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Pyroptosis is a gasdermin-mediated programmed necrosis that occurs via membrane perforation and that can be exploited for biomedical applications in cancer therapy. However, inducing specific pyroptotic cancer cell death while sparing normal cells is challenging. Here, we report an acid-activatable nanophotosensitizer library that can be used to spatiotemporally target distinct stages of endosomal maturation, enabling tunable cellular pyroptosis. Specific activation of phospholipase C signalling transduction in early endosomes triggers gasdermin-E-mediated pyroptosis, which is dramatically reduced when acid-activatable nanophotosensitizers are transported into late endosomes/lysosomes. This nanotuner platform induces pyroptotic cell death with up to 40-fold tunability in various gasdermin-E-positive human cancers, resulting in enhanced anti-tumour efficacy and minimized systemic side effects. This study offers new insights into how to engineer nanomedicines with tunable pyroptosis activity through specific targeting of distinct endocytic signalling for biomedical applications.

Toll-like receptor (TLR) agonists are potent immune-stimulators that hold great potential in vaccine adjuvants as well as cancer immunotherapy. However, TLR agonists in free form are prone to be eliminated quickly by the circulatory system and cause systemic inflammation side effects. It remains a challenge to achieve precise release of TLR7/8 agonist in the native form at the receptor site in the endosomal compartments while keeping stable encapsulation and inactive in nontarget environment. Here, we report a pH-/enzyme-responsive TLR7/8 agonist-conjugated nanovaccine (TNV), which responds intelligently to the acidic environment and cathepsin B in the endosome, precisely releases TLR7/8 agonist to activate its receptor signaling at the endosomal membrane, stimulates DCs maturation, and provokes specific cellular immunity. In vivo experiments demonstrate outstanding prophylactic and therapeutic efficacy of TNV in mouse melanoma and colon cancer. The endosome-targeted responsive nanoparticle strategy provides a potential delivery toolbox of adjuvants to advance the development of tumor nanovaccines.

An efficient nickel-catalyzed cross-coupling for the synthesis of 2-sulfonylthiazoles from readily available 2-chlorobenzothiazoles and sodium sulfinates has been developed. A variety of 2-chlorobenzothiazoles and sulfinates having a diverse range of substitution patterns can undergo the coupling process successfully at room temperature. Avoiding the use of precious catalysts and sensitive ligands, moderate to excellent yields of various 2-sulfonylthiazoles were observed.

Multiple organ failure (MOF) is the main cause of early death in septic shock. Lungs are among the organs that are affected in MOF, resulting in acute lung injury. Inflammation is an important factor that causes immune cell dysfunction in the pathogenesis of sepsis. Autophagy is involved in the process of inflammation and also occurs in response to cell and tissue injury in several diseases. We previously demonstrated that hydrogen alleviated the inflammation-induced cell injury and organ damage in septic mice. The focus of the present study was to elucidate whether mitophagy mediates the inflammatory response or oxidative injury in sepsis in vitro and in vivo. Furthermore, we evaluated the role of mitophagy in the protective effects of hydrogen against cell injury or organ dysfunction in sepsis. RAW 264.7 macrophages induced by lipopolysaccharide (LPS) were used as an in vitro model for inflammation, and cecal ligation and puncture (CLP)-induced acute lung injury mice were used as an in vivo model for sepsis. The key protein associated with mitophagy, PTEN-induced putative kinase 1 (PINK1), was knocked down by PINK1 shRNA transfection in RAW 264.7 macrophages or mice. Hydrogen ameliorated cell injury and enhanced mitophagy in macrophages stimulated by LPS. PINK1 was required for the mitigation of the cell impairment in LPS-stimulated macrophages by hydrogen treatment. PINK1 knockdown abrogated the beneficial effects of hydrogen on mitophagy in LPS-stimulated macrophages. Hydrogen inhibited acute lung injury in CLP mice via activation of PINK1-mediated mitophagy. These results suggest that PINK1-mediated mitophagy plays a key role in the protective effects of hydrogen against cell injury in LPS-induced inflammation and CLP-induced acute lung injury.

