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.

Bismuth nanomaterials as contrast agents for radiography and computed tomography imaging and their quality/safety considerations.

Contrast agents for radiography and computed tomography (CT) scans are substances that can enhance the contrast of blood vessels and soft tissue with detailed imaging information of the diseased sites. However, the large doses, short circulation time and adverse effects are the intrinsic limitations of CT contrast agents, preventing their extended and safe use in the clinical setting. Bismuth nanoparticles (NPs) have gained attention for the high X-ray absorption of bismuth elements with acceptable biocompatibility, showing their potential to be translated into commercialized CT contrast agents. Compared with traditional iodine contrast agents, bismuth NPs are characterized by prolonged circulation time and enhanced contrast, largely due to the surface modification and enhanced permeability and retention effect of NPs. Bismuth NPs can also be flexibly upgraded into sophisticated nanoagents for multimodal imaging and therapeutic purposes by complexation with supporting chemicals, small molecule drugs, fluorescence labels, and other functional agents. Additionally, the affinity and retention of the bismuth NPs in the diseased sites can be further improved by modification of the targeting moiety on the NPs surface. However, a simple synthetic process and low complexity of bismuth NPs are highly recommended for scaling out and quality control of nanoagents with commercialization potential. Since product safety is a prerequisite for the translation of bismuth NPs from bench to the clinic, we focus on recent advances in the distribution, elimination, and toxicity of bismuth NPs previously reported. Finally, we delineate the associated mechanisms for nephrotoxicity and the strategy to reduce the toxicity of bismuth NPs. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials.

[Study on potential hepatotoxicity of main monomers of Polygonum multiflorum based on liver micro-tissue].

In this study, we aimed to establish a rat liver micro-tissue evaluation system to evaluate the hepatotoxicity of the main monomers in Polygonum multiflorum. Rat primary hepatocytes were isolated and purified by two-step in situ perfusion method to prepare hepatic parenchymal cells. The ultra-low adsorption plate and the inverted model were used to establish an in vitro hepatotoxicity evaluation system. After the system was established, the main monomer components(monanthone with emodin type, rhein, emodin, emodin-8-O-ß-D-glucopyranoside, physcion) of P. multiflorum were selected for in vitro hepatotoxicity evaluation. This study showed that the primary cells of the liver can form liver micro-tissues in the low adsorption plate method and the mold perfusion method, with good liver structure and function, which can be used to evaluate the hepatotoxicity of the drug to be tested after long-term administration. The five monomers to be tested in P. multiflorum can significantly affect the proliferation of primary liver micro-tissues in rats in a dose-and time-dependent manner. The hepatotoxic effects were as follows: monanthone with emodin type > rhein > emodin > emodin-8-O-ß-D-glucopyranoside > physcion. The results suggested that the emodin-type monoterpene and rhein might be the potential hepatotoxic components, while the metabolites of emodin-8-O-ß-D-glucoside and emodin methyl ether showed more toxic risks. The rat primary hepatocyte micro-tissue model system established in this experiment could be used to achieve long-term drug administration in vitro, which was consistent with the clinical features of liver injury caused by long-term use of P. multiflorum. The experimental results provided important information and reference on the clinical application and toxic component of P. multiflorum.

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.

A NanoFlare-Based Strategy for In Situ Tumor Margin Demarcation and Neoadjuvant Gene/Photothermal Therapy.

Accurate tumor margin demarcation in situ remains a paramount challenge. Herein, a NanoFlare (also known as spherical-nucleic-acid technology) based strategy is reported for in situ tumor margin delineation by transforming and amplifying the pathophysiological redox signals of tumor microenvironment. The NanoFlare designed (named AuNS-ASON) is based on gold nanostar (AuNS) coated with a dense shell of disulfide bridge-inserted and cyanine dyes-labeled antisense oligonucleotides (ASON) targeting survivin mRNA. The unique anisotropic ASON-spike nanostructure endows the AuNS-ASON with universal cellular internalization of tumor cells, while the disulfide bridge inserted confers response specificity toward redox activation. In vitro experiments demonstrate that the AuNS-ASON can discriminate tumor cells rapidly with activated fluorescence signals (>100-fold) in 2 h, and further achieve synergistic gene/photothermal tumor cells ablation upon near-infrared laser irradiation. Remarkably, in situ tumor margin delineation with high accuracy and outstanding spatial resolution (<100 µm) in mice bearing different tumors is obtained based on the AuNS-ASON, providing intraoperative guidance for tumor resection. Moreover, the AuNS-ASON can enable efficient neoadjuvant gene/photothermal therapy before surgery to reduce tumor extent and increase resectability. The concept of NanoFlare-based microenvironment signal transformation and amplification could be used as a general strategy to guide the design of activatable nanoprobes for cancer theranostics.

Dose matters: Direct killing or immunoregulatory effects of natural polysaccharides in cancer treatment.

Polysaccharides from natural resources possess anti-tumor activities for decades, but the efficacy of polysaccharides as the adjuvant drugs for cancer treatment at prescribed doses remains open for debate. In this review, molecular mechanisms involved in direct killing effects of polysaccharides, including apoptosis, cell cycle arrest and mitochondria/DNA damage were described. However, the concentrations/doses used to reach the direct killing effects are too high to be applicable. Polysaccharides can also exert anti-tumor effects through immunoregulation at lower doses, and the effects of polysaccharides on natural killer cells, dendritic cells and other lymphocytes for tumor destruction, along with the receptor recognition and downstream signaling pathways, were delineated. Unfortunately, the prescribed doses of polysaccharides are too low to stimulate immunoresponse, resulting in the failure of some clinical trials. Therefore, understanding the sophisticated mechanisms of the immunoregulatory function of natural polysaccharides with refined doses for clinical use will help the standardization of traditional medicine.

