Live Imaging and Quantitation of Lipid Droplets and Mitochondrial Membrane Potential Changes with Aggregation‐Induced Emission Luminogens in an in Vitro Model of Liver Steatosis

Abstract

High specificity, low background, good biocompatibility and photostability are common properties of aggregation‐induced emission luminogens (AIEgens). In this study, an AIEgen FAS was used in live HepG2 cells, an in vitro model of liver steatosis, to quantify lipid droplet number and size instead of the traditional method of only measuring fluorescence intensity emitted from fluorescence dye stained in lipid droplet. In parallel, another AIEgen, TPE‐Ph‐In, was used to perform continuous monitoring and quantitation of mitochondrial membrane potential in the same batch of live HepG2 cells. The data show a significant increase in lipid droplet numbers after 24 h treatment by amiodarone and a significant increase in both lipid droplet numbers and size after 48 h amiodarone treatment. Moreover, the data suggest a significant increase in mitochondria membrane potential in cells treated with amiodarone for 24 and 48 h, with restoration to pre‐treatment level 24 h after removal of the amiodarone. Further investigation is needed to fully understand the underlying mechanism.

The Biological Applications of Two Aggregation‐Induced Emission Luminogens

“…Compared with the results before treatment, after treatment with amiodarone, there was an obvious Δψ m increase in the HepG2 cells. Long‐term detection of the Δψ m with TPE‐Ph‐In confirmed that the treatment of amiodarone on HepG2 cells increased the Δψ m over a 48 h period, while the removal of amiodarone restored the Δψ m to its original level within 24 h …”

“…The high background, however, always makes quantifying the lipid droplet sizes and numbers challenging . FAS, which can label the intracellular lipid droplets and TPE‐Ph‐In, was used to quantitate lipid droplets and the Δψ m in HepG2 cells . To study the effects of lipid accumulation on the Δψ m , Zhou et al.…”

“…Compared with ACQ systems, the new AIE systems have multiple notable advantages, such as excellent stability, facile fabrication, high signal‐to‐noise ratio, and low detection limits. Moreover, in response to recent progress, the scope of the AIEgen applications has expanded to include an increasing number of scientific fields …”

Tuning aggregation-induced emission nanoparticle properties under thin film formation

“…AIEgens are mainly soluble in an organic solvent and are insoluble in water. 11 Therefore, the addition of an AIEgen solution into water results in the formation of AIEgen particles in a very short time. Within such a short period of time and in the absence of proper mixing under shear, AIE particles are likely to be distributed in a wide range of sizes, thereby affecting their ultimate brightness and applications.…”

Synthesis, Photophysics and Solvatochromic Studies of an Aggregated-Induced-Emission Luminogen Useful in Bioimaging

“…AIE makes these molecules excellent probes in the fields of biomedicine and life sciences [12]. AIE probes have been used for biosensing and/or bioimaging in DNA [13] and ATP [14] detection, as a mitochondria marker [15], for determining lipid droplet and mitochondria membrane potential [16], and for detecting multiple ions and species such as Al 3+ in food and cells [17], intracellular cyanide [18], bilirubin and Fe 3+ [19]. These molecules present a promising future as probes in in vivo diagnosis and therapy [20].…”