Southwest University

About: Southwest University is a education organization based out in Chongqing, China. It is known for research contribution in the topics: Population & Bombyx mori. The organization has 29772 authors who have published 27755 publications receiving 409441 citations. The organization is also known as: Southwest University in Chongqing & SWU.

A new type of pH-responsive coordination polymer sphere as a vehicle for targeted anticancer drug delivery and sustained release

Abstract: A new type of coordination polymer sphere prepared by combining 1,1′-(1,4-butanediyl)bis(imidazole) (bbi) and ferrous ions has been demonstrated as a targeted delivery system for in situ encapsulating anticancer drugs. These stable coordination polymer spheres can be fabricated simply by a deposition method. Drugs, doxorubicin hydrochloride (DOX·HCl) for example, can be easily in situ encapsulated by simply mixing the drug with bbi ligand through the deposition method and results in a high drug loading efficiency up to 98% and a drug loading content of nearly 40%, which is remarkably high for not only metal–organic but also other materials. A noticeable feature of the drug loaded coordination polymer spheres is that they show sustainable drug release for several days due to their superior stability, and are sensitive to external pH owing to the coordination bonds. The drug can be released faster in mild acidic conditions in comparison to physiological acidity. By conjugating folic acid to the surface of the coordination polymer spheres, the vehicles can be taken up selectively by cancer cells through cell surface receptor-mediated mechanisms. Cell viability experiments with HeLla cells demonstrated the low toxicity of the delivery vehicles and the good anticancer efficacy of the drug-loaded coordination polymer spheres.

Water-Soluble Nonconjugated Polymer Nanoparticles with Strong Fluorescence Emission for Selective and Sensitive Detection of Nitro-Explosive Picric Acid in Aqueous Medium

Abstract: Water-soluble nonconjugated polymer nanoparticles (PNPs) with strong fluorescence emission were prepared from hyperbranched poly(ethylenimine) (PEI) and d-glucose via Schiff base reaction and self-assembly in aqueous phase. Preparation of the PEI–d-glucose (PEI-G) PNPs was facile (one-pot reaction) and environmentally friendly under mild conditions. Also, PEI-G PNPs showed a high fluorescence quantum yield in aqueous solution, and the fluorescence properties (such as concentration- and solvent-dependent fluorescence) and origin of intrinsic fluorescence were investigated and discussed. PEI-G PNPs were then used to develop a fluorescent probe for fast, selective, and sensitive detection of nitro-explosive picric acid (PA) in aqueous medium, because the fluorescence can be easily quenched by PA whereas other nitro-explosives and structurally similar compounds only caused negligible quenching. A wide linear range (0.05–70 μM) and a low detection limit (26 nM) were obtained. The fluorescence quenching mechani...

Hyaluronic acid-functionalized polymeric nanoparticles for colon cancer-targeted combination chemotherapy

Abstract: Nanoparticle (NP)-based combination chemotherapy has been proposed as an effective strategy for achieving synergistic effects and targeted drug delivery for colon cancer therapy. Here, we fabricated a series of hyaluronic acid (HA)-functionalized camptothecin (CPT)/curcumin (CUR)-loaded polymeric NPs (HA-CPT/CUR-NPs) with various weight ratios of CPT to CUR (1 : 1, 2 : 1 and 4 : 1). The resultant spherical HA-CPT/CUR-NPs had a desirable particle size (around 289 nm), relative narrow size distribution, and slightly negative zeta potential. These NPs exhibited a simultaneous sustained release profile for both drugs throughout the time frame examined. Subsequent cellular uptake experiments demonstrated that the introduction of HA to the NP surface endowed NPs with colon cancer-targeting capability and markedly increased cellular uptake efficiency compared with chitosan-coated NPs. Importantly, the combined delivery of CPT and CUR in one HA-functionalized NP exerted strong synergistic effects. HA-CPT/CUR-NP (1 : 1) showed the highest antitumor activity among the three HA-CPT/CUR-NPs, resulting in an extremely low combination index. Collectively, our findings indicate that this HA-CPT/CUR-NP can be exploited as an efficient formulation for colon cancer-targeted combination chemotherapy.

Near-infrared aggregation-induced enhanced electrochemiluminescence from tetraphenylethylene nanocrystals: a new generation of ECL emitters

Abstract: Herein, we observed near-infrared electrochemiluminescence (NIR ECL) emission from tetraphenylethylene nanocrystals (TPE NCs), which exhibit high ECL efficiency and excellent biocompatibility compared with the current NIR ECL emitters (such as semiconductor quantum dots and metal nanoclusters). The strong ECL signal of TPE NCs originates from the aggregation-induced enhanced ECL emission via improvement of the efficiency of electron hole recombination and suppression of the nonradiative transition. Impressively, the TPE NCs exhibit an enormous red-shifted ECL emission (678 nm) relative to the blue-light photoluminescence (PL) emission (440 nm). Compared to fluorescence imaging which is limited by photobleaching and autofluorescence, the NIR ECL emission of TPE NCs is highly favorable to diminish background interference over visible light and realize deeper tissue penetration, which expands the ECL emission of organic nanomaterials to the NIR region for broader biological applications.