Stimuli-Responsive Polymersomes: Reshaping the Immunosuppressive Tumor Microenvironment.

The progression of cancer involves mutations in normal cells, leading to uncontrolled division and tissue destruction, highlighting the complexity of tumor microenvironments (TMEs). Immunotherapy has emerged as a transformative approach, yet the balance between efficacy and safety remains a challenge. Nanoparticles such as polymersomes offer the possibility to precisely target tumors, deliver drugs in a controlled way, effectively modulate the antitumor immunity, and notably reduce side effects. Herein, stimuli-responsive polymersomes, with capabilities for carrying multiple therapeutics, are highlighted for their potential in enhancing antitumor immunity through mechanisms like inducing immunogenic cell death and activating STING (stimulator of interferon genes), etc. The recent progress of utilizing stimuli-responsive polymersomes to reshape the TME is reviewed here. The advantages and limitations to applied stimuli-responsive polymersomes are outlined. Additionally, challenges and future prospects in leveraging polymersomes for cancer therapy are discussed, emphasizing the need for future research and clinical translation.

A polymeric nanoplatform enhances the cGAS-STING pathway in macrophages to potentiate phagocytosis for cancer immunotherapy.

Immunosuppressive tumor-associated macrophages (TAMs) account for a high proportion of the tumor tissue and significantly impede immunoefficacy. Furthermore, the signal regulatory protein α (SIRPα) expressed in TAMs adversely correlates with macrophage activation and phagocytosis, resulting in immunosurveillance escape. To address these difficulties, a mannose-modified, pH-responsive nanoplatform with resiquimod (R848) and 2', 3'-cyclic GMP-AMP (cGAMP) co-encapsulation (named M-PNP@R@C) is designed to polarize TAMs and lower SIRPα expression. The co-delivery of R848 and cGAMP synergistically facilitates the polarization of TAMs from the anti-inflammatory M2 phenotype into the pro-inflammatory M1 phenotype, thereby enhancing antitumor immunotherapy. Remarkably, activation of the cGAMP-mediated stimulator of interferon genes (STING) in TAMs significantly downregulates the expression of SIRPα, which synergizes with the cluster of differentiation 47 (CD47) antibody for the dual blockade of the CD47-SIRPα axis. Further analysis of single-cell RNA sequencing indicates that STING activation downregulates SIRPα by regulating intracellular fatty acid oxidation metabolism. In vivo studies indicate that M-PNP@R@C significantly inhibits tumor growth with a potent antitumor immune response in melanoma graft tumor models. After synergy with anti-CD47, the double blockade strategies of the SIRPα/CD47 axis result in a notable inhibition of lung metastasis. A prolonged survival rate is observed after combination treatment with CD47 and programmed death ligand-1 antibodies for the triple immune checkpoint blockade. In summary, our study provides original insights into the potential role of the STING pathway in macrophage-based immunotherapy, thus offering a potential combinatorial strategy for cancer therapy.

RPLP1 restricts HIV-1 transcription by disrupting C/EBPß binding to the LTR.

Long-term non-progressors (LTNPs) of HIV-1 infection may provide important insights into mechanisms involved in viral control and pathogenesis. Here, our results suggest that the ribosomal protein lateral stalk subunit P1 (RPLP1) is expressed at higher levels in LTNPs compared to regular progressors (RPs). Functionally, RPLP1 inhibits transcription of clade B HIV-1 strains by occupying the C/EBPß binding sites in the viral long terminal repeat (LTR). This interaction requires the α-helixes 2 and 4 domains of RPLP1 and is evaded by HIV-1 group M subtype C and group N, O and P strains that do not require C/EBPß for transcription. We further demonstrate that HIV-1-induced translocation of RPLP1 from the cytoplasm to the nucleus is essential for antiviral activity. Finally, knock-down of RPLP1 promotes reactivation of latent HIV-1 proviruses. Thus, RPLP1 may play a role in the maintenance of HIV-1 latency and resistance to RPLP1 restriction may contribute to the effective spread of clade C HIV-1 strains.

