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Excess iron accumulation is a risk factor for osteopenia and osteoporosis, and ferroptosis is becoming well understood as iron-dependent form of cell death resulting from lipid peroxide accumulation. However, any pathological impacts of ferroptosis on osteoporosis remain unknown. Here, we show that ferroptosis is involved in excess-iron-induced bone loss and demonstrate that osteoporotic mice and humans have elevated skeletal accumulation of the NADPH oxidase 4 (NOX4) enzyme. Mechanistically, we found that the NOX4 locus contains iron-response element-like (IRE-like) sequences that are normally bound (and repressed) by the iron regulatory protein 1 (IRP1) protein. Binding with iron induces dissociation of IRP1 from the IRE-like sequences and thereby activates NOX4 transcription. Elevated NOX4 increases lipid peroxide accumulation and causes obvious dysregulation of mitochondrial morphology and function in osteoblasts. Excitingly, the osteoporotic bone loss which we initially observed in an excessive-iron accumulating mouse line (Hepc1−/−) was blocked upon treatment with the ferroptosis-inhibitor ferrostatin-1 (Ferr-1) and with the iron chelator deferoxamine (DFO), suggesting a potential therapeutic strategy for preventing osteoporotic bone loss based on disruption of ferroptosis.

Background. The purpose of this study was to demonstrate the pharmacodynamic material basis and molecular mechanism of pilose antler (PA) in the prevention and treatment of osteoporosis (OP) by the method of network pharmacology. Methods. First, the active components of PA were screened by BATMAN-TCM database, and the component targets were obtained from the SwissTargetPrediction online tool. Moreover, the relevant target genes of OP were obtained by searching the DisGeNET database. Second, the Venn diagram was drawn to obtain the PA-OP common targets, and the protein-protein interaction (PPI) network and drug-component-target (D-C-T) network were constructed by Cytoscape software. Finally, the GO functional annotation and KEGG pathway enrichment analysis of common targets were performed using the Metascape online tool. Results. 82 common targets were identified by generating a Venn diagram. The PPI network of 82 common targets indicated that the top 5 nodal targets, including PIK3CA, MAPK1, ESR1, AKT1, and SRC, were strongly associated with other proteins. The D-C-T network suggested that the active components with high degree of connectivity include Prostaglandin E1, 17-Beta-Estradiol, Alpha-Estradiol, and Estrone. Furthermore, the GO enrichment analysis revealed that the biological process categories were dominated by response to peptide, cellular response to lipid, regulation of MAPK cascade, and so on. Additionally, the KEGG pathway analysis indicated the estrogen signaling pathway, osteoclast differentiation, and HIF-1 signaling pathway might have critical effects on the development of OP. Conclusion. The study shows that PA has the characteristics of multi-component, multi-target, and multi-pathway in treating osteoporosis.

As a necessary trace element, iron is involved in many physiological processes. Clinical and basic studies have found that disturbances in iron metabolism, especially iron overload, might lead to bone loss and even be involved in postmenopausal osteoporosis. Hepcidin is a key regulator of iron homeostasis. However, the exact role of hepcidin in bone metabolism and the underlying mechanism remain unknown. In this study, we found that in postmenopausal osteoporosis cohort, the concentration of hepcidin in the serum was significantly reduced and positively correlated with bone mineral density. Ovariectomized (OVX) mice were then used to construct an osteoporosis model. Hepcidin overexpression in these mice significantly improved bone mass and rescued the phenotype of bone loss. Additionally, overexpression of hepcidin in OVX mice greatly reduced the number and differentiation of osteoclasts in vivo and in vitro. This study found that overexpression of hepcidin significantly inhibited ROS production, mitochondrial biogenesis, and PGC-1β expression. These data showed that hepcidin protected osteoporosis by reducing iron levels in bone tissue, and in conjunction with PGC-1β, reduced ROS production and the number of mitochondria, thus inhibiting osteoclast differentiation and bone absorption. Hepcidin could provide new targets for the clinical treatment of postmenopausal osteoporosis.

