continue Reading

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.