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Jing Liu,1,2 Fei Peng,1,2 Yi Kang,1,2 Deying Gong,1,2 Jing Fan,1,2 Wensheng Zhang,1,2 Feng Qiu1,2 1Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, 610041, People’s Republic of China; 2National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, 610041, People’s Republic of ChinaCorrespondence: Feng Qiu; Wensheng Zhang Email fengqiu@scu.edu.cn; zhang_ws@scu.edu.cnPurpose: Typical hydrophobic amino acids (HAAs) are important motifs for self-assembling peptides (SAPs), but they lead to low water-solubility or compact packing of peptides, limiting their capacity for encapsulating hydrophobic drugs. As an alternative, we designed a peptide GQY based on atypical HAAs, which could encapsulate hydrophobic drugs more efficiently. Although hydrophobic general anesthetics (GAs) have been formulated as lipid emulsions, their lipid-free formulations have been pursued because of some side effects inherent to lipids. Using GAs as targets, potential application of GQY as a carrier for hydrophobic drugs was evaluated.Methods: Thioflavin-T (ThT) binding test, dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to examine the self-assembling ability of GQY. Pyrene and 8-Anilino-1-naphthalenesulfonic acid (ANS) were used to confirm formation of hydrophobic domain in GQY nanoparticles. Using pyrene as a model, GQY’s capacity to encapsulate hydrophobic drugs was evaluated. GAs including propofol, etomidate and ET26 were encapsulated by GQY. Loss of righting reflex (LORR) test was conducted to assess the anesthetic efficacy of these lipid-free formulations. Paw-licking test was used to evaluate pain-on-injection of propofol-GQY (PROP-GQY) formulation. Hemolytic and cytotoxicity assay were used to evaluate biocompatibility of GQY.Results: Stable nanoparticles containing plenty of hydrophobic cavities could be formed by GQY, which could encapsulate hydrophobic drugs at very high concentration and form stable suspensions. Propofol, etomidate and ET26 formulated by GQY showed anesthetic efficacy comparable to their currently available formulations. Unlike clinic lipid emulsion, PROP-GQY formulation did not cause pain-on-injection in rats. Neither obvious cytotoxicity nor hemolytic activity of GQY was observed.Conclusion: GQY could encapsulate GAs to obtain stable and effective formulations. As a lipid-free carrier, GQY exhibited considerable biocompatibility and other side benefits such as reducing pain-on-injection. More SAPs based on atypical HAAs could be designed as promising carriers for hydrophobic drugs.Keywords: self-assembling peptides, nanoparticles, hydrophobic drugs, lipid-free formulations, general anesthetics

Objectives Monoacylglycerol lipase participates in organ protection by regulating the hydrolysis of the endocannabinoid 2-arachidonoylglycerol. This study investigated whether blocking monoacylglycerol lipase protects against postresuscitation myocardial injury and improves survival in a rat model of cardiac arrest and cardiopulmonary resuscitation. Design Prospective randomized laboratory study. Setting University research laboratory. Subjects Male Sprague-Dawley rat (n = 96). Interventions Rats underwent 8-minute asphyxia-based cardiac arrest and resuscitation. Surviving rats were randomly divided into cardiopulmonary resuscitation + URB602 group, cardiopulmonary resuscitation group, and sham group. One minute after successful resuscitation, rats in the cardiopulmonary resuscitation + URB602 group received a single dose of URB602 (5 mg/kg), a small-molecule monoacylglycerol lipase inhibitor, whereas rats in the cardiopulmonary resuscitation group received an equivalent volume of vehicle solution. The sham rats underwent all of the procedures performed on rats in the cardiopulmonary resuscitation and cardiopulmonary resuscitation + URB602 groups minus cardiac arrest and asphyxia. Measurements and main results Survival was recorded 168 hours after the return of spontaneous circulation (n = 22 in each group). Compared with vehicle treatment (31.8%), URB602 treatment markedly improved survival (63.6%) 168 hours after cardiopulmonary resuscitation. Next, we used additional surviving rats to evaluate myocardial and mitochondrial injury 6 hours after return of spontaneous circulation, and we found that URB602 significantly reduced myocardial injury and prevented myocardial mitochondrial damage. In addition, URB602 attenuated the dysregulation of endocannabinoid and eicosanoid metabolism 6 hours after return of spontaneous circulation and prevented the acceleration of mitochondrial permeability transition 15 minutes after return of spontaneous circulation. Conclusions Monoacylglycerol lipase blockade may reduce myocardial and mitochondrial injury and significantly improve the resuscitation effect after cardiac arrest and cardiopulmonary resuscitation.

