Mechanotransduction-Piloted Whole-Cell Vaccines for Spatiotemporal Modulation of Postoperative Antitumor Immunity.

Whole tumor cell vaccines hold promise by presenting a broader spectrum of autologous-origin tumor antigens to combat postoperative recurrence and metastasis. However, challenges such as intractable adjuvant modification and obscure interactions with antigen-presenting cells in the postoperative microenvironment impede their translation into effective personalized immunotherapies. In this study, we propose cancer vaccines derived from manganese oxide-immobilized resected tumor cells, featuring whole tumor antigens and adjustable stiffness to modulate interactions with antigen-presenting cells in the postoperative microenvironment. These vaccines effectively stimulate dendritic cell phagocytosis and function through sequential stiffness-mediated mechanotransduction and interferon signaling. We evaluated their efficacy using an orthotopic triple-negative breast cancer mouse model and found that combining the vaccines with radiotherapy effectively inhibits postoperative tumor recurrence and metastasis. Our study underscores the potential of utilizing mechanotransduced adjuvants alongside directly inactivated whole-cell vaccines as a universal solution for preventing postoperative tumor recurrence.

Endocytic pathways and metabolic fate of colloidal bismuth subcitrate in human renal cells.

Bismuth compounds, particularly colloidal bismuth subcitrate (CBS), have been widely used in the treatment of gastrointestinal diseases. However, overdose of CBS has been linked to cases of acute renal failure, primarily due to the intracellular accumulation of bismuth in the kidney. To date, the detailed mechanisms of CBS internalization and its metabolic fate remain unclear. In this study, CBS was characterized as a type of nano-object using transmission electron microscopy and dynamic light scattering. Renal cells internalized CBS primarily via clathrin-mediated endocytosis in an active transport manner. Gene knockdown techniques revealed that CBS binds to the transferrin receptor likely through complexing with transferrin before cellular uptake. Once internalized, CBS was sorted into early endosomes, late endosomes, and lysosomes, mediated by microtubules and the Golgi apparatus. Additionally, differentially expressed genes analysis revealed that CBS endocytosis stimulated oxidative stress, significantly affecting the metabolism of glutathione and cysteine within cells. This led to the formation of black bismuth sulfide particles as a result of CBS conjugating with intracellular glutathione. These findings provide crucial insights into the cellular mechanisms underlying excessive CBS exposure, which is essential for understanding and potentially mitigating the risks associated with the use of bismuth compounds in medical treatments.

Tumor Metabolism Aiming Cu2-xS Nanoagents Mediate Photothermal-Derived Cuproptosis and Immune Activation.

Cuproptosis is an emerging form of cell death that relies on the targeted delivery of copper ions to lipoylated tricarboxylic acid cycle proteins. However, a major challenge associated with cuproptosis is its potential to kill both normal and tumor cells without discrimination. Therefore, it is crucial to develop strategies for precise intracellular delivery and redox control of copper to create effective cuproptosis-based tumor therapies. We have introduced a class of nanoagents called metabolism aiming Cu2-xS (MACuS) through a glucose-mediated biomineralization approach. MACuS nanoagents can be specifically targeted to tumors via the glucose transport receptor 1, and we found that NIR-II irradiation can not only result in direct hyperthermia ablation of tumor cells but also facilitate efficient cuproptosis and enhance reactive oxygen species-induced cytotoxicity in tumor cells. As a result, the triple effect of MACuS treatment induced immunogenic cell death, which triggered systemic antitumor immune responses and demonstrated potent efficacy in inhibiting growth, metastasis, and recurrence in mouse and rabbit breast cancer models. The precise intracellular delivery and redox control of copper provided by MACuS hold great potential for the development of highly efficient cuproptosis-based tumor therapies with minimal off-target effects.

Mechanoimmune-Driven Backpack Sustains Dendritic Cell Maturation for Synergistic Tumor Radiotherapy.

