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Guo, Yuxin; Jia, Hao‐Ran; Zhang, Xiaodong; Zhang, Xinping; Sun, Qing; Wang, Shao‐Zhe; Zhao, Jing; Wu, Fu‐Gen

doi: 10.1002/smll.202070174pmid: N/A

Liu, Jianping; Wu, Yilun; Fu, Changkui; Li, Bei; Li, Li; Zhang, Run; Xu, Tiefeng; Xu, Zhi Ping

doi: 10.1002/smll.202002115pmid: 32608187

Nanotheranostics have been actively sought in precision nanomedicine in recent years. However, insufficient tumor accumulation and limited cell uptake often impede the nanotheranostic efficacy. Herein, pH‐sensitive charge‐reversible polymer‐coated layered double hydroxide (LDH) nanohybrids are devised to possess long circulation in blood but reserve surface charges in the weakly acidic tumor tissue to re‐expose therapeutic LDH nanoparticles for enhanced tumor accumulation and cell uptake. In vitro experimental data demonstrate that charge‐reversible nanohybrids mitigate the cell uptake in physiological conditions (pH 7.4), but remarkably facilitate internalization by tumor cells after charge reversion in the weakly acidic environment (pH 6.8). More significantly, about 6.0% of injected charge‐reversible nanohybrids accumulate in the tumor tissue at 24 h post injection, far higher than the average accumulation (0.7%) reported elsewhere for nanoparticles. This high tumor accumulation clearly shows the tumor tissues in T1‐weighted magnetic resonance imaging. As a consequence, >95% inhibition of tumor growth in the B16F0‐bearing mouse model is achieved via only one treatment combining RNAi and photothermal therapy under very mild irradiation (808 nm laser, 0.3 W cm−2 for 180 s). The current research thus demonstrates a new strategy to functionalize nanoparticles and simultaneously enhance their tumor accumulation and cell internalization for effective cancer theranostics.

Cörek, Emre; Rodgers, Griffin; Siegrist, Stefan; Einfalt, Tomaz; Detampel, Pascal; Schlepütz, Christian M.; Sieber, Sandro; Fluder, Pascal; Schulz, Georg; Unterweger, Harald; Alexiou, Christoph; Müller, Bert; Puchkov, Maxim; Huwyler, Jörg

doi: 10.1002/smll.202000746pmid: 32567135

Metal‐based nanoparticles are clinically used for diagnostic and therapeutic applications. After parenteral administration, they will distribute throughout different organs. Quantification of their distribution within tissues in the 3D space, however, remains a challenge owing to the small particle diameter. In this study, synchrotron radiation‐based hard X‐ray tomography (SRμCT) in absorption and phase contrast modes is evaluated for the localization of superparamagnetic iron oxide nanoparticles (SPIONs) in soft tissues based on their electron density and X‐ray attenuation. Biodistribution of SPIONs is studied using zebrafish embryos as a vertebrate screening model. This label‐free approach gives rise to an isotropic, 3D, direct space visualization of the entire 2.5 mm‐long animal with a spatial resolution of around 2 µm. High resolution image stacks are available on a dedicated internet page (http://zebrafish.pharma-te.ch). X‐ray tomography is combined with physico‐chemical characterization and cellular uptake studies to confirm the safety and effectiveness of protective SPION coatings. It is demonstrated that SRμCT provides unprecedented insights into the zebrafish embryo anatomy and tissue distribution of label‐free metal oxide nanoparticles.

Guo, Yuxin; Jia, Hao‐Ran; Zhang, Xiaodong; Zhang, Xinping; Sun, Qing; Wang, Shao‐Zhe; Zhao, Jing; Wu, Fu‐Gen

doi: 10.1002/smll.202000897pmid: 32537936

Fenton reaction‐mediated chemodynamic therapy (CDT) can kill cancer cells via the conversion of H2O2 to highly toxic HO•. However, problems such as insufficient H2O2 levels in the tumor tissue and low Fenton reaction efficiency severely limit the performance of CDT. Here, the prodrug tirapazamine (TPZ)‐loaded human serum albumin (HSA)–glucose oxidase (GOx) mixture is prepared and modified with a metal–polyphenol network composed of ferric ions (Fe3+) and tannic acid (TA), to obtain a self‐amplified nanoreactor termed HSA–GOx–TPZ–Fe3+–TA (HGTFT) for sustainable and cascade cancer therapy with exogenous H2O2 production and TA‐accelerated Fe3+/Fe2+ conversion. The HGTFT nanoreactor can efficiently convert oxygen into HO• for CDT, consume glucose for starvation therapy, and provide a hypoxic environment for TPZ radical‐mediated chemotherapy. Besides, it is revealed that the nanoreactor can significantly elevate the intracellular reactive oxygen species content and hypoxia level, decrease the intracellular glutathione content, and release metal ions in the tumors for metal ion interference therapy (also termed “ion‐interference therapy” or “metal ion therapy”). Further, the nanoreactor can also increase the tumor’s hypoxia level and efficiently inhibit tumor growth. It is believed that this tumor microenvironment‐regulable nanoreactor with sustainable and cascade anticancer performance and excellent biosafety represents an advance in nanomedicine.

