Radioresponsive Delivery of Toll-like Receptor 7/8 Agonist for Tumor Radioimmunotherapy Enabled by Core-Cross-Linked Diselenide Nanoparticles.

The development of a radioresponsive delivery platform has led to an innovative combination radioimmunotherapy strategy for treating tumors. However, controlling the release of immunomodulators by local radiotherapy in vivo remains a significant challenge in order to minimize off-target toxicity, reduce radiation-induced immunosuppression, and maximize synergistic radioimmunotherapy efficacy. In this study, we report the development of core-cross-linked diselenide nanoparticles (dSeNPs) as carriers for radioresponsive delivery of the toll-like receptors 7/8 agonist through systemic administration to achieve combined radioimmunotherapy of tumors. The dSeNPs were fabricated from a ring-opening reaction between 2,2'-diselenidebis(ethylamine) and the ethylene oxide group of an amphiphilic block copolymer. The diselenide bonds were naturally protected in the core of the self-assembled nanostructure, making the dSeNPs extremely stable in the physiological environment. However, they exhibited dose- and time-dependent radiosensitivity, meaning that X-ray irradiation could spatiotemporally control the release of R848 from the dSeNPs. In vivo results showed that local radioresponsive R848 release from dSeNPs greatly improved the synergistic efficacy of combined radioimmunotherapy via the programmed cooperative immune system activation process. This process included macrophage polarization, dendritic cell maturation, and cytotoxic T cell activation. Our findings suggest that core-cross-linked dSeNPs are a promising platform for combined radiotherapy due to their spatiotemporal controllability of radioresponsive drug release.

Targeting STING Activation by Antigen-Inspired MnO2 Nanovaccines Optimizes Tumor Radiotherapy.

Immune checkpoint blockers therapy can improve the radiotherapy-induced immunosuppression by enhancing interferon secretion, but still suffer from low clinical response rate and potential adverse effects. Mn2+ -mediated activation of interferon gene stimulator (STING) pathway provides an alternative for combination radioimmunotherapy of tumor. However, it is still a challenge for specific delivery of Mn2+ to innate immune cells and targeting activation of STING pathway. Herein, a novel antigen-inspired MnO2 nanovaccine is fabricated as Mn2+ source and functionalized with mannose, enabling it to target innate immune cells to activate the STING pathway. Meanwhile, the release of Mn2+ in the intracellular lysosomes can also be for magnetic resonance imaging to monitor the dynamic distribution of nanovaccines in vivo. The targeting activation of STING pathway can enhance radiotherapy-induced immune responses for inhibiting local and distant tumors, and resisting tumor metastasis. The study proposes an optimized radiotherapy strategy through targeting STING activation of antigen-inspired nanovaccines.

Chemotherapy-Sensitized In Situ Vaccination for Malignant Osteosarcoma Enabled by Bioinspired Calcium Phosphonate Nanoagents.

How to effectively treat malignant osteosarcoma remains clinically challenging. Programmed delivery of chemotherapeutic agents and immunostimulants may offer a universal strategy for killing osteosarcoma cells while simultaneously eliciting in situ antitumor immunity. However, targeted chemoimmunotherapy lacks a reliable delivery system. To address this issue, we herein developed a bioinspired calcium phosphonate nanoagent that was synthesized by chemical reactions between Ca2+ and phosphonate residue from zoledronic acid using bovine serum albumin as a scaffold. In addition, methotrexate combination with a phosphorothioate CpG immunomodulator was also loaded for pH-responsive delivery to enable synergistic chemoimmunotherapy of osteosarcoma. The calcium phosphonate nanoagents were found to effectively accumulate in osteosarcoma for nearly 1 week, which is favorable for exerting the vaccination effects in situ by maturing dendritic cells and priming CD8+ T cells to suppress the osteosarcoma progression and pulmonary metastasis through controlled release of the three loaded agents in the acidic tumor microenvironment. The current study may thus offer a reliable delivery platform for achieving targeted chemotherapy-induced in situ antitumor immunity.

Gadolinium-Bisphosphonate Nanoparticle-Based Low-Dose Radioimmunotherapy for Osteosarcoma.

