CD44-Targeted Photoactivatable Polymeric Nanosystem with On-Demand Drug Release as a "Photoactivatable Bomb" for Combined Photodynamic Therapy-Chemotherapy of Cancer.

Nowadays, the combined use of chemotherapy and photodynamic therapy (PDT) remains the most popular strategy for cancer treatment with high theraprutic efficacy. However, targeted therapy with the on-demand release of drugs is what most clinical treatments lack, leading to heavy side effects. Herein, a new CD44-targeted and red-light-activatable nanosystem, Ru-HA@DOX nanoparticles (NPs), was developed by conjugating hydrophilic biodegradable hyaluronic acid (HA) and hydrophobic photoresponsive ruthenium (Ru) complexes, which could encapsulate the chemotherapeutic drug doxrubicin (DOX). Ru-HA@DOX NPs can selectively accumulate at the tumor through the enhanced permeability and retention (EPR) effect and CD44-mediated endocytosis, thus avoiding off-target toxicity during circulation. After 660 nm of irradiation at the tumor site, Ru-HA@DOX NPs, as a "photoactivatable bomb", was split via the photocleavable Ru-N coordination bond to fast release DOX and produce singlet oxygen (1O2) for PDT. In general, Ru-HA@DOX NPs retained its integrity before irradiation and possessed minimal cytotoxicity, while under red-light irradiation, Ru-HA@DOX NPs showed significant cytotoxicity due to the release of DOX and production of 1O2 at the tumor. Chemotherapy-PDT of Ru-HA@DOX NPs resulted in a significant inhibition of tumor growth in A549-tumor-bearing mice and reduced the cardiotoxicity of DOX. Therefore, this study offers a novel CD44-targeted drug-delivery system with on-demand drug release for synergistic chemotherapy-PDT.

All-in-one: Accurate quantification, on-site detection, and bioimaging of sulfite using a colorimetric and ratiometric fluorescent probe in vitro and in vivo.

SO2 and its derivatives (SO32-/HSO3-) are used widely in food, beverages, and pharmaceutical production. However, they could induce multiple diseases in respiratory, nervous, and cardiovascular systems. Although several fluorescent probes have been developed for detecting SO32-/HSO3-, reports on rapid fluorescent probes for the on-site detection of SO2 derivatives are scarce. Herein, a colorimetric and ratiometric fluorescent probe 1 based on the intramolecular charge transfer (ICT) was reported. Probe 1 resulted in a 122 nm blue-shift in fluorescent emission and decrement of absorbance at 500 nm upon the addition of sulfite. Therefore, probe 1 could quantify SO32-/HSO3- using both UV-Vis and fluorescent methods (LOD: UV-Vis method 34 nM; fluorescent method 51 nM). Importantly, probe 1 was used for a rapid (60 s) and convenient (1 step, on-site) measurement of the SO2 derivatives in real samples (LOD: 0.47 µM) using smartphone based on the colorimetric method. The SO32-/HSO3--sensing mechanism was confirmed as the Michael addition reaction. Furthermore, the probe was used for the real-time monitoring of SO32-/HSO3- in A549 cells and zebrafish. In summary, an all-in-one fluorescent probe was successfully developed for the accurate quantification, on-site detection, and bioimaging of SO32-/HSO3-.

A Carrier-Free Folate Receptor-Targeted Ursolic Acid/Methotrexate Nanodelivery System for Synergetic Anticancer Therapy.

