Salinomycin and IR780-loaded upconversion nanoparticles influence biological behavior of liver cancer stem cells by persistently activating the MAPK signaling pathway.

The combination of chemotherapy and phototherapy has emerged as a promising therapeutic approach for enhancing the efficacy of cancer treatment and mitigating drug resistance. Salinomycin (SAL), a polyether antibiotic, exhibits potent cytotoxicity against chemotherapy-resistant cancer cells. IR780 iodide, a novel photosensitive reagent with excellent near-infrared (NIR) light absorption and photothermal conversion abilities, is suitable for use in photothermal therapy for cancers. However, both SAL and IR780 exhibit hydrophobic properties that limit their clinical applicability. Upconversion nanoparticles (UCNPs) are an emerging class of fluorescent probe materials capable of emitting high-energy photons upon excitation by low-energy NIR light. The UCNPs not only function as nanocarriers for drug delivery but also serve as light transducers to activate photosensitizers for deep-tissue photodynamic therapy. Here, to enhance the targeting and bioavailability of hydrophobic drugs in liver cancer stem cells (LCSCs), we employ distearoyl phosphorethanolamine-polyethylene glycol (DSPE-PEG) to encapsulate SAL and IR780 on the surface of UCNPs. Cell viability was evaluated using the CCK-8 assay. Cell migration was assessed by the Transwell Boyden Chamber. The activation of the mitogen-activated protein kinase (MAPK) signaling pathway was measured via western blot. The results demonstrated successful loading of both IR780 and SAL onto the UCNPs, and the SAL and IR780-loaded UCNPs (UISP) exhibited a robust photothermal effect under NIR light irradiation. The UISP effectively inhibited the viability of HCCLM3 and LCSCs. Under NIR light irradiation, the UISP further suppressed HCCLM3 viability but had no impact on LCSC viability; however, it could further inhibit LCSC migration. Meanwhile, under NIR light irradiation, the UISP persistently activated the MAPK pathway more significantly in LCSCs. These findings suggest that exposure to NIR light results in persistent activation of the MAPK pathway by UISP, thereby influencing the biological behavior of LCSCs and enhancing their therapeutic efficacy against liver cancer.

Hollow MnO2-Based Nanoprobes for Enhanced Photothermal/Photodynamic /Chemodynamic Co-Therapy of Hepatocellular Carcinoma.

PURPOSE: The effect of monotherapy in cancer is frequently influenced by the tumor's unique hypoxic microenvironment, insufficient drug concentration at the treatment site, and tumour cells' increased drug tolerance. In this work, we expect to design a novel therapeutic nanoprobe with the ability to solve these problems and improve the efficacy of antitumor therapy. METHODS: We have prepared a hollow manganese dioxide nanoprobes loaded with photosensitive drug IR780 for the photothermal/photodynamic/chemodynamic co-therapy of liver cancer. RESULTS: The nanoprobe demonstrates efficient thermal transformation ability under a single laser irradiation, and under the synergistic influence of photo heat, accelerates the Fenton/ Fenton-like reaction efficiency based on Mn2+ ions to produce more ·OH under the synergistic effect of photo heat. Moreover, the oxygen released under the degradation of manganese dioxide further promotes the ability of photosensitive drugs to produce singlet oxygen (ROS). The nanoprobe has been found to efficiently destroy tumour cells in vivo and in vitro experiments when used in combination with photothermal/photodynamic/ chemodynamic modes of treatment under laser irradiation. CONCLUSION: In all, this research shows that a therapeutic strategy based on this nanoprobe could be a viable alternative for cancer treatment in the near future.

Intravesical IR-780 instillation prevents radiation cystitis by protecting urothelial integrity.