Dexmedetomidine, as a safe sedative, mainly exerts on the central nervous system particularly in the locus coeruleus producing arousable sedation with potential analgesic and anxiolytic effects. The quantification and pharmacokinetic investigation of dexmedetomidine in the central nervous system have been described rarely. In order to estimate the unbound dexmedetomidine concentrations in brain extracellular fluid and blood simultaneously, we employed microdialysis technique as a sampling method and primarily established a rapid, sensitive and selective high-performance liquid chromatography coupled with tandem mass spectrometry method (HPLC-MS/MS). Dexmedetomidine and the internal standard (dexmedetomidine-d4) were extracted in liquid–liquid extraction procedure with ethyl acetate from 10 μL of alkalinized microdialysate sample. After evaporation under nitrogen at room temperature, the analytes were reconstituted in acetonitrile and transferred to be detected. HPLC was performed on an Agilent Poroshell 120 Hilic column (4.6 × 100 mm, 2.7 μm) with isocratic elution at a flow rate of 0.3 mL/min by 0.1% formic acid/acetonitrile (60:40, v/v). The detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction monitoring (MRM) mode using the respective [M+H]+ ions m/z 201.2 to m/z 95.1 for DEX and m/z 205.2 to m/z 99.1 for IS (DEX-d4). The concentration–response relationship was of good linearity over a concentration range of 1.00–1000.00 ng/mL with the correlation coefficient above 0.999. The lower limit of quantification was 1.00 ng/mL with a relative standard deviation of less than 20%. The intra- and inter-day accuracy were within ±5.00% and precision was

As a trace element nutrient, cobalt is critical for both prokaryotes and eukaryotes. In the current study, a turn-on Cobalt Bioluminescent Probe 1 (CBP-1) for the detection of cobalt has been successfully developed based on oxidative C–O bond cleavage. This probe exhibited high selectivity and sensitivity toward cobalt over other analytes. By using CBP-1, the successful in vivo imaging of cobalt accumulation was carried out in a mouse model. Such an ability to determine cobalt in living animals provides a powerful technology for studying the system distribution, toxic potency, and biological effect of Co2+.

QX-OH, a new synthetic local anesthetic, produced concentration-dependent, reversible, and long-acting local anesthesia in animal models, with moderate local toxicity. As part of preclinical research for drug development, we developed and validated a method for the determination of QX-OH in the plasma, muscle, and sciatic nerve using liquid chromatography-mass spectrometry. After a simple protein precipitation procedure, analysis was performed on an Extend C18 column (100mm×3mm, 3.5μm) by isocratic elution with 0.05% formic acid/acetonitrile (78:22, v/v) at a flow rate of 0.3mL/min. A multiple-reaction monitoring mode at the transitions of m/z 279.1→102.1 for QX-OH and m/z 275.2→126.1 for an internal standard (ropivacaine hydrochloride) was used for the quantification, with a positive electrospray ionization interface. The approach was validated as per the U.S. Food and Drug Administration guidelines and successfully used in a pharmacokinetic study of QX-OH after a sciatic nerve block with 0.2mL of 35mM QX-OH. The results demonstrated that the new local anesthetic, QX-OH, had a high concentration in tissue, low systemic exposure, and long duration in the sciatic nerve.