Feng, Tanglue; Tao, Songyuan; Yue, Da; Zeng, Qingsen; Chen, Weihua; Yang, Bai

doi: 10.1002/smll.202001295pmid: 32529773

Exploitation and utilization of sustainable energy sources has increasingly become the common theme of global social development, which has promoted tremendous development of energy conversion devices/technologies. Owing to excellent and unique optical/electrical properties, carbon dots (CDs) have attracted extensive research interest for numerous energy conversion applications. Strong absorption, downconversion photoluminescence, electron acceptor/donor characteristics, and excellent electron conductivity endow CDs with enormous potential for applications in optoelectronic devices. Furthermore, excellent electron transfers/transport capacities and easily manipulable structural defects of CDs offer distinct advantages for electrocatalytic applications. Recent advances in CD‐based energy conversion applications, including optoelectronic devices such as light‐emitting diodes and solar cells, and electrocatalytic reactions including the hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, and carbon dioxide reduction reaction, are summarized. Finally, current challenges and future prospects for CD‐based energy conversion applications are proposed, highlighting the importance of controllable structural design and modifications.

Li, Xuejin; Tang, Yongchao; Zhu, Jiaxiong; Lv, Haiming; Zhao, Lianming; Wang, Wenlong; Zhi, Chunyi; Li, Hongfei

doi: 10.1002/smll.202001935pmid: 32603014

Cathodes of rechargeable Zn batteries typically face the issues of irreversible phase transformation, structure collapse, and volume expansion during repeated charge/discharge cycles, which result in an increased transfer resistance and poor long‐term cycling stability. Herein, a facile F doping strategy is developed to boost the cycling stability of nickel cobalt carbonate hydroxide (NiCo–CH) cathode. Benefiting from the extremely high electronegativity, the phase and morphology stabilities as well as the electrical conductivity of NiCo–CH are remarkably enhanced by F incorporation (NiCo–CH–F). Phase interface and amorphous microdomains are also introduced, which are favorable for the electrochemical performance of cathode. Benefiting from these features, NiCo–CH–F delivers a high capacity (245 mA h g−1), excellent rate capability (64% retention at 8 A g−1), and outstanding cycling stability (maintains 90% after 10 000 cycles). Moreover, the quasi‐solid‐state battery also manifests superior cycling stability (maintains 90% after 7200 cycles) and desirable flexibility. This work offers a general strategy to boost the cycling stability of cathode materials for aqueous Zn batteries.

Du, Yang; Yang, Chuang; Li, Fangyuan; Liao, Hongwei; Chen, Zheng; Lin, Peihua; Wang, Nan; Zhou, Yan; Lee, Ji Young; Ding, Qiang; Ling, Daishun

doi: 10.1002/smll.202002537pmid: 32519453

Thangasamy, Pitchai; Oh, Saewoong; Nam, Sanghee; Randriamahazaka, Hyacinthe; Oh, Il‐Kwon

doi: 10.1002/smll.202001665pmid: 32597017

Here, ferrocene(Fc)‐incorporated cobalt sulfide (CoxSy) nanostructures directly grown on carbon nanotube (CNT) or carbon fiber (CF) networks for electrochemical oxygen evolution reaction (OER) using a facile one‐step solvothermal method are reported. The strong synergistic interaction between Fc‐CoxSy nanostructures and electrically conductive CNTs results in the superior electrocatalytic activity with a very small overpotential of ≈304 mV at 10 mA cm−2 and a low Tafel slope of 54.2 mV dec−1 in 1 m KOH electrolyte. Furthermore, the Fc‐incorporated CoxSy (FCoS) nanostructures are directly grown on the acid pretreated carbon fiber (ACF), and the resulting fabricated electrode delivers excellent OER performance with a low overpotential of ≈315 mV at 10 mA cm−2. Such superior OER catalytic activity can be attributed to 3D Fc‐CoxSy nanoarchitectures that consist of a high concentration of vertical nanosheets with uniform distribution of nanoparticles that afford a large number of active surface areas and edge sites. Besides, the tight contact interface between ACF substrate and Fc‐CoxSy nanostructures could effectively facilitate the electron transfer rate in the OER. This study provides valuable insights for the rational design of energy storage and conversion materials by the incorporation of other transition metal into metal sulfide/oxide nanostructures utilizing metallocene.

Wang, Yu‐Cheng; Wan, Li‐Yang; Cui, Pei‐Xin; Tong, Lei; Ke, Yu‐Qi; Sheng, Tian; Zhang, Miao; Sun, Shu‐Hui; Liang, Hai‐Wei; Wang, Yue‐Sheng; Zaghib, Karim; Wang, Hong; Zhou, Zhi‐You; Yuan, Jiayin

Du, Yang; Yang, Chuang; Li, Fangyuan; Liao, Hongwei; Chen, Zheng; Lin, Peihua; Wang, Nan; Zhou, Yan; Lee, Ji Young; Ding, Qiang; Ling, Daishun

doi: 10.1002/smll.202070173pmid: N/A