PURPOSE: To explore an efficient preventive strategy for radiation cystitis. METHODS: We instilled IR-780 into the bladders of rats 1 h before bladder irradiation, and its bio-distribution was observed at different times. Bladders were then examined for pathogenic alterations and inflammation levels by day 3 and week 12 postirradiation, and the functional characteristics of the bladder were tested via cystometry by week 12. Human uroepithelial sv-huc-1 cells were used to determine the effect of IR-780 on cell viability, regardless of irradiation. We measured the intracellular levels of oxidative stress, DNA damage, apoptosis proportion, and the expression of antioxidant proteases and apoptotic caspases in IR-780 pretreated cells after radiation. RESULTS: IR-780 is localized in the urothelium after intravesical instillation in vivo. Ionizing radiation could induce acute impairment of the bladder urothelium and inflammation in the bladder on day 3. Fibrosis of the irradiated bladder progressed and eventually affected voiding function at 12 weeks. Treatment with IR-780 before irradiation ameliorated these changes. In vitro, IR-780 protected against cell viability and apoptosis of sv-huc-1 cells after irradiation. Additionally, IR-780 may assist in eliminating reactive oxygen species and repairing irradiation-induced DNA damage. CONCLUSION: Our data indicate that IR-780 can be used before irradiation to prevent acute urinary mucosal injury and late bladder dysfunction. Moreover, early urothelial impairment plays a significant role in radiation cystitis development.

IR780 loaded gelatin-PEG coated gold core silica shell nanorods for cancer-targeted photothermal/photodynamic therapy.

Gold core silica shell (AuMSS) nanorods present excellent physicochemical properties that allow their application as photothermal and drug delivery agents. Herein, AuMSS nanorods were dual-functionalized with Polyethylene glycol methyl ether (PEG-CH3 ) and Gelatin (GEL) to enhance both the colloidal stability and uptake by HeLa cancer cells. Additionally, the AuMSS nanorods were combined for the first time with IR780 (a heptamethine cyanine molecule) and its photothermal and photodynamic capacities were determined. The obtained results reveal that the encapsulation of IR780 (65 µg per AuMSS mg) increases the photothermal conversion efficiency of AuMSS nanorods by 10%, and this enhanced heat generation was maintained even after three irradiation cycles with a NIR (808 nm) laser. Moreover, the IR780-loaded AuMSS/T-PEG-CH3 /T-GEL presented ≈2-times higher uptake in HeLa cells, when compared to the non-coated counterparts, and successfully mediated the light-triggered generation of reactive oxygen species. Overall, the combination of photodynamic and photothermal therapy mediated by IR780-loaded AuMSS/T-PEG-CH3 /T-GEL nanorods effectively promoted the ablation of HeLa cancer cells.

[Preparation and effect against cervical cancer invasion in vitro of harmine-loaded photosensitive liposomes].

Despite the development of HPV vaccines and screening programs, cervical cancer is still a serious threat to women's health. Early-stage cervical cancer is mainly treated by surgery. However, considering the serious complications after surgery, hyperthermia is recommended to enhance the effect of chemotherapy, retain the integrity of cervix, improve the treatment effect, which provides a therapeutic basis for the early treatment of cervical cancer. The photosensitive liposomes containing harmine and dye IR-780 were prepared by thin-film dispersion method and separated by Sephadex G-50 dextran gel column. The preparation conditions were optimized as the mass ratio of phospholipid to cholesterol membrane material being 8∶1 and that of drug to lipid being 1∶20. The results of HPLC showed that the encapsulation efficiency of harmine was 55.6%±0.18%. The prepared photosensitive liposomes were round and evenly distributed under transmission electron microscope, with the particle size of(125.2±0.62) nm determined by Marvin particle size analyzer and the Zeta potential of(-2.55±0.76) mV. Additionally, the photosensitive liposomes had the photothermal conversion efficiency, an important property of photothermal agent, of 27.1%±0.86%. The photosensitive liposomes stored at 4 ℃ showed stable encapsulation efficiency in the first 14 days without flocculation. The sulforhodamine B(SRB) assay was employed to determine the inhibitory effect of the liposomes on the proliferation of HeLa cells under near-infrared(NIR) irradiation or not, which showcased stronger inhibitory effect under NIR irradiation. The results of Transwell assay indicated that the prepared liposomes significantly inhibited the invasion and migration of HeLa cells in vitro. The findings of this study provide a basis for the treatment of cervical cancer with harmine.

Design, synthesis and application of near-infrared fluorescence probe IR-780-Crizotinib in detection of ALK positive tumors.