Anticancer immunotherapy is hampered by poor immunogenicity and a profoundly immunosuppressive microenvironment in solid tumors and lymph nodes. Herein, sequential pH/redox-responsive nanoparticles (SRNs) are engineered to activate the immune microenvironment of tumor sites and lymph nodes. The two-modular SRNs could sequentially respond to the acidic tumor microenvironment and endosome compartments of dendritic cells (DCs) to precisely deliver doxorubicin (DOX) and imidazoquinolines (IMDQs). In the tumor microenvironment, released DOX triggers immunogenic cell death. In sentinel lymph nodes, the IMDQ nanoparticle module is dissociated in the acidic endosome compartment to specifically stimulate toll-like receptor 7/8 for DC maturation. Thus, the orchestrated nanoparticle system could enhance the infiltration of CD8α+ T cells in tumors and provoke a strong antitumor immune response toward primary and abscopal tumors in B16-OVA and CT26 tumor-bearing mice models. The cooperative self-assembled nanoparticle strategy provides a potential candidate of nanomedicine to advance the synergistic cancer chemo-immunotherapy.

Fast and simple detection of C-reactive protein (CRP) is highly significant for the diagnosis and prognosis of inflammatory or infectious diseases. Lateral flow immunoassay has the advantages of rapid detection, simple operation and low cost, but it is usually limited by the quantitative ability and speed of data extraction. Herein, a gold-nanorod-based lateral flow immunoassay was developed to rapidly detect CRP by simultaneously monitoring the colorimetric and temperature signals. In this method, anti-CRP antibody-modified gold nanorods (GNRs) were designed as colorimetric and photothermal conversion probes. A mouse anti-CRP monoclonal antibody and goat anti-mouse IgG were used as test and control lines, respectively. Then, a lateral flow immunochromatographic strip was constructed by a sandwich-type method for detecting CRP by introducing antibody-modified GNRs, and this procedure needed less than 15 min. Finally, the detection signals can be directly observed by eyes and directly read using a thermal imager. The as-synthesized GNR showed high photothermal conversion efficiency (η = 39%) and strong localized surface plasmon resonance (LSPR) absorption. For CRP detection, the proposed immunochromatographic strip exhibited good specificity, high sensitivity, good linearity within the range of 50–10 000 ng mL−1 and a low limit of detection (LOD, 1.3 ng mL−1). This method was successfully applied for CRP detection in clinical plasma samples, and it correlated very well with the diagnostic kit of immunoturbidimetry (r = 0.96). The results indicated that the developed GNR-based immunochromatographic strip has immense potential for use as a rapid and cost-effective in vitro diagnostic kit.

In vitro detection of low abundance biomolecules including microRNAs (miRNAs) is essential to biological research and early clinical diagnosis. In this work, a versatile magnetic bead (MB)-based flow cytometric assay was developed for the detection of hsa-miR-221-3p, which is strongly associated with papillary thyroid carcinoma (PTC). In the presence of hsa-miR-221-3p, the complementary DNA probe attached to the surface of MBs is hybridized with the target to form DNA/RNA heteroduplexes. After the recognition of the DNA/RNA heteroduplexes by PicoGreen, the fluorescence signals of each MB were readily detected using a flow cytometer. This assay can selectively detect hsa-miR-221-3p with a detection limit of 2.1 pM. The practicality of the assay is demonstrated by the discrimination of thyroid cancer tissues from normal tissues, and a satisfactory result is obtained. Moreover, this assay can be rapidly carried out in one step at room temperature, providing a generic method for the sensitive detection of miRNAs in molecular diagnosis.