Beyond Immune Balance: The Pivotal Role of Decidual Regulatory T Cells in Unexplained Recurrent Spontaneous Abortion.

Recurrent spontaneous abortion (RSA) is defined as two or more consecutive pregnancy failures, which brings tremendous stress to women of childbearing age and seriously affects family well-being. However, the reason in about 50% of cases remains unknown and is defined as unexplained recurrent spontaneous abortion (URSA). The immunological perspective in URSA has attracted widespread attention in recent years. The embryo is regarded as a semi-allogeneic graft to the mother. A successful pregnancy requires transition to an immune environment conducive to embryo survival at the maternal-fetal interface. As an important member of regulatory immunity, regulatory T (Treg) cells play a key role in regulating immune tolerance at the maternal-fetal interface. This review will focus on the phenotypic plasticity and lineage stability of Treg cells to illustrate its relationship with URSA.

A Triple-Responsive Polymeric Prodrug Nanoplatform with Extracellular ROS Consumption and Intracellular H2O2 Self-Generation for Imaging-Guided Tumor Chemo-Ferroptosis-Immunotherapy.

High reactive oxygen species (ROS) levels in tumor microenvironment (TME) impair both immunogenic cell death (ICD) efficacy and T cell activity. Furthermore, tumor escapes immunosurveillance via programmed death-1/programmed death ligand-1 (PD-L1) signal, and the insufficient intracellular hydrogen peroxide weakens ferroptosis efficacy. To tackle the above issues, a glutathione (GSH)/ROS/pH triple-responsive prodrug nanomedicine that encapsulates Fe2O3 nanoparticle via electrostatic interaction is constructed for magnetic resonance imaging (MRI)-guided multi-mode theranostics with chemotherapy/ferroptosis/immunotherapy. The diselenide bond consumes ROS in TME to increase T cells and ICD efficacy, the cleavage of which facilitates PD-L1 antagonist D peptide release to block immune checkpoint. After intracellular internalization, Fe2O3 nanoparticle is released in the acidic endosome for MRI simultaneously with lipid peroxides generation for tumor ferroptosis. Doxorubicin is cleaved from polymers in the condition of high intracellular GSH level accompanied by tumor ICD, which simultaneously potentiates ferroptosis by NADPH oxidase mediated H2O2 self-generation. In vivo results indicate that the nanoplatform strengthens tumor ICD, induces cytotoxic T lymphocytes proliferation, inhibits 4T1 tumor regression and metastasis, and prolongs survival median. In all, a new strategy is proposed in strengthening ICD and T cells activity cascade with ferroptosis as well as immune checkpoint blockade for effective tumor immunotherapy.

Cell Death Pathway Regulation by Functional Nanomedicines for Robust Antitumor Immunity.

Cancer immunotherapy has become a mainstream cancer treatment over traditional therapeutic modes. Cancer cells can undergo programmed cell death including ferroptosis, pyroptosis, autophagy, necroptosis, apoptosis and cuproptosis which are find to have intrinsic relationships with host antitumor immune response. However, direct use of cell death inducers or regulators may bring about severe side effects that can also be rapidly excreted and degraded with low therapeutic efficacy. Nanomaterials are able to carry them for long circulation time, high tumor accumulation and controlled release to achieve satisfactory therapeutic effect. Nowadays, a large number of studies have focused on nanomedicines-based strategies through modulating cell death modalities to potentiate antitumor immunity. Herein, immune cell types and their function are first summarized, and state-of-the-art research progresses in nanomedicines mediated cell death pathways (e.g., ferroptosis, pyroptosis, autophagy, necroptosis, apoptosis and cuproptosis) with immune response provocation are highlighted. Subsequently, the conclusion and outlook of potential research focus are discussed.

Nanotechnology-Assisted Immunogenic Cell Death for Effective Cancer Immunotherapy.

Tumor vaccines have been used to treat cancer. How to efficiently induce tumor-associated antigens (TAAs) secretion with host immune system activation is a key issue in achieving high antitumor immunity. Immunogenic cell death (ICD) is a process in which tumor cells upon an external stimulus change from non-immunogenic to immunogenic, leading to enhanced antitumor immune responses. The immune properties of ICD are damage-associated molecular patterns and TAA secretion, which can further promote dendritic cell maturation and antigen presentation to T cells for adaptive immune response provocation. In this review, we mainly summarize the latest studies focusing on nanotechnology-mediated ICD for effective cancer immunotherapy as well as point out the challenges.