At present, the early diagnosis and treatment of NSCLC has become an international research hotspot. However, how to realize the organic combination of highly sensitive and high-resolution tumor imaging diagnosis and effective treatment, and to provide effective information for the diagnosis and treatment of cancer is still a major problem in the integration of cancer diagnosis and treatment. In this study, based on the Crizotinib has a good targeted inhibitory effect on ALK positive tumor cells, the near-infrared targeted fluorescent dye IR-780 was covalently bound with the drug molecule Crizotinib, thus the near-infrared fluorescent probe IR-780-Crizotinib targeting ALK positive tumor cells was synthesized. The probe structure is confirmed by NMR and MS. The optical properties of the fluorescent probe and the imaging process in ALK positive tumor-bearing mice were analyzed using ultraviolet spectrophotometer, near-infrared fluorescence spectrometer, and near-infrared fluorescence imaging system. The results show that the probe had better photoactivity. In vivo imaging shows that the probe maintained the biological activity of Crizotinib, effectively targeting the tumor site involved with clear imaging, and ultimately excreted from the body. It was confirmed that the probe could be used for the tracking, positioning and targeted therapy of nude mice with ALK positive tumors in vivo, thus exploring a new approach for the clinical application of near-infrared fluorescent probe to detect ALK positive tumors in the future.

Dye-loaded mesoporous polydopamine nanoparticles for multimodal tumor theranostics with enhanced immunogenic cell death.

BACKGROUND: Tumor phototherapy especially photodynamic therapy (PDT) or photothermal therapy (PTT), has been considered as an attractive strategy to elicit significant immunogenic cell death (ICD) at an optimal tumor retention of PDT/PTT agents. Heptamethine cyanine dye (IR-780), a promising PDT/PTT agent, which can be used for near-infrared (NIR) fluorescence/photoacoustic (PA) imaging guided tumor phototherapy, however, the strong hydrophobicity, short circulation time, and potential toxicity in vivo hinder its biomedical applications. To address this challenge, we developed mesoporous polydopamine nanoparticles (MPDA) with excellent biocompatibility, PTT efficacy, and PA imaging ability, facilitating an efficient loading and protection of hydrophobic IR-780. RESULTS: The IR-780 loaded MPDA (IR-780@MPDA) exhibited high loading capacity of IR-780 (49.7 wt%), good physiological solubility and stability, and reduced toxicity. In vivo NIR fluorescence and PA imaging revealed high tumor accumulation of IR-780@MPDA. Furthermore, the combined PDT/PTT of IR-780@MPDA could induce ICD, triggered immunotherapeutic response to breast tumor by the activation of cytotoxic T cells, resulting in significant suppression of tumor growth in vivo. CONCLUSION: This study demonstrated that the as-developed compact and biocompatible platform could induce combined PDT/PTT and accelerate immune activation via excellent tumor accumulation ability, offering multimodal tumor theranostics with negligible systemic toxicity.

Biomimetic recombinant of red blood cell membranes for improved photothermal therapy.

BACKGROUND: RBC membrane derived nanoparticles (NPs) represent an emerging platform with prolonged circulation capacity for the delivery of active substances. For functionalize derived RBCs NPs, various strategies, such as biomimetic rebuilding of RBCs, chemical modification or inserting ligands, have been carried out to improve their performance. However, one potential adverse effect for these methods is the structural failure of membrane proteins, consequently affecting its original immune escape function. RESULTS: In this study, we reported a green technology of "disassembly-reassembly" to prepare biomimetic reconstituted RBCs membrane (rRBCs) by separating the endogenous proteins and lipids from nature RBC membrane. IR780 iodide was used as a pattern drug to verify the property and feasibility of rRBCs by constructing IR780@rRBC NPs with IR780@RBC NPs and free IR780 as controls. The results demonstrated the superiority of IR780@rRBC NPs in toxicity, stability, pharmacokinetics and pharmacodynamics compared with IR780@rRBC and free IR780. CONCLUSIONS: The reported "disassembly-reassembly" strategy shows great potential to produce controllable and versatile rRBC membrane-inspired delivery platform, which may be used to overcome the deficiency of functionalization in cell membrane coated nanoparticles .