Polymer-drug conjugates (PDCs) fabricated as nanoparticles have hogged the limelight in cancer theranostics in the past decade. Many researchers have devoted to developing novel and efficient polymeric drug delivery system since the first generation of poly(N-[2-hydroxypropyl]methacrylamide) copolymer-drug conjugates. However, none of them has been approved for chemotherapy in clinic. An ideal PDC nanoparticle for cancer theranostics should possess several properties, including prolonged circulation in blood, sufficient accumulation and internalization in tumors, and efficient drug release in target sites. To achieve these goals, it is important to rationally design the nanoparticulate PDCs based on circulation, accumulation, penetration, internalization, and drug release (CAPIR) cascade. Specifically, CAPIR cascades are divided into five steps: (1) circulation in the vascular compartment without burst release, (2) accumulation in tumors via enhanced permeability and retention effect, (3) subsequent penetration into the deep regions of tumors, (4) internalization into tumor cells, and (5) release of drugs as free molecules to exert their pharmacological effects. In this review, we focus on the development and novel approaches of nanoparticulate PDCs based on CAPIR cascade, and provide an outlook on future clinical application. This article is categorized under: Therapeutic Approaches and Drug DiscoveryNanomedicine for Oncologic Disease.

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. It has been showed that the change of mitochondrial dynamics has been proved to be one of the main causes of death in patients with severe sepsis. And hydrogen has been proved to exert its protective effects against sepsis via heme oxygenase-1 (HO-1). This study was designed to demonstrate that whether the benefit effects of hydrogen can maintain the dynamic process of mitochondrial fusion/fission to mitigate human umbilical vein endothelial cells (HUVECs) injury exposed to endotoxin through HO-1.HUVECs cells cultured with medium which contained Lipopolysaccharides (LPS), Saline, hydrogen, Mdivi-1 (a dynamin-related protein 1 [Drp1] inhibitor) or zinc protoporphyrin IX (Znpp) (a HO-1 inhibitor) were also used in the research. Cell death and apoptosis were assessed using FITC annexin V and PI. Mitochondria were stained with Mitotracker orange and observed by confocal microscope. Oxygen consumption rate was assessed by seahorse xf24 extracellular analyzer. Mitochondrial membrane potential monitored by JC-1 dye. The expressions of Drp1 and HO-1 were tested by Western blot. The co-localization of Drp1 and mitochondria was determined by immunofluorescence.LPS caused a decrease in ATP content, mitochondrial membrane potential, and maximal respiration rate. At the same time, increased expression of Drp1 were observed in LPS-stimulated HUVECs, concomitantly with excessive mitochondrial fission. We found that hydrogen-rich medium can increase ATP content, mitochondrial membrane potential and maximal respiration rate, and decrease the expression of Drp1 in LPS-treated HUVECs. Meanwhile, hydrogen can ameliorate excessive mitochondrial fission caused by LPS. Furthermore, hydrogen-rich medium had a similar effect to Mdivi-1, a mitochondrial fission blocker. Both of them rescued the up-regulation of Drp1 and mitochondrial fission induced by LPS, then normalized mitochondrial shape after LPS stimulation. But after Znpp pretreatment, HO-1 expression was inhibited and the protective effects of hydrogen were abrogated.Hydrogen-rich medium can alleviate the LPS-induced mitochondrial fusion/fission and dysfunction in HUVECs via HO-1 up-regulation.

Objective Sepsis-associated intestinal injury has a higher morbidity and mortality in patients with sepsis, but there is still no effective treatment. Our research team has proven that inhaling 2% hydrogen gas (H2) can effectively improve sepsis and related organ damage, but the specific molecular mechanism of its role is not clear. In this study, isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics analysis was used for studying the effect of H2 on intestinal injury in sepsis. Methods Male C57BL/6J mice were used to prepare a sepsis model by cecal ligation and puncture (CLP). The 7-day survival rates of mice were measured. 4-kd fluorescein isothiocyanate-conjugated Dextran (FITC-dextran) blood concentration measurement, combined with hematoxylin-eosinstain (HE) staining and Western blotting, was used to study the effect of H2 on sepsis-related intestinal damage. iTRAQ-based liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis was used for studying the proteomics associated with H2 for the treatment of intestinal injury. Results H2 can significantly improve the 7-day survival rates of sepsis mice. The load of blood and peritoneal lavage bacteria was increased, and H2 treatment can significantly reduce it. CLP mice had significant intestinal damage, and inhalation of 2% hydrogen could significantly reduce this damage. All 4194 proteins were quantified, of which 199 differentially expressed proteins were associated with the positive effect of H2 on sepsis. Functional enrichment analysis indicated that H2 may reduce intestinal injury in septic mice through the effects of thyroid hormone synthesis and nitrogen metabolism signaling pathway. Western blot showed that H2 was reduced by down-regulating the expressions of deleted in malignant brain tumors 1 protein (DMBT1), insulin receptor substrate 2 (IRS2), N-myc downregulated gene 1 (NDRG1) and serum amyloid A-1 protein (SAA1) intestinal damage in sepsis mice. Conclusion A total of 199 differential proteins were related with H2 in the intestinal protection of sepsis. H2-related differential proteins were notably enriched in the following signaling pathways, including thyroid hormone synthesis signaling pathway, nitrogen metabolism signaling pathways, digestion and absorption signaling pathways (vitamins, proteins and fats). H2 reduced intestinal injury in septic mice by down-regulating the expressions of SAA1, NDRG1, DMBT1 and IRS2.

