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Laser desorption ionization mass spectrometry (LDI-MS) has been developed to be an essential tool for the analysis and identification of a large variety of species, ranging from small metabolites, drugs and pollutants to peptides and proteins and even to bacteria. Matrix assisted LDI-MS has shown a great power for macromolecules, but its analytical capability to low mass compounds is limited due to inherent drawbacks, including abundant interference in low mass range (800 Da) caused by matrix self-dissociation and poor reproducibility due to inhomogeneous crystallization. Several matrix-free methods have been developed to solve these issues, mainly through altering organic matrix with inorganic nanostructured surfaces or nanomaterials as LDI medium. In the past five years, improvements on conventional silicon-based, metal-based, metal oxide-based and carbon-based LDI media as well as emerging novel materials such as 2D nanomaterials and organic frameworks have gained important progresses. Meanwhile, with the deep research in light-matter interaction, LDI mechanism studies begin to grow and become to attach great importance. Advances in both medium and mechanism promote to expand the applicable potential of nanostructure/nanomaterial-assisted LDI-MS in many aspects, including trace analysis, structural analysis and MS imaging. In this review, we survey the major progresses in this area in recent years. We also sketch remaining challenges and directions for future development.

The purpose of this study was to fabricate a novel binary hydrogel, and the insulin-loaded hydrogel was used as rectal suppository to prevent type I diabetes. The binary hydrogel was synthesized via solution polymerization. Its structure was studied by Fourier transform infrared spectroscopy (FTIR) and Raman spectra. The swelling behaviors of binary hydrogels were revealed in pH 1.2, 6.8 and 7.4 buffers, respectively. Their inner morphologies were observed with a scanning electron microscope (SEM). Insulin (INS) was selected as a model drug and encapsulated into the binary hydrogels. INS release study was carried out in pH 7.4 buffer. The hypoglycemic effects of INS-loaded hydrogels were studied by rectal administration. FTIR and Raman spectra confirmed the obtaining of binary hydrogels. The hydrogel showed a high swelling ratio in pH 7.4 (rectum environment). SEM photographs illustrated that many micro-pores in the inner of binary hydrogels, which could accommodate abundant guest molecule (e.g. INS). INS release profile suggested that INS-loaded hydrogels could diffuse INS at a sustained manner. Animal studies proved that INS-loaded binary hydrogel had an obvious hypoglycemic effect. Therefore, it could be speculated that the binary hydrogel had a potential application on treating type I diabetes by rectal administration.

The vanadium oxide V2O5•4VO2 cathode material has aroused significant interest due to its high theoretical capacity and wide availability. However, the poor rate and cycle performance of the V2O5•4VO2 electrode severely hindered its further application in high-energy density lithium-ion batteries. Herein, a kind of Al/Mn co-doped V2O5•4VO2 prepared via facile solvothermal method combined with annealing process was reported. Theoretical and experimental results reveal that [AlO6] and [MnO6] not only serve as an octahedral pillar to extend the interlayer spacing, but introduce oxygen vacancies that provide more lithium ion active sites and higher ionic and electronic conductivity in lithium ion (de)intercalation process. Paired with lithium metal anode, Al/Mn co-doped V2O5•4VO2 cathode exhibits better performance metrics of 322.5 mAh/g at 0.1 A/g, 91.7% capacity retention after 50 cycles, and 195.8 mAh/g after 200 cycles at a current density of 1 A/g, while the values corresponding to the pure phase V2O5•4VO2 are 248.7 mAh/g, 66.9% as well as 97.7 mAh/g respectively. Actually, the insight into the performance of potential electrode materials improved by double ion doping was provided in the present work.