A Lipophilic IR-780 Dye-Encapsulated Zwitterionic Polymer-Lipid Micellar Nanoparticle for Enhanced Photothermal Therapy and NIR-Based Fluorescence Imaging in a Cervical Tumor Mouse Model.

To prolong blood circulation and avoid the triggering of immune responses, nanoparticles in the bloodstream require conjugation with polyethylene glycol (PEG). However, PEGylation hinders the interaction between the nanoparticles and the tumor cells and therefore limits the applications of PEGylated nanoparticles for therapeutic drug delivery. To overcome this limitation, zwitterionic materials can be used to enhance the systemic blood circulation and tumor-specific delivery of hydrophobic agents such as IR-780 iodide dye for photothermal therapy. Herein, we developed micellar nanoparticles using the amphiphilic homopolymer poly(12-(methacryloyloxy)dodecyl phosphorylcholine) (PCB-lipid) synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The PCB-lipid can self-assemble into micelles and encapsulate IR-780 dye (PCB-lipid-IR-780). Our results demonstrated that PCB-lipid-IR-780 nanoparticle (NP) exhibited low cytotoxicity and remarkable photothermal cytotoxicity to cervical cancer cells (TC-1) upon near-infrared (NIR) laser irradiation. The biodistribution of PCB-lipid-IR-780 showed higher accumulation of PCB-lipid-IR-780 than that of free IR-780 in the TC-1 tumor. Furthermore, following NIR laser irradiation of the tumor region, the PCB-lipid-IR-780 accumulated in the tumor facilitated enhanced tumor ablation and subsequent tumor regression in the TC-1 xenograft model. Hence, these zwitterionic polymer-lipid hybrid micellar nanoparticles show great potential for cancer theranostics and might be beneficial for clinical applications.

Photothermal, Targeting, Theranostic Near-Infrared Nanoagent with SN38 against Colorectal Cancer for Chemothermal Therapy.

Cancer research regarding near-infrared (NIR) agents for chemothermal therapy (CTT) has shown that agents with specific functions are able to inhibit tumor growth. The aim of current study was to optimize CTT efficacy for treatment of colorectal cancer (CRC) by exploring strategies which can localize high temperature within tumors and maximize chemotherapeutic drug uptake. We designed a new and simple multifunctional NIR nanoagent composed of the NIR cyanine dye, polyethylene glycol, and a cyclic arginine-glycine-aspartic acid peptide and loaded with the anti-CRC chemotherapeutic agent, 7-ethyl-10-hydroxy-camptothecin (SN38). Each component of this nanoagent exhibited its specific functions that help boost CTT efficacy. The results showed that this nanoagent greatly strengthens the theranostic effect of SN38 and CTT against CRC due to its NIR imaging ability, photothermal, enhanced permeability and retention (EPR) effect, reticuloendothelial system avoidance, and angiogenic blood vessel-targeting properties. This NIR nanoagent will help facilitate development of new strategies for treating CRC.

Preparation of Biocompatible Near-Infrared Fluorescent Nanoparticles for Cellular Imaging.

This study presents a novel and simple method to prepare a new biocompatible near-infrared (NIR) IR-780 nanoparticles (NPs) by modifying a bio-inspired silification approach. The solubility of as-prepared IR-780 NPs was greatly increased and the fluorescence intensity was dramatically enhanced by 5­7 fold compared to free IR-780 dye. Also, an exceptionally small size of 28 nm and the colloidal stability of the IR-780 NPs were sufficient to realize the desired permeability and retention effect (EPR). Furthermore, the in vitro cell viability assays indicated that the IR-780 NPs were highly safe even at the highest concentration of 1.0 mg/mL. The in vitro studies using MDA-231 breast cancer cells showed that the IR-780 NPs were successfully uptaken by the cancer cells and located at the cytoplasm of the cells. The results suggest that the IR-780 NPs may be a promising fluorescence imaging agent for clinical application.

Novel dual-mode nanobubbles as potential targeted contrast agents for female tumors exploration.