PURPOSE: To avoid undefined metabolic mechanisms and to eliminate potential side effects of traditional nanocarriers, new green carriers are urgently needed in cancer treatment. Carrier-free nanoparticles (NPs) based on ursolic acid (UA) have attracted significant attention, but the UA NPs targeting the folate receptor have never been explored. We designed a novel self-assembled UA-Methotrexate (MTX) NPs targeting the folate-receptor and its synergetic anticancer activity was studied in vitro and in vivo. METHODS: UA-MTX NPs were prepared using the solvent precipitation method. Characterization of the UA-MTX NPs preparation was performed using a size analyzer, transmission electron microscopy, and UV-vis spectrophotometry. The in vitro pH-responsive drug release capability of UA-MTX NPs was tested at different pH values. The UA-MTX NPs targeting of folates was determined by comparing the endocytosis rates of cell lines with low or overexpression of the folate receptor (A549 and MCF-7 cells). The cytotoxicity and cell apoptosis of UA-MTX NPs were also studied to determine the in vitro synergistic effects. Combination chemotherapy of UA-MTX NPs in vivo was evaluated using MCF-7 xenografted tumor models. RESULTS: Compared with free UA or MTX, the water solubility of UA-MTX NPs improved significantly. Drug-release from the UA-MTX NPs was faster at pH 5.0 than pH 7.4, suggesting MTX-UA NPs could rapidly release MTX in the acidic conditions of the tumor microenvironment. Confocal laser scanning microscopy revealed the excellent folate receptor targeting of UA-MTX NPs in MCF-7 cells. Cytotoxicity and cell apoptosis results demonstrated greater antiproliferative capacity of UA-MTX NPs than that of free drug in folate receptor overexpressing MCF-7 cells. Anticancer effects in vivo suggested MTX-UA NPs exhibited good biological safety and could enhance antitumor efficacy due to the combination therapy. CONCLUSION: Our findings indicate that the UA-MTX NPs targeting folate-receptors is an efficient strategy for combination chemotherapy.

Design and synthesis of novel 3,4-dihydrocoumarins as potent and selective monoamine oxidase-B inhibitors with the neuroprotection against Parkinson's disease.

The monoamine oxidase-B (MAO-B) inhibitors with neuroprotective effects are better for Parkinson's disease (PD) treatment, due to the complicated pathogenesis of PD. To develop new hMAO-B inhibitors with neuroprotection, a novel series of 3,4-dihydrocoumarins was designed as selective and reversible hMAO-B inhibitors to treat PD. Most compounds showed potent and selective inhibition for hMAO-B over hMAO-A with IC50 values ranging from nanomolar to sub-nanomolar. Among them, compound 4d was the most potent hMAO-B inhibitor (IC50 = 0.37 nM) being about 20783-fold more active than iproniazid, and exhibited the highest selectivity for hMAO-B (SI > 270,270). Kinetic studies revealed that compound 4d was a reversible and competitive inhibitor of hMAO-B. Neuroprotective studies indicated that compound 4d could protect PC12 cells from the damage induced by 6-OHDA and rotenone. Besides, compound 4d did not exhibit acute toxicity at a dose up to 2500 mg/kg (po), and could cross the BBB in parallel artificial membrane permeability assay. More importantly, compound 4d was able to significantly prevent the motor deficits in the MPTP-induced PD model. These results indicate that compound 4d is an effective and promising candidate against PD.

A novel mitochondria-targetted near-infrared fluorescent probe for selective and colorimetric detection of sulfite and its application in vitro and vivo.

Overdoses of SO2 and its derivatives (SO32-/HSO3-) in food or organisms are harmful to health. To detect SO32-/HSO3-, a novel NIR fluorescent probe 1, based upon the intramolecular charge transfer (ICT) mechanism, was developed. This probe was easily synthesized, and gave noticeable colorimetric and linear fluorescence changes at 690 nm after reaction with sulfite from 3.13 to 200 µM. Moreover, probe 1 displayed high sensitivity (LOD = 0.46 µM), excellent selectivity (among 13 kinds of anions and 3 kinds of biothiols) and quick response (within 30 min) towards SO32-/HSO3-. The SO32-/HSO3- sensing mechanism was confirmed as the Michael addition reaction. Furthermore, the probe showed wide applications for measuring SO32-/HSO3- in real samples, including sugar, tap water, wine and traditional Chinese medicine. The probe could also be used to detect SO32-/HSO3- in mitochondria of HepG2 cells and zebrafish, which suggested potential application for monitoring SO2 derivatives in clinical diagnostics.

Rational modulation of coumarin-hemicyanine platform based on OH substitution for higher selective detection of hypochlorite.