We reported the first synthesis of Mn2+ doped Cs3Sb2Clx/Br9-x (0 ≤ x ≤ 9) perovskite quantum dots (PQDs) by regulating the coprecipitation of Mn2+ and Sb3+ with thiol ligands. These lead-free PQDs demonstrated bright photoluminescence emission centered at 660 nm and a high quantum yield of ∼49%, making them suitable for optical applications.

Precise, sensitive, and reversible thermochromic luminescent sensing can be achieved by PEAMnBrxI3−x (x = 0/1/2/3). Their luminescence ratios of green to red exhibited a reversible linear response to the temperature increment process (from 40 °C to 120 °C), bright luminescence under high temperature, and reversible heating–cooling circulation performance. Based on the thermochromic luminescence properties, the PEAMnBr2I–polymer film was used for precise and real-time temperature sensing. A deep understanding of their thermochromic luminescence mechanism can facilitate the design of thermochromic materials with high performance and their wider applications.

In recent years, two-dimensional (2D) layered tin halide perovskites have attracted much attention due to their excellent luminescence properties compared with their three-dimensional (3D) analogs. Here, we synthesized 2D perovskites of the form (RNH3)2SnBr4 through a facile hot-injection approach without the use of toxic tri-n-octylphosphine (TOP) as the solvent. We found that these compounds have strong photoluminescence (PL) emission with high PL quantum yields (QY) of 35% ((C6H13NH3)2SnBr4), 82% ((C8H17NH3)2SnBr4), 60% ((C12H25NH3)2SnBr4) and 50% ((C18H35NH3)2SnBr4). Among them, ((C6H13NH3)2SnBr4) was synthesized for the first time; however, (C18H36NH3)2SnBr4 perovskites showed the best stability with a PL QY decrease of less than 1% after 30 days under ambient air and humidity conditions. In addition, other 2D (C8H17NH3)2SnX4 (X = Br, I, or mixture) perovskites were prepared by adjusting the halide ratio, resulting in spectral tunability from yellow to red. Interestingly, through Zn2+ doping, the morphology became more uniform, and the PL stability was significantly improved. Finally, we used Zn2+-doped (C8H17NH3)2SnBr4 yellow phosphor to fabricate UV-pumped yellow LEDs. We expect these 2D perovskites to be promising phosphors in future solid-state lighting and display technologies.

Recently, two-dimensional (2D) metal halide perovskite materials with wide application in perovskite-based solar cells have attracted significant attention. Among them, 2D mixed lead–tin perovskites have not been systematically explored. Herein, we synthesize a 2D phenethylammonium (PEA) tin–lead bromide perovskite, PEA2SnxPb1−xBr4, via a simple solution-phase approach without toxic reagents and high temperatures. By tuning the ratio of Sn and Pb, the UV-vis absorption spectra showed unique bandgap bending behaviors. DFT calculations indicate the key effects of spin–orbital coupling (SOC) without the interference of lattice distortion. Moreover, we provided the standard equation with a correction term to introduce the influence of SOC. These results not only provide a step forward towards the bandgap engineering of perovskites, but also help to expand the application of 2D perovskite materials.

