Chaoqun You

Magnetic observation of above room-temperature spin transition in vesicular nano-spheres

Nano-scale materials are acquiring a leading role in the fabrication of new generation devices, especially for the practical application of molecular bi-stability. However, the preparation of purely bi-stable nano-objects without the use of surfactants/polymers remains a challenging task. Here, we present a new approach to prepare spin-crossover (SCO) vesicular nano-spheres with single-external diameters of approximately 100 nm using a CHCl3–H2O mixture. The nano-spheres are based on a series SCO complexes, [Fe(H2Bpz2)2(dialkyl-bipy)] (H2Bpz2 = dihydrobis(1-pyrazolyl)borate, dialkyl-bipy = N4,N4′-dialkyl-(2,2′-bipyridine)-4,4′-dicarbo-xamide, alkyl = propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl and cetyl), and are prepared through a self-assembly process that is similar to liposomal assembly, with the dialkyl-bipy moiety acting as the hydrophobic tail and the Fe(H2Bpz2) moiety acting as the hydrophilic head. This study reveals that the alkyl chain length plays a key role in the formation of these nano-spheres and the determination of their spin transition temperatures. The spin transition temperatures for the bulk materials are centered at around 160 K, and show a positive correlation with the alkyl chain length. Meanwhile, for the vesicular nano-spheres in the solid state, their transition temperatures are above room-temperature, and the correlation with the alkyl chain length is negative. These results provide an effective strategy for the design of new metal–organic materials for nano-technological applications.

Near-Infrared Light and pH Dual-Responsive Targeted Drug Carrier Based on Core-Crosslinked Polyaniline Nanoparticles for Intracellular Delivery of Cisplatin

Biodegradable polymeric nanoparticles have received growing interest as one of the most promising agents for drug delivery. In the present work, functional and core-crosslinked poly(ethylene glycol) with poly(ϵ-caprolactone) (PEG5k -PCL10k ) block copolymer and lecithin as biodegradable polymer doped with polyaniline was used to assemble nanoparticles which were prepared for targeted delivery and controlled release of cisplatin. The morphology of the polyaniline nanoparticles was determined by dynamic light scattering and the prepared nanoparticles showed a size of 83(±1) nm and a uniform spherical shape. For targeting to HER2 receptors, Herceptin was applied to guide the nanoparticles to breast cancer cells. Studies on cellular uptake and drug release of the nanocarriers showed that the prepared nanoparticles were efficiently taken up by breast cancer cells and the drug was released efficiently under acidic conditions when exposed to a near-infrared laser (808 nm, 1.54 W) for 5 min. Our research highlights the great potential of near-infrared light and pH dual-responsive release by core-crosslinked nanoparticles in nanobiomedicine.

Enhanced cytotoxicity by a benzothiazole-containing cisplatin derivative in breast cancer cells

In recent years, the concept of nanoparticles being used as an intelligent drug carrier has gained great attention. In this paper, the formulation of a liposome delivery system loaded with a novel benzothiazole-containing cisplatin derivative (CJM-Pt) was carried out. The particle size distributions were determined using dynamic light scattering, and the prepared liposomes showed a suitable size of around 98 nm. Stability studies showed that the CJM-Pt loaded liposomes were stable at 4 °C for more than four weeks. Investigation of triggered release indicated that the release performance of the prepared liposomes was controllable and the releasing effect was remarkable under low pH ( 42 °C). To test the suitability of the chosen formulation, CJM-Pt loaded liposomes were investigated against several tumor cell lines: MGC-803, SGC-7901, MCF-7 and MDA-MB-231. Furthermore, the cell cycle arrest was examined. The CJM-Pt loaded liposomes have the potential to be applied in drug delivery systems (DDS) for breast cancer therapy.

Near infrared radiated stimulus-responsive liposomes based on photothermal conversion as drug carriers for co-delivery of CJM126 and cisplatin

Synergistic therapy has caused increasing interest in recent treatment of cancer owing to its preferable therapeutic efficiency to most single antineoplastic protocol. Herein, we design a co-delivery two drugs nanosystem based on biodegradable liposomes, loading cisplatin, Indocyanine green (ICG), and CJM126 coupled with cholesterol derivative (CJM-Chol) for the purpose of synergistic therapy. The obtained nanoparticles showed a uniform diameter of 103.8nm and a favorable morphology. The investigation on near infrared radiated (NIR) responsive release showed that NIR mediated photothermal conversion induced a controllable drug release from liposomes. Furthermore, the designed liposomes (only 50μg/mL) displayed an inspiring photothermal conversion efficiency and received a high temperature (65.6°C, Tm=42°C) when exposed to an 808nm near infrared laser (1.54W, 5min). Besides, it turned out that the delivery system could be efficiently endocytosed by tumor cells, which attributed to its admirable biocompatibility and the targeting role of folate. The prepared nanoparticles showed significantly excellent inhibitory effect (3.05% cell viability in 24h) on MDA-MB-231 cells when added irradiation as compared with free cisplatin (28.41%) or treatment without NIR (11.24%) in our study. Our research highlights the present nanoparticles provide a promising strategy for targeted delivery and photothermal treatment.