ET-26 hydrochloride (ET-26HCl), a novel analog of etomidate, induces as effective sedation, with good cardiac and respiratory stability, as etomidate but with mild adrenocortical suppression. The objective of this study was to evaluate the potential adverse effects of ET-26HCl in rats. In a single-dose toxicity study, abnormal urine color (red) was observed in all groups: control (100%), 8 mg/kg (10%), 16 mg/kg (50%), and 20 mg/kg (70%) ET-26HCl, which returned to normal on the day of dosing. There were no mortalities or serious toxicological signs; the maximum tolerable dose of ET-26HCl was 20 mg/kg. In the repeated-dose toxicity study, deaths occurred in the 12- (13.33% of males) and 16-mg/kg/day (20% of males and 3.33% of females) groups. Abnormal urine color (red or brown) was detected in the control group (10%) and all treatment groups (30%, 46.67%, and 40% at 8, 12 and 16 mg/kg/day, respectively), at a frequency of 1.43% in the control group, 4.76% in 8 mg/kg/day, 7.62% in 12 mg/kg/day, and 4.29% in 16 mg/kg/day. Increases in neutrophils and plasma fibrinogen were temporary and recoverable effects. Macroscopic and histopathologic changes were found only at the injection sites: abnormal skin color, scabbing, thrombus, ulceration, and inflammation. During the recovery period, there was evidence of reversibility, including fibroblast proliferation and vessel recanalization. The no-observed-adverse-effect level of ET-26HCl was 8 mg/kg/day. Toxicokinetic variables of ET-26HCl, except the calculated initial concentration in females on Day 1, showed a dose-dependent increase to exposure, with no gender difference and no evidence of accumulation.

Etomidate is a sedative-hypnotic with excellent pharmacological effects, including rapid onset and hemodynamic stability. However, etomidate causes adrenocortical toxicity via binding to 11β-hydroxylase. Therefore, developing an approach to screen new etomidate analogues without endocrine-disrupting effects is urgently warranted. In this study, we employed the adrenocortical tumour cell line, NCI-H295R, as an in vitro system for etomidate analogues screening and detected the hormone levels in these cells using a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method. After obtaining the concentration-response curves of hormone release, the "Adrenocortical Inhibitory Index" was used to evaluate the adrenocortical inhibitory potency of each compound. In summary, we demonstrate the benefits of our methods for screening of etomidate analogues that lack adrenocortical suppression, especially when this in vitro system is combined with in vivo testing.

Background: ET-26 hydrochloride is a novel intravenous anesthetic, approved for clinical trials, that produces a desirable sedative-hypnotic effect with stable myocardial performance and mild adrenocortical suppression in rats and beagle dogs. The objective of this study was to assess the absorption, distribution, metabolism, and excretion of ET-26 hydrochloride. Methods: Hepatocytes from human, monkey, dog, rat, and mouse were used to determine the metabolites of ET-26 hydrochloride. Distribution and excretion were assessed in rats and pharmacokinetic studies were performed in beagle dogs. Results: The metabolic pathway and proposed structure of metabolites were fully assessed resulting from the biotransformation reactions of hydrolysis, dehydrogenation, demethylation and glucuronic acid conjugation. The main distribution of the drug was in fat (15067 ± 801 ng/ml) and liver (13647 ± 1126 ng/ml), and the kidney was the primary excretion route (4.47%-11.94%). The Cmax after injection with 1.045 mg/kg, 2.09 mg/kg, and 4.18 mg/kg was 1476.5 ± 138.9 ng/ml, 2846.1 ± 223.3 ng/ml, and 6233.3 ± 238.9 ng/ml, respectively. The t1/2 of the drug was similar across dose groups at 74.8 ± 10.8 min to 81.4 ± 4.2 min. The AUC0-t values were 30208.1 ± 2026.5 min*ng/ml, 62712.8 ± 1808.3 min*ng/ml, and 130465.2 ± 7457.4 min*ng/ml, respectively. Conclusion: The metabolic pathway and the proposed structure of metabolites for ET-26 hydrochloride were fully assessed. The majority of distribution for ET-26 hydrochloride occurs in the fat and liver, while the primary route of excretion for ET-26 hydrochloride is through the kidney. In dogs, pharmacokinetic features of ET-26 hydrochloride had a linear relationship with dosage.