Numerous studies have demonstrated that iron overload is a risk factor of osteoporosis. However, there has been no systematic and in-depth studies on the effect of iron overload on osteocytes and its role in iron overload-induced bone loss. Therefore, to address this problem, we carried out in vitro and in vivo studies using MLO-Y4 osteocyte-like cells and Hepcidin(1) MLO-Y4 cells were treated with ferric ammonium citrate (FAC). Intracellular reactive oxygen species (ROS) levels and apoptosis of MLO-Y4 cells were determined by flow cytometry. Western blotting was performed to evaluate the effect of FAC on the expression of sclerostin and RANKL/OPG. (2) The conditioned medium of MLO-Y4 cells after treatment with FAC was collected and used to treat pre-osteoblasts and monocytes. Alkaline phosphatase (ALP) staining and alizarin red (AR) staining were used to evaluate osteogenic differentiation capacity, and tartrate-resistant acid phosphatase (TRAP) staining was performed to demonstrate osteoclast differentiation capacity. (3) In vivo studies included a wild type mouse, Hepcidin(1) FAC increased intracellular ROS and apoptosis in MLO-Y4 cells, while FAC enhanced the expression of sclerostin and RANKL/OPG in MLO-Y4 cells. (2) Conditioned medium of MLO-Y4 cells inhibited the osteogenic capacity of osteoblasts while stimulating osteoclast differentiation. (3) By increasing oxidative stress, iron overload promotes the apoptosis of osteocytes and undermines the morphology of osteocytes in HepcidinOsteocyte apoptosis due to increased ROS and resultant sclerostin and RANKL/OPG expression alteration was the main reason for bone loss in Hepcidin

Introduction: Many previous studies have reported a close relationship between body mass index (BMI) and bone mineral density (BMD). However, the effects of fat on bone health remain controversial, particularly for fat tissue distribution.Methods: This study enrolled 18,263 participants who had undergone health examinations. Body composition and BMD were measured using dual-energy X-ray absorptiometry. The relationships of BMI and regional fat percentage with BMD were detected by multiple linear regression and generalized additive models. The risk of low BMD was calculated using logistic regression.Results: There was a negative relationship between the regional fat percentage and FN BMD or LS BMD in both genders (PConclusions: Overall, the body fat content was a negative predictor of the BMD, and this effect was gender- and location-dependent. In males, waist fat has a greater effect on the FN BMD, whereas in females, hip fat exerts a more negative influence on the LS BMD, which implies a cross-influence between regional fat content and bone mineral density in males and females.

Objective Hepcidin deficiency is known to cause body iron accumulation and bone microarchitecture defects, but the exact underlying mechanisms of hepcidin deficiency-induced bone loss remain unclear. Our objective was to understand the molecular mechanism of hepcidin deficiency-induced bone loss. Methods The bone phenotypes of wild type (WT) and hepcidin knockout (Hepcidin-KO) mice were measured by microcomputed tomography. The osteoclastic marker of the bone was measured by tartrate-resistant acid phosphatase staining. The osteoblastic marker of the bone was measured by immunostaining of osteocalcin. Primary osteoblastic and osteoclastic differentiation was performed using bone marrow cells. The mature osteoclast was determined by tartrate-resistant acid phosphatase staining, pit formation assay and relative gene expression. The mature osteoblast was determined by alkaline phosphatase activity, alkaline phosphatase staining, Alizarin Red staining and relative gene expression. The protein expression of β-catenin, TCF4/TCF7L2 and Forkhead box O3a (FOXO3a) was measured by Western blot and their combination by co-immunoprecipitation. In vivo study was performed by tail vein administration of FOXO3a-RNAi using an adeno-associated virus in Hepcidin-KO mice. Results We found that Hepcidin-KO mice exhibited iron accumulation and bone loss compared with WT mice. The osteoclastic differentiation of bone marrow-derived macrophages from Hepcidin-KO mice was not significantly different from that of bone marrow–derived macrophages from WT mice. However, the osteoblastic differentiation of bone marrow–derived mesenchymal stem cells from Hepcidin-KO mice was obviously decreased compared with that of bone marrow–derived mesenchymal stem cells from WT mice. Furthermore, it was confirmed in this study that upon hepcidin deficiency, β-catenin, TCF4/TCF7L2 and FOXO3a expression in bone tissues was not altered, but β-catenin combination with TCF4/TCF7L2 was strongly inhibited by β-catenin combination with FOXO3a, indicating that the canonical Wnt/β-catenin pathway was affected. Tail vein administration of FOXO3a-RNAi using an adeno-associated virus in Hepcidin-KO mice resulted in bone mass recovery. Conclusion These findings suggested that hepcidin deficiency might cause bone loss by interfering with the canonical Wnt/β-catenin pathway via FOXO3a, and FOXO3a inhibition would be a possible approach to treat hepcidin deficiency-induced bone loss. The translational potential of this article Hepcidin deficiency, as well as iron accumulation, has been considered as a risk factor for osteoporosis. For this kind of osteoporosis, inhibition of FOXO3a either by neutralized antibody or AAV-mediated RNAi, represents an effective and promising method.