Sevoflurane may exert neurotoxic effects on the developing brain. Coenzyme Q10 (CoQ10) has been reported to reduce sevoflurane anesthesia‑induced cognitive deficiency in 6‑day‑old mice. However, its specific mechanisms remain unknown. Apolipoprotein E (ApoE) has been reported to lead to the initiation of neurodegeneration in patients with Alzheimer's disease (AD) and may serve an important role in anesthesia‑induced neurotoxicity. The present study aimed to reveal the role of ApoE in the pathogenesis of tau protein hyperphosphorylation and neuroinflammation enhancement caused by sevoflurane anesthesia, as well as the protective mechanism of CoQ10 in an anesthetic sevoflurane treatment model of primary mouse hippocampal neurons. For that purpose, the neurons were randomly assigned to the following groups: i) Control; ii) sevoflurane; iii) control+corn oil; iv) sevoflurane+corn oil; v) control+CoQ10; and vi) control+CoQ10. CoQ10 or corn oil alone was added to the medium on day 4 of neuron culture. The neurons in the sevoflurane group were treated with 21% O2, 5% CO2 and 4.1% sevoflurane for 4 h, whereas the control group only with 21% O2 and 5% CO2 on day 5. Samples were collected immediately after anesthesia or control treatment. ATP, superoxidase dismutase (SOD)1, ApoE mRNA, total ApoE, full‑length ApoE, ApoE fragments, Tau5, Tau‑PS202/PT205 (AT8), Tau‑PSer396/404 (PHF1), tumor necrosis factor (TNF)‑α, interleukin (IL)‑6 and IL‑1β levels were measured with ELISA, quantitative PCR, western blotting and immunocytochemistry. The results of the present study indicated that sevoflurane anesthesia significantly decreased the ATP and SOD levels, but increased ApoE mRNA, total ApoE protein, full‑length ApoE, ApoE fragments, phosphorylated tau (AT8 and PHF1) and neuroinflammatory factor (TNF‑α, IL‑6 and IL‑1β) expression levels compared with those in the control group. The use of CoQ10 reversed the expression of these factors. These results suggested that sevoflurane treatment damaged mouse hippocampal neurons, which may be associated with the expression of ApoE and its toxic fragments. CoQ10 improved energy replenishment and inhibited oxidative stress, which may lead to a decrease in ApoE and phosphorylated tau protein expression, thus mitigating the sevoflurane‑induced neuroinflammation in mouse hippocampal neurons.