To monitor delicate changes of biological HOCl in vivo, a new probe (OH-substituted coumarin-hemicyanine, probe 2) was synthesized for NIR and ratiometric HOCl detection. Selectivity studies indicated that the electron-donating group (OH) substituted on the indolium moiety enhanced the selectivity to detect HOCl. With HOCl, the probe showed a ratiometric fluorescence (I500/I650) with a low detection limit (49.1 nM) and a rapid response (within 2 min). In addition, probe 2 was successfully applied to visualize exogenous and endogenous HOCl in living cells and animals and exhibited a perfect mitochondria target ability. This probe has been further studied as a potential and powerful tool to probe HOCl in arthritis models.

Design, synthesis and evaluation of novel ferulic acid derivatives as multi-target-directed ligands for the treatment of Alzheimer's disease.

A series of new ferulic acid derivatives were designed, synthesized and evaluated as multi-target inhibitors against Alzheimer's disease. In vitro studies indicated that most compounds showed significant potency to inhibit self-induced ß-amyloid (Aß) aggregation and acetylcholinesterase (AChE), and had good antioxidant activity. Specifically, compound 4g exhibited the potent ability to inhibit cholinesterase (ChE) (IC50, 19.7 nM for hAChE and 0.66 µM for hBuChE) and the good Aß aggregation inhibition (49.2% at 20 µM), and it was also a good antioxidant (1.26 trolox equivalents). Kinetic and molecular modeling studies showed that compound 4g was a mixed-type inhibitor, which could interact simultaneously with the catalytic anionic site (CAS) and the peripheral anionic site (PAS) of AChE. Moreover, compound 4g could remarkably increase PC12 cells viability in hydrogen peroxide-induced oxidative cell damage and Aß-induced cell damage. Finally, compound 4g had good ability to cross the BBB using the PAMPA-BBB assay. These results suggested that compound 4g was a promising multifunctional ChE inhibitor for the further investigation.

A near-infrared Nile red fluorescent probe for the discrimination of biothiols by dual-channel response and its bioimaging applications in living cells and animals.

Biothiols, including cysteine (Cys), homocysteine (Hcy), glutathione (GSH) and H2S, play important roles in human physiological processes. However, it is a great difficulty to distinguish biothiols from each other because of their similar chemical properties. Based on Nile red, we have designed and synthesized a near-infrared fluorescent probe for discriminating Cys/Hcy from GSH/H2S by a dual-channel detection method. Using an ether bond, near-infrared Nile red was attached to 7-nitrobenzofurazan to construct the probe. Due to the photo-induced electron transfer, the probe showed almost no fluorescence from the green to red emission band. But upon the addition of Cys (0-150 µM) or Hcy (0-200 µM), the probe exhibited a noteworthy fluorescence "turn-on" signal in two unique emission bands (Green and Red) with a fast response (within 30 min). In contrast, the probe displayed an increase in fluorescence only in the red channel when encountering GSH (0-70 µM) or H2S (0-50 µM), and GSH/H2S could be tested respectively by different response time. The limit of detection was calculated to be 0.09 µM (Cys), 0.30 µM (Hcy), 0.24 µM (GSH), and 0.04 µM (H2S), respectively (based on S/N = 3). The desirable dual-channel detection could be achieved in serum samples and living cells. Moreover, the probe could be applied for bioimaging in mice, which indicated its potential application in the clinic.

Long non-coding RNA-ENST00000434223 suppresses tumor progression in gastric cancer cells through the Wnt/ß-catenin signaling pathway.

BACKGROUND: Gastric cancer (GC) develops from the lining of the stomach. The present study aimed to explore the effects of long non-coding RNA-ENST00000434223 (lncRNA ENST00000434223) on gastric cancer (GC) cells. METHODS: One hundred and four GC tissues and paracancerous tissues were collected from GC patients, and expression of ENST00000434223, Wnt2b, ß-catenin, cyclinD1, E-cadherin, N-cadherin, vimentin, and snail was subsequently assessed. Morphological changes in cells were assessed using an inverted microscope, and expression of Bcl-2, Bax and caspase-3 was examined. RESULTS: We found that expression of Wnt2b, ß-catenin, cyclinD1, N-cadherin, vimentin, and snail was increased in GC tissues, while expression of ENST00000434223 and E-cadherin was decreased. SGC-7901 cells were closely arranged, and expression of Wnt2b, ß-catenin, CyclinD1, N-cadherin, Vimentin, snail and Bcl-2 was increased, whereas expression of ENST00000434223, E-cadherin, Bax and caspase-3 was decreased. Furthermore, the rate of apoptosis was decreased and cell proliferation, invasion and migration were increased in response to downregulation of ENST00000434223. By contrast, upregulation of ENST00000434223 exhibited the opposite effects in MKN-45 cells. CONCLUSION: The results of this study provide a promising experimental basis for the treatment of gastric cancer through interventional targeting of lncRNA ENST00000434223.