Cell backpacks present significant potential in both therapeutic and diagnostic applications, making it essential to further explore their interactions with host cells. Current evidence indicates that backpacks can induce sustained immune responses. Our original objective was to incorporate a model antigen into the backpacks to promote dendritic cell maturation and facilitate antigen presentation, thereby inducing immune responses. However, we unexpectedly discovered that both antigen-loaded backpacks and empty backpacks demonstrated comparable abilities to induce dendritic cell maturation, resulting in nearly identical potency in T-cell proliferation. Our mechanistic studies suggest that the attachment of backpacks induces mechanical forces on dendritic cells via opening the PIEZO1 mechanical ion channel. This interaction leads to the remodeling of the intracellular cytoskeleton and facilitates the production of type I interferons by dendritic cells. Consequently, the mechano-immune-driven dendritic cell backpacks, when combined with radiotherapy, induce a robust antitumor effect. This research presents an avenue for leveraging mechanotransduction to enhance combination immunotherapeutic strategies, potentially leading to groundbreaking advancements in the field.

Radiotherapy-Driven Nanoprobes Targeting for Visualizing Tumor Infiltration Dynamics and Inducing Ferroptosis in Myeloid-Derived Suppressor Cells.

Myeloid-derived suppressor cells (MDSCs) significantly hinder the immune response to tumor radiotherapy (RT) because of their massive accumulation in tumors after RT, resulting in immunosuppression and poor clinical prognosis. Herein, we developed an anti-PD-L1 antibody-conjugated iron oxide nanoprobe (Fe3O4-αPD-L1) to target and induce ferroptosis in MDSCs, thereby alleviating RT resistance. Overexpression of PD-L1 in MDSCs following RT enables noninvasive in vivo magnetic resonance and positron emission tomography imaging using 89Zr-labeled nanoprobes to track the movement of MDSCs and their infiltration into the tumor. After uptake by MDSCs that infiltrated the tumor, Fe3O4-αPD-L1 nanoprobes were mainly found within the lysosome and triggered the Fenton reaction, resulting in the generation of abundant reactive oxygen species. This process leads to ferroptosis of MDSCs, characterized by lipid peroxidation and mitochondrial dysfunction, and effectively reprograms the immunosuppressive environment within the tumor following RT. This study highlights a strategy for monitoring and regulating the fate of MDSCs to alleviate RT resistance and ultimately achieve improved treatment outcomes.

Radioactive Hydroxyapatite Microspheres Empower Sustainable In Situ Tumor Vaccination.

Tumor in situ vaccination (ISV) strategies have emerged in clinical trials as promising approaches, involving the release of tumor antigens through local radiotherapy and intratumorally adjuvant injections. However, the current fabrication strategy for achieving a sustainable immune response to ISV remains a pressing challenge. In this study, we present an empowered sustainable ISV method for antitumor therapy using 177Lu-labeled manganese-doped mesoporous hydroxyapatite (177Lu/Mn-HAP) microspheres. The ISV enables the sustained utilization of tumor antigens, leading to the activation of dendritic cells and polarization of macrophages toward the M1 subtype. Consequently, it facilitates the generation of potent CD8+ T-cell responses, enhancing the antitumor effects of internal radiation in both primary and distant tumors. Importantly, this approach achieves complete remission in all tumor-bearing mice and stimulates immune memory to prevent tumor recurrence. Our study highlights a universal and safe ISV strategy capable of inducing potent tumor-specific and sustainable immune response.

Improving combination cancer immunotherapy by manipulating dual immunomodulatory signals with enzyme-triggered, cell-penetrating peptide-mediated biomodulators.

