Xu Yi,Kutsanedzie Felix Y. H.,Ali Shujat,Wang Pingyue,Li Chunyan,Ouyang Qin,Li Huanhuan,Chen Quansheng
Lead ion (Pb 2+ ) accumulation in food consumed by humans and animals possess health threats and effects. The development of a senor for its monitoring at its minutest accumulation in edible materials becomes an antidote to safeguarding human lives. A fabricated fluorescence-based sensor made of carboxyl modified upconversion nanoparticles (UCNPs), gold nanorods (GNRs), and cysteamine (Cys) were used as energy donor, receptor and a bridge respectively for the rapid sensing of Pb 2+ in Matcha. The UCNPs-Cys-GNRs sensor showed weak fluorescence signals due to the FRET, and was inhibited in the presence of Pb 2+ to form a complex with Cys, and the consequent recovery of fluorescence signals. Under optimized conditions, a good linear relationship was established between the relative fluorescence intensity and Pb 2+ concentrations from 1 to 100 μM with a low detection limit (LOD) of 0.5 μM. The developed sensor was applied to detect Pb 2+ in Matcha samples with recoveries within 93.99—102.16% and relative standard deviations (RSD) < 8%. Satisfactory results (p > 0.05) were obtained upon validation using a standard inductively coupled plasma mass spectrometry (ICP-MS).
Lujing Geng,Tong Lu,Huaqing Jing,Yue Zhou,Xiaoyang Liang,Jiao Li,Nan Li
Ferroptosis (FPT), a novel form of programmed cell death, is characterized by overwhelming iron/reactive oxygen species (ROS)-dependent accumulation of lipid peroxidation (LPO). However, the insufficiency of endogenous iron and ROS level limited the FPT therapeutic efficacy to a large extent. To overcome this obstacle, the bromodomain-containing protein 4 (BRD 4 )-inhibitor (+)-JQ1 (JQ1) and iron-supplement ferric ammonium citrate (FAC)-loaded gold nanorods (GNRs) are encapsulated into the zeolitic imidazolate framework-8 (ZIF-8) to form matchbox-like [email protected] /ZIF-8 for the amplified FPT therapy. The existence of matchbox (ZIF-8) is stable in physiologically neutral conditions but degradable in acidic environment, which could prevent the loaded agents from prematurely reacting. Moreover, GNRs as the drug-carriers induce the photothermal therapy (PTT) effect under the irradiation of near-infrared II (NIR-II) light owing to the absorption by localized surface plasmon resonance (LSPR), while the hyperthermia also boosts the JQ1 and FAC releasing in the tumor microenvironment (TME). On one hand, the FAC-induced Fenton/Fenton-like reactions in TME can simultaneously generate iron (Fe 3+ /Fe 2+ ) and ROS to initiate the FPT treatment by LPO elevation. On the other hand, JQ1 as a small molecule inhibitor of BRD 4 protein can amplify FPT through downregulating the expression of glutathione peroxidase 4 (GPX4), thus inhibiting the ROS elimination and leading to the LPO accumulation. Both in vitro and in vivo studies reveal that this pH-sensitive nano-matchbox achieves obvious suppression of tumor growth with good biosafety and biocompatibility. As a result, our study points out a PTT combined iron-based/BRD 4 -downregulated strategy for amplified ferrotherapy which also opens the door of future exploitation of ferrotherapy systems.
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