Selective separation of aqueous sulphate anions via crystallization of sulphate–water clusters

In this study, the potential of oxoanion separation with the ligands N-4-methylbenzyl-4-amino-1,2,4-triazole (L1), N-4-fluorobenzyl-4-amino-1,2,4-triazole (L2), N-4-hydroxy benzyl-4-amino-1,2,4-triazole (L3), and N-3-methoxy-4-hydroxybenzyl-4-amino-1,2,4-triazole (L4) was explored. The salts of sulphate, nitrate, and perchlorate were crystallized in the form of [HL1]+[HSO4]−·H2O, [HL2]+[HSO4]−·H2O, 2[HL3]+[SO4]2−·2(H2O), and 2[HL4]+[SO4]2−·H2O, [HL3]+[NO3]−·H2O and [HL4]+[NO3]−, and [HL3]+[ClO4]− and [HL4]+[ClO4]−, respectively. Competitive crystallization and competitive sulphate-binding experiments demonstrated special recognition of the sulphate–water clusters (in the forms of [HSO4−·H2O]n or [SO42−·H2O]n) via the parallel packed 3-D architectures of HL1+, HL2+, and HL4+ cations, which were far more effective and selective than the non-3-D structure of HL3+ cation. The observed selectivity for sulphate, nitrate, and perchlorate was found to be anti-Hofmeister. In addition, the selective separation of sulphate anions in seawater was investigated, which demonstrated the real-world application of the present strategy.

Co-delivery of cisplatin and CJM-126 via photothermal conversion nanoparticles for enhanced synergistic antitumor efficacy

Polymeric biomaterials that can be smartly disassembled through the cleavage of the covalent bonds in a controllable way upon an environmental stimulus such as pH change, redox, special enzymes, temperature, or ultrasound, as well as light irradiation, but are otherwise stable under normal physiological conditions have attracted great attention in recent decades. The 2-(4-aminophenyl) benzothiazole molecule (CJM-126), as one of the benzothiazole derivatives, has exhibited a synergistic effect with cisplatin (CDDP) and restrains the bioactivities of a series of human breast cancer cell lines. In our study, novel NIR-responsive targeted binary-drug-loaded nanoparticles encapsulating indocyanine green (ICG) dye were prepared as a new co-delivery and combined therapeutic vehicle. The prepared drug-loaded polymeric nanoparticles (TNPs/CDDP-ICG) are stable under normal physiological conditions, while burst drugs release upon NIR laser irradiation in a mild acidic environment. The results further confirmed that the designed co-delivery platform showed higher cytotoxicity than the single free CDDP due to the synergistic treatment of CJM-126 and CDDP in vitro. Taken together, the work might provide a promising approach for effective site-specific antitumor therapy.

Folate-modified, indocyanine green-loaded lipid-polymer hybrid nanoparticles for targeted delivery of cisplatin

Abstract Cisplatin is a potent antitumor drug, which is widely applied in clinical cancer treatment. However, cisplatin can hardly distinguish between healthy tissue and tumor tissue, resulting in serious toxic side effects. Indocyanine green (ICG) is a FDA-approved near-infrared (NIR) fluorescence dye which has been used in photothermal therapy and optically mediated diagnostic, but the application of ICG is limited by its concentration-dependent aggregation, poor aqueous stability in vitro, lack of target specificity and rapid elimination from the body. Herein, to overcome these limitations of cisplatin and ICG, we fabricated folate-modified, cisplatin, ICG-loaded lipid-polymer hybrid nanoparticles (FCINPs) using a single-step sonication method. The FCINPs exhibited well-defined monodispersity, significant stability and excellent NIR penetration ability. The intracellular uptake experiment showed that the targeting efficacy of the FCINPs was more effective in folate receptors (FRs) over-expressing MCF-7 cells than FRs negative A549 cells. In addition, compared with chemo or photothermal treatment alone, the treatment of FCINPs in combination with 808 nm NIR laser irradiation can significantly induce the apoptosis and necrosis of MCF-7 cells. These findings indicated that the FCINPs would be a promising nanosized drug formulation for tumor-targeted therapy in the future.