Immunosuppressive tumor microenvironments challenge the effectiveness of protein-based biopharmaceuticals in cancer immunotherapy. Reestablishing tumor cell immunogenicity by enhancing calreticulin (CRT) exposure is expected to improve tumor immunotherapy. Given that CRT translocation is inherently modulated by phosphorylated eIF2α, the selective inhibition of protein phosphatase 1 (PP1) emerges as an effective strategy to augment tumor immunogenicity. To harness the PP1-disrupting potential of GADD34-derived motifs and address their limited intracellular delivery, we integrated these sequences into an enzyme-triggered, cell-penetrating peptide-mediated chimeric protein scaffold. This design not only facilitates efficient cytoplasmic delivery of these immunostimulatory motifs to induce "eat-me" signaling, but also provides a versatile platform for combination immunotherapy. Fabrication of biomodulators with cytotoxic BLF1 provides additional "eat-me" signaling through phosphatidylserine exposure or that with an immunomodulatory designed ankyrin repeat protein disables "don't-find-me" signaling by antagonizing PD-L1. Notably, these bifunctional biomodulators exhibit remarkable ability to induce macrophage phagocytosis, dendritic cell maturation, and CD8+ T activation, ultimately substantially inhibiting tumor growth. This study presents a modular genetic coding strategy for PP1-centered therapies that enables seamless integration of immunostimulatory sequences into protein-based anti-tumor cocktail therapies, thereby offering novel alternatives for improving antitumor efficacy.

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.

Neutrophils-mediated bioinspired nanoagents for noninvasive monitoring of inflammatory recruitment dynamics and navigating phototherapy in rheumatoid arthritis.

Neutrophils play a crucial role in inflammatory immune responses, but their in vivo homing to inflammatory lesions remains unclear, hampering precise treatment options. In this study, we employed a biomineralization-inspired multimodal nanoagent to label neutrophils, enabling noninvasive monitoring of the dynamic process of inflammatory recruitment and guiding photothermal therapy in rheumatoid arthritis. Our nanoagents allowed visualization of neutrophil fate through magnetic resonance imaging, photoacoustic imaging, and fluorescence imaging in the first and second near-infrared windows. Histopathology and immunofluorescence analysis revealed pronounced inflammatory cell infiltration in rheumatoid arthritis compared to the normal limb. Furthermore, the recruitment quantity of neutrophils positively correlated with the inflammatory stage. Additionally, the inherent photothermal effect of the nanoagents efficiently ablated inflammatory cells during the optimal homing time and inflammatory phase. This neutrophil imaging-guided photothermal therapy precisely targeted inflammatory nuclei in rheumatoid arthritis and downregulated pro-inflammatory cytokines in serum. These results demonstrate that in vivo tracking of inflammatory immune response cells can significantly optimize the treatment of inflammatory diseases, including rheumatoid arthritis.

Harnessing astaxanthin-loaded diselenium cross-linked apotransferrin nanoparticles for the treatment of secretory otitis media.

Secretory otitis media (SOM) is a clinical condition characterized by the accumulation of fluids and oxidative stress in the middle ear, leading to hearing impairment and infection complications. One potential solution for mitigating oxidative stress associated with SOM is the use of antioxidants such as astaxanthin. However, its effectiveness is limited due to its poor bioavailability and rapid oxidation. Herein, we developed a novel diselenium-crosslinked apotransferrin enriched with astaxanthin (AST@dSe-AFT) nanoparticles to augment the transport of astaxanthin across biological membranes, resulting in increased bioavailability and reduced oxidative stress in SOM. Our research demonstrated that AST@dSe-AFT efficiently accumulated in the middle ear, allowing for controlled delivery of astaxanthin in response to reactive oxygen species and reducing oxidative stress. Additionally, AST@dSe-AFT stimulated macrophages to polarize towards M2 phenotype and neutrophils to polarize towards N2 phenotype, thereby facilitating an anti-inflammatory response and tissue restoration. Importantly, AST@dSe-AFT exhibited no toxicity or adverse effects, suggesting its potential for safety and future clinical translation. Our findings suggested that AST@dSe-AFT represents a promising approach for the treatment of secretory otitis media and other oxidative stress-related disorders.