A novel triphenylphosphine (TPP) treatment strategy was developed to prepare the near-infrared emission CsPbI3 nanocrystal (NC)-polymer composite thin-film luminescent solar concentrators (LSCs) featuring high absolute photoluminescence quantum yield (PLQY), low reabsorption, and high stability. The PL emission of the LSCs is centered at about 700 nm with 99.4±0.4 % PLQY and narrow full width at half maximum (FWHM) of 75 meV (30 nm). Compared with LSCs prepared with classic CsPbI3 NCs, the stability of the LSCs after TPP treatments has been greatly improved, even after long-term (30 days) immersion in water and strong mercury-lamp irradiation (50 mW cm-2 ). Owing to the presence of lone-pair electrons on the phosphorus atom, TPP is also used as a photoinitiator, with higher efficiency than other common photoinitiators. Large-area (ca. 75 cm2 ) infrared LSCs were achieved with a high optical conversion efficiency of 3.1 % at a geometric factor of 10.

Lead halide perovskites always emerge complex interactions among different elemental ions, which lead to multiple intrinsic imperfections. Elemental defects, such as amine, Pb, and I vacancies at A-, B-, and X-sites, are main issues to deteriorate perovskite solar cells (PSCs). Unfortunately, most previous passivators can only temporarily fix partial inactive vacancies as sacrificial agents. Herein, we propose a recovery agent - ferrocene (Fc), which can form a one-dimensional perovskite with adequate steric cavities and suitable dissociation energy to recover all elemental defects back to active light-harvesting perovskites, and regenerate Fc itself meanwhile. Based on this perpetual chain-reaction cycle, corresponding PSCs maintain >10,000-hour lifetime in inert condition and >1,000-hour durabilities under various extreme environments, including continuous 85oC heating, 50% relative humidity wetting, and 1-sun light soaking.

Cesium lead halide perovskites have been arise as a new promising materials for optoelectronic applications. On this basis, zero-dimensional inorganic perovskites, Cs4PbBr6 can be an important candidate because of the excellent stability. However, obtaining the high photoluminescence quantum yield (PLQY) of phase-pure Cs4PbBr6 Perovskites still remains a challenge. Here, we synthesized the phase-pure Cs4PbBr6 crystals through a simple ligand-assisted, reprecipitation strategy under room-temperature. We altered the assisted ligands that used in the experiment synthesis, such as substitute dodecylamine for oleylamine, and obtained high near PLQY (95.1%) of phase-pure Cs4PbBr6 Perovskites. We revealed the extra oleic acid (OA), such as the ratio of OA and dodecylamine for 10 : 1 , would improve their PLQY. Most importantly, we demonstrated the short lifetime decay is caused by the recombination of trapped exciton inside the crystal but the long lifetime decay is attributed to the recombination of the surface energy states, and provided a great comprehension in photophysical of Cs4PbBr6 Perovskite materials.