Osteosarcoma is a malignant osteogenic tumor with a high metastatic rate commonly occurring in adolescents. Although radiotherapy is applied to treat unresectable osteosarcoma with radiation resistance, a high dose of radiotherapy is required, which may weaken the immune microenvironment. Therefore, there is an urgent need to develop novel agents to maximize the radiotherapeutic effects by eliciting immune activation effects. In this study, we synthesized therapeutic gadolinium-based metal-bisphosphonate nanoparticles (NPs) for osteosarcoma treatment that can be combined with radiotherapy. The gadolinium ion (Gd) was chelated with zoledronic acid (Zol), a commonly used drug to prevent/treat osteoporosis or bone metastases from advanced cancers, and stabilized by ovalbumin (OVA) to produce OVA-GdZol NPs. OVA-GdZol NPs were internalized into K7M2 osteosarcoma cells, showing a high sensitization effect under X-ray irradiation. Cell pretreatment of OVA-GdZol NPs significantly enhanced the radiation therapeutic effect in vitro by reducing the cell colonies and increased the signal of γH2AX-positive cells. More importantly, OVA-GdZol NPs promoted the maturation of bone marrow-derived dendritic cells (BMDCs) and M1 polarization of macrophages. The inhibitory effect on K7M2 osteosarcoma of OVA-GdZol NPs and X-ray radiation was evident, indicated by a significantly reduced tumor volume, high survival rate, and decreased lung metastasis. Meanwhile, both innate and adaptive immune systems were activated to exert a strong antitumor effect. The above results highly suggest that OVA-GdZol NPs serve as both radiosensitizers and immune adjuvants, suitable for the sequential combination of vaccination and radiotherapy.

Apoferritin-Engineered Nanoprobe for Tumor-Targeted Triple-NIR Imaging and Phototherapy.

Considering that pathological hallmarks are directly related to structural and chemical information of tumor, noninvasive, real-time, spatially resolved quantitative chemical imaging is significant for treatment decisions. The discovery of the transparency window of biological tissues and the advancement of near-infrared technology provide exciting prospects for in vivo imaging. Herein, an engineering apoferritin-conjugated cypate nanoprobe is fabricated for near-infrared photoacoustic imaging and fluorescence imaging in the first and second window. As the analogue of indocyanine green, dicarboxylic cypate is directly conjugated with the apoferritin molecules for forming assembly nanoprobes. Resulting from the intrinsic targeting and optical capacity of the nanoprobes, the triple near-infrared imaging can perform multimeasurements of the target analyte in real-time. This imaging methodology not only provides the structural background information of the tumor, each pixel also contains quantitative in situ information of the tumor. In particular, part of the absorbed light energy is released as heat energy in the near-infrared photoacoustic imaging process. The constructed triple near-infrared nanoprobes therefore naturally navigate the photothermal treatment plan of tumor and finally realize the efficient assistance of tumor photothermal ablation. The tumor metabolomics reveal that the nanoprobe-assisted tumor ablation has a potential mechanism toward glutamine- and phenylalanine-related metabolism perturbation and the disordered oxidative stress state. The tumor-specific bioconjugate nanoprobes hold great potential as a versatile theranostic platform for tumor imaging and therapy.

Hepatotoxicity of copper sulfide nanoparticles towards hepatocyte spheroids using a novel multi-concave agarose chip method.

Aim: To explore the hepatotoxicity of copper sulfide nanoparticles (CuSNPs) toward hepatocyte spheroids. Materials & methods: Other than the traditional agarose method to generate hepatocyte spheroids, we developed a multi-concave agarose chip (MCAC) method to investigate changes in hepatocyte viability, morphology, mitochondrial membrane potential, reactive oxygen species and hepatobiliary transporter by CuSNPs. Results: The MCAC method allowed a large number of spheroids to be obtained per sample. CuSNPs showed hepatotoxicity in vitro through a decrease in spheroid viability, albumin/urea production and glycogen deposition. CuSNPs also introduced hepatocyte spheroid injury through alteration of mitochondrial membrane potential and reactive oxygen species, that could be reversed by N-acetyl-l-cysteine. CuSNPs significantly decreased the activity of BSEP transporter by downregulating its mRNA and protein levels. Activity of the MRP2 transporter remained unchanged. Conclusion: We observed the hepatotoxicity of CuSNPs in vitro with associated mechanisms in an advanced 3D culture system.

Iodinated BSA Nanoparticles for Macrophage-Mediated CT Imaging and Repair of Gastritis.

