Targeted hexagonal Pd nanosheet combination therapy for rheumatoid arthritis via the photothermal controlled release of MTX.

Methotrexate (MTX) is a drug that is used for the clinical treatment of rheumatoid arthritis (RA), a stubborn disease caused by over-immunization. However, the toxicity that arises as a result of poor selectivity to inflammatory cells severely limits the application of MTX. Therefore, new therapeutic strategies are needed for treating RA. Here, we describe the design and synthesis of a nanotherapy agent, Pd-Cys@MTX@RGD, which can target inflammatory cells and control MTX release. The novel hexagonal palladium (Pd) nanosheets were used as a near-infrared (NIR) photothermal agent modified with arginine-glycineaspartic acid (RGD) peptides on the surface to enhance the ability of the nanosheet targeting of inflammatory cells. In subsequent experiments, the Pd-Cys@MTX@RGD nanosheets were observed to greatly reduce the toxicity of MTX, showing controlled MTX release under irradiation of 808 nm (0.3 W cm-2). Moreover, taking advantage of the fact that MTX can be combined with multiple therapeutic methods, the photothermal therapy (PTT) of Pd nanosheets provided a compensatory effect to enhance the therapeutic efficacy of MTX. Under combination therapy, Pd-Cys@MTX@RGD was shown to effectively inhibit the inflammatory response induced by vascular endothelial growth factor (VEGF) and IL-1ß. And, in vivo, multifunctional Pd-Cys@MTX@RGD effectively inhibited the symptoms of RA by inhibiting the expression of pro-inflammatory cytokines (TNF-α,COX-2). We hope that the construction of nanomaterials can add potential value to the design of chemical drugs and therapeutic strategies for RA.

Se/Ru-Decorated Porous Metal-Organic Framework Nanoparticles for The Delivery of Pooled siRNAs to Reversing Multidrug Resistance in Taxol-Resistant Breast Cancer Cells.

We report here a novel and personalized strategy of selenium/ruthenium nanoparticles modified metal organic frameworks MIL-101(Fe) for delivering pooled small interfering RNAs (siRNAs) to enhance therapy efficacy by silencing multidrug resistance (MDR) genes and interfere with microtubule (MT) dynamics in MCF-7/T (Taxol-resistance) cell. The existence of coordinatively unsaturated metal sites in MIL-101(Fe) can strongly interact with the electron-rich functional groups of cysteine, which can be regarded as the linkage between selenium/ruthenium nanoparticles and MIL-101(Fe). Se@MIL-101 and Ru@MIL-101 loaded with MDR gene-silencing siRNAs via surface coordination can significantly enhance protection of siRNAs against nuclease degradation, increase siRNA cellular uptake, and promote siRNA escape from endosomes/lysosome to silence MDR genes in MCF-7/T cell, resulting in enhanced cytotoxicity through the induction of apoptosis with the signaling pathways of phosphorylation of p53, MAPK, and PI3K/Akt and the dynamic instability of MTs and disrupting normal mitotic spindle formation. Furthermore, in vivo investigation of the nanoparticles on nude mice bearing MCF-7/T cancer xenografts confirmed that Se@MIL-101-(P+V)siRNA nanoparticles can significantly enhance cancer therapeutic efficacy and decrease systemic toxicity in vivo.

Co-delivery of Se nanoparticles and pooled SiRNAs for overcoming drug resistance mediated by P-glycoprotein and class III ß-tubulin in drug-resistant breast cancers.

Drug resistance mediated by P-glycoprotein (P-gp) and class III ß-tubulin (ß-tubulin III) is a major barrier in microtubule-targeting cancer chemotherapy. In this study, layered double hydroxide nanoparticles (LDHs) were employed to simultaneously deliver selenium (Se) and pooled small interfering RNAs (siRNAs) to achieve therapeutic efficacy. LDH-supported Se nanoparticles (Se@LDH) were compacted with siRNAs (anti-P-gp and anti-ß-tubulin III) via electrostatic interactions, which could protect siRNA from degradation. Se@LDH showed excellent abilities to deliver siRNA into cells, including enhancing siRNA internalization, and promoting siRNA escape from endosomes. siRNA transfection experiments further confirmed a higher gene silencing efficiency of Se@LDH than LDH. Interestingly, we found Se@LDH may be a microtubule (MT) stabilizing agent which could inhibit cell proliferation by blocking cell cycle at G2/M phase, disrupting normal mitotic spindle formation and inducing cell apoptosis. When complexed with different specific siRNAs, Se@LDH/siRNA nanoparticles, especially the Se@LDH-pooled siRNAs, exhibit an efficient gene-silencing effect that significantly downregulate the expression of P-gp and ß-tubulin III. Moreover, Se@LDH-pooled siRNAs could induce cell apoptosis, change cell morphology and increase cellular ROS levels through change the expression of Bcl-2/Bax, activation of caspase-3, PI3K/AKT/mTOR and MAPK/ERK pathways. These results suggested that co-delivery of Se and pooled siRNAs may be a promising strategy for overcoming the drug resistance mediated by P-gp and ß-tubulin III in drug-resistant breast cancers.

Preparation of different sized nano-silver loaded on functionalized graphene oxide with highly effective antibacterial properties.

Graphene oxide (GO) has attracted great interest in many different areas, as a delivery vehicle for antibacterial agents, and has shown high potential. Although silver nanoparticles (AgNPs) have a strong antibacterial effect, the biological application of AgNPs is often hindered by their aggregation and low stability. In this study, we developed an approach of polyoxyethylene bis(amine) (PEG) directed AgNPs grown on GO, then we combined the two materials to prepare a series of functionalized GO bearing different sized AgNPs, and studied the size effects of AgNPs on growth inhibition of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). We evaluated the antibacterial effect of GO@PEG@AgNPs on E. coli and S. aureus by various methods such as minimum inhibitory concentration (MIC) experiment, cell wall/membrane integrity assay and scanning electron microscopy (SEM) characterisation of bacterial morphology. The GO@PEG@AgNPs composites exhibited markedly higher antibacterial efficacy than AgNPs alone. The smallest GO@PEG@AgNPs (10 nm) particularly demonstrated higher antibacterial activity than other sizes (30, 50, and 80 nm). We believe that these findings contribute to great potential application as a regulated graphene-based antibacterial solution.