A pH-sensitive doxorubicin (Dox) prodrug was prepared, and its release in vitro and distribution in vivo were studied by using a high performance liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) method. The prodrug, mPEG–P(LA-co-DHP/Dox) (P(Dox)), was amphiphilic in nature, with a hydrophilic mPEG block and a hydrophobic P(LA-co-DHP/Dox) block. The Dox was connected to the carrier polymer chain via a hydrazine linkage. The in vitro release results showed that the release rate of Dox from P(Dox) in acidic medium (pH = 5.0) was dramatically higher than that under physiological conditions (pH = 7.4). The absorption of Dox from P(Dox) in HeLa cells was much faster than that of free Dox. The MTT cell viability study demonstrated the higher cytotoxicity of P(Dox) than free Dox at the same concentration. The Dox concentration from P(Dox) in the mouse liver was dramatically higher than those in other tissues. The above results showed that P(Dox), as a prodrug of Dox, greatly favors the bioavailability of doxorubicin and prolongs its circle time in vivo.

In this study a cisplatin-loaded, multilayered polylactide (PLA) electrospun nanofibers, with the structure of two layers of drug-loaded mat being sandwiched by three layers of blank mat, were designed for prolonged cisplatin release at surgical margin to prevent local cancer recurrence following surgical resection in a murine model. In vivo drug release and biodistribution study suggested that the multilayered fibrous mat displayed a slower cisplatin release behavior and a more stable drug rentention in the local tissue within 24 h than that of single-layered fibrous mat. By covering the surgical site with the multilayered fibrous mat following resection of subcutaneous liver cancer in mice, retarded tumor recurrence, prolonged survival time and less systemic toxicity were observed compared with other treatment groups.

Iron is one of the most important elements in the metabolic process for all living system. However, both its deficiency and excess from normal permissible limits can induce serious disorders. We synthesized a europium-based metal–organic framework (Eu-MOF), EuL3 (L = 4′-(4-carboxyphenyl)-2,2′: 6′,2″-terpyridine), under hydrothermal conditions, and used it as a solid luminescence sensor for Fe3+ ions. The robust EuL3 shows fast response (∼ 1 min) and high sensitivity (Stern–Volmer constant KSV = 4.1 × 103 L/mol) for Fe3+ ions in aqueous solution or biological systems due to the existence of chelating terpyridine and open channels. The simple and portable test paper based on the EuL3 fluorescent sensor system provides a convenient and reliable detection of Fe3+ in every day applications. This pioneering work contributes to extend the potential application of Ln-MOFs to the biological and environmental areas.Keywords: europium metal organic framework; Fe3+ ion; Fe3+ test paper; fluorescent probe; open channel; terpyridine;

Chromium(VI) [Cr(VI)] is considered as a severe environmental pollutant, due to its highly toxic and carcinogenic properties. Therefore, low cost, highly sensitive sensors for the determination of Cr(VI) are highly demanded. It is well-known that highly luminescent carbon dots (CDs) have been successfully applied as fluorescent nanosensors for pH, ions, and molecular substances. In the present work, we have demonstrated an on–off fluorescent CD probe for detecting Cr(VI) based on the inner filter effect (IFE) because the absorption bands of Cr(IV) fully covered the emission and excitation bands of CDs. This CD-based nanosensor provides obvious advantages of simplicity, convenience, rapid response, high selectivity, and sensitivity, which have potential application for the detection of Cr(VI) in the environmental industry. In addition, because Cr(VI) can be reduced to low valent chromium species easily by reductant, resulting in the elimination of the IFE and recovery of CD fluorescence, the CD–Cr(VI) mixture could behave as an off–on type fluorescent probe for reductant. We employed ascorbic acid (AA) as an example molecule to demonstrate this off–on type fluorescent probe.Keywords: ascorbic acid; carbon dots; chromium(VI); inner filter effect (IFE); nanochemosensor; on−off−on fluorescent;

4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) dyes are organic dyes which have excellent thermal and photochemical stability, high fluorescence quantum yield and good solubility. Four BODIPY dyes were made and used to investigate the oxidation of thioanisole under visible light. BODIPY dyes were shown to be highly active photocatalysts which are comparable to the metal complex, like Ru(bpy)32+. This work highlights the potential of using BODIPY as photocatalysts for a number of important organic transformations.Highlights► BODIPY was synthesized using electrophilic carbonyl compound as bridging unit. ► BODIPY structure was confired by NMR, absorption and emission spectra. ► BODIPY was shown to be highly active photocatalyst for oxidation of thioanisole.

A pH-sensitive doxorubicin (Dox) prodrug was prepared, and its release in vitro and distribution in vivo were studied by using a high performance liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) method. The prodrug, mPEG–P(LA-co-DHP/Dox) (P(Dox)), was amphiphilic in nature, with a hydrophilic mPEG block and a hydrophobic P(LA-co-DHP/Dox) block. The Dox was connected to the carrier polymer chain via a hydrazine linkage. The in vitro release results showed that the release rate of Dox from P(Dox) in acidic medium (pH = 5.0) was dramatically higher than that under physiological conditions (pH = 7.4). The absorption of Dox from P(Dox) in HeLa cells was much faster than that of free Dox. The MTT cell viability study demonstrated the higher cytotoxicity of P(Dox) than free Dox at the same concentration. The Dox concentration from P(Dox) in the mouse liver was dramatically higher than those in other tissues. The above results showed that P(Dox), as a prodrug of Dox, greatly favors the bioavailability of doxorubicin and prolongs its circle time in vivo.