Carbapenem-resistant gram-negative bacterial prevention practice in nosocomial infection and molecular epidemiological characteristics in a pediatric intensive care unit.

Introduction: The increasing prevalence of carbapenem-resistant gram-negative bacilli infection has emerged as a substantial threat to human health. Methodology: In January 2017, a screening program for carbapenem-resistant gram-negative bacilli colonization was performed in a pediatric intensive care unit (PICU). Subsequently, different strategies for carbapenem-resistant gram-negative bacilli cohorting and patient placements were introduced in January 2018. Results: The increase in the single room isolation (type A) and the resettlement of the same area placement (type B) resulted in a significant decrease in the nosocomial infection rate from 2.57% (50/1945) in 2017 to 0.87% (15/1720) in 2021 (P < 0.001). Notably, the incidence of nosocomial carbapenem-resistant gram-negative bacilli infections decreased in 2019 (P = 0.046) and 2020 (P = 0.041) compared with that in the respective previous year. During 2019 and 2020, a statistically significant increasing trend of type A and type B placements was observed (P < 0.05, each), which may have contributed to the decline of carbapenem-resistant gram-negative bacilli infection. The primary carbapenemase genes identified in carbapenem-resistant isolates of Klebsiella pneumoniae and Acinetobacter baumannii were blaKPC-2 from sequence type 11 and blaOXA-23 from sequence type 1712. Conclusion: The integration of various placements for patients with carbapenem-resistant gram-negative bacilli infection with active screening has been demonstrated as an effective preventive strategy in the management of carbapenem-resistant gram-negative bacilli infection.

Bioinspired fine-tuning of the mechanical rigidity of SNEDDS for the efficient crossing of multiple gastrointestinal barriers.

Nanoproperties, such as size, charge, and rigidity, have been demonstrated to be crucial for nanovehicles to overcome numerous gastrointestinal obstacles. However, the facile approach of modifying the rigidity of nanovehicles remains scarce, limiting understanding of how rigidity impacts their oral delivery. Inspired by the fact that cellular phospholipid content regulates plasma membrane rigidity, the rigidity of self-nanoemulsifiying drug delivery system (SNEDDS) could be fine-tuned via phosphocholine content while their size and zeta potential remain unchanged, using insulin as a model drug. Notably, soft SNEDDS exerted longer gastrointestinal transit time, higher drug release rate, stronger gastrointestinal stability and relatively lower mucus permeation but superior epithelial transcytosis than their hard counterparts in a macropinocytosis-dependent manner. The rigidity-related enhanced transcytosis was attributed to improved endocytosis, lysosome escape capability and exocytosis. Rats with type 1 diabetes exhibited greater oral insulin absorption and blood glucose lowering effect with soft SNEDDS. This study demonstrated the regulatory role of phospholipids in nanovehicle rigidity, which could help develop mechanically optimized nanomedicines in the future.

Transformable prodrug nanoplatform via tumor microenvironment modulation and immune checkpoint blockade potentiates immunogenic cell death mediated cancer immunotherapy.

