Recent advances of sonodynamic therapy in cancer treatment

Sonodynamic therapy(SDT) is an emerging approach that involves a combination of low-intensity ultrasound and specialized chemical agents known as sonosensitizers. Ultrasound can penetrate deeply into tissues and can be focused into a small region of a tumor to activate a sonosensitizer which offers the possibility of non-invasively eradicating solid tumors in a site-directed manner.In this article, we critically reviewed the currently accepted mechanisms of sonodynamic action and summarized the classification of sonosensitizers. At the same time, the breath of evidence from SDT-based studies suggests that SDT is promising for cancer treatment.

Mechanism of Mg2+ dissolution from olivine and serpentine: Implication for bioleaching of high-magnesium nickel sulfide ore at elevated pH

To inhibit the dissolution of Mg^2+ during the bioleaching process of high-magnesium nickel sulfide ore, the effect of major bioleaching factors on the dissolution of Mg^2+ from olivine and serpentine was investigated and kinetics studies were carried out. The results indicated that the dissolution rate-controlling steps are chemical reaction for olivine and internal diffusion for serpentine. The most influential factor on the dissolution of Mg^2+ from olivine and serpentine was temperature, followed by p H and particle size. A novel method of bioleaching at elevated pH was used in the bioleaching of Jinchuan ore. The results showed that elevated pH could significantly reduce the dissolution of Mg^2+ and acid consumption along with slightly influencing the leaching efficiencies of nickel and cobalt. A model was used to explain the leaching behaviors of high-magnesium nickel sulfide ore in different bioleaching systems. The model suggested that olivine will be depleted eventually, whereas serpentine will remain because of the difference in the rate-controlling steps. Bioleaching at elevated pH is a suitable method for treating high-magnesium nickel sulfide ores.

Feasibility study on heap bioleaching of chalcopyrite

Bioleaching of chalcopyrite often encountered the formation of passivation layer, which inhibited the leaching process and resulted in a low leaching rate. This inhibitory effect can be eliminated by thermophilic biole- aching. The industrial test of BioCOP technology based on thermophiles was successfully completed, which confirmed the feasibility of chalcopyrite bioleaching. However, industrial leaching rate of chalcopyrite heap bioleaching is lower. This paper described the development status and industrial test of chalcopyrite heap bioleaching technology. The reasons for the lower efficiency of chalcopyrite heap bioleaching were analyzed. The strategies for successful chalcopyrite heap bioleaching were proposed.

Frankincense myrrh attenuates hepatocellular carcinoma by regulating tumor blood vessel development through multiple epidermal growth factor receptor-mediated signaling pathways