Introduction: Previous studies demonstrated that 35 mM QX-OH/10 mM Levobupivacaine (LL-1), a fixed-dose combination, produced a long-acting effect in rat local anesthesia models. All preclinical pharmacodynamic results indicated that LL-1 had potential for postsurgical pain treatment. The objective of this study was to investigate the pharmacokinetics of LL-1. Then, the possible mechanism of the extended duration by the combination was examined. Methods and Results: All experiments were examined and approved by the Committee of Animal Care of the West China Hospital Sichuan University (Ethical approval number, 2015014A). The compound action potentials were recorded to verify the pharmacodynamic result in ex vivo. In frog sciatic nerve, LL-1 produced an effective inhibition with rapid onset time. The concentration-time profiles of LL-1 were determined in plasma and local tissues after sciatic nerve block. The maximum concentration of QX-OH and levobupivacaine were 727.22 ± 43.38 µg/g and 256.02 ± 28.52 µg/g in muscle, 634.26 ± 36.04 µg/g and 429.63 ± 48.64 µg/g in sciatic nerve, and 711.71 ± 25.14 ng/ml and 114.40 ± 10.19 ng/ml in plasma, respectively. The absorption of QX-OH into circulation was very rapid at 0.71 ± 0.06 h, which was faster than that of levobupivacaine (4.11 ± 0.39 h, p = 0.003). The half-time of QX-OH in plasma and local tissues had no significant difference (p = 0.329), with the values of 2.64 h, 3.20 h, and 3.79 h in plasma, muscle, and sciatic nerve, respectively. The elimination profile of levobupivacaine differed from that of QX-OH, which was slower eliminated from plasma (4.89 ± 1.77 h, p = 0.036) than from muscle (1.38 ± 0.60 h) or sciatic nerve (1.28 ± 0.74 h). When levobupivacaine was used alone, the Tmax in plasma was 1.07 ± 0.16 h. Interestingly, the Tmax of levobupivacaine in the plasma was increased by four times in combination with QX-OH (4.11 ± 0.39 h). Levobupivacaine promotes cellular QX-OH uptake. Conclusion: The preclinical pharmacokinetic study of LL-1 in the rat plasma, muscle, and sciatic nerve was accomplished. Then, the possible mechanism of the prolonged duration was that QX-OH delayed the absorption of levobupivacaine from the injection site into circulation, and levobupivacaine accelerated QX-OH to accumulate into cells.

Lung ischemia-reperfusion injury (LIRI) is a common and severe postoperative pathologic complication that often occurs when the oxygen supply disrupted to the lung tissue fallowed by reperfusion period, in most cases after lung transplantation and cardiopulmonary bypass. Endocannabinoids such as 2-arachidonoylglycerol (2-AG) have very important role as regulators of inflammation. Monoacylglycerol lipase (MAGL) is the main 2-AG-degrading enzyme, and the downstream metabolites of 2-AG play a role in the inflammation. Ischemia reperfusion (IR) was induced by clamping the left pulmonary hilum for 60 min, followed by 120 min of reperfusion in male C57BL/6 mice. Effects of URB602, a MAGL inhibitor, were evaluated in a preventive or therapeutic regimen (5 min before ischemia or reperfusion, respectively). Oxygenation index, wet-to-dry weight ratio and lung injury score were analyzed. Endocannabinoids including 2-AG, anandamide (AEA) and arachidonic acid (AA) levels, metabolites such as Prostaglandin I2 (PGI2), Thromboxane B2 (TXB2) and Leukotrienes B4 (LTB4) and inflammatory markers (Interleukin 6 (IL-6) andTumor necrosis factor-α (TNF-α)) in lung tissues were measured by using mass spectrometry or ELISA analyses. We found that IR increased the wet-to-dry weight ratio of lung and lung injury score and decreased oxygenation index as compared to the sham group. Moreover, treatment with URB602 in preventive or therapeutic regimen reduced the wet-to-dry weight ratio and lung injury score while increased oxygenation index when compared with the IR group, with a more improvement in the preventive regimen group. In addition, treatment with URB602 before ischemia increased 2-AG level but decreased metabolites (AA, PGI2, TXB2, LTB4) and inflammatory markers (IL-6, TNF-α). Thus, our study demonstrated that a pretreatment with URB602 significantly reduced IR-induced lung injury and inflammation. URB602 inhibited LIRI and inflammation by increasing 2-AG level and reducing downstream metabolites from AA to PGI2, TXB2 and LTB4 in lung tissues.

