No abstract

Sulfur dioxide (SO) is a dangerous environmental pollutant. Excessive intake of it may cause some respiratory diseases and even lung cancer. The development of effective methods for detection of SO is of great importance for the environment and physiology. Herein, we have designed and synthesized a novel two-photon (TP) and deep-red emission ratiometric fluorescent probe (CP) for detection of SO. Notably, the novel probe CP exhibited ultrafast response to SO in less than 5 s and displayed a great emission shift (195 nm) and a large emission signal ratio variation (enhancement from 0.1347 to 100.14). In addition, the unique probe was successfully employed for imaging SO not only in the mitochondria of living cells but also in brain tissues and zebrafishes.

No abstract

The interplay between mitochondria and lipid droplets (LDs) plays a central role in regulating the β-oxidation and storage of fatty acids (FA) and is also engaged in responding to external stimuli such as nutrient deficiency. However, a single fluorescent probe enabling the discriminative and simultaneous visualization of the two organelles has not been reported yet, which brings limitation for the in-depth study on their interplay. In this work, utilizing the intramolecular spirocyclization reaction of rhodamine dyes that can dramatically change the optical and soluble properties, we have designed a new single fluorescent probe for labeling LDs and mitochondria in clearly separated dual-emission channels. The newly designed “biform” probe, MT-LD, presented in a ring-opened form in mitochondria to give a strong red emission, while it underwent the intramolecular spirocyclization reaction to target LDs showing an intense blue fluorescence. In this manner, MT-LD can label LDs and mitochondria in blue and red fluorescence, respectively. With this robust probe, the increase of mitochondria–LD contact and peridroplet mitochondria (PDM) amount during oleic acid treatment and starvation-induced autophagy has been successfully revealed. The interaction between the two organelles was also visualized in different tissues, which revealed an obviously higher level of mitochondria–LD contact and PDM amount in brown adipose tissue and lung tissue. This work provides a promising molecular tool to investigate the interplay between mitochondria and LDs and promotes studies on FA metabolism and autophagy.

A versatile strategy using amphiphilic copolymers to prepare micelles with cell membrane mimetic phosphorylcholine shell and PCL core showing potential anti-phagocytic clearance properties was reported.