Mechanistic study for drug induced cholestasis using batch-fabricated 3D spheroids developed by agarose-stamping method.

Cell spheroid culture can recapitulate the tissue microstructure and cellular responses in vivo. While there is a strong need to understand the modes of toxic action using the spheroid culture method, existing preparation techniques suffer from low efficiency and high cost. Herein, we developed a metal stamp containing hundreds of protrusions for batch bulk preparation of cell spheroids in each well of the culture plates. The agarose matrix imprinted by the stamp can form an array of hemispherical pits, which facilitated the fabrication of hundreds of uniformly sized rat hepatocyte spheroids in each well. Chlorpromazine (CPZ) was used as a model drug to investigate the mechanism for drug induced cholestasis (DIC) by agarose-stamping method. Hepatocyte spheroids showed a more sensitive detection of hepatotoxicity compared to 2D and Matrigel-based culture systems. Cell spheroids were also collected for staining of cholestatic protein and showed a CPZ-concentration-dependent decrease of bile acid efflux related proteins (BSEP and MRP2) and tight junction (ZO-1). In addition, the stamping system successfully delineated the DIC mechanism by CPZ that may be associated with the phosphorylation of MYPT1 and MLC2, two central proteins in the Rho-associated protein kinase pathway (ROCK), which were significantly attenuated by ROCK inhibitors. Our results demonstrated a large-scale fabrication of cell spheroids by the agarose-stamping method, with promising benefits for exploring the mechanisms for drug hepatotoxic responses.

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.

Derivation of the toxicological threshold of silicon element in the extractables and leachables from the pharmaceutical packaging and process components.

Silicon is one of the most monitored elements in extractables and leachables studies of pharmaceutical packaging systems and related components. There is a need to review and evaluate toxicological thresholds of silicon because of its direct contact with drug products (DP) especially a liquid form of DP with the widely used pharmaceutical packaging systems made of silicon materials like glass and silicone. It is required by regulatory authorities to test silicon content in DP; however, there are no official guidelines on the toxicology of silicon that are currently available, yet the knowledge of toxicological thresholds of silicon is critical to justify the analytical limit of quantification (LOQ). Therefore, we reviewed the toxicity of silicon to derive a toxicological threshold by literature review of toxicity studies of both inorganic and organic silicon compounds. Oral toxicity is low for inorganic silicon like silicon dioxide or organic silicon polymers such as silicone tube/silicone oil (polydimethylsiloxane, or namely, PDMS as the major ingredient). In comparison, inhalational toxicity of silicon dioxide leads to pulmonary silicosis or even lung cancer. When orally administered, the toxicity of silicon dioxide, glass, polymers, or PDMS oligomers varies depending on their morphology, molecular weight (MW), and degrees of polymerization. PDMS with high MW has minimal toxic symptoms with non-detectable degradation/elimination by both intraperitoneal and subcutaneous administration routes, while exposure to either PDMS or small molecule dimethyl silicone compounds by the intravenous administration route may lead to death. We here determined a general parenteral permitted daily exposure (PDE) of 93 µg/day for inorganic silicon element and 100 µg/day for organic silicon element by reviewing toxicological data of both forms of silicon. In conclusion, this work provides evidence for pharmaceutical companies and regulatory agencies on the PDEs of silicon elements in pharmaceutical packaging and process components through a variety of administration routes.

Injectable pH-responsive hydrogel for combinatorial chemoimmunotherapy tailored to the tumor microenvironment.