The purpose of this study was to prepare tumor-specific dual-mode nanobubbles as both ultrasound contrast agents (UCAs) and near-infrared fluorescence (NIRF) imaging agents for female tumors. Recent studies have demonstrated the conjugation of anti-tumor ligands on the surface of nanobubbles for use as molecule-targeting ultrasound contrast agents for tumor visualization. However, this complicated procedure has also posed a challenge to nanobubble stability. Thus, in the present study, we combined the fluorescent dye, NIRF IR-780 iodide, which has lipid solubility and tumor-targeting characteristics, with the phospholipid film of nanobubbles that we constructed. We then characterized the physical features of the IR-780-nanobubbles, observed their tumor-targeting capacity in multiple female tumor cell types in vitro, and verified their capability for use in tumor-specific ultrasound contrast imaging and NIRF imaging in vivo. The results showed that the new IR-780-nanobubbles had a uniform nano-size (442.5 ± 48.6 nm) and stability and that they were safe and effective at NIRF imaging and ultrasound imaging in vitro. The IR-780-nanobubbles were found to automatically accumulate on different female tumor cells in vitro with a considerable targeting rate (close to 40 %) but did not accumulate on cardiac muscle cells used as a negative control. Importantly, the IR-780-nanobubbles can detect female tumors precisely via dual-mode imaging in vivo. In conclusion, the new dual-mode IR-780-nanobubbles are stable and have potential advantages in non-invasive tumor-specific detection for female tumors via contrast-enhanced ultrasound and NIRF imaging.

Photothermal Ablation of in Situ Renal Tumor by PEG-IR780-C13 Micelles and Near-Infrared Irradiation.

PEG-IR780-C13 micelles have been demonstrated to be a novel photothermal agent with tumor-targeting property. This study was designed to explore the feasibility of applying PEG-IR780-C13 micelles and near-infrared (NIR) irradiation for thermal ablation of renal tumor by using an in situ tumor model. In addition, the potential thermal injury to normal renal tissue was evaluated. PEG-IR780-C13 micelles were intended to accumulate in renal tumor after systemic delivery. In vitro results revealed that PEG-IR780-C13 micelles were uptaken by RENCA cells mainly through caveola-mediated endocytosis and mainly distributed in late endosomes and lysosomes. Upon NIR irradiation, PEG-IR780-C13 micelles generated heat effectively both in vitro and in vivo, exhibiting a promising photothermal therapeutic property. The photothermal effect of PEG-IR780-C13 micelles could effectively destroy RENCA cells in vitro and adequately inhibit growth of in situ renal tumor in vivo. Meanwhile, PEG-IR780-C13 micelles mediated photothermal therapy (PTT) resulting in only limited injury to normal renal tissue surrounding tumor sites. Our data indicated that PEG-IR780-C13 micelles mediating PTT could generate tumor-specific heat for destruction of renal tumor in a minimally invasive way, providing a novel strategy for thermal ablation of renal tumor.

Tumor-oriented and chemo-photothermal nanoplatform capable of sensitizing chemotherapy and ferroptosis against osteosarcoma metastasis.

The clinical use of chemotherapy for refractory osteosarcoma (OS) is limited due to its multiorgan toxicity. To overcome this challenge, new dosage forms and combination treatments, such as phototherapy, are being explored to improve targeted delivery and cytocompatibility of chemotherapeutic agents. In addition, inducing ferroptosis in iron-rich tumors could be a promising strategy to enhance OS therapy. In this study, a novel formulation was developed using natural biological H-ferritin (HFn) encapsulating the photosensitizer IR-780 and the chemotherapy drug gemcitabine (Gem) for OS-specific targeted therapy (HFn@Gem/IR-780 NPs). HFn@Gem/IR-780 NPs were designed to specifically bind and internalize into OS cells by interacting with transferrin receptor 1 (TfR1) which is overexpressed on the surface of OS cell membranes. The Gem and IR-780 were then released responsively under mildly acidic conditions in tumors. HFn@Gem/IR-780 NPs achieved cascaded antitumor therapeutic efficacy through the combination of chemotherapy and phototherapy under near-infrared irradiation in vitro and in vivo. Importantly, HFn@Gem/IR-780 NPs demonstrated excellent safety profile with significantly decreased drug exposure to normal organs, indicating its potential for reducing systemic toxicity. Thus, utilizing HFn as a vehicle to encapsulate highly effective antitumor drugs provides a promising approach for the treatment of OS metastasis and relapse.