Sepsis-associated encephalopathy (SAE) is a major cause of mortality worldwide. Oxidative stress, inflammatory response and apoptosis participate in the pathogenesis of SAE. Nuclear factor erythroid 2-related factor 2 (Nrf2) and nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) pathway is involved in oxidative stress and inflammatory response. We reported that hydrogen gas protected against sepsis in wild-type (WT) but not Nrf2 knockout (KO) mice. Therefore, it is vital to identify the underlying cause of hydrogen gas treatment of sepsis-associated encephalopathy. SAE was induced in WT and Nrf2 KO mice by cecal ligation and puncture (CLP). As a NLRP3 inflammasome inhibitor, MCC950 (50 mg/kg) was administered by intraperitoneal (i.p.) injection before operation. Hydrogen gas (H2)-rich saline solution (5 mL/kg) was administered by i.p. injection at 1 h and 6 h after sham and CLP operations. Brain tissue was collected to assess the NLRP3 and Nrf2 pathways by western blotting, reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence. SAE increased NLRP3 and Nrf2 expression in microglia. MCC950 inhibited SAE-induced NLRP3 expression, interleukin (IL)-1β and IL-18 cytokine release, neuronal apoptosis and mitochondrial dysfunction. SAE increased NLRP3 and caspase-1 expression in WT mice compared to Nrf2 KO mice. Hydrogen increased Nrf2 expression and inhibited the SAE-induced expression of NLRP3, caspase-1, cytokines IL-1β and IL-18, neuronal apoptosis, and mitochondrial dysfunction in WT mice but not Nrf2 KO mice. SAE increased NLRP3 and Nrf2 expression in microglia. Hydrogen alleviated inflammation, neuronal apoptosis and mitochondrial dysfunction via inhibiting Nrf2-mediated NLRP3 pathway.

A facile method has been developed for the rapid and efficient enrichment of DNAs from different media including synthetic single-strand DNAs (ssDNAs) from buffer solutions and cell-free DNAs (cfDNAs) from blood plasma through electric field-driven adsorption and desorption of DNAs by a polyacrylamide/phytic acid/polydopamine (PAAM/PA/PDA) hydrogel. The as-prepared PAAM/PA/PDA hydrogel possesses regular porosity with a large surface area, strong electric field responsiveness/good conductivity, and a rich aromatic structure, which can be used as an ideal adsorbent for DNA enrichment under a positive electric field. The enriched DNAs can be released efficiently when the positive electric field is converted to a negative electric field. The PAAM/PA/PDA hydrogel-based electrochemical method enables the completion of the process of DNA adsorption and release within 5 min and exhibits reasonable enrichment efficiencies and recovery rates of various DNAs. For instance, the high enrichment sensitivity (0.1 pmol L-1) together with the excellent recovery (>75%) of an ssDNA with 78 nucleotides is obtained. Combined with the PCR amplification technique, the practicability of the as-proposed method is demonstrated by the screening of circulating tumor DNAs (ctDNAs) with a BRAFV600E mutation in cfDNAs from the blood plasma samples of patients with papillary thyroid cancer or thyroid nodule and random patients from a clinical laboratory.

Thermohydrogen processing (THP) is an attractive technique that uses hydrogen as a temporary alloying element to modify the microstructure and properties of titanium alloys. However, the hydrogen diffusion behavior during THP is not fully understood owing to limited scope of methods to detect hydrogen distributions. Herein, we introduce neutron tomography as an efficient tool for three-dimensional (3D) hydrogen distribution analysis and quantitative determination in hydrogenated titanium alloys after THP. Thus motivated, a series of calibration samples of Ti-6Al-4V alloys with varying hydrogen contents were prepared and elaborated neutron tomography experiments and image data processing were performed. In this way, the 3D hydrogen distribution of the hydrogenated samples was obtained and the quantitative relationship between the hydrogen contents and the tomographic images was determined. To the best of our knowledge, this enabled for the first time the direct 3D visualization and characterization of the hydrogen distribution and concentration in titanium alloys after THP. It was deduced that hydrogen diffused from the surface to the interior of the hydrogenated sample in all directions during THP. In addition, the feasibility of neutron tomography for 3D quantitative hydrogen distribution was validated using continuous sample segmentation and the traditional heat conductivity method. Consequently, neutron tomography can be efficient for determining the hydrogen distribution and concentration in bulk metals and shed light on the hydrogen diffusion behavior and the mechanism of hydrogen-related materials and processing.

