Surface-Functionalized Modified Copper Sulfide Nanoparticles Enhance Checkpoint Blockade Tumor Immunotherapy by Photothermal Therapy and Antigen Capturing.

Nanomaterial-based tumor photothermal therapy (PTT) has attracted increasing attention and been a promising method for cancer treatment because of its low level of adverse effects and noninvasiveness. However, thermotherapy alone still cannot control tumor metastasis and recurrence. Here, we developed surface-functionalized modified copper sulfide nanoparticles (CuS NPs). CuS NPs can not only be used as photothermal mediators for tumor hyperthermia but can adsorb tumor antigens released during hyperthermia as an antigen-capturing agent to induce antitumor immune response. We selected maleimide polyethylene glycol-modified CuS NPs (CuS NPs-PEG-Mal) with stronger antigen adsorption capacity, in combination with an immune checkpoint blocker (anti-PD-L1) to evaluate the effect of hyperthermia, improving immunotherapy in a 4T1 breast cancer tumor model. The results showed that hyperthermia based on CuS NPs-PEG-Mal distinctly increased the levels of inflammatory cytokines in the serum, leading to a tumor immunogenic microenvironment. In cooperation with anti-PD-L1, PTT mediated by CuS NPs-PEG-Mal enhanced the number of tumor-infiltrating CD8+ T cells and inhibited the growth in primary and distant tumor sites of the 4T1 tumor model. The therapeutic strategies provide a simple and effective treatment option for metastatic and recurrent tumors.

One-pot synthesis of PEGylated plasmonic MoO(3-x) hollow nanospheres for photoacoustic imaging guided chemo-photothermal combinational therapy of cancer.

Engineering design of plasmonic nanomaterials as on-demand theranostic nanoagents with imaging, drug carrier, and photothermal therapy (PTT) functions have profound impact on treatment of cancer. Here, a facile 'one-pot' template-free hydrothermal route was firstly developed for synthesis of plasmonic oxygen deficiency molybdenum oxide hollow nanospheres functionalized by poly(ethylene glycol) (PEG-MoO(3-x) HNSs). The as-prepared PEG-MoO(3-x) HNSs not only have good biocompatibility but also exhibit obvious localized surface plasmon resonance (LSPR) absorption in the near-infrared (NIR) region. Especially, due to its intrinsic mesoporous properties and effective photothermal conversion efficiency upon 808-nm NIR laser irradiation, the PEG-MoO(3-x) HNSs can be applied as a pH/NIR laser dual-responsive camptothecin (CPT) drug delivery nanoplatform for chemotherapy as well as PTT to cancer cells. A remarkably improved synergistic therapeutic effect to pancreatic (PANC-1) tumor-bearing mice was obtained compared to the result of chemotherapy or PTT alone. Apart from its application for drug delivery, the PEG-MoO(3-x) HNSs can also be employed as an effective contrast nanoagent for photoacoustic (PAT) imaging because of its high NIR absorption, making it promising as a theranostic nanoagent for PAT imaging-guided chemo-photothermal combinational cancer therapy in the nanomedicine field.

Plasmon-mediated generation of reactive oxygen species from near-infrared light excited gold nanocages for photodynamic therapy in vitro.

We have performed fundamental assays of gold nanocages (AuNCs) as intrinsic inorganic photosensitizers mediating generation of reactive oxygen species (ROS) by plasmon-enabled photochemistry under near-infrared (NIR) one/two-photon irradiation. We disclosed that NIR light excited hot electrons transform into either ROS or hyperthermia. Electron spin resonance spectroscopy was applied to demonstrate the production of three main radical species, namely, singlet oxygen ((1)O2), superoxide radical anion (O2(-•)), and hydroxyl radical ((•)OH). The existence of hot electrons from irradiated AuNCs was confirmed by a well-designed photoelectrochemical experiment based on a three-electrode system. It could be speculated that surface plasmons excited in AuNCs first decay into hot electrons, and then the generated hot electrons sensitize oxygen to form ROS through energy and electron transfer modes. We also compared AuNCs' ROS generation efficiency in different surface chemical environments under one/two-photon irradiation and verified that, compared with one-photon irradiation, two-photon irradiation could bring about much more ROS. Furthermore, in vitro, under two-photon irradiation, ROS can trigger mitochondrial depolarization and caspase protein up-regulation to initiate tumor cell apoptosis. Meanwhile, hyperthermia mainly induces tumor cell necrosis. Our findings suggest that plasmon-mediated ROS and hyperthermia can be facilely regulated for optimized anticancer phototherapy.

Cytotoxicity and therapeutic effect of irinotecan combined with selenium nanoparticles.