Rationale: Chemoimmunotherapy is a promising approach in cancer immunotherapy. However, its therapeutic efficacy is restricted by high reactive oxygen species (ROS) levels, an abundance of cancer-associated fibroblasts (CAFs) in tumor microenvironment (TME) as well as immune checkpoints for escaping immunosurveillance. Methods: Herein, a new type of TME and reduction dual-responsive polymersomal prodrug (TRPP) nanoplatform was constructed when the D-peptide antagonist (DPPA-1) of programmed death ligand-1 was conjugated onto the surface, and talabostat mesylate (Tab, a fibroblast activation protein inhibitor) was encapsulated in the watery core (DPPA-TRPP/Tab). Doxorubicin (DOX) conjugation in the chain served as an immunogenic cell death (ICD) inducer and hydrophobic part. Results: DPPA-TRPP/Tab reassembled into a micellar structure in vivo with TME modulation by Tab, ROS consumption by 2, 2'-diselanediylbis(ethan-1-ol), immune checkpoint blockade by DPPA-1 and ICD generation by DOX. This resolved the dilemma between a hydrophilic Tab release in the TME for CAF inhibition and intracellular hydrophobic DOX release for ICD via re-assembly in weakly acidic TME with polymersome-micelle transformation. In vivo results indicated that DPPA-TRPP/Tab could improve tumor accumulation, suppress CAF formation, downregulate regulatory T cells and promote T lymphocyte infiltration. In mice, it gave a 60% complete tumor regression ratio and a long-term immune memory response. Conclusion: The study offers potential in tumor eradication via exploiting an "all-in-one" smart polymeric nanoplatform.

Active constituents of saffron (Crocus sativus L.) and their prospects in treating neurodegenerative diseases (Review).

Crocus sativus L. (saffron) is widely used as a traditional spice for flavoring, coloring and medicinal purposes. As a traditional Chinese herb, saffron promotes blood circulation, removes blood stasis, cools and detoxifies the blood, relieves depression and calms the mind. According to modern pharmacological studies, the active constituents of saffron, including crocetin, safranal and crocus aldehyde, exhibit antioxidant, anti-inflammatory, mitochondrial function-improving and antidepressant effects. Thus, saffron has the potential to treat neurodegenerative diseases (NDs) associated with oxidative stress, inflammation and impaired mitochondrial function, such as Alzheimer's disease, Parkinson's disease, multiple sclerosis and cerebral ischemia. The present article provides a review of the pharmacological effects of saffron and its constituents in terms of neuroprotective effects, including antioxidant and anti-inflammatory effects and the improvement of mitochondrial dysfunction, as well as their clinical application in treating NDs.

Recent Progress in Multiple Sclerosis Treatment Using Immune Cells as Targets.

Multiple sclerosis (MS) is an autoimmune-mediated demyelinating disease of the central nervous system. The main pathological features are inflammatory reaction, demyelination, axonal disintegration, reactive gliosis, etc. The etiology and pathogenesis of the disease have not been clarified. The initial studies believed that T cell-mediated cellular immunity is the key to the pathogenesis of MS. In recent years, more and more evidence has shown that B cells and their mediated humoral immune and innate immune cells (such as microglia, dendritic cells, macrophages, etc.) also play an important role in the pathogenesis of MS. This article mainly reviews the research progress of MS by targeting different immune cells and analyzes the action pathways of drugs. The types and mechanisms of immune cells related to the pathogenesis are introduced in detail, and the mechanisms of drugs targeting different immune cells are discussed in depth. This article aims to clarify the pathogenesis and immunotherapy pathway of MS, hoping to find new targets and strategies for the development of therapeutic drugs for MS.

Nanoparticle-Mediated STING Activation for Cancer Immunotherapy.

As the first line of host defense against pathogenic infections, innate immunity plays a key role in antitumor immunotherapy. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) (cGAS-STING) pathway has attracted much attention because of the secretion of various proinflammatory cytokines and chemokines. Many STING agonists have been identified and applied into preclinical or clinical trials for cancer immunotherapy. However, the fast excretion, low bioavailability, nonspecificity, and adverse effects of the small molecule STING agonists limit their therapeutic efficacy and in vivo application. Nanodelivery systems with appropriate size, charge, and surface modification are capable of addressing these dilemmas. In this review, the mechanism of the cGAS-STING pathway is discussed and the STING agonists, focusing on nanoparticle-mediated STING therapy and combined therapy for cancers, are summarized. Finally, the future direction and challenges of nano-STING therapy are expounded, emphasizing the pivotal scientific problems and technical bottlenecks and hoping to provide general guidance for its clinical application.

Application of 3D reconstruction technology based on an improved MC algorithm in a shotcreting robot.