Intraperitoneal (IP) chemotherapy is a preferable treatment option for peritoneal carcinomatosis of malignancies by delivering chemotherapeutic drugs into the abdominal cavity. A persistent major challenge in IP chemotherapy is the need to provide effective drug concentration in the peritoneal cavity for an extended period of time. In the present work, the thermosensitive hydrogel system (PTX/PECT(gel)) assembled by PTX (paclitaxel)-loaded amphiphilic copolymer (PECT, poly (ε-caprolactone-co-1,4,8-trioxa [4.6]spiro-9-undecanone)-poly(ethylene glycol)-poly (ε-caprolactone-co-1,4,8-trioxa [4.6]spiro-9-undecanone)) nanoparticles was developed for sustained IP chemotherapy of peritoneal carcinomatosis model. Cytotoxicity assay indicated that PECT hydrogel was biocompatible with very low cytotoxicity and PTX/PECT(gel) had enhanced cytotoxicity than free PTX. In vivo toxicity study demonstrated the biocompatibility and biosafety of PECT hydrogel as an IP chemotherapy carrier. The fluorescence imaging method was employed to monitor the intraperitoneal degradation of PECT hydrogel by labeling PECT with rhodamine B. PECT hydrogel with the dose of 200μL showed about 8days' retention time and most of the injected hydrogel was located in the intestine. The anti-tumor efficacy study was carried out in mice bearing CT26 intraperitoneal ascites fluid as colorectal peritoneal carcinomatosis model. The result showed that intraperitoneal administration of PTX/PECT(gel) could effectively suppress growth and metastasis of CT26 peritoneal carcinomatosis in vivo, compared with Taxol® group. The pharmacokinetic studies demonstrated that PTX/PECT(gel) could improve the bioavailability of PTX by being formulated in PECT hydrogel. Overall, sustained drug concentration at peritoneal levels in combination with drug in the form of nanoparticle contributes to the enhanced anti-tumor efficacy. Thus, our results suggested that PTX/PECT(gel) may have great potential applications in IP chemotherapy.

Embelin, an active ingredient of traditional herbal medicine, is used to treat many diseases such as cancer. However, embelin is hydrophobic and insoluble in water, which makes it unsuitable for in vivo applications. In this study, we constructed an embelin-loaded thermosensitive injectable hydrogel system that we named Embelin/PECT(gel) based on the amphiphilic triblock copolymer of poly (ε-caprolactone-co-1,4,8-trioxa[4.6]spiro-9-undecanone)-poly (ethylene glycol)-poly (ε-caprolactone-co-1,4,8-trioxa[4.6]spiro-9-undecanone) (PECT). The cytotoxicity and the antitumor effects of Embelin/PECT(gel) on mouse hepatic cancers were investigated in vitro and in vivo. Results indicated that embelin was formulated in PECT hydrogel and could be continuously released from Embelin/PECT(gel) , showing a higher cytotoxicity for H22 cells in vitro compared with free embelin. The aqueous solution of Embelin/PECT(gel) transformed into gel at the injection site within seconds, which later eroded and degraded over time in vivo. A single local peritumoral injection of Embelin/PECT(gel) in liver at a low dosage of 0.5 mg per mouse exhibited a significant antitumor effect, which was comparable to the antitumor effect of the embelin solution treatment at a total dose of 6 mg per mouse in mouse hepatic cancer. Embelin/PECT(gel) , as a drug delivery system in liver, represents a novel therapeutic drug candidate for the clinical treatment of advanced hepatocellular carcinoma.

Eighteen organochlorine contaminants from the water samples of the Yangtse River have been qualitatively and quantitatively analyzed. The analysis of polychlorinated organic compounds (PCOCs) extracted by C18 Solid Phase Extract (SPE) was performed using HP6890 gas chromatograph coupled by ECD detector. The analytical results demonstrate that the analytical methods are reliable based on the fact that most of the recoveries for the targeted compounds are 60-90%. Most of the concerned contaminants, i.e. chlorinated pesticides and PCBs were found in the water samples of the Yangtse River, but their concentration was very low,2.97 ng l(-1), which is far less than 1 microg l(-1)--the standard of drinking water of China. It is apparent that the PCOCs were in high concentration during the dry season, and in low concentration during the rainy season. The situation of PCOCs contamination in the water of the Yangtse River in 1999 was greatly improved in comparison with 10 years ago.