Enhanced breast cancer treatment using phototherapy and RNS therapy with macrophage membrane-coated liposomes.

Breast cancer, the predominant malignancy afflicting women, continues to pose formidable challenges despite advancements in therapeutic interventions. This study elucidates the potential of phototherapy, comprising both photothermal and photodynamic therapy (PTT/PDT), as a novel and promising modality. To achieve this goal, we devised liposomes coated with macrophage cell membranes including macrophage-associated membrane proteins, which have demonstrated promise in biomimetic delivery systems for targeting tumors while preserving their inherent tumor-homing capabilities. This integrated biomimetic delivery system comprised IR780, NONOate, and perfluorocarbon. This strategic encapsulation aims to achieve a synergistic combination of photodynamic therapy (PDT) and reactive nitrogen species (RNS) therapy. Under near-infrared laser irradiation at 808 nm, IR780 demonstrates its ability to prolifically generate reactive oxygen species (ROS), including superoxide anion (O2•-), singlet oxygen, and hydroxyl radical (·OH). Simultaneously, NONOate releases nitric oxide (NO) gas upon the same laser irradiation, thereby engaging with IR780-induced ROS to facilitate the formation of peroxynitrite anion (ONOO-), ultimately inducing programmed cell death in cancer cells. Additionally, the perfluorocarbon component of our delivery system exhibits a notable affinity for oxygen and demonstrates efficient oxygen-carrying capabilities. Our results demonstrate that IR780-NO-PFH-Lip@M significantly enhances breast cancer cell toxicity, reducing proliferation and in vivo tumor growth through simultaneous heat, ROS, and RNS production. This study contributes valuable insights to the ongoing discourse on innovative strategies for advancing cancer therapeutics.

Molecular Probe with Potential for Combined Boron Neutron Capture and Photothermal Antitumor Therapy.

Both boron neutron capture therapy (BNCT) and photothermal therapy (PTT) have been applied to tumor treatment in clinical. However, their therapeutic efficacy is limited. For BNCT, the agents not only exhibit poor targeting ability but also permit only a single irradiation session within a course due to significant radiation risks. In the context of PTT, despite enhanced selectivity, the limited photothermal effect fails to meet clinical demands. Hence, the imperative arises to combine these two therapies to enhance tumor-killing capabilities and improve the targeting of BNCT agents by leveraging the advantages of PTT agents. In this study, we synthesized a potential responsive agent by linking 4-mercaptophenylboronic acid (MPBA) and IR-780 dye that served as the agents for BNCT and PTT, respectively, which possesses the dual capabilities of photothermal effects and thermal neutron capture. Results from both in vitro and in vivo research demonstrated that IR780-MPBA effectively inhibits tumor growth through its photothermal effect with no significant toxicity. Furthermore, IR780-MPBA exhibited substantial accumulation in tumor tissues and superior tumor-targeting capabilities compared with MPBA, which demonstrated that IR780-MPBA possesses significant potential as a combined antitumor therapy of PTT and BNCT, presenting a promising approach for antitumor treatments.

New Evidence on the Antiproliferative Activity of Campomanesia Adamantium (Cambess.) O. Berg Extracts in Melanoma Lung Metastasis.

Given the importance of discovering plant species from the Brazilian Cerrado biome with anticancer potential, this study evaluated the antitumor activity of two extracts of Campomanesi adamantium fruits in in vitro and in vivo models of melanoma lung metastasis. Pulp and peel extracts (DEGPU and DEGPE, respectively) were extracted from fresh fruit using dichloromethane as a solvent. As cytotoxicity parameter, concentration values that inhibited 50% cell growth (GI50), total growth inhibition (TGI), and selectivity index (SI) were established. The melanoma lung metastasis model was obtained by injecting 5 × 105/50 µL B16-F10 cells via the tail vein of mice, which received treatment on the 15th day. Metastatic lungs were collected for fluorescence analysis with the IR-780 marker and also macro- and microscopic assessment. In vitro analyses showed that DEGPU was active in K562 (GI50 32.99; TGI 47.93) and U-251 (GI50 32.10; TGI 249.92), whereas DEGPE showed better cytotoxicity results for all tumor cell lines, but was more efficient in K562 (GI50 27.42; TGI 40.20) and U-251 (GI50 4.89; TGI 12.77). Both showed a cytocidal effect on B16F10 at the highest concentration tested, with approximately 25% (DEGPU) and 88% (DEGPE) of cell death. In vivo analyzes showed that both extracts showed significant activity in metastatic lung. Fluorescence images showed differences in intensity between groups owing to greater tumor involvement. Macro- and microscopic images showed that treatments with extracts limited tumor growth and prevented proliferation. The extracts tested have promising activity, thus requiring further research on their active compounds.