Although combination chemoimmunotherapy shows promising clinical results for cancer treatment, this approach is largely restricted by variable objective response rate and severe systemic adverse effects of immunotherapeutic antibody and chemotherapeutic drugs. Therefore, an in situ-formed therapeutic silk-chitosan composite scaffold is fabricated in this study to allow local release of the chemotherapeutic drug doxorubicin (DOX) and JQ1 (small molecular inhibitor used for the extraterminal protein BRD4 and bromodomain) with control release kinetics. DOX-JQ1@Gel contains a pH-degradable group that releases therapeutics in a weak acidic tumor microenvironment. The released DOX could directly kill tumor cells or lead to immunogenic cell death, thereby triggering the response of antitumor immunity. Meanwhile, chemotherapy-triggered antigen release and JQ1-mediated PD-L1 checkpoint blockade cumulatively contribute to trigger the response of antitumor immunity. Finally, the DOX-JQ1@Gel is locally injected to evaluate its synergistic cancer therapeutic effect, which is expected to improve objective response rate of immunotherapy and minimize systemic side effects.

Preclinical safety and hepatotoxicity evaluation of biomineralized copper sulfide nanoagents.

Albumin-biomineralized copper sulfide nanoparticles (Cu2-xS NPs) have attracted much attention as an emerging phototheranostic agent due to their advantages of facile preparation method and high biocompatibility. However, comprehensive preclinical safety evaluation is the only way to meet its further clinical translation. We herein evaluate detailedly the safety and hepatotoxicity of bovine serum albumin-biomineralized Cu2-xS (BSA@Cu2-xS) NPs with two different sizes in rats. Large-sized (LNPs, 17.8 nm) and small-sized (SNPs, 2.8 nm) BSA@Cu2-xS NPs with great near-infrared absorption and photothermal conversion efficiency are firstly obtained. Seven days after a single-dose intravenous administration, SNPs distributed throughout the body are cleared primarily through the feces, while a large amount of LNPs remained in the liver. A 14-day subacute toxicity study with a 28-day recovery period are conducted, showing long-term hepatotoxicity without recovery for LNPs but reversible toxicity for SNPs. Cellular uptake studies indicate that LNPs prefer to reside in Kupffer cells, leading to prolonged and delayed hepatotoxicity even after the cessation of NPs administration, while SNPs have much less Kupffer cell uptake. RNA-sequencing analysis for gene expression indicates that the inflammatory pathway, lipid metabolism pathway, drug metabolism-cytochrome P450 pathway, cholesterol/bile acid metabolism pathway, and copper ion transport/metabolism pathway are compromised in the liver by two sizes of BSA@Cu2-xS NPs, while only SNPs show a complete recovery of altered gene expression after NPs discontinuation. This study demonstrates that the translational feasibility of small-sized BSA@Cu2-xS NPs as excellent nanoagents with manageable hepatotoxicity.

Endotoxin contamination in ovalbumin as viewed from a nano-immunotherapy perspective.

Ovalbumin (OVA) is a model antigen commonly incorporated in smartly designed nanoparticles for delivery into antigen-presenting cells (APC), aiming to investigate the immune activity and therapeutic efficacy of nanoparticles that contain immunoregulatory compounds. However, the immunoresponse observed in nano-immunotherapy may unexpectedly arise from endotoxin impurity of OVA in the nanoparticles. Literature review shows that most researchers did not notice the importance of endotoxin-free OVA when used in nano-immunotherapy studies. Concentration at as low as 5 µg/ml OVA from Sigma-Aldrich (contains 0.625 ng/ml endotoxin) was able to activate APC such as dendritic cells and macrophages. Here, we proposed that the endotoxin impurity in OVA or the finished nanoproducts should be determined by both Limulus Amebocyte Lysate (LAL) and cell-based assay, to ensure the endotoxin-free quality of the nanoparticles. The endotoxin in OVA can be removed by endotoxin removal column and phase separation methods and endotoxin-free OVA can be purchased. This perspective alerts the researchers of endotoxin impurity of OVA that may transfer into the finished nanoparticles and introduce an unfavorable immunoregulatory function with false-positive results. OVA with minimal endotoxin level should be used in nano-immunotherapy studies to accurately reflect the true effects of nanoparticles on the immune system. This article is categorized under: Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

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.