Recently, lead halide perovskites with outstanding emission performance have become new candidate materials for light-emitting devices and displays; however, the toxicity of lead and instability of halide perovskites remain significant challenges. Herein, we report the aqueous acid-based synthesis of highly emissive two-dimensional (2D) tin halide perovskites, (octylammonium)2SnX4 (X = Br, I, or mixtures thereof), which displayed a high absolute photoluminescence (PL) quantum yield of near-unity in the solid-state, PL emission centered at 600 nm with a broad bandwidth (136 nm), a large Stokes shift (250 nm), long-lived luminescence (τ = 3.3 μs), and zero overlap between their absorption and emission spectra. Significantly, the stability study of 2D tin halide perovskites monitored by the PL quantum yield showed no changes after 240 days of storage at room temperature under ambient air and humidity conditions. The PL emission of the 2D tin halide perovskites was tuned from yellow to deep red by controlling halide composition. Furthermore, new yellow phosphors with superior optical properties are used to fabricate UV pumped white light emitting diodes (WLEDs). We expect these results to facilitate the development of new environmentally friendly and high-performance phosphors for future lighting and display technologies.

The cost of conventional chemotherapeutic drugs is substantially high, and biomedical researchers are constantly hunting for cheap and effective chemotherapeutic alternatives. Recently, curcumin has emerged as a cost effective anticancer remedy, however, the low bioavailability of curcumin has been a major impediment to its successful utilization for disease management. In this work, we developed a highly biocompatible magnesium hydroxide as an intelligent nanocarrier for delivering curcumin into cancer cells. Curcumin was loaded onto magnesium hydroxide nanoplates via a complexation strategy. Furthermore, these drug conjugated nanoparticles not only achieve efficient loading of a highly hydrophobic drug, but also exhibit pH responsive release in extracellular or intracellular acid environments, validated by in vitro drug release, confocal microscopy and MTT assay. These biocompatible nanoplates can be promising candidates for the further development of smart drug delivery nanodevices.

In the present study, we investigated the changes of the coagulation state, bone microthrombus, microvascular bed and bone density levels in iron accumulation rats. Meanwhile,the effect of anticoagulation therapy on bone mineral density was further investigated. We established two groups: a control (Ctrl) group and an iron intervention (FAC) group. Changes in coagulation function, peripheral blood cell counts, bone microthrombus, bone vessels and bone mineral density were compared between the two groups. We designed the non-treatment group and treatment group to study the changes of bone mineral density by preventing microthrombus formation with the anticoagulant fondaparinux. We found that the fibrinogen and D-dimer contents were significantly higher, whereas the thrombin time (TT) and prothrombin time (PT) were significantly shorter in the FAC group. After ink staining, the microvascular bed in the FAC group was significantly reduced compared with that in the Ctrl group. HE and Martius Scarlet Blue (MSB) staining showed microthrombus in the bone marrow of the iron accumulation rats. Following anticoagulation therapy, the bone microcirculation vascular bed areas in the treatment group rats were significantly increased. Furthermore, the bone mineral density was increased in the treatment group compared with that in the non-treatment group. Through experiments, we found that the blood in iron accumulation rat was relatively hypercoagulable; moreover, there was microthrombus in the bone marrow, and the bone vascular bed was reduced. Additionally, anticoagulation was helpful for improving bone microcirculation, reducing microthrombus and decreasing bone loss.

Controlled synthesis of colloidal all-inorganic lead halide perovskite semiconductor nanocrystals, such as CsPbBr3, with tunable size, shape, composition, and crystalline phase have recently attracted wide interest for photonic and optoelectronic applications. Herein, we report a new strategy for using alkyl-thiols to induce the transformation of CsPbBr3 to perovskite-related cesium lead halide (CsPb2Br5) with controlled morphology and a crystalline phase at room temperature. By rational tuning the ratios of the alkyl-thiol ligands to alkyl-amines or to alkyl-acids, the as-synthesized colloidal nanocrystals can be rationally controlled from orthorhombic crystalline-phase CsPbBr3 to tetragonal-phase CsPb2Br5 nanosheets and nanowires with high yield. Significantly, the tetragonal CsPb2Br5 nanowires and nanosheets have high stability in high-temperature and high-humidity environments. These findings may open new directions for large-scale synthesis of shape- and crystalline phase-controlled perovskite nanocr...