A Fluorescent Coumarin-Based Probe for the Fast Detection of Cysteine with Live Cell Application.

A new coumarin-based fluorescent probe, containing an allylic esters group, has been designed and synthesized for sensing cysteine in physiological pH. In this fluorescent probe, the coumarin was applied as the fluorophore and an allylic esters group was combined as both a fluorescence quencher and a recognition unit. The probe can selectively and sensitively detect cysteine (Cys) over homocysteine, glutathione, and other amino acids, and has a rapid response time of 30 min and a low detection limit of 47.7 nM. In addition, the probe could be applied for cell imaging with low cytotoxicity.

Determination of dexmedetomidine in children's plasma by ultra-performance liquid chromatography tandem mass spectrometry and application to pharmacokinetic study.

A rapid, sensitive, and selective ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed and validated for the determination and pharmacokinetic investigation of dexmedetomidine in children's plasma. Sample preparation was accomplished through a simple one-step deproteinization procedure with 0.2mL of acetonitrile to a 0.1mL plasma sample. Plasma samples were separated by UPLC on an Acquity UPLC BEH C18 column using a mobile phase consisting of acetonitrile-0.1% formic acid in water with gradient elution. The total run time was 3.1min and the elution of dexmedetomidine was at 1.24min. The detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction-monitoring mode using the respective transitions m/z 201.3→95.1 for dexmedetomidine and m/z 204.2→98.0 for the internal standard, respectively. The calibration curve was linear over the range of 0.05-10ng/mL with a lower limit of quantitation of 0.05ng/mL. Mean recovery rate of dexmedetomidine in plasma was in the range of 86.7-89.1%. Intra-day and inter-day precision were both <11.6%. This method was successfully applied in pharmacokinetic study after commencement of 1.0µg/kg dexmedetomidine infusion in children.

Dose requirements of remifentanil for intubation in nonparalyzed Chinese children.

BACKGROUND: The objective of this study was to determine ED50 and ED95 of remifentanil for intubation combined with propofol in nonparalyzed Chinese children. METHODS: Forty-seven American Society of Anesthesiologists Class I children aged 4-11 years weighing 14-33.5 kg underwent general anesthesia with 2.5 mg·kg(-1) of intravenous propofol followed by remifentanil in Wenzhou, China. The initial dose of remifentanil was 2.5 µg·kg(-1) injected over 60 s. Intubation was attempted 30 s after the completion of remifentanil injection. Level of difficulty to intubate was graded on a scoring system. If the initial intubation condition was deemed satisfactory, subsequent remifentanil doses were decreased by 0.25 µg·kg(-1). If the intubating condition was deemed unsatisfactory, subsequent remifentanil doses were increased by 0.25 µg·kg(-1). Mean arterial pressure, heart rate, and pulse oximetry were documented before and after induction, immediately after intubation, and 1 min after intubation. RESULTS: The ED50 of remifentanil used to render a satisfactory intubating condition used in combination with 2.5 mg·kg(-1) of propofol in nonparalyzed Chinese children was 2.30 µg·kg(-1) (95% confidence interval: 2.28-2.31 µg·kg(-1)), and the ED95 is 2.75 µg·kg(-1) (95% confidence interval: 2.59-3.35 µg·kg(-1)). These doses were lower than previously reported. CONCLUSION: When used in combination with 2.5 mg·kg(-1) of intravenous propofol, ED50 and ED95 of remifentanil for adequate intubation in nonparalyzed children were lower than previously reported, at 2.30 and 2.75 µg·kg(-1), respectively.