Efficient delivery of payload to intracellular targets has been identified as the central principle for nanomedicine development, while the extracellular targets are equally important for cancer treatment. Notably, the contribution of extracellularly distributed nanoparticles to therapeutic outcome is far from being understood. Herein, we develop a pH/light dual-responsive monochromatic ratiometric imaging nanoparticle (MRIN), which functions through sequentially lighting up the intracellular and extracellular fluorescence signals by acidic endocytic pH and near-infrared light. Enabled by MRIN nanotechnology, we accurately quantify the extracellular and intracellular distribution of nanoparticles in several tumor models, which account for 65-80% and 20-35% of total tumor exposure, respectively. Given that the majority of nanoparticles are trapped in extracellular regions, we successfully dissect the contribution of extracellularly distributed nanophotosensitizer to therapeutic efficacy, thereby maximize the treatment outcome. Our study provides key strategies to precisely quantify nanocarrier microdistribtion and engineer multifunctional nanomedicines for efficient theranostics.

Neuropathic pain is a complication after a spinal nerve injury. The inflammasomes are now identified to be responsible for triggering inflammation in neuropathic pain. Autophagy participates in the process of neuropathic pain and can regulate the inflammasome activation in different diseases. Our previous research reported that hydrogen exerted a protective effect against neuropathic pain. Therefore, we focused on the mechanism and role of autophagy and inflammasome, by which hydrogen alleviated the hyperpathia induced by neuropathic pain. The results showed that neuropathic pain stimulated activation of inflammasome NLRP3 and autophagy pathway in the microglial cells of the spinal cord. The inhibition of NLRP3 inhibited the hyperpathia induced by spinal nerve litigation surgery. The absence of autophagy aggravated the inflammasome activity and hyperpathia. Hydrogen promoted autophagy related protein expression, inhibited the inflammasome NLRP3 pathway activation, and relieved the hyperpathia induced by neuropathic pain. Hydrogen treatment could alleviate hyperpathia by autophagy-mediated NLRP3 inactivation.

Herein, an array-based in situ fluorescence assay is proposed for high-throughput analysis and localization of multiplex matrix metalloproteinases (MMPs) activities in cell monolayers and tissue sections. Five specific MMPs (MMP-2, -3, -7, -9, and -14) peptide substrates containing FAM/Dabcyl fluorescent resonance energy transfer (FRET) pair are directly spotted on the surface of cell monolayers or tissue sections, and hydrolyzed by localized MMPs, resulting in fluorescence recovery of FAM. MMPs activities are determined by the fluorescence intensity of stained cells/tissues due to the cellular internalization of peptide fragments with FAM moiety. We demonstrate that the array-based in situ fluorescence assay is suitable for identifying the MMPs expression patterns of cells, as well as determining the secreted MMPs activities in cell monolayer with high sensitivity (as low as hundreds of cells per square centimeter). The feasibility of the assay is further confirmed by evaluating inhibition potencies of six compounds toward five MMPs. Profiling of five MMPs activities in the localized parts of 32 thyroid tissues is performed without separation or extraction procedures, demonstrating the good practicality of the method.

The macrophage is an innate immune response cell that plays an important role in the development of sepsis. Dexmedetomidine (DEX) is a sedation drug, which have anti-oxidative, anti-inflammatory and anti-apoptosis effects and can be used on sepsis patients in the ICU. However, its mechanisms of action remain poorly understood. PTEN-induced putative kinase 1 (PINK1) is a mitochondrial serine/threonine protein kinase that recognizes damaged mitochondria and leads to mitophagy. This study investigated the effects of DEX on Lipopolysaccharides(LPS)-induced macrophage injury and explained the underlying mechanisms. The results showed that LPS treatment caused mitochondrial damage, mitochondria-dependent apoptosis and PINK1-mediated mitophagy; at the same time, PINK1 has a protective effect on LPS-induced macrophage apoptosis and inflammation by mitophagy that eliminates dysfunctional mitochondria. DEX could promote the clearance of damaged mitochondria characterized by low Mitochondrial membrane potential (MMP) and high reactive oxygen species(ROS), thus exerting a protective effect in LPS treated macrophages, and PINK1 mediated mitophagy is required for this protective effect.