Although chemotherapeutic drugs are widely applied for clinic tumor treatment, severe toxicity restricts their therapeutic efficacy. In this study, we reported a new form of selenium, selenium nanoparticles (Nano Se) which have significant lower toxicity and acceptable bioavailability. We investigated Nano Se as chemotherapy preventive agent to protect against toxicities of anticancer drug irinotecan and synergistically enhance the anti-tumor treatment effect in vitro and in vivo. The underlying mechanisms were also investigated. The combination of Nano Se and irinotecan showed increased cytotoxic effect with HCT-8 tumor cells likely by p53 mediated apoptosis. Nano Se inhibited growth of HCT-8 tumor cells partially through caspases mediated apoptosis. In vivo experiment showed Nano Se at a dose of 4 mg/kg/day significantly alleviated adverse effects induced by irinotecan (60 mg/kg) treatment. Nano Se alone treatment did not induce any toxic manifestations. The combination of Nano Se and irinotecan dramatically inhibited tumor growth and significantly induced apoptosis of tumor cells in HCT-8 cells xenografted tumor. Tumor inhibition rate was about 17.2%, 48.6% and 62.1% for Nano Se, irinotecan and the combination of Nano Se and irinotecan, respectively. The beneficial effects of Nano Se for tumor therapy were mainly ascribed to selectively regulating Nrf2-ARE (antioxidant responsive elements) pathway in tumor tissues and normal tissues. Our results suggest Nano Se is a promising selenium species with potential application in cancer treatment.

Supramolecular adducts of squaraine and protein for noninvasive tumor imaging and photothermal therapy in vivo.

Extensive efforts have been devoted to the development of near-infrared (NIR) dye-based imaging probes and/or photothermal agents for cancer theranostics in vivo. However, the intrinsic chemical instability and self-aggregation properties of NIR dyes in physiological condition limit their widely applications in the pre-clinic study in living animals. Squaraine dyes are among the most promising NIR fluorophores with high absorption coefficiencies, bright fluorescence and photostability. By introducing dicyanovinyl groups into conventional squaraine (SQ) skeleton. These acceptor-substituted SQ dyes not only show superior NIR fluorescence properties (longer wavelength, higher quantum yield) but also exhibit more chemical robustness. In this work, we demonstrated highly stable and biocompatible supramolecular adducts of SQ and the natural carrier protein, i.e., bovine serum albumin (BSA) (SQ⊂BSA) for tumor targeted imaging and photothermal therapy in vivo. SQ was selectively bound to BSA hydrophobic domain via hydrophobic and hydrogen bonding interactions with up to 80-fold enhanced fluorescence intensity. By covalently conjugating target ligands to BSA, the SQ⊂BSA was capable of targeting tumor sites and allowed for monitoring the time-dependent biodistribution of SQ⊂BSA, which consequently determined the protocol of photothermal therapy in vivo. We envision that this supramolecular strategy for selectively binding functional imaging agents and/or drugs into human serum albumin might potentially utilize in the preclinical and even clinic studies in the future.

Hyperthermia inhibits the proliferation and invasive ability of mouse malignant melanoma through TGF-ß(1).

The degradation of basement membranes by tumor cells involves secretion and activation of proteinases, such as the matrix metalloproteinases (MMPs), and results from an imbalance between their inhibitors and activators that are controlled by various growth factors or cytokines, among which TGF-ß(1) may be the most intriguing. In order to study the therapeutic effect and molecular mechanism of hyperthermia on aggressive malignant melanoma, the expression levels of TGF-ß(1) and Smad4 in B16F10 cells were dynamically analyzed by RT-PCR and western blotting for 24 h after heat treatment, from which time-dependent changes were determined. As expected, the proliferation and invasive ability of B16F10 cells were suppressed strongly by heat treatment. Furthermore, we compared the expression of TGF-ß(1) in melanoma mouse models before and after magnetic fluid hyperthermia (MFH) in vivo. After hyperthermia, the tumor growth rate was reduced with a decline in TGF-ß(1) protein expression. We conclude that changes in the TGF-ß(1) pathway induced by hyperthermia may be an important part of the molecular mechanism involved.

[Changes of brain oxidative stress induced by nano-alumina in ICR mice].

