Persulfate activation with biochar supported nanoscale zero- valent iron: Engineering application for effective degradation of NCB in soil.

Nitrochlorobenzene (NCB) is very common in pesticide and chemical industries, which has become a major problem in soil environment. However, the remediation of NCB contaminated soil is received finite concern. Using biochar as a substrate for nanoscale-zero valent iron (nZVI/p-BC) to activate peroxodisulfate (PDS), a novel heterogeneous oxidative system had been applied in the current study to remediate NCB contaminants in soil. The degradation efficiencies and kinetics of m-NCB, p-NCB, and o-NCB by various systems were contrasted in soil slurry. Key factors including the dosage of nZVI/p-BC, the molar ratio of nZVI/PDS, initial pH and temperature on degradation of NCB were further examined. The results confirmed that the nZVI/p-BC/PDS displayed the remarkable performance for removing NCB compared with other systems. Higher temperature with nZVI/PDS molar ratio of 2:1 under the acidic condition favored the reduction of NCB. The treatment for NCB with optimal conditions were evaluated for the engineering application. The mechanism of nZVI/p-BC/PDS indicated that electron transfer between p-BC and nZVI was responsible for activation of PDS, generating active species (SO4•-, •OH and 1O2) via both the free and non-free radical pathways. Experimental results revealed prominent availability of nZVI/p-BC/PDS system in remediation of actual contaminated field by NCB.

Functionalized Selenium Nanoparticles Synergizes With Metformin to Treat Breast Cancer Cells Through Regulation of Selenoproteins.

Owing to high blood sugar level and chronic inflammation, diabetes tend to cause the overproduction of free radicals in body, which will damage tissue and cells, reduce autoimmunity, and greatly increase the incidence of tumors. Selenium nanoparticles (SeNPs) exhibit high antioxidant activity with anti-tumor ability. In addition, metformin is considered as a clinical drug commonly for the treatment of stage II diabetes. Therefore, in this study, different functionalized SeNPs combined with metformin were performed to detect the feasibility for cancer therapy. The combination of Tween 80 (TW80)-SeNPs and metformin was found to have a synergistic effect on MCF-7 cells. The mechanism of this synergistic effect involved in the induction of DNA damage by affecting the generation of reactive oxygen species through selenoproteins; the upregulation of DNA-damage-related proteins including p-ATM, p-ATR, and p38; the promotion of p21 expression; and the downregulation of cyclin-dependent kinases and cyclin-related proteins causing cell cycle arrest. Furthermore, the expression of AMPK was affected, which in turn to regulate the mitochondrial membrane potential to achieve the synergistic treatment effect.

Systematic acute and subchronic toxicity evaluation of polysaccharide-protein complex-functionalized selenium nanoparticles with anticancer potency.

Functionalized selenium nanoparticles (SeNPs) have demonstrated potential for applications in cancer chemotherapy, radio-sensitization, nephroprotection and drug delivery. However, their clinical application requires further systemic safety evaluation. Therefore, in this study, we examine the systematic acute and subchronic toxicity of polysaccharide-protein complex coated SeNPs (PTR-SeNPs). These particles exhibited a low oral acute toxicity (higher LD50) in SPF grade ICR mice and SD rats, and the evaluation of subchronic toxicity demonstrated that the no observed effect level (NOAEL) of the PTR-SeNPs was less than 200 µg Se per kg BW per day, which is about 30 times the tolerable upper intake levels of Se in the human body. In addition, we also found that, under a safe dose (0.75-7.5 mg kg-1), the oral administration of PTR-SeNPs dramatically inhibited the growth of cancer in a tumor-bearing nude mouse model, and the results of the histological analysis indicated that PTR-SeNPs did not significantly damage the major organs, including the liver, spleen, heart, kidneys and lungs. Moreover, the induction of caspase activation and mitochondrial dysfunction was the major anticancer action mechanism of PTR-SeNPs. Taken together, the results of this study provide a simple approach for the facile and large-scale manufacturing of SeNPs with reduced toxicity and enhanced anticancer activity through the regulation of the surface properties of SeNPs. Furthermore, this study generates evidence for the future exploration and translational application of these materials through oral administration in nanomedicine and nutritional sciences.

Highly Uniform Synthesis of Selenium Nanoparticles with EGFR Targeting and Tumor Microenvironment-Responsive Ability for Simultaneous Diagnosis and Therapy of Nasopharyngeal Carcinoma.

Rational design of multifunctional and smart drug-delivered nanoplatforms is a promising strategy to achieve simultaneous diagnosis, real-time monitoring, and therapy of cancers. Herein, highly uniform and stable selenium nanoparticles with epidermal growth factor receptor (EGFR) targeting and tumor microenvironment-responsive ability (Se-5Fu-Gd-P(Cet/YI-12)) were designed and synthesized by using EGFR as the targeting molecule, gadolinium chelate as the magnetic resonance imaging contrast agent, 5-fluorouracil (5Fu) and cetuximab as drug payloads, polyamidoamine (PAMAM) and 3,3'-dithiobis (sulfosuccinimidyl propionate) as the response agents of intratumoral glutathione, and pH for the treatment and diagnosis of nasopharyngeal carcinoma (NPC). This Se nanoplatform showed excellent magnetic resonance imaging capability and has the potential for its clinical application as a diagnostic agent for tumor tissue specimens. Additionally, in vitro cellular experiments showed that by means of introducing clinical targeted drugs and peptides not only validly increased the intracellular uptake of the Se nanoplatform in NPC cells but also enhanced its penetration ability toward CNE tumor spheroids, resulting in simultaneous inhibition of CNE cell growth, invasion, and migration. In addition, the sequentially triggered bioresponsive property of the nanoplatform in a tumor microenvironment effectively improved the targeting delivery and anticancer efficiency of payloads. Overall, this study not only provides a strategy for facile synthesis of highly uniform and stable nanomedicines and tailing of the bioresponsive property but also sheds light on its application in targeting theranosis of NPC.

A highly hemocompatible erythrocyte membrane-coated ultrasmall selenium nanosystem for simultaneous cancer radiosensitization and precise antiangiogenesis.

Radiotherapy is a vitally important strategy for clinical treatment of malignant cancers. Therefore, rational design and development of radiosensitizers that could enhance radiotherapeutic efficacy has attracted tremendous attention. Antiangiogenesis therapy could be a potentially effective strategy to regulate tumor growth and metastasis due to angiogenesis plays a pivotal role for tumor growth, invasion and metastasis to other organs. Herein, we have rationally designed a smart and effective nanosystem by combining ultrasmall selenium nanoparticles and bevacizumab (Avastin™, Av), for simultaneous radiotherapy and antiangiogenic therapy of cancer. The nanosystem was further coated with red blood cell (RBC) membranes to develop the final construct, RBCs@Se/Av. The RBC membrane coating effectively prolongs the blood circulation time and reduces the elimination of the nanosystem by autoimmune responses. As expected, RBCs@Se/Av, when irradiated with X-ray demonstrated potent anticancer and antiangiogenesis response in vitro and in vivo, as evidenced by strong inhibition of A375 tumor growth in nude mice, without causing any obvious histological damage to the non-target major organs. Taken together, this study demonstrates an effective strategy for design of smart Se-based nanosystem decorated with RBC membrane for simultaneous cancer radiosensitization and precise antiangiogenesis.