BACKGROUND Neuropathic pain is often associated with depression. Enhancing endocannabinoids by fatty acid amide hydrolase (FAAH) inhibitors relieves neuropathic pain and stress-induced depressive-like behaviors in animal models. However, it is unclear whether FAAH inhibitor can relieve neuropathic pain-induced depression by or not by its antinociceptive effects. METHODS Adult male Wistar rats with chronic constriction injury (CCI) to the sciatic nerve were treated with the systemic FAAH inhibitor URB597 (5.8 mg·kg·day, intraperitoneally) or peripherally acting FAAH inhibitor URB937 (1.6 mg·kg·d, intraperitoneally; n = 11-12). The treatment was applied from the 15th day after surgery and continued for 15 days. Mechanical withdrawal threshold was examined by Von Frey test before surgery and on the 28th day after CCI. Depressive-like behaviors were evaluated by forced swimming test (FST) and novelty-suppressed feeding (NSF) after 15-day treatment. The levels of anandamide and 2-arachidonoylglycerol in hippocampus were examined by liquid chromatography and mass spectrometry. Hippocampal neurogenesis including proliferation, differentiation, and survival of newborn cells was assessed by immunohistochemistry. RESULTS After CCI injury, the rats developed significantly nociceptive and depressive-like behaviors, indicated by persistent mechanical hypersensitivity in Von Frey test, significantly prolonged immobility time in FST (sham: 84.2 ± 13.4 seconds versus CCI: 137.9 ± 18.8 seconds; P < .001), and protracted latency to feed in NSF (sham: 133.4 ± 19.4 seconds versus CCI: 234.9 ± 33.5 seconds; P < .001). For the CCI rats receiving treatment, compared to vehicle placebo group, pain threshold was increased by both URB597 (3.1 ± 1.0 vs 11.2 ± 1.2 g; P < .001) and URB937 (3.1 ± 1.0 vs 12.1 ± 1.3 g; P < .001). Immobility time of FST was reduced by URB597 (135.8 ± 16.6 vs 85.3 ± 17.2 seconds; P < .001) but not by URB937 (135.8 ± 16.6 vs 129.6 ± 17.8 seconds; P = .78). Latency to feed in NSF was also reduced by URB597 (235.9 ± 30.5 vs 131.8 ± 19.8 seconds; P < .001) but not by URB937 (235.9 ± 30.5 vs 232.2 ± 33.2 seconds; P = .72). Meanwhile, CCI decreased the number of proliferating cells and reduced survival of new mature neurons in hippocampus. URB597 but not URB937 treatment improved these cellular deficits. CONCLUSIONS Inhibition of FAAH can improve depressive-like behaviors induced by neuropathic pain independent of its peripheral antinociceptive action. Enhanced neurogenesis in hippocampus might contribute to the antidepressive effects of URB597.

Mercury is a highly toxic environmental pollutant that negatively affects human health. Thus, an in vivo method for noninvasive imaging of mercury(II) and visualization of its accumulation within living systems would be advantageous. Herein, we describe a reaction-based bioluminescent probe for detection of mercury(II) in vitro and accumulation in vivo. The application of this probe would help to shed light on the intricate contributions of mercury(II) to various physiological and pathological processes.

Considering that hydrogen sulfide (H2S) is an endogenous signaling molecule involved in numerous biological processes, a method for monitoring H2S as a powerful tool for investigating its complicated functions and mechanisms is urgently demanded. Herein, a bioluminescent turn-on probe was reported based on caged strategy for the detection of H2S in vitro and in vivo. This probe will help us understand the intricate contribution of H2S to a variety of physiological and pathological processes.

A series of atypical asymmetric gemini surfactants with an amphiphilic carbonate group (–O–CO–O–) have been prepared. Some of these compounds could self-assemble in water into gourd-shaped Janus particles (JPs). Initial results suggested that the formation of JPs was highly likely to be related to their atypical gemini surfactant structure. To our knowledge, this is the first report on JPs that are self-assembled from a single kind of small organic molecule. We believe that our results will be utilized in many fields.

A rhodium complex with an amphiphilic, chiral surfactant-type ligand is applied to the asymmetric transfer hydrogenation of long-chained aliphatic ketoesters.

A series of amphiphilic ligands were designed and synthesized. The rhodium complexes with the ligands were applied to the asymmetric transfer hydrogenation of broad range of long-chained aliphatic ketoesters in neat water. Quantitative conversion and excellent enantioselectivity (up to 99% ee) was observed for α-, β-, γ-, δ- and e-ketoesters as well as for α- and β-acyloxyketone using chiral surfactant-type catalyst 2. The CH/π interaction and the strong hydrophobic interaction of long aliphatic chains between the catalyst and the substrate in the metallomicelle core played a key role in the catalytic transition state. Synergistic effects between the metal-catalyzed site and the hydrophobic microenvironment of the core in the micelle contributed to high stereoselectivity.