The development of a specific and noninvasive technology for understanding gastritic response together with efficient therapy is an urgent clinical issue. Herein, we fabricated a novel iodinated bovine serum albumin (BSA) nanoparticle based on gastritic microenvironment for computed tomography (CT) imaging and repair of acute gastritis. Derived from the characteristic mucosa defect and inflammatory cell (e.g., macrophage and neutrophil) infiltration in acute gastritis, the pH-sensitive nanoparticles can sedimentate under acidic conditions and be uniformly distributed in the defected mucosal via the phagocytosis of inflammatory cells. Hence, enhanced CT images can clearly reveal the mucosal morphology in the nanoparticle-treated gastritic rat over a long time window comparison with nanoparticle-treated healthy rats and clinical small-molecule-treated gastritic rat. In addition, we have discovered that nanoparticles can repair the atrophic gastric mucosa to a normal state. This repair process mainly stems from inflammatory immune response caused by phagocytized nanoparticles, such as the polarization of proinflammatory macrophages (M1) to anti-inflammatory macrophages (M2). The biocompatible nanoparticles that avoid the inherent defects of the clinical small molecules have great potential for accurate diagnosis and treatment of gastritis in the early stage.

Bioactive Polysaccharide Nanoparticles Improve Radiation-Induced Abscopal Effect through Manipulation of Dendritic Cells.

Radiotherapy was considered to induce an abscopal effect initiated through antigen release and presented by dendritic cells (DC), while the immunosuppressive tumor microenvironment (TEM) attenuated the effects. Herein, we utilized bioactive polysaccharides extracted from the natural herb Astragalus membranaceus and developed polysaccharide nanoparticles (ANPs) that can reverse TEM and, accordingly, enhance the radiation-induced abscopal effect. ANP showed ability to prolong the survival rate of tumor-bearing mice. In addition, ANP dramatically inhibited the growth of the primary tumor subjected to radiation as well as the secondary tumor distant from the primary lesion. Mechanistic study demonstrated that an ANP-induced immune response was mainly reflected by DC activation, represented by phenotypic maturation and enhanced antigen presentation through the TLR4 signaling pathway. Mature DC induced by ANP migrated to the tumor-draining lymph node and initiated T-cell expansion. Specifically, DC activation was successfully translated into an increase in CD4+ T/Treg and CD8+ T/Treg ratios within both primary (irradiated) and secondary (unirradiated) tumors. Our results also indicated that the systemic antitumor immune response and immune memory were enhanced with the increase in IFN-γ production and effector memory T-cell population. Our work provided a novel strategy to facilitate the incorporation of immunoactive macromolecules purified from natural herbs into modern nanotechnology in the era of immunotherapy.

Immunoactive polysaccharide functionalized gold nanocomposites promote dendritic cell stimulation and antitumor effects.

Aim: To investigate the immune responses and antitumor efficacy of immunoactive polysaccharide functionalized gold nanocomposites (APS-AuNP). Materials & methods: Immunoregulation of APS-AuNP on dendritic cells/T cells in vitro was evaluated by flow cytometry and their inhibitions against primary/metastatic tumors were determined on 4T1-bearing mice model. Results & conclusion: APS-AuNP exhibited remarkable capability to induce dendritic cells maturation through phenotypic markers with functional changes, which further promoted T-cell proliferation and enhanced cytotoxicity against 4T1 tumor cells. The inhibitory rate of APS-AuNP against 4T1 primary tumor growth and pulmonary metastasis in mice was higher than paclitaxel-treated group. In addition, APS-AuNP exhibited strong capability to increase the population of CD4+/CD8+ T lymphocytes as well as effector memory cells rather than central memory cells.

In Vivo Photoacoustic/Single-Photon Emission Computed Tomography Imaging for Dynamic Monitoring of Aggregation-Enhanced Photothermal Nanoagents.

Emerging nanomedical strategy is to construct a nanoagent that affords not only diagnostic and therapeutic functions but also imaging-guided treatment. It is crucial to understand the in vivo biological processes of nanoagents for improving theranostic function and biosafety. Herein, we report a multimodal photoacoustic/single-photon emission computed tomography (SPECT) imaging technique to dynamically monitor the in vivo behaviors of nanoagents. Near-infrared cypate-induced silk fibroin nanoassembly was chosen as the nanoagent object due to their promise in biocompatibility and aggregation-enhanced photothermal effect. This unique effect makes the nanoagents useful for the integration of photoacoustic imaging and photothermal therapy. Moreover, the nanoagents are also labeled with the radionuclides (99mTc) to render SPECT imaging. Multimodal photoacoustic/SPECT imaging provides real time, noninvasive, sensitive, and whole-body 3D information about nanoagents' distribution in vivo. These results highlight the significance of visualizing the in vivo behaviors of nanoagents and locating the tumor in vivo, substantially benefiting the better treatment planning.