Exposure and nephrotoxicity concern of bismuth with the occurrence of autophagy.

Metal nanoparticles or metal-based compounds have drawn attention in various fields ranging from industry to medicine because of their unique physicochemical properties. Bismuth (Bi) compounds and nanomaterials have been commonly used in alloys, electronic industry, batteries, and as flame retardants as well as for anti- Helicobacter pylori therapy, while the nanomaterial form has great potential for computed tomography imaging and thermotherapy, both of which will be introduced in this review. Although Bi was used for several decades, there is a lack of detailed information concerning their toxicity and mechanisms on human health. We described the toxicity of Bi on the kidney that seemed to be relatively known by researchers, while the mechanisms remain unclear. Recently, our group has found that Bi compounds, including bismuth nitrate (BN) and Bi nanomaterials, can induce autophagy in kidney cells. We also extended our findings by selecting five Bi compounds, and the results showed that BN, bismuth oxychloride, bismuth citrate, colloidal bismuth subcitrate, and Bi nanomaterials all induced slight cytotoxicity accompanied with autophagy. Although the role of autophagy in Bi-induced cytotoxicity and kidney injury is under investigation by us, autophagy may help with the exploration of the mechanisms of nephrotoxicity by Bi.

Protective effects of folic acid on PM2.5-induced cardiac developmental toxicity in zebrafish embryos by targeting AhR and Wnt/ß-catenin signal pathways.

Our previous observations indicated that extractable organic matter (EOM) from PM2.5 induced malformations in the heart of zebrafish embryos by activating AhR and inhibiting canonical Wnt/ß-catenin signal pathway. As a nutritional factor, folic acid (FA) is reported to prevent cardiac defects during embryo development. Hence, we hypothesize that FA may prevent PM2.5-induced heart defects by interfering with AhR and Wnt/ß-catenin signaling pathways. Our results showed that FA supplementation alleviated the EOM-induced heart defects in zebrafish embryos, and both AhR inhibitor CH223191 and Wnt activator CHIR99021 enhanced the protective efficiency of FA. Furthermore, FA supplementation attenuated the EOM-induced upregulation of AhR and its target genes including Cyp1a1, Cyp1b1, Ahrra, and Ahrrb. EROD assay confirmed that the EOM agonized Cyp1a1 activity was diminished by FA. The EOM-induced downregulation of ß-catenin and its target genes including Nkx2.5, Axin2, Sox9b, and Cox2b were recovered or even overexpressed in embryos exposed to EOM plus FA. In conclusion, our study suggested that FA supplementation protected against PM2.5 cardiac development toxicity by targeting AhR and Wnt/ß-catenin signal pathways.

Comparison of immunoregulatory effects of polysaccharides from three natural herbs and cellular uptake in dendritic cells.

Polysaccharides from different types of natural herbs have not been compared with each other to determine their differential potencies on innate immune response, such as maturation of dendritic cells (DC). In addition, the role of endocytosis of polysaccharides in DC maturation has not been explored previously. Polysaccharides isolated from Astragalus membranaceus (APS), Ganoderma lucidum (GLP) and Radix ophiopogonis (OGP) were characterized and applied in bone marrow derived DC. Compared to immature DC, three polysaccharides with immunoactivities showed elongated dendrites, decreased phagocytic abilities, phenotypic changes (CD40/MHCII/CD80/CD86) and increased level of nitric oxide (NO) in a dose dependent manner. Interestingly, blockage of NO by iNOS inhibitor slightly decreased CD40 and MHCII but not CD80/CD86 expression induced by polysaccharides, indicating that NO was partially involved in DC maturation. In addition, GLP can enter cells in a dose and time dependent manner, shown as punctate distribution in the cytoplasm. Endocytic inhibitors sodium azide and brefeldinA that were demonstrated to inhibit cellular uptake of GLP can block phenotypic maturation of DC. Taken together, these results suggested that polysaccharides from natural herbs are effective immunostimulators with variable potencies ranking as GLP>APS>OGP, and the increase of NO level as well as the increase in polysaccharide endocytosis could be the novel strategies for improved innate response and immunotherapy.

Safety assessment of potential food ingredients in canine hepatocytes.

This research aimed to develop in vitro methods to assess hazard of canine food ingredients. Canine hepatocytes were harvested and cell viability of clove-leaf oil (CLO), eugenol (EUG), lemongrass oil (LGO), guanosine monophosphate (GMP), inosine monophosphate (IMP), sorbose, ginger-root extract (GRE), cinnamon-bark oil (CBO), cinnamaldehyde (CINA), thymol oil (TO), thymol (THYM), and citric acid were assessed with positive controls: acetaminophen (APAP), aflatoxin B1 and xylitol. Molecular Toxicology PathwayFinder array (MTPF) analyzed toxicity mechanisms for LGO. LC50 for APAP was similar among human (3.45), rat (2.35), dog (4.26 mg/ml). Aflatoxin B1 had an LC50 of 4.43 (human), 5.78 (rat) and 6.05 (dog) µg/ml; xylitol did not decrease viability. LC50 of CLO (0.185 ± 0.075(SD)), EUG (0.165 ± 0.112), LGO (0.220 ± 0.012), GRE (1.54 ± 0.31) mg/ml; GMP (166.03 ± 41.83), GMP + IMP (208.67 ± 15.27) mM; CBO (0.08 ± 0.03), CINA (0.11 ± 0.01), TO (0.21 ± 0.03), THYM (0.05 ± 0.01), citric acid (1.58 ± 0.08) mg/ml, while sorbose was non-toxic. LGO induced upregulation of 16 and down-regulation of 24 genes, which CYP and heat shock most affected. These results suggest that in vitro assays such as this may be useful for hazard assessment of food ingredients for altered hepatic function.