A shotcreting robot needs to reconstruct the arch surface in three dimensions (3D) during the process of spraying a tunnel. To solve this problem, we propose an improved marching cube (MC) reconstruction method based on a point cloud splice and normal re-orient. First, we use the explosion-proof LIDAR to acquire the point cloud data of the tunnel arch, followed by the use of the iterative closest point algorithm, a PassThrough filter, and a StatisticalOutlierRemoval filter for point cloud splicing, data segmentation, and simplification, respectively. In order to improve the reconstruction accuracy, we adjusted the estimated point cloud normal for normal consistency and obtained the geometric features of the complex point cloud surface. Furthermore, combined with the improved MC algorithm, the 3D reconstruction of the tunnel arch is realized. The experimental results show that the proposed method can reconstruct the 3D model of the tunnel arch surface quickly and accurately, which lays a foundation for further research on a trajectory plan, spraying status monitors, and control strategies.

Improved A* Path Planning Method Based on the Grid Map.

In obstacle spatial path planning, the traditional A* algorithm has the problem of too many turning points and slow search speed. With this in mind, a path planning method that improves the A* (A-Star) algorithm is proposed. The mobile robot platform was equipped with a lidar and inertial measurement unit (IMU). The Hdl_graph_slam mapping algorithm was used to construct a two-dimensional grid map, and the improved A* algorithm was used for path planning of the mobile robot. The algorithm introduced the path smoothing strategy and safety protection mechanism, and it eliminated redundant points and minimal corner points by judging whether there were obstacles in the connection of two path nodes. The algorithm effectively improved the smoothness of the path and facilitated the robot to move in the actual operation. It could avoid the wear of the robot by expanding obstacles and improving the safety performance of the robot. Subsequently, the algorithm introduced the steering cost model and the adaptive cost function to improve the search efficiency, making the search purposeful and effective. Lastly, the effectiveness of the proposed algorithm was verified by experiments. The average path search time was reduced by 13%. The average search extension node was reduced by 11%. The problems of too many turning points and slow search speed of traditional A* algorithm in path planning were improved.

A Novel Chemical-Electrochemical Hydrogen Production from Coal Slurry by a Two-Step Process: Oxidation of Coal by Ferric Ions and Electroreduction of Hydrogen Ions.

Hydrogen production from the electrolysis of coal slurry is a promising approach under the condition of low voltage (0.8-1.2 V) and medium temperature. However, the rate of hydrogen production is slugged by poor anode kinetics, under an electrochemical condition that results from the collision of the coal particles with the anode surface. This paper reports a novel process that consists of two steps: the oxidation of the coal slurry by ferric ions(III) in a hydrothermal reactor at a temperature of 120-160 °C and the electro-oxidation of ferric ions(II) in the electrochemical cell to produce hydrogen. This technique circumvents the technical issues experienced in the conventional coal slurry electrolysis process by adopting a two-step process consisting of solid-liquid reactions instead of solid-solid reactions. This indirect oxidation process produced a current density of 120 mA/cm2 at room temperature and a voltage of 1 V, which is higher than the values reported in the conventional processes. An investigation of the oxidation mechanism was carried out via scanning electron microscopy, Fourier-transform infrared spectroscopy and elemental analysis. The results obtained showed that the oxidation of coal by ferric ions occurs from the surface to the inner parts of the coal particles in a stepwise manner. It was also revealed that the ferric ions in the media increased the active interfaces both of the coal particles and of the anode electrode. This explains the high hydrogen production rate obtained from this process. This novel discovery can pave the way for the commercialization of coal slurry electrolysis.

Hybrid-Membrane-Decorated Prussian Blue for Effective Cancer Immunotherapy via Tumor-Associated Macrophages Polarization and Hypoxia Relief.