OBJECTIVE: To investigate the brain oxidative stress injury induced by nano-alumina particles in ICR mice. METHODS: Sixty male ICR mice were randomly divided into 6 groups: control group, solvent control group, 100 mg/kg micro-alumina particles group, 3 groups exposed to nano-alumina particles at the doses of 50, 100 and 200 mg/kg. The mice were exposed by nasal drip for 30 days. Then levels of malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-PX) in brain tissues of mice were detected. RESULTS: There was no difference of SOD activity in mouse brain between control group [(17.32 +/- 6.23)U/gHb] and 50 mg/kg nano-alumina particles group [(17.89 +/- 1.82) U/gHb]. The SOD activity [(4.93 +/- 2.30)U/gHb] in 200 mg/kg nano-alumina particles group was significantly lower than that in control group (P < 0.05). The MDA levels in 3 nano-alumina particles groups were (0.76 +/- 0.13), (1.00 +/- 0.30) and (1.16 +/- 0.39)nmol/ml, respectively, which were significantly higher than that [( 0.24 +/- 0.09)nmol/ml] in control group (P < 0.05). The GSH levels in 3 nano-alumina particles groups were (0.72 +/- 0.08), (0.55 +/- 0.19) and (0.61 +/- 0.20)mg/gpro, respectively, which were significantly lower than that [(1.55 +/- 0.34)mg/gpro]] in control group (P < 0.05). The CAT activity in 50 and 100 mg/kg nano-alumina particles groups were (10.40 +/- 3.84) and (10.40 +/- 2.00)U/mgpro, respectively, which were significantly higher than that [(5.79 +/- 0.96) U/mgpro] in control group (P < 0.05). The CAT activity [(3.25 +/- 1.04)U/mgpro] in 200 mg/kg nano-alumina particles group was significantly lower than that in control group (P < 0.05 ). CONCLUSION: Nano-alumina particles can induce the oxidative stress damage in brain tissues of mice.

Effect of hyperthermia on invasion ability and TGF-ß1 expression of breast carcinoma MCF-7 cells.

The present study aimed to investigate heating-induced alterations of breast cancer cell invasion abilities and the potential mechanisms associated with TGF-ß1 expression. MCF-7 cells were heated at 43, 45, 47 and 37 °C for 30 min. In vitro cell invasion ability was evaluated by matrigel invasion assay. The activity of matrix metalloproteinase (MMP)-2/9 was investigated by gelatin zymographic assays. Expression of vascular endothelial growth factor (VEGF) and transforming growth factor-ß1 (TGF-ß1) was investigated by immunocytochemistry and RT-PCR. Apoptosis was analysed by flow-cytometry. The invasive potential of MCF-7 cells was reduced by heating, and MMP-2/9 secretion and enzymatic activity were suppressed. Furthermore, VEGF and TGF-ß1 mRNA and proteins were suppressed by hyperthermia. These results suggest that down-regulation of the expression of TGF-ß1, EGF and MMPs by hyperthermia probably accounts for the inhibition of the invasive abilities of MCF-7 cells.

Glutaraldehyde mediated conjugation of amino-coated magnetic nanoparticles with albumin protein for nanothermotherapy.

A novel bioconjugation of amino saline capped Fe3O4 magnetic nanoparticles (MNPs) with bovine serum albumin (BSA) was developed by applying glutaraldehyde as activator. Briefly, Fe3O4 MNs were synthesized by the chemical co-precipitation method. Surface modification of the prepared MNPs was performed by employing amino saline as the coating agent. Glutaraldehyde was further applied as an activation agent through which BSA was conjugated to the amino-coated MNPs. The structure of the BSA-MNs was confirmed by FTIR analysis. Physico-chemical characterizations of the BSA-MNPs, such as surface morphology, surface charge and magnetic properties were investigated by Transmission Electron Microscopy (TEM), zeta-Potential and Vibrating Sample Magnetometer (VSM), etc. Magnetic inductive heating characteristics of the BSA-MNPs were analyzed by exposing the MNPs suspension (magnetic fluid) under alternative magnetic field (AMF). The results demonstrate that BSA was successfully conjugated with amino-coated MNs mediated through glutaraldehyde activation. The nanoparticles were spherical shaped with approximately 10 nm diameter. Possessing ideal magnetic inductive heating characteristics, which can generate very rapid and efficient heating while upon AMF exposure, BSA-MNPs can be applied as a novel candidature for magnetic nanothermotherapy for cancer treatment. In vitro cytotoxicity study on the human hepatocellular liver carcinoma cells (HepG-2) indicates that BSA-MNP is an efficient agent for cancer nanothermotherapy with satisfied biocompatibility, as rare cytotoxicity was observed in the absence of AMF. Moreover, our investigation provides a methodology for fabrication protein conjugated MNPs, for instance monoclonal antibody conjugated MNPs for targeting cancer nanothermotherapy.

[Cell toxicity assessment methodologies applied in the study of the toxicity of nano-alumina to nerve cells].

