Emerging noninvasive treatments, such as sonodynamic therapy (SDT) and chemodynamic therapy (CDT), have developed as promising alternatives or supplements to traditional chemotherapy. However, their therapeutic effects are limited by the hypoxic environment of tumors. Here, a biodegradable nanocomposite-mesoporous zeolitic-imidazolateframework@MnO 2 /doxorubicin hydrochloride (mZMD) is developed, which achieves enhanced SDT/CDT/chemotherapy through promoting oxidative stress and overcoming the multidrug resistance. The mZMD decomposes under both ultrasound (US) irradiation and specific reactions in the tumor microenvironment (TME). The mZM composite structure reduces the recombination rate of e − and h + to improve SDT. MnO 2 not only oxidizes glutathione in tumor cells to enhance oxidative stress, but also converts the endogenic H 2 O 2 into O 2 to improve the hypoxic TME, which enhances the effects of chemotherapy/SDT. Meanwhile, the generated Mn 2+ catalyzes the endogenic H 2 O 2 into •OH for CDT, and acts as magnetic resonance imaging agent to guide therapy. In addition, dissociated Zn 2+ further breaks the redox balance of TME, and co-inhibits the expression of P-glycoprotein (P-gp) with generated ROS to overcome drug resistance. Thus, the as-prepared intelligent biodegradable mZMD provides an innovative strategy to enhance SDT/CDT/chemotherapy.

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Multifunctional biomimetic nanozyme (SSMA/DOX) is fabricated, which enables tumor microenvironment responsive self-cascade catalysis to reach MRI guided enhanced chemo/chemodynamic therapy.

Objective The characteristic constituents of essential oils from aromatic plants have been widely applied as antimicrobial agents in the last decades. However, their mechanisms of action remain obscure, especially from the metabolic perspective. The aim of the study was to explore the antimicrobial effect and mechanism of menthone, a main component of peppermint oil, against methicillin resistant Staphylococcus aureus (MRSA). Methods An integrated approach including the microbiology and the high-coverage lipidomics was applied. The changes of membrane properties were studies by the fluorescence and electron microscopical observations. The lipid profile was analyzed by ultra-high performance liquid chromatography coupled with quadruple Exactive mass spectrometry (UHPLC-QE-MS). The lipid-related key targets which were associated with the inhibitory effect of menthone against MRSA, were studied by network analysis and molecular docking. Results Menthone exhibited antibacterial activities against MRSA, with minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of 3,540 and 7,080 μg/mL, respectively. The membrane potential and membrane integrity upon menthone treatment were observed to change strikingly. Further, lipids fingerprinting identified 136 significantly differential lipid species in MRSA cells exposed to menthone at subinhibitory level of 0.1× MIC. These metabolites span 30 important lipid classes belonging to glycerophospholipids, glycolipids, and sphingolipids. Lastly, the correlations of these altered lipids, as well as the potential metabolic pathways and targets associated with menthone treatment were deciphered preliminarily. Conclusion Menthone had potent antibacterial effect on MRSA, and the mechanism of action involved the alteration of membrane structural components and corresponding properties. The interactions of identified key lipid species and their biological functions need to be further determined and verified, for the development of novel antimicrobial strategies against MRSA.

Radiotherapy has been widely used to manage primary and metastatic brain tumors. However, hippocampal damage and subsequent cognitive dysfunction are common complications of whole brain radiation (WBI). In this study, Se@SiO2 nanoparticles (NPs) with antioxidant properties were synthesized. Se@SiO2 NPs were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The reactive oxygen species (ROS) scavenging ability of Se@SiO2 NPs was assessed using a dichloro-dihydro-fluorescein diacetate (DCFH-DA) probe. Apoptosis of HT-22 cells treated with H2O2 and Se@SiO2 NPs was assessed by annexin V-FITC/PI and JC-1 staining. Western blotting was used to evaluate inflammation-related signaling pathways. In vivo, the distribution and excretion of Se@SiO2 NPs were assessed using in vivo imaging system (IVIS). The biosafety and antioxidant effects of Se@SiO2 NPs were assessed. Neurogenesis in the hippocampus of mice was detected through neuron-specific nuclear protein (NeuN) and 5-bromo-2′-deoxyuridine (BrdU) immunofluorescence staining. The cognitive abilities of mice were also assessed using the Morris water maze test. Results showed that porous Se@SiO2 NPs were successfully synthesized with uniform spherical structures. In vitro, Se@SiO2 NPs inhibited ROS levels in mouse hippocampal neuronal cell line HT-22 treated with H2O2. Furthermore, Se@SiO2 NPs suppressed the apoptotic rate of HT-22 cells by regulating apoptosis-related proteins. Se@SiO2 NPs regulated the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, thereby reducing the expression of inflammatory factors. In vivo, Se@SiO2 NPs showed high biocompatibility at a concentration of 1.25 μg/μL. Se@SiO2 NPs inhibited ROS and promoted neurogenesis in the hippocampus, as well as improved cognitive ability in radiation-induced mice. In conclusion, Se@SiO2 NPs protected the hippocampus from oxidative stress injury and neuroinflammation. Se@SiO2 NPs treatment may be a potential therapeutic strategy for radiation-induced cognitive dysfunction.