An Endogenous H2S-Activated Nanoplatform for Triple Synergistic Therapy of Colorectal Cancer.

Overproduced hydrogen sulfide (H2S) is a highly potential target for precise colorectal cancer (CRC) therapy; herein, a novel 5-Fu/Cur-P@HMPB nanomedicine is developed by coencapsulation of the natural anticancer drug curcumin (Cur) and the clinical chemotherapeutic drug 5-fluorouracil (5-Fu) into hollow mesoporous Prussian blue (HMPB). HMPB with low Fenton-catalytic activity can react with endogenous H2S and convert into high Fenton-catalytic Prussian white (PW), which can generate in situ a high level of •OH to activate chemodynamic therapy (CDT) and meanwhile trigger autophagy. Importantly, the autophagy can be amplified by Cur to induce autophagic cell death; moreover, Cur also acted as a specific chemosensitizer of the chemotherapy drug 5-Fu, achieving a good synergistic antitumor effect. Such a triple synergistic therapy based on a novel nanomedicine has been verified both in vitro and in vivo to have high efficacy in CRC treatment, showing promising potential in translational medicine.

Fe3O4 Mesocrystals with Distinctive Magnetothermal and Nanoenzyme Activity Enabling Self-Reinforcing Synergistic Cancer Therapy.

Magnetite (Fe3O4) nanoparticles have been extensively used in noninvasive cancer treatment, for example, magnetic hyperthermia (MH) and chemodynamic therapy (CDT). However, how to achieve a highly efficient MH-CDT synergistic therapy based only on a single component of Fe3O4 still remains a challenge. Herein, hollow Fe3O4 mesocrystals (MCs) are constructed via a modified solvothermal method. Owing to the distinctive magnetic property of the mesocrystalline structure, Fe3O4 MCs show excellent magnetothermal conversion efficiency with a specific absorption rate of 722 w g-1 at a Fe concentration of 0.6 mg mL-1, much higher than that of Fe3O4 polycrystals (PCs). Moreover, Fe3O4 MCs also exhibit higher peroxidase-like activity than Fe3O4 PCs, which may be ascribed to the higher ratio of Fe2+/Fe3+ and more oxygen defects in the Fe3O4 MCs. Detailed in vivo results confirm that Fe3O4 MCs can instantly initiate CDT by producing the detrimental •OH, and such boosted reactive oxygen levels not only induces cell apoptosis but also reduces the expression of heat shock proteins, thus enabling low-temperature-mediated MH. More importantly, the in situ rising temperature resulted from MH in turn facilitates CDT, thus achieving a self-augmented synergistic effect between MH and CDT.

Hypoxia-Induced Photogenic Radicals by Eosin Y for Efficient Phototherapy of Hypoxic Tumors.

The current reported photosensitizers generally show a decreased reactive oxygen species (ROS) generation property under hypoxia conditions, which is the main reason for the clinical failure of photodynamic therapy (PDT) in treatment of solid tumors. Herein, for the first time, hypoxia-induced photogenic radicals by eosin Y (Eos) were reported for efficient phototherapy of hypoxic tumors. More importantly, Eos shows a higher ROS and radical production efficiency under hypoxia conditions than under normoxia conditions. The photogenic radicals were captured by electron paramagnetic resonance and further verified by ROS and radical probe. Introducing CoCl2 as a hypoxia inducer, the photoinduced therapy of the hypoxia cancer cell model and tumor-bearing mice indicated that bovine serum albumin-Eos in hypoxic tumor sites can produce even higher tumor toxicity, thereby crossing the clinical obstacles of hypoxic tumor therapy. This non-oxygen-dependent PDT may open up an avenue for fighting with hypoxia.

Clearable Theranostic Platform with a pH-Independent Chemodynamic Therapy Enhancement Strategy for Synergetic Photothermal Tumor Therapy.

