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Radiotherapy is the mainstay for abdomen and pelvis cancers treatment. However, high energy ray would inflict gastrointestinal (GI) system and adversely disrupt the treatment. The anti-oxidative agents provide a potential route for protecting body from radiation-induced injuries. Herein, highly catalytic nanocubes with dislocation structure are developed for treatment of intestinal injury. Structural and catalytic properties show that Mo incorporation can enhance antioxidant activity by dislocation structure in the alloy. In vitro studies showed that PtPdMo improved cell survival by scavenging radiation-induced ROS accumulation. Furthermore, after animals were exposed to lethal dose of radiation, the survival was increased by 50% with the PtPdMo i.p. treatment. Radioprotection mechanism revealed that PtPdMo alleviated the oxidative stress in multi-organs especially the small intestine by inhibiting intestinal epithelium apoptosis, reducing DNA strands breaks and enhancing repairing ability. In addition, PtPdMo protected hematopoietic system by improving the number of bone marrow and peripheral blood cells.

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Metal nanozyme has attracted wide interest for biomedicine, and a highly catalytic material in the physiological environment is highly desired. However, catalytic selectivity of nanozyme is still highly challenging, limiting its wide application. Here, we show a trimetallic (triM) nanozyme with highly catalytic activity and environmental selectivity. Enzyme-mimicked investigations find that the triM system possesses multi-enzyme-mimetic activity for removing reactive oxygen species (ROS) and reactive nitrogen species (RNS), such as 1O2, H2O2, •OH, and •NO. Importantly, triM nanozyme exhibits the significant neutral environment preference for removing the •OH, 1O2, and •NO free radical, indicating its highly catalytic selectivity. The density functional theory (DFT) calculations reveal that triM nanozyme can capture electrons very easily and provides more attraction to reactive oxygen and nitrogen species (RONS) radicals in the neutral environment. In vitro experiments show that triM nanozyme can improve the viability of injured neural cell. In the LPS-induced brain injury model, the superoxide dismutase (SOD) activity and lipid peroxidation can be greatly recovered after triM nanozyme treatment. Moreover, the triM nanozyme treatment can significantly improve the survival rate, neuroinflammation, and reference memory of injured mice. Present work provides a feasible route for improving selectivity of nanozyme in the physiological environment as well as exploring potential applications in brain science.

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Catalytic nanomaterials can be used extrinsically to combat diseases associated with a surplus of reactive oxygen species (ROS). Rational design of surface morphologies and appropriate doping can substantially improve the catalytic performances. In this work, a class of hollow polyvinyl pyrrolidone-protected PtPdRh nanocubes with enhanced catalytic activities for in vivo free radical scavenging is proposed. Compared with Pt and PtPd counterparts, ternary PtPdRh nanocubes show remarkable catalytic properties of decomposing H2 O2 via enhanced oxygen reduction reactions. Density functional theory calculation indicates that the bond of superoxide anions breaks for the energetically favorable status of oxygen atoms on the surface of PtPdRh. Viability of cells and survival rate of animal models under exposure of high-energy γ radiation are considerably enhanced by 94% and 50% respectively after treatment of PtPdRh nanocubes. The mechanistic investigations on superoxide dismutase (SOD) activity, malondialdehyde amount, and DNA damage repair demonstrate that hollow PtPdRh nanocubes act as catalase, peroxidase, and SOD analogs to efficiently scavenge ROS.

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Black phosphorus (BP), as an emerging successor to layered two-dimensional materials, has attracted extensive interest in cancer therapy. Toxicological studies on BP are of great importance for potential biomedical applications, yet not systemically explored. Herein, toxicity and oxidative stress of BP quantum dots (BPQDs) at cellular, tissue, and whole-body levels are evaluated by performing the systemic in vivo and in vitro experiments. In vitro investigations show that BPQDs at high concentration (200 µg/mL) exhibit significant apoptotic effects on HeLa cells. In vivo investigations indicate that oxidative stress, including lipid peroxidation, reduction of catalase activity, DNA breaks, and bone marrow nucleated cells (BMNC) damage, can be induced by BPQDs transiently but recovered gradually to healthy levels. No apparent pathological damages are observed in all organs, especially in the spleen and kidneys, during the 30-day period. This work clearly shows that BPQDs can cause acute toxicities by oxidative stress responses, but the inflammatory reactions can be recovered gradually with time for up to 30 days. Thus, BPQDs do not give rise to long-term appreciable toxicological responses.

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High energy ionizing radiation was widely used in medical diagnosis and cancer radiation therapy. The high dose of X ray or γ ray can cause the damage of cancerous tissue as well as healthy tissue during therapy. Therefore, it is urgent to develop chemical agents to protect the healthy tissue from high energy ray invasion. Here, the ultrasmall Pt clusters were employed as the anti-radiation agents for protecting healthy cells and improving survival rate of irradiated mice. It was found that Pt clusters can reduce the DNA damages in irradiated cells. In vivo experiments show that the Pt clusters treatment can improve the survival rate of irradiated mice up to 30%. As a contrast, only-irradiated mice without Pt clusters treatment completely died after 15 days. The detailed biological experiments showed that Pt clusters can recover the bone marrow DNA level and superoxide dismutase activities via scavenging free radicals. Importantly, the ultrasmall Pt clusters can be excreted rapidly by kidney and do not cause long-term toxicity.

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Two-dimensional WS2 materials have attracted wide attention in condensed physics and materials science due to its unique geometric and electronic structures. Particularly, WS2 shows extraordinary catalytic activities when its size decreases to ultrasmall, which provides potential opportunities for medical applications. In this work, WS2 quantum dots with strong catalytic properties were used for in vitro and in vivo protection from ionizing radiation induced cell damages. WS2 quantum dots possess unique optical properties of blue photoluminescence emission and excitation-wavelength dependent emission profiles. In vitro studies showed that cell viability can be considerably improved and cellular reactive oxygen species (ROS) can be removed by WS2 quantum dots. In vivo studies showed WS2 quantum dots can effectively protect the hematopoietic system and DNA from damages caused by high-energy radiation through removing whole-body excessive ROS. Furthermore, WS2 quantum dots showed nearly 80% renal clearance within 24 h post injection and did not cause any obvious toxicities in up to 30 days after treatment.