Mitochondria are highly dynamic and undergo constant fusion and fission that are essential for maintaining physiological functions of cells. Although dysfunction of mitochondria has been implicated in tumorigenesis, little is known about the roles of mitochondrial dynamics in metastasis, the major cause of cancer death. In the present study, we found a marked upregulation of mitochondrial fission protein dynamin-related protein 1 (Drp1) expression in human invasive breast carcinoma and metastases to lymph nodes. Compared to non-metastatic breast cancer cells, mitochondria also were more fragmented in metastatic breast cancer cells that express higher levels of total and active Drp1 and less mitochondrial fusion protein 1 (Mfn1). Silencing Drp1 or overexpression of Mfn1 resulted in mitochondria elongation or clusters, respectively, and significantly suppressed metastatic abilities of breast cancer cells. In contrast, silencing Mfn proteins led to mitochondrial fragmentation and enhanced metastatic abilities of breast cancer cells. Interestingly, these manipulations of mitochondrial dynamics altered the subcellular distribution of mitochondria in breast cancer cells. For example, silencing Drp1 or overexpression of Mfn1 inhibited lamellipodia formation, a key step for cancer metastasis, and suppressed chemoattractant-induced recruitment of mitochondria to lamellipodial regions. Conversely, silencing Mfn proteins resulted in more cell spreading and lamellipodia formation, causing accumulation of more mitochondria in lamollipodia regions. More importantly, treatment with a mitochondrial uncoupling agent or ATP synthesis inhibitor reduced lamellipodia formation and decreased breast cancer cell migration and invasion, suggesting a functional importance of mitochondria in breast cancer metastasis. Together, our findings show a new role and mechanism for regulation of cancer cell migration and invasion by mitochondrial dynamics. Thus targeting dysregulated Drp1-dependent mitochondrial fission may provide a novel strategy for suppressing breast cancer metastasis.

All cells have the capacity to accumulate neutral lipids and package them into lipid droplets. Recent proteomic analyses indicate that lipid droplets are not simple lipid storage depots, but rather complex organelles that have multiple cellular functions. One of these proposed functions is to distribute neutral lipids as well as phospholipids to various membrane-bound organelles within the cell. Here, we summarize the lipid droplet-associated membrane-trafficking proteins and review the evidence that lipid droplets interact with endoplasmic reticulum, endosomes, peroxisomes, and mitochondria. Based on this evidence, we present a model for how lipid droplets can distribute lipids to specific membrane compartments.

Transition-metal selenides have emerged as promising anode materials for sodium ion batteries (SIBs). Nevertheless, they suffer from volume expansion, polyselenide dissolution, and sluggish kinetics, which lead to inadequate conversion reaction toward sodium and poor reversibility during the desodiation process. Therefore, the transition-metal selenides are far from long cycling stability, outstanding rate performance, and high initial Coulombic efficiency, which are the major challenges for practical application in SIBs. Here, an efficient anode material including an FeSe 2 core and N-doped carbon shell with inner void space as well as high conductivity is developed for outstanding rate performance and long cycle life SIBs. In the ingeniously designed FeSe 2 @NC microrods, the N-doped carbon shell can facilitate mass transport/ electron transfer, protect the FeSe 2 core from the electrolyte, and accommodate volume variation of FeSe 2 with the help of the inner void of the core. Thus, the FeSe 2 @NC microrods can maintain strong structural integrity upon long cycling and ensure a good reversible conversion reaction of FeSe 2 during the discharge/charge process. As a result, the as-prepared FeSe 2 @NC microrods exhibit excellent sodium storage performance and ultrahigh stability, achieving an excellent rate capability (411 mAh g −1 at 10.0 A g −1 ) and a long-term cycle performance (401.3 mAh g −1 after 2000 cycles at 5.0 A g −1 ).

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A novel non-aqueous hybrid supercapacitor was fabricated from two spherical materials -an activated mesocarbon microbead (AMCMB) and MnO 2 nanowire-sphere, as the negative and positive electrodes, respectively. The preliminary results for this energy-storage device, which operates over a wide voltage range (0.0-3.0 V) using 1 M Et 4 NBF 4 in acetonitrile (AN) as electrolytes, are presented. On the basis of a single electrode, the AMCMB|MnO 2 supercapacitor displays a high specific capacitance of 228 F g À1 at a scan rate of 10 mV s À1 , corresponding to specific energy of 128 W h kg À1 based on based on the total mass of active materials, while maintaining desirable cycling stability and rate capability. The combination of the spherical AMCMB and MnO 2 in a non-aqueous electrolyte is proved to be suitable for high-performance hybrid supercapacitor applications.

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Recycling of spent lithium-ion batteries is of great importance for environmental protection and resusing resources. This work proposes a green and environmentally friendly recycling strategy of LiNi 1/3 Co 1/3 Mn 1/3 O 2 cathode material for spent batteries by an electrochemical method. In the designed electrolysis cell, the produced gaseous species from oxidation of solvent molecules occurring at the interfaces between electrode/cathode materials and active particles/binder exert the force to separate bonded particles from current collector. Meanwhile, the efficient leaching of lithium (>98%) into electrolyte was achieved under an electric field without additional leaching process. The Al can also be recovered in the form of metallic foil. The separation of active material, the selective leaching of lithium, and recovery of Al foil are conducted by one-step electrolysis in a short operating cycle. The remaining transition metals in residues were reused to synthesize LiNi 1/3 Co 1/3 Mn 1/3 O 2 material. As the cathode material, the regenerated active material delivers an initial capacity of 161 mAh g −1 at 0.1 C and 88.3% remains after 200 cycles. The superior cycling stability is comparable to the unused commercial batteries. This innovative approach can be readily extended to recover other types of cathode materials for spent lithium-ion batteries.

Sn@SnO2@C nanosheets decorated with MoS2 are prepared via a facile ball milling and hydrothermal method, and the Sn@SnO2@C@MoS2 composite shows high capacity and long-term cycling stability when used as an anode material for lithium-ion batteries.