Hollow nanocrystals have attracted considerable attention in many areas of materials science because of their unique geometry, large surface area, high loading capacity and low density, and potential applications in catalysis, energy storage, drug delivery, and molecular separation. So far, numerous hollow nanostructured materials, such as noble metals, metallic oxides, hydroxides, and chalcogenides, have been reported. However, there is no report about the hollow metal halide perovskite nanocrystals yet. Herein, for the first time, we report the controlled synthesis of metal halide perovskite hollow nanocrystals, i.e., CsSnBr3 cubic nanocages, through a facile hot-injection colloidal approach. The formation of nanocages was controlled by rationally choosing the precursors and reaction temperature and was achieved through the self-assembly driven process. The as-synthesized CsSnBr3 nanocages exhibit excellent oxygen resistibility under desiccation conditions. Furthermore, treatment of CsSnBr3 nanocages wi...

Lead halide perovskites with well-defined morphology have attracted attention for their unique properties as a promising new class of semiconductor materials in photovoltaics and optoelectronics. However, controlling morphologies and compositions of perovskite nanostructures with improved stability, especially for double cation lead halide perovskite, still remains a challenge. Here, we demonstrate a colloidal synthetic approach for direct synthesis of stable single-crystal formamidinium (FA) cesium double cation lead halide FA0.33Cs0.67PbBr3–xIx (0 ≤ x ≤ 3) perovskite nanostructures with controllable morphology over a wide range of halide compositions, without using a previous anion-exchange process. The presence of FA alloyed in the A site for the pure cesium lead halide perovskite structure can stabilize the nanocrystals while delivering a better balance between structure and composition. On the basis of the FA0.33Cs0.67PbBr3–xIx alloy perovskite system, we achieved nanowires and nanosheets with high y...

Highly efficient lead halide perovskites with tunable emission performance have become new candidate materials for light‐emitting devices and displays; however, the toxicity of lead and instability of halide perovskites greatly limits their application. Herein, rapid and large‐scale synthesis of highly emissive organic–inorganic manganese halide perovskites, (C5H6N)2MnBr4 and C5H6NMnCl3, are presented by a one‐pot solution‐based method, of which (C5H6N)2MnBr4 displays a high absolute photoluminescence quantum yield (95%) in the solid‐state. The developed (C5H6N)2MnBr4 perovskite noticeably exhibits high stability. Therefore both as‐synthesized green and red emissive manganese‐based phosphors with superior optical properties are used to fabricate blue light pumped white light‐emitting diodes (WLEDs), displaying excellent quality white light with a high color rendering index value of 91 and a correlated color temperature of 5331 K. This study not only presents the robust large‐scale production synthetic approach for organic–inorganic manganese halide perovskites, but also facilitates the development of high‐performance phosphors for future lighting and display technologies.

Colloidal nanocrystals of lead halide perovskites have recently received great attention due to their remarkable performance in optoelectronic applications (e.g., light-emitting devices, flexible electronics, and photodetectors). However, the use of lead remains of great concern due to its toxicity and bioaccumulation in the ecosystem; herein we report a strategy to address this issue by using tetravalent tin (Sn4+) instead of divalent lead (Pb2+) to synthesize stable Cs2SnI6 perovskite nanocrystals. The shapes of as-synthesized Cs2SnI6 nanocrystals are tuned from spherical quantum dots, nanorods, nanowires, and nanobelts to nanoplatelets via a facile hot-injection process using inexpensive and nontoxic commercial precursors. Spherical aberration corrected scanning transmission electron microscopy (Cs-corrected STEM) and simulation studies revealed a well-defined face-centered-cubic (fcc) perovskite derivative structure of Cs2SnI6 nanocrystals. The solution-processed Cs2SnI6 nanocrystal-based field effect...