OBJECTIVE: To observe the effect of nano-alumina on nerve cell viability through different detection kits of cell viability, using micro-alumina and nano-carbon as controls. METHODS: Primary culturing nerve cells of mouse in vitro, which were exposed to 7 doses of 0 µmol/L, 62.5 µmol/L, 125.0 µmol/L, 250.0 µmol/L, 500.0 µmol/L, 1.0 mmol/L, 2.0 mmol/L concentrations of nano-alumina (nano-Al), micro alumina (micro-Al) and nano-carbon (nano-C), detecting cell viability (A(570) values) with CCK-8, MTT and LDH methods. RESULTS: (1) The results of CCK-8 kit showed that, in doses of 250.0 µmol/L - 2.0 mmol/L, the cell viability values of nano-alumina (the values of A(570) were 0.878 ± 0.009, 0.823 ± 0.016, 0.647 ± 0.008, 0.594 ± 0.013, respectively) were significantly lower than that of micro-Al (the values of A(570) were 0.960 ± 0.008, 0.951 ± 0.036, 0.833 ± 0.008, 0.708 ± 0.012, respectively) and nano-C (the values of A(570) were 0.977 ± 0.003, 0.973 ± 0.002, 0.924 ± 0.006, 0.891 ± 0.023, respectively). While, comparing nano-Al with the same dose of micro-Al, there was significant difference (the t values were -0.082, -0.128, -0.186, -0.114, respectively, P < 0.01), and so as to the comparison of nano-Al with the same dose of nano-C (the t values were -0.099, -0.150, -0.277, -0.297, respectively, P < 0.01). (2) MTT results showed that in the doses of 500.0 µmol/L and 1.0 mmol/L, the cell viability of nano-Al (the values of A(570) were 0.648 ± 0.095 and 0.575 ± 0.061) were lower than that of micro-Al (the values of A(570) were 0.830 ± 0.044 and 0.816 ± 0.014) and nano-C (the values of A(570) were 0.889 ± 0.009 and 0.765 ± 0.049), and the differences were significant (nano-Al compared with the same dose of micro-Al, the t values were -0.183 and -0.242, P < 0.01; nano-Al compared with the same dose of nano-C, the t values were -0.241 and -0.190, P < 0.01). (3) LDH results showed that in the dose from 125.0 µmol/L to 2.0 mmol/L, the LDH release of nano-Al group (the values of A(570) were 1.862 ± 0.102, 1.905 ± 0.066, 1.930 ± 0.037, 1.946 ± 0.033, 1.967 ± 0.068, respectively) were higher than that of nano-C (the values of A(570) were 1.484 ± 0.110, 1.559 ± 0.039, 1.663 ± 0.014, 1.732 ± 0.076, 1.765 ± 0.073, respectively), and the differences were significant (the t values were -0.377, 0.346, 0.266, 0.213, 0.202, respectively, P < 0.01). In the dose from 125.0 µmol/L to 1.0 mmol/L, the LDH release of nano-Al group were higher than that of micro-Al (the values of A(570) were 1.578 ± 0.011, 1.639 ± 0.025, 1.727 ± 0.024, 1.808 ± 0.020, respectively), and the differences were significant (the t values were 0.284, 0.266, 0.202, 0.172, respectively, P < 0.01). CONCLUSION: The toxicity of nano-Al is greater than nano-C and micro-Al on the viability of nerve cells; LDH is more suitable for detecting changes of cell viability after the effect of nano-materials than CCK-8 and MTT.

Thermoseed hyperthermia treatment of mammary orthotopic transplantation tumors in rats and impact on immune function.

To evaluate the effect of thermoseed inductive heating on mammary orthotopic transplantation tumors and immunologic function in rats. Walker-256 tumor cells were inoculated subcutaneously into the mammary glands of Wistar rats. Rats were allocated to five treatment groups as follows: i) C group (control group); ii) M group (magnetic field group); iii) T group (thermoseed control group); iv) H1 group (hyperthermia treatment, 45 degrees C for 30 min); v) H2 group (hyperthermia treatment, 50-55 degrees C for 10 min). Immediately, 12 and 24 h after hyperthermia, two rats were sacrificed in each group for pathological and immunohistochemical examination of the expression of PCNA and HSP70. Tumor volume was measured and long-term survival was observed. The T lymphocyte subgroup IL-2 and IFN-gamma levels were measured in C, H1 and H2 groups. Both types of hyperthermia induced necrosis and apoptosis in the tumor tissue, decreased tumor volume (P<0.05), and increased survival time (P<0.01). The expression of PCNA and HSP70 in hyperthermia group was significantly different compared to the C, M and T groups (P<0.05), Hyperthermia increased CD4+ T lymphocytes and the levels of IL-2 and IFN-gamma (P<0.05). Both types of hyperthermia can suppress the growth of mammary tumors and improve immunological function of rats.