Both tumor-associated macrophages (TAMs) and hypoxia condition severely restrict the antitumor potency during cancer immunotherapy. It is essential to overcome the two issues for improving therapeutic efficacy. In this study, a hollow mesoporous Prussian blue (HMPB) nanosystem with mannose decoration and hydroxychloroquine (HCQ) adsorption is built, to form Man-HMPB/HCQ. It can facilitate cellular internalization via mannose-receptor mediated endocytosis and induce TAM polarization via iron ion/HCQ release with HMPB degradation. The hybrid macrophage and thylakoid (TK) membrane is camouflaged on the Man-HMPB/HCQ surface, denoted as TK-M@Man-HMPB/HCQ, to reduce in vivo reticuloendothelial system uptake, enhance tumor accumulation, and mitigate hypoxia. The in vivo results indicate that TK-M@Man-HMPB/HCQ notably inhibits tumor growth, induces TAM polarization, facilitates cytotoxic T lymphocytes infiltration, and alleviates hypoxia microenvironment. The rational design may provide a new pathway to modulate the tumor microenvironment for promoting cancer immunotherapy effects.

Oral insulin delivery by epithelium microenvironment-adaptive nanoparticles.

Oral protein drug delivery using nano-based systems remains challenging, as contradictory surface properties are required for efficient navigation through the intestinal mucus and epithelium barriers. Therefore, new nanoplatforms with tunable surface properties in vivo are urgently needed. Inspired by the slightly acidic microclimate of the jejunal epithelial surface, we report a novel epithelium microenvironment-adaptive nanoplatform that undergoes a hydrophilicity-hydrophobicity transition at the epithelial surface. First, we synthesized and characterized a biodegradable copolymer consisting of PEG and PLGA building blocks linked by a hydrazone bond (PLGA-Hyd-PEG) to fabricate the pH-sensitive core-shell architecture of an oral insulin system. Then we loaded the system as a freeze-dried powder into enteric-coated capsules. PLGA-Hyd-PEG nanoparticles showed excellent drug protection and rapid mucus penetration owing to the high stability of the PEG coating in jejunal fluid. In the acidic microenvironment of the jejunal epithelial surface (pH ~5.5), PEG was rapidly cleaved and the hydrazone bond was hydrolyzed, converting the nanoparticle surface from hydrophilic to hydrophobic, thereby facilitating internalization into cells. Pharmacodynamic studies showed that PLGA-Hyd-PEG nanoparticles resulted in significant decrease in blood glucose level after intrajejunal administration in both normal and diabetic rats relative to control nanoparticles. In addition, enteric-coated capsules containing PLGA-Hyd-PEG nanoparticles reduced blood glucose by 35% for up to 10 h after oral administration to diabetic rats. Our findings provide a new strategy for regulating the surface properties of nanoparticles for efficient oral drug delivery.

Rational formulation engineering of fraxinellone utilizing 6-O-α-D-maltosyl-ß-cyclodextrin for enhanced oral bioavailability and hepatic fibrosis therapy.

Although Fraxinellone (Frax) isolated from Dictamnus albus L. possessed excellent anti-hepatic fibrosis activity, oral administration of Frax suffered from the inefficient therapeutic outcome in vivo due to negligible oral absorption. At present, the oral formulation of Frax is rarely exploited. For rational formulation design, we evaluated preabsorption risks of Frax and found that Frax was rather stable while poorly dissolved in the gastrointestinal tract (78.88 µg/mL), which predominantly limited its oral absorption. Further solubility test revealed the outstanding capacity of cyclodextrin derivatives (CDs) to solubilize Frax (6.8-12.8 mg/mL). This led us to study the inclusion complexes of Frax with a series of CDs and holistically explore their drug delivery performance. Characterization techniques involving 1H-NMR, FT-IR, DSC, PXRD, and molecular docking confirmed the most stable binding interactions when Frax complexed with 6-O-α-D-maltosyl-ß-cyclodextrin (G2-ß-CD-Frax). Notably, G2-ß-CD-Frax exhibited the highest solubilizing capacity, fast dissolution rate, and superior Caco-2 cell internalization with no obvious toxicity. Pharmacokinetic studies demonstrated markedly higher oral bioavailability of G2-ß-CD-Frax (5.8-fold that of free drug) than other Frax-CDs. Further, long-term administration of G2-ß-CD-Frax (5 mg/kg) efficiently inhibited CCl4-induced hepatic fibrosis in the mouse without inducing any toxicity. Our results will inspire the continued advancement of optimal oral Frax formulations for anti-fibrotic therapy.