Chemodynamic therapy (CDT) is an emerging field, which utilizes intratumoral iron-mediated Fenton chemistry for cancer therapy. However, the slightly acidic tumor environment is improper for the classical Fenton reaction, which is generally energetic in a narrow pH range (e.g., pH = 3-4). Herein, a kind of ultrasmall bovine serum albumin (BSA)-modified chalcopyrite nanoparticles (BSA-CuFeS2 NPs) was synthesized via a facile aqueous biomineralization strategy, which shows high dispersity and biocompatibility. Interestingly, the obtained BSA-CuFeS2 shows a pH-independent Fenton-like reaction, which could exert Fenton-like activity to efficiently generate •OH under a weak acidic tumor environment. Combined with the extraordinarily high photothermal conversion (38.8%), BSA-CuFeS2 shows the synergistic function of high photothermal therapy (PTT) and enhanced CDT, that is, PTT/CDT. Importantly, such ultrasmall BSA-CuFeS2 NPs measuring around 4.9 nm can be quickly cleared out of the body through kidneys and liver, thus effectively avoiding long-term toxicity and systemic toxicity. Moreover, BSA-CuFeS2 NPs can act as an efficient T2-weighted magnetic resonance imaging (MRI) contrast agent to guide tumor ablation in vivo. This work offers a universal approach to boost production •OH by a pH-independent Fenton-like reaction strategy and achieves MRI-guided synergistic enhanced photothermal-CDT for highly efficient tumor treatment.

Physical and antibacterial properties of açaí edible films formulated with thyme essential oil and apple skin polyphenols.

UNLABELLED: Thyme essential oil (TEO) and apple skin polyphenols (ASP) are natural compounds considered as generally recognized as safe by FDA, with biological effects against bacteria and fungi. This work aimed to evaluate physical and antimicrobial properties of açaí edible films formulated with TEO and ASP at 3% and 6% (w/w) individually or combined at 3% (w/w) each. Physical properties studied include mechanical resistance, water vapor permeability (WVP), color, and thermal resistance. Antimicrobial activity against Listeria monocytogenes was determined using the overlay diffusion test. Addition of ASP resulted in improved mechanical properties. TEO at 6% (w/w) resulted in increased elongation. ASP films had significant higher WVP than control film. ASP films were lighter and had more red color than other films. Incorporation of ASP resulted in improved film thermal stability, whereas TEO caused rapid thermal decomposition. Presence of clusters was observed on the surface of films. Addition of ASP resulted in a smoother surface, whereas addition of TEO led to the formation of crater-like pits on the film surface. Açaí edible film incorporated with 6% (w/w) TEO presented the highest antimicrobial activity. However, both antimicrobials are necessary in the açaí films in order to obtain edible films with suitable physical-mechanical properties. The results of the present study showed that TEO and ASP can be used to prepare açaí edible films with adequate physical-mechanical properties and antimicrobial activity for food applications by direct contact. PRACTICAL APPLICATION: Developed açaí edible films presented antimicrobial activity against L. monocytogenes and good physical-mechanical properties, showing the potential use of açaí edible films in food preservation.

Ultraviolet-B light treatment increases antioxidant capacity of carrot products.

BACKGROUND: The effect of ultraviolet-B (UV-B) light as a postharvest treatment to enhance the antioxidant content of carrots and fresh-cut carrot products was evaluated. Four levels of UV-B dose ranging from 1.3 to 12 kJ m⁻² were applied to whole, baby and various styles of cut carrots, and the changes in antioxidant capacity, total soluble phenolics and phenylalanine ammonia-lyase (PAL, EC 4.3.1.24) activity were measured after a 3 day incubation period at 15 °C and 45% relative humidity. RESULTS: Both cutting style and dose level were factors in determining carrot responses to UV-B treatment. Antioxidant capacity increased significantly (1.4-6.6-fold). Total soluble phenolic results correlated directly with those of antioxidant capacity (R² = 0.953), indicating that the enhancements achieved were due to an increase in phenolic content. High-performance liquid chromatography analysis revealed that 5-O-caffeoylquinic acid (5-CQA) was the primary phenolic responsible for this increase. Higher PAL activity was also observed in UV-B-treated samples, indicating that the increase in 5-CQA was a biological response to UV-B exposure. CONCLUSION: UV-B treatment has the potential to increase the nutritional value of carrots and offers an exciting opportunity to increase consumer accessibility to dietary choices that are rich in antioxidants.