Thermosensitive liposomes (TSLs) have been widely investigated for controlled drug release at specific pathophysiological sites. Although excellent thermo-sensitivity under hyperthermia (HT) was already realized for TSLs, their in vivo stability under physiological temperature still remains challenging. To overcome this limitation, optimized polymer-based thermosensitive liposomes (P-TSLs) with good thermo-sensitivity as well as satisfactory in vivo stability were developed in this study for tumor-specific controlled delivery of doxorubicin (DOX). In particular, polymers including p(NIPAM-r-HPMA) and p(HPMA-r-APMA) were successfully synthesized based on a reversible addition–fragmentation chain transfer (RAFT) technique. Next, thermosensitive polymer p(NIPAM-r-HPMA) was first proposed to be inserted into the lipid bilayer of TTSL by a postinsertion method. The resulting P-TTSL had a phase transition temperature (Tm) of around 42 °C and displayed excellent thermo-sensitivity under HT: nearly 70% of DOX was...

Singlet oxygen (1O2) plays a vital role in pathophysiological processes and is the dominant executor of photodynamic therapy (PDT). Several small molecular probes have been designed to detect singlet oxygen for the evaluation of PDT efficacy. However, little attention was paid to the precise visualization of the 1O2 signal at the subcellular organelle level in living biological systems. Herein, a super-pH-resolved (SPR) nanosensor was developed to specifically illuminate 1O2 in endocytic organelles through encoding the cell-impermeant singlet oxygen sensor green (SOSG) into pH-sensitive micelles. The acid-activatable SPR-SOSG achieved more than 10-fold amplification of the 1O2 signal, leading to extremely higher sensitivity of singlet oxygen detection in specific endocytic organelles of living cells and animals, as compared with the nonactivatable nanoprobe and the commercially available 2',7'-dichlorofluorescein diacetate (DCFH-DA) probe. Hence, the SPR-SOSG nanoplatform provides a promising tool to evaluate the efficacy and mechanism of nanocarrier-based photodynamic therapy.

Background and aims The lung is the first organ to fail in sepsis. Our previous studies have proven that 2% molecular hydrogen (H2) inhalation remain a protective effect on a septic animal model via its anti-inflammatory and anti-apoptosis properties. This current research aims to observe the therapeutic effect of high concentration hydrogen (67%, HCH) on lipopolysaccharide (LPS) induced acute lung injury (ALI), and further investgate the role of Nrf2 signaling pathway. Methods ALI model was induced by LPS areosol inhalation. HCH were treated for 1 h at 1 and 6 h after modelling. Lung tissues and bronchoalveolar lavage fluid (BALF) were collected 4 and 24 h after the exposure of LPS. The histological scores, wet/dry weight ratios, myeloperoxidase (MPO) activity, protein content and cytokine levels in BALF, apoptosis condition of lung cells, expression of Nrf2 and NF-κB were assessed in both wild type and Nrf2-knockout mice. Results HCH Inhalation significantly alleviated LPS-induced pathological alterations of lung, and reduced the protein concentration, the wet/dry weight ratio, and the MPO activity of lung tissue. HCH Inhalation improved LPS-induced increasement in caspase-3 activity and the number of TUNEL-positive cells. HCH inhalation attenuated the LPS induced increased total cell content and polymorphonuclear granulocyte content, and pro-inflammatory cytokines, Nrf2 and NF-κB expression. HCH could not produce protective effct in Nrf2-knockout mice. Conclusion HCH can effectively alleviate LPS-induced ALI, which may be related to activation of Nrf2 signaling pathway and inhibition of inflammatory response and cell apoptosis mediated by NF-κB.

Active‐targeted nanoparticles are attractive carriers due to their potentials to facilitate specific delivery of drugs into tumor cells while sparing normal cells. However, the therapeutic outcomes of active‐targeted nanomedicines are hampered by the multiple physiological barriers in the tumor microenvironment (TME). Herein, an epidermal growth factor receptor‐targeted ultra‐pH‐sensitive nanophotosensitizer is fabricated, and the regulation of the TME to augment the active targeting ability and therapeutic efficacy is pinpointed. The results reveal that tumor vasculature normalization with thalidomide indiscriminately enhance the tumor accumulation of passive and active targeted nanoparticles, both of which are sequestered in the stromal bed of tumor mass. Whereas, photoablation of stromal cells located in perivascular regions significantly improves the accessibility of antibody‐modified nanophotosensitizer to receptor‐overexpressed cancer cells. After sequential regulation of TME, the antitumor efficacy of antibody‐modified nanophotosensitizer is drastically enhanced through synergistic enhancements of tumor accumulation and cancer cell accessibility of active‐targeted nanoparticles. The study offers deep insights about the intratumoral barriers that hinder the active‐targeted nanoparticles delivery, and provides a basis for developing more effective strategies to accelerate the clinical translation of active‐targeted nanomedicines., Sequential regulations of tumor microenvironment by thalidomide and pre‐photodynamic therapy (pre‐PDT) treatments are exploited to achieve synergistic enhancements of tumor accumulation and cancer cell accessibility of epidermal growth factor receptor (EGFR)‐targeted micelle, thereby improve the targeting ability and therapeutic outcome of the active‐targeted nanoparticles.

