Recovery of valuable metals from spent lithium-ion batteries via zinc powder reduction roasting and cysteine leaching.

With the annual increase in lithium-ion batteries (LIBs) disposal, valuable resources are being generated with worrying waste, so it is strategically important to recover the critical metals from them. Individual high temperature or leaching processes do not apparently achieve very satisfactory results. In the present work, the reduction with zinc powder was able to convert the lithium in LiNixCoyMnzO2 (NCM) to soluble LiOH, while the reduction and ammonia complexation environment generated by the decomposition of cysteine (Cys) achieved an efficient leaching of transition metals without additional additives. The leaching efficiency of Li can reach more than 92 %, while that of Ni/Co/Mn reaches more than 97 % through the regulation of the parameters of each process. In particular, an in-situ redox mechanism is proposed to explain the efficient leaching of transition metals, which further enriches the theory of spent LIBs recycling and provides a promising idea for various hydrometallurgical extraction systems.

Polyphosphazene nanodrugs for targeting delivery and inflammation responsive release of curcumin to treat acute lung injury by effectively inhibiting cytokine storms.

An excessive inflammatory response induced by cytokine storms is the primary reason for the deterioration of patients with acute lung injury (ALI). Though natural polyphenols such as curcumin (CUR) have anti-inflammation activity for ALI treatment, they often have limited efficacy due to their poor solubility in water and oxidising tendency. This study investigates a highly cross-linked polyphosphazene nano-drug (PHCH) developed by copolymerisation of CUR and acid-sensitive units (4-hydroxy-benzoic acid (4-hydroxy-benzylidene)-hydrazide, D-HBD) with hexachlorotripolyphosphonitrile (HCCP) for improved treatment of ALI. PHCH can prolong the blood circulation time and targeted delivery into lung inflammation sites by enhancing CUR's water dispersion and anti-oxidant properties. PHCH also demonstrates the inflammation-responsive release of CUR in an inflammation environment due to the acid-responsive degradation of hydrazine bonds and triphosphonitrile rings in PHCH. Therefore, PHCH has a substantial anti-inflammation activity for ALI treatment by synergistically improving CUR's water-solubility, bioavailability and biocompatibility. As expected, PHCH attenuates the cytokine storm syndrome and alleviates inflammation in the infected cells and tissues by down-regulating several critical inflammatory cytokines (TNF-α, IL-1ß, and IL-8). PHCH also decreases the expression of p-p65 and C-Caspase-1, inhibiting NLRP3 inflammasomes and suppressing NF-κB signalling pathways. The administrated mice experiments confirmed that PHCH accumulation was enhanced in lung tissue and showed the efficient scavenging ability of reactive oxygen species (ROS), effectively blocking the cytokine storm and alleviating inflammatory damage in ALI. This smart polyphosphazene nano-drug with targeting delivery property and inflammation-responsive release of curcumin has excellent potential for the clinical treatment of various inflammatory diseases, including ALI.