Colloidal nanocrystals of fully inorganic cesium lead halide (CsPbX3, X = Cl, Br, I, or combinations thereof) perovskites have attracted much attention for photonic and optoelectronic applications. Herein, we demonstrate a facile room-temperature (e.g., 25 °C), ligand-mediated reprecipitation strategy for systematically manipulating the shape of CsPbX3 colloidal nanocrystals, such as spherical quantum dots, nanocubes, nanorods, and nanoplatelets. The colloidal spherical quantum dots of CsPbX3 were synthesized with photoluminescence (PL) quantum yield values up to80%, and the corresponding PL emission peaks covering the visible range from 380 to 693 nm. Besides spherical quantum dots, the shape of CsPbX3 nanocrystals could be engineered into nanocubes, one-dimensional nanorods, and two-dimensional few-unit-cell-thick nanoplatelets with well-defined morphology by choosing different organic acid and amine ligands via the reprecipitation process. The shape-dependent PL decay lifetimes have been determined to be several to tens to hundreds of nanoseconds. Our method provides a facile and versatile route to rationally control the shape of the CsPbX3 perovskites nanocrystals, which will create opportunities for applications such as displays, lasing, light-emitting diodes, solar concentrators, and photon detection.

Iron accumulation is an independent risk factor for type I osteoporosis, but the molecular mechanisms of the phenomenon are not well defined, and effective therapy has not been reported. Here, we found that the level of mTOR was increased both in wild-type mouse models with iron accumulation and transgenic mouse models (Hepc-/-) of high-turnover osteoporosis with iron accumulation. We show that an increased level of mTOR can depress osteogenesis and angiogenesis by Cxcl9 both in bone and in vitro. Suppression of mTOR in mouse models by rapamycin and in vitro by siRNA transfection recovered both osteogenesis and angiogenesis. These findings revealed the role of mTOR in osteogenesis and angiogenesis in high-turnover osteoporosis with iron accumulation and showed that rapamycin targeting of mTOR ameliorates osteogenesis and angiogenesis to improve bone mass.

Inflammation is a complex and dynamic defensive cellular approach to safeguard against deleterious agents; however, an overexpression of such responses frequently results in the development of a number of devastating diseases, such as atherosclerosis, cancer, inflammatory bowel, Alzheimer's and Parkinson's diseases. At the site of the inflammation, excessive amount of reactive oxygen species (ROS) are produced, and therefore researchers are now earnestly trying to exploit ROS pathological signals to design oxidative triggered drug release systems. In this study, we report a straightforward strategy to develop an oxidative stress responsive drug release systems. Newly developed, ultra-small, and thiol stabilized zinc sulfide quantum dots (ZnS QDs) are used as nanocaps to regulate the release of anticancer drug (camptothecin) from mesoporous silica nanoparticles (MSNs) in response to oxidative environment. The exposure of capped nanocarrier to a higher concentration of H2O2 fails to open the drug loaded nanochannels; however, an addition of a minute amount of divalent iron, the most abundant transition-metal in the body, readily unseals the nanochannels at considerably lower H2O2 concentrations due to the generation of highly reactive hydroxyl radicals (˙OH). Thiol groups, which stabilize the ZnS nanolids, are actually oxidized by ˙OH and as a result unleash the loaded drug molecules from the channels of silica. In addition to the inflammation-induced drug delivery, this study also provides basic insight into the fate of thiol stabilized nanoparticles upon interaction with hydroxyl radicals.

Controlled synthesis of colloidal all-inorganic lead halide perovskite semiconductor nanocrystals, such as CsPbBr

Lead halide perovskites exhibit outstanding optoelectronic and optical properties. However, some applications of perovskites are hindered by their instability in polar environments; thus, how to balance stability with conductivity is a great challenge. Here, we report a new approach of using X-type ligands to address this issue. Surface treatments containing multi-step ligand exchanges and ion filling were necessary to obtain X-type ligand-protected perovskites. Performances of this material show that: (1) the crystal structure of perovskites is stable in ethanol; (2) surface defects can be fixed by a photoactivation process and photoluminescence intensity can be enhanced to 136%; and (3) electronic devices fabricated from such materials show stabilility even after washing with ethanol. X-type ligand-protected perovskites with high stability and good conductivity are promising new materials for wide applications in electronic and optoelectronics devices.