BACKGROUND In traditional Chinese medicine(TCM),frankincense and myrrh are the main components of the antitumor drug Xihuang Pill.These compounds show anticancer activity in other biological systems.However,whether frankincense and/or myrrh can inhibit the occurrence of hepatocellular carcinoma(HCC)is unknown,and the potential molecular mechanism(s)has not yet been determined.AIM To predict and determine latent anti-HCC therapeutic targets and molecular mechanisms of frankincense and myrrh in vivo.METHODS In the present study,which was based on the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(http://tcmspw.com/tcmsp.php),Universal Protein database(http://www.uniprot.org),GeneCards:The Human Gene Database(http://www.genecards.org/)and Comparative Toxicogenomics Database(http://www.ctdbase.org/),the efficacy of and mechanism by which frankincense and myrrh act as anti-HCC compounds were predicted.The core prediction targets were screened by molecular docking.In vivo,SMMC-7721 human liver cancer cells were transplanted as xenografts into nude mice to establish a subcutaneous tumor model,and two doses of frankincense plus myrrh or one dose of an EGFR inhibitor was administered to these mice continuously for 14 d.The tumors were collected and evaluated:the tumor volume and growth rate were gauged to evaluate tumor growth;hematoxylineosin staining was performed to estimate histopathological changes;immunofluorescence(IF)was performed to detect the expression of CD31,α-SMA and collagen IV;transmission electron microscopy(TEM)was conducted to observe the morphological structure of vascular cells;enzyme-linked immunosorbent assay(ELISA)was performed to measure the levels of secreted HIF-1αand TNF-α;reverse transcription-polymerase chain reaction(RT-qPCR)was performed to measure the mRNA expression of HIF-1α,TNF-α,VEGF and MMP-9;and Western blot(WB)was performed to determine the levels of proteins expressed in the EGFR-mediated PI3K/Akt and MAPK signaling pathways.RESULTS The results of the network pharmacology analysis showed that there were 35 active components in the frankincense and myrrh extracts targeting 151 key targets.The molecular docking analysis showed that both boswellic acid and stigmasterol showed strong affinity for the targets,with the greatest affinity for EGFR.Frankincense and myrrh treatment may play a role in the treatment of HCC by regulating hypoxia responses and vascular system-related pathological processes,such as cytokine-receptor binding,and pathways,such as those involving serine/threonine protein kinase complexes and MAPK,HIF-1 and ErbB signaling cascades.The animal experiment results were verified.First,we found that,through frankincense and/or myrrh treatment,the volume of subcutaneously transplanted HCC tumors was significantly reduced,and the pathological morphology was attenuated.Then,IF and TEM showed that frankincense and/or myrrh treatment reduced CD31 and collagen IV expression,increased the coverage of perivascular cells,tightened the connection between cells,and improved the shape of blood vessels.In addition,ELISA,RT-qPCR and WB analyses showed that frankincense and/or myrrh treatment inhibited the levels of hypoxia-inducible factors,inflammatory factors and angiogenesis-related factors,namely,HIF-1α,TNF-α,VEGF and MMP-9.Furthermore,mechanistic experiments illustrated that the effect of frankincense plus myrrh treatment was similar to that of an EGFR inhibitor with regard to controlling EGFR activation,thereby inhibiting the phosphorylation activity of its downstream targets:the PI3K/Akt and MAPK(ERK,p38 and JNK)pathways.CONCLUSION In summary,frankincense and myrrh treatment targets tumor blood vessels to exert anti-HCC effects via EGFR-activated PI3K/Akt and MAPK signaling pathways,highlighting the potential of this dual TCM compound as an anti-HCC candidate.

Research progress in biohydrometallurgy of rare metals and heavy nonferrous metals with an emphasis on China

In the past decade, progress in the field of biohydrometallurgy had been significant. A total of 17 novel biomining microorganisms were discovered, and eight copper heap bioleaching plants and 11 gold biooxidation plants were established or expanded. In this review, it was summarized the physiological properties of the newly isolated biomining microorganisms and three novel microbial ecological methods for studying microbial community dynamics and structure. In addition, biohy- drometallurgy research on rare metals such as uranium, molybdenum, tellurium, germanium, indium, and sec- ondary rare metal resources, as well as heavy nonferrous metals such as copper, nickel, cobalt, and gold has been reviewed, with an emphasis on China. In future, further studies on bioleaching of chalcopyrite, rare metals, secondary resources from waste, and environmental pollution caused by resource utilization are necessary.

Control of redox potential by oxygen limitation in selective bioleaching of chalcocite and pyrite

Based on the bioleaching mechanism and electrochemical studies of metal sulfides, the dissolution rates of chalcocite and pyrite are controlled by redox potentials. Experiment on the bioleaching of chalcocite and pyrite under constant redox potential by sparging with nitrogen gas was demonstrated. By leaching at low and constant redox potential（〈760 mV, vs SHE）, copper recoveries of 90 %–98 % are achieved, which are 10 times more than iron recoveries. The iron-oxidizing bacterial populations are observed to continue to reduce under oxygen limitation conditions, but the Acidithiobacillus that have only sulfur-oxidizing capabilities are an attractive alternative for redox-controlled bioleaching of chalcocite.Thus, the described redox control technique might be one of the effective approaches to balance acid and iron in Zijinshan copper bio-heap leaching practice.