The mechanism underlying the high incidence of remifentanil-induced postoperative hyperalgesia is unclear. Also, no effective prevention method exists. Inflammatory pain-related studies showed that P2X4 purinergic receptors (P2X4Rs) in the dorsal horn of the spinal cord and dorsal root ganglia are essential for maintaining allodynia caused by inflammation. However, little is known about its role in opioid-induced hyperalgesia. This study aimed to determine the role of P2X4R and related signaling pathways in the remifentanil-induced postoperative hyperalgesia (RIH) model. The study simulated the remifentanil infusion and surgical incision during general anesthesia. The mRNA and protein expression level of P2X4R in rats with RIH model increased from 2 h to 48 h after the surgery. The administration of P2X4R inhibitors prevented the occurrence of RIH, resulting in a reduction in mechanical and thermal pain. Moreover, P2X4R was involved in RIH in male and female rats, indicating no sex-specific difference. P2X4R also increased the expression of AMPA receptor subunit GluA1 in a brain-derived neurotrophic factor (BDNF) / tyrosine receptor kinase B (TrkB) dependent manner. The results from whole-cell patch-clamp recording suggested that P2X4R also regulated AMPA receptor-mediated miniature excitatory postsynaptic currents and participated in the synaptic plasticity of spinal dorsal horn neurons. In summary, P2X4R was involved in AMPAR expression, electrophysiological function, and synaptic plasticity of spinal dorsal horn neurons through BDNF/TrkB signaling. This might be the mechanism underlying RIH, and hence inhibition of P2X4R might be a potential treatment strategy.

Background Dexmedetomidine, a potent α2-adrenoceptor agonist with analgesic, sedative, anti-inflammatory, and anti-apoptotic effects, is commonly used in patients with critical illness in intensive care units. Accumulating evidence indicates that dexmedetomidine can protect against intestinal dysfunction. However, the specific mechanisms of its protective effects against burn-induced intestinal barrier injury remain unclear. Here, we aimed to explore the possible positive effects of dexmedetomidine on burn-induced intestinal barrier injury and the role of the myosin light chain kinase (MLCK)/phosphorylated myosin light chain (p-MLC) signalling pathway in an experimental model of burn injury.Methods In this study, the intestinal permeability of burn-induced intestinal barrier damage was assessed by estimating the plasma concentration of 4.4 kDa fluorescein isothiocyanate-labelled dextran (FITC-dextran). Histological changes were evaluated using haematoxylin and eosin (HE) staining. Tight junction proteins were evaluated by western blot and immunofluorescence analyses to assess the structural integrity of intestinal tight junctions. The level of inflammation was determined by enzyme-linked immunosorbent assay (ELISA).Results Our findings demonstrated that the increase in intestinal permeability caused by burn injury is accompanied by histological damage to the intestine, decreases in the expression of the tight junction proteins Zonula Occludens-1 (ZO-1) and Occludin, increases in inflammatory cytokine levels and elevation of both MLCK protein expression and MLC phosphorylation. After dexmedetomidine treatment, the burn-induced changes were ameliorated.Conclusions In conclusion, dexmedetomidine exerted an anti‑inflammatory effect and protected tight junction complexes against burn‑induced intestinal barrier damage by inhibiting the MLCK/p-MLC signalling pathways, suggesting that it may be an effective drug in the treatment of burn-induced intestinal injury.Trial registration Not appliance.