Enhanced legumain-recognition and NIR controlled released of cisplatin-indocyanine nanosphere against gastric carcinoma.

&NA; Cisplatin‐therapy has faced limitations in the gastric cancer therapy. To settle the bottleneck, enhanced specificity and controlled‐release property are choosen. We synthesize cisplatin and indocyanine green (ICG) loaded PLGA‐(DSPE‐PEG2000) nanoparticles, which is abbreviated as CINPs. And we conjugate the Gly‐Cys‐Gly‐Ala‐Ala‐Asn‐Leu (GCGAANL) heptapeptide upon the surface of CINPs, the product is abbreviated as ACINPs. ACINPs with nearly 110 nm exhibit good monodispersity and size stability. The EE (efficiency of encapsulation) and LE (loading of encapsulation) of cisplatin loaded into ACINPs are optimized as 29.81% and 3.88%. MGC803 cells overexpressing the legumain and MKN28 cells, which negatively express the legumain as well as the normal stomach cells, are selected. In vitro studies have suggested ACINPs, compared with CINPs, could be recognized by MGC803 cells and efficiently killed the cancer cells, while be harmless to MKN28 cells, which indicates the specificity and safety of ACINPs. Under irradiation of 808 nm NIR irradiation, ICG loaded in ACINPs could rapidly transform the light to heat up to 60 °C. Nanoparticles compared with non‐irraditaion group could be quickly disrupted and release the cisplatin which could enhance the controlled‐release ability. Hence, the ACINPs exhibit great potential in avoiding the side effects and enhancing the therapy ability of cisplatin.

Synthesis and biological evaluation of redox/NIR dual stimulus-responsive polymeric nanoparticles for targeted delivery of cisplatin

Functional drug delivery systems enabling various favorable characteristics including specific targets, efficient cellular uptake and controllable release. At present work, a folate and cRGD dual modified nanoparticles based on NIR light and glutathione dual stimuli-responsive release system was successfully prepared and which simultaneously deliver cisplatin and ICG to tumor sites to enhance controllability. The prepared nanoparticles showed a stable uniform spherical morphology of 77.59 nm particle size range in PBS (pH = 7.4, 25 °C) and the encapsulated cisplatin were rapidly released in acidic environment especially added glutathione (GSH) and NIR irradiation. Moreover, the prepared nanoparticles can be efficiently internalized by tumor cells through the enhanced dual targeted ligands (folate and cRGD) for ICG imaging. The cytotoxicity assays showed that the cells viability decreased to 1.95% (SGC-7901) when been exposed to NIR light, and which further decreased to 1.25% in MCF-7 cells. Thus, the prepared nanoparticles showed excellent performance for photothermal conversion therapy of tumor cells and especially on human breast tumor cells. Our research highlights the great potential of stimuli-responsive smart nanoparticles in biomaterial and nano-biomedicine.

A dual-targeting strategy for enhanced drug delivery and synergistic therapy based on thermosensitive nanoparticles

Abstract The functionalized nanoparticles have been widely studied and reported as carriers of drug transport recently. Furthermore, many groups have focused more on developing novel and efficient treatment methods, such as photodynamic therapy and photothermal therapy, since both therapies have shown inspiring potential in the application of antitumor. The mentioned treatments exhibited the superiority of cooperative manner and showed the ability to compensate for the adverse effects caused by conventional monotherapy in proposed strategies. In view of the above descriptions, we formulated a thermosensitive drug delivery system, which achieved the enhanced delivery of cisplatin and two photosensitizers (ICG and Ce6) by dual-targeting traction. Drawing on the thin film hydration method, cisplatin and photosensitizers were encapsulated inside nanoparticles. Meanwhile, the targeting peptide cRGD and targeting molecule folate can be modified on the surface of nanoparticles to realize the active identification of tumor cells. The measurements of dynamic light scattering showed that the prepared nanoparticles had an ideal dispersibility and uniform particle size of 102.6 nm. On the basis of the results observed from confocal laser scanning microscope, the modified nanoparticles were more efficient endocytosed by MCF-7 cells as a contrast to SGC-7901 cells. Photothermal conversion-triggered drug release and photo-therapies produced a significant apoptosis rate of 85.9% on MCF-7 cells. The distinguished results made it believed that the formulated delivery system had conducted great efforts and innovations for the realization of concise collaboration and provided a promising strategy for the treatment of breast cancer.