Perceived stress status and sympathetic nervous system activation in young male patients with coronary artery disease in China.

BACKGROUND AND PURPOSE: Young Chinese male adults have faced increasing psychological stress. Whether this is associated with the increased risk of coronary artery disease (CAD) in young Chinese males remains unclear. This study aimed to evaluate the correlation and underlying mechanisms of perceived stress and CAD in young male patients. METHODS: A total of 178 male patients diagnosed as young CAD (aged ≤ 55 years) by coronary angiography (CAG) were enrolled, and 181 age-matched non-CAD individuals were set as control group. Traditional cardiovascular risk factors and levels of epinephrine and norepinephrine were measured, and perceived stress status was accessed by Perceived Stress Scale (PSS). RESULTS: The PSS score was correlated with levels of epinephrine (r=0.45), norepinephrine (r=0.41), high-sensitivity C-reactive protein (hs-CRP) (r=0.38, p<0.01), and current smoking (r=0.32) (all p<0.05). Multivariate logistic regression analysis showed that smoking (OR, 3.12; 95%CI, 1.23-7.91), triglycerides (OR, 1.42; 95%CI, 1.04-1.94), hs-CRP (OR, 3.57; 95%CI, 1.65-7.72), and PSS score (OR, 1.81; 95%CI, 1.23-2.66) were independently correlated with CAD in young patients. The association between PSS score and risk of CAD become insignificant (OR, 1.43; 95%CI, 0.96-2.13) when further adjusted for the levels of epinephrine and norepinephrine. CONCLUSIONS: After adjustment for multiple cardiovascular risk factors, high perceived stress was an independent risk factor for CAD in young Chinese male patients. Abnormal activation of the sympathetic nervous system may play an important role linking perceived stress with the risk of CAD.

Plasma oxidized low-density lipoprotein is an independent risk factor in young patients with coronary artery disease.

OBJECTIVES: Oxidized low-density lipoprotein (ox-LDL) is considered to be a key factor of initiating and accelerating atherosclerosis. The objective of this study was to investigate the role of ox-LDL in young patients with coronary artery disease (CAD). METHODS: 128 consecutive angiographically proven young CAD patients (aged ⩽ 55 years) were enrolled, and 132 age-matched non-CAD individuals (coronary angiography normal or negative finding by coronary ultrafast CT) were set as control group. Conventional risk factors (hypertension, dyslipidemia, diabetes mellitus, obesity, smoking) were evaluated in the two groups. Ox-LDL was measured by competitive ELISA. Framingham risk score (FRS) and absolute 10-year CAD events risk were calculated for each individual. RESULTS: Male sex was more prevalent in group CAD than in control (87.5% vs. 62.1%; P< 0.01). There were significant differences in smoking history (P< 0.01) and triglyeride (TG) and ratio of apolipoprotein B/apolipoprotein A1 (ApoB/ApoA1) (both P< 0.05) but no remarkable difference in other conventional risk factors (all P> 0.05) between group CAD and control. Level of ox-LDL was significantly higher in group CAD than in control (P< 0.01). Multivariate logistic regression showed that male sex (OR, 4.54; 95%CI, 1.76-9.77), smoking quantity (OR, 2.78; 95%CI, 1.34-4.25), TG (OR, 1.42; 95%CI, 1.18-2.83), ApoB/ApoA1 (OR, 1.73; 95%CI, 1.32-4.23), and ox-LDL (OR, 2.15; 95%CI, 1.37-6.95) were independently correlated with CAD in young patients. Area under the curve (AUC) of receiver operating characteristic (ROC) curve of TG, ApoB/ApoA1, and ox-LDL was 0.831, 0.866, and 0.935, respectively (P< 0.001). CONCLUSIONS: Ox-LDL is an important independent risk factor for CAD in young patients after adjusting other risk factors such as smoking, TG, and ApoB/ApoA1.