Simultaneous delivery of multiple therapeutic agents is of great importance for effective chemotherapy due of its well-known drug synergism and suppression to chemoresistance. We report a new theranostic nanoformulation to shuttle multiple chemotherapeutic agents for successfully exterminating cancer cells. This strategy is based on the fabrication of magnetite doped mesoporous silica nanoparticles (MSNs) in which both internal porous and external surface of MSN are respectively exploited to load two different kinds of cytotoxic cargoes. Notably, an exceptionally high quantity (29%) of poorly hydrophobic drug camptothecin (CPT) is loaded into the nanopores of MSNs; however, in previous reports less than 1% loading efficiency is reported. Following CPT loading in the pores of MSNs, another unconventional but FDA approved arsenic trioxide (ATO) is conjugated onto the surface of nanocomposite via exploiting the thiophilic nature of ATO. Cell inhibition performance of dual drug nanoformulation is significantly higher than single drug formulation, possibly due to additional or synergistic effect, as low as 3 μg/ml of double drug nanocarrier were found effective to exterminate cancer cells. Besides drug delivery, the presence of superparamagnetic magnetite nanocrystals additionally empowers this system to be used as a contrast agent in magnetic resonance (MR) imaging for either monitoring diseased tissues or feedback of chemotherapy. We anticipate that the integration of combination therapy with nanotechnology coupled with versatile magnetic manipulation feature may prove a significant step forward toward the development of effective theranostic agents.

After a substantial advancement in single drug nanocarrier, nanomedicine now demands an integration of nanotechnology with combination therapy to achieve synergistic therapeutic effects. In this respect, a smart and multiple drug shuttling nanotheranostic system is developed which transport diverse kinds of anticancer drugs to cancer cells in a controlled and responsive manner respectively. Synthetically, a significantly high dose of hydrophobic camptothecin (CPT) is first loaded into the porous structure of quantum dots (CdS) coupled mesoporous silica nanocomposite. Subsequently, fluorescent doxorubicin (DOX) molecules are exclusively anchored onto the surface of CdS; as a result, the fluorescence of both CdS and DOX is quenched. Upon exposing to mildly acidic conditions, the fluorescence of both species is recovered, such fluorescent "on-off" states provides an added opportunity to real time sense drug release. In-vitro cell experiment reveals an excellent anticancer efficacy of drug cocktail, merely 3 μg/ml concentration of multiple drugs loaded nanocarrier reduces the cell viability to 30%. Furthermore, confocal imaging indicates a successful release of both therapeutic entities. We visualize that our newly fabricated multifunctional double drug-carrying nanoparticles can be a valuable addition to next generation of materials that simultaneously deliver cocktail of drugs with imaging functionality.

Regeneratable antioxidant property of nanoceria has widely been explored to minimize the deleterious influences of reactive oxygen species. Limited information is, however, available regarding the biological interactions and subsequent fate of nanoceria in body fluids. This study demonstrates a surprising dissolution of stable and ultrasmall (4 nm) cerium oxide nanoparticles (CeO2 NPs) in response to biologically prevalent antioxidant molecules (glutathione, vitamin C). Such a redox sensitive behavior of CeO2 NPs is subsequently exploited to design a redox responsive drug delivery system for transporting anticancer drug (camptothecin). Upon exposing the CeO2 capped and drug loaded nanoconstruct to vitamin c or glutathione, dissolution-accompanied aggregation of CeO2 nanolids unleashes the drug molecules from porous silica to achieve a significant anticancer activity. Besides stimuli responsive drug delivery, immobilization of nanoceria onto the surface of mesoporous silica also facilitates us to gain a basic insight into the biotransformation of CeO2 in physiological mediums.