Cancer Cytomembrane-Cloaked Prussian Blue Nanoparticles Enhance the Efficacy of Mild-Temperature Photothermal Therapy by Disrupting Mitochondrial Functions of Cancer Cells

Despite its success against cancer, photothermal therapy (PTT) (>50 °C) suffers from several limitations such as triggering inflammation and facilitating immune escape and metastasis and also damage to the surrounding normal cells. Mild-temperature PTT has been proposed to override these shortcomings. We developed a nanosystem using HepG2 cancer cell membrane-cloaked zinc glutamate-modified Prussian blue nanoparticles with triphenylphosphine-conjugated lonidamine (HmPGTL NPs). This innovative approach achieved an efficient mild-temperature PTT effect by downregulating the production of intracellular ATP. This disrupts a section of heat shock proteins that cushion cancer cells against heat. The physicochemical properties, anti-tumor efficacy, and mechanisms of HmPGTL NPs both in vitro and in vivo were investigated. Moreover, the nanoparticles cloaked with the HepG2 cell membrane substantially prolonged the circulation time in vivo. Overall, the designed nanocomposites enhance the efficacy of mild-temperature PTT by disrupting the production of ATP in cancer cells. Thus, we anticipate that the mild-temperature PTT nanosystem will certainly present its enormous potential in various biomedical applications.

Near-Infrared Radiation-Assisted Drug Delivery Nanoplatform to Realize Blood-Brain Barrier Crossing and Protection for Parkinsonian Therapy

Mitochondrial dysfunction, which is directly involved in Parkinson's disease (PD), is characterized by the production of reactive oxygen species (ROS) and aberrant energy metabolism. Thus, regulating mitochondrial function might be an effective strategy to treat PD. However, the blood-brain barrier (BBB) presents a significant challenge for the intracerebral delivery of drugs. Here, we synthesized a zeolitic imidazolate framework 8-coated Prussian blue nanocomposite (ZIF-8@PB), which was encapsulated with quercetin (QCT), a natural antioxidant, to treat PD. ZIF-8@PB-QCT exhibited superior near-infrared radiation (NIR) response and penetrated through the BBB to the site of mitochondrial damage guided by the photothermal effect. In the mice model of PD, the QCT released from ZIF-8@PB-QCT significantly increased the adenosine triphosphate levels, reduced the oxidative stress levels, and reversed dopaminergic neuronal damage as well as PD-related behavioral deficits without any damage to the normal tissues. Furthermore, we explored the underlying neuroprotective mechanism of ZIF-8@PB-QCT that was mediated by activating the PI3K/Akt signaling pathway. Thus, combined with noninvasive NIR radiation, the biocompatible ZIF-8@PB-QCT nanocomposite could be used to treat neurodegenerative diseases.

Photolytic degradation of hexacyanoferrate (II) in aqueous media: the determination of the degradation kinetics

Upon exposure to ultraviolet (UV) radiation, non-toxic hexacyanoferrate (II) (Fe(CN)6(-4)) undergoes direct photolysis, resulting in the liberation of toxic free cyanide (HCN,CN-). This experimental study employed manipulation of several environmental parameters with the objective of characterizing their effects on the photolysis rate of hexacyanoferrate (II). The photolysis rate was not affected significantly by varying (1) the initial hexacyanoferrate (II) concentration (from 10 to 400 microg/l as total CN), (2) the solution turbidity (kaolin clay concentration from 0 to 5 mg/l), and (3) pH (from pH 4 to 12). Parameters that exhibited a significant effect (significance level, alpha < 0.05) on the photolysis rate included the intensity of incident ultraviolet radiation (from 30 to 110 micromol/m2s photons) and the concentration of dissolved organic matter (color) from added humic acid (from 0 to 10 mg/l). In addition, observations made by spiking both deionized and natural waters demonstrated that the rate of hexacyanoferrate (II) photolysis (1) significantly exceeded the rate of free cyanide formation from photolysis and (2) exhibited significant retardation that directly depended on the free cyanide concentration in solution. The hexacyanoferrate (II) photolysis data were consistent with a simple, semi-empirical kinetic model that included the reversible formation of at least one cyanoferrate intermediate. The reverse reaction, in turn, behaved in a manner that was consistent with a second order rate law with respect to free cyanide concentration.

The gamma-irradiation of aqueous hydrogen cyanide in the presence of ferrocyanide or ferricyanide: implications to prebiotic chemistry

The gamma-irradiation of 0.1 M, O2-free, aqueous HCN was studied in the presence of ferrocyanide or ferricyanide in the concentration range 10(-3) - 10(-5) M. This study was carried out in order to get an insight into the possible role that cyanocomplexes of iron may have played in promoting prebiotic syntheses via the free-radical oligomerization of HCN. It was found that ferrocyanide or ferricyanide have no effect on the irradiation of 0.1 M HCN solutions at concentrations < or = 10(-4) M. At high concentrations, 10(-3) M, they lead to a marked decrease in the conversion of HCN. There was no significant difference due to the oxidation state of iron used, particularly at high doses > or = 100 kGy.