Evaluation of the cytotoxic and immunomodulatory effects of sonodynamic therapy in human pancreatic cancer spheroids.

Sonodynamic therapy (SDT) exploits the energy generated by ultrasound (US) to activate sound-sensitive drugs (sonosensitizers), leading to the generation of reactive oxygen species (ROS) and cancer cell death. Two-dimensional (2D) and three-dimensional (3D) cultures of human pancreatic cancer BxPC-3 cells were chosen as the models with which to investigate the therapeutic effects of the US-activated sonosensitizer IR-780 as pancreatic cancer is still one of the most lethal types of cancer. The effects of SDT, including ROS production, cancer cell death and immunogenic cell death (ICD), were extensively investigated. When subjected to US, IR-780 triggered significant ROS production and caused cancer cell death after 24 h (p ≤ 0.01). Additionally, the activation of dendritic cells (DCs) led to an effective immune response against the cancer cells undergoing SDT-induced death. BxPC-3 spheroids were developed and studied extensively to validate the findings observed in 2D BxPC-3 cell cultures. An analysis of the pancreatic cancer spheroid section revealed significant SDT-induced cancer cell death after 48 h after the treatment (p ≤ 0.01), with this being accompanied by the presence of SDT-induced damage-associated molecular patterns (DAMPs), such as calreticulin (CRT) and high mobility group box 1 (HMGB1). In conclusion, the data obtained demonstrates the anticancer efficacy of SDT and its immunomodulatory potential via action as an ICD-inducer.

IR-780 Dye-based Targeting of Cancer-associated Fibroblasts Improves Cancer Immunotherapy by Increasing Intra-tumoral T Lymphocytes Infiltration.

BACKGROUND: Immune-checkpoint inhibitors (ICIs) against programmed death (PD)-1/PD-L1 pathway immunotherapy have been demonstrated to be effective in only a subset of patients with cancer, while the rest may exhibit low response or may develop drug resistance after initially responding. Previous studies have indicated that extensive collagen-rich stroma secreted by cancer-associated fibroblasts (CAFs) within the tumor microenvironment is one of the key obstructions of the immunotherapy for some tumors by decreasing the infiltrating cytotoxic T cells. However, there is still a lack of effective therapeutic strategies to control the extracellular matrix by targeting CAFs. METHODS: The enhanced uptake of IR-780 by CAFs was assessed by using in vivo or ex vivo nearinfrared fluorescence imaging, confocal NIR fluorescent imaging, and CAFs isolation testing. The fibrotic phenotype down-regulation effects and in vitro CAFs killing effect of IR-780 were tested by qPCR, western blot, and flow cytometry. The in vivo therapeutic enhancement of anti-PD-L1 by IR-780 was evaluated on EMT6 and MC38 subcutaneous xenograft mice models. RESULTS: IR-780 has been demonstrated to be preferentially taken up by CAFs and accumulate in the mitochondria. Further results identified low-dose IR-780 to downregulate the fibrotic phenotype, while high-dose IR-780 could directly kill both CAFs and EMT6 cells in vitro. Moreover, IR-780 significantly inhibited extracellular matrix (ECM) protein deposition in the peri-tumoral stroma on subcutaneous EMT6 and MC38 xenografts, which increased the proportion of tumor-infiltrating lymphocytes (TILs) in the deep tumor and further promoted anti-PD-L1 therapeutic efficacy. CONCLUSION: This work provides a unique strategy for the inhibition of ECM protein deposition in the tumor microenvironment by targeted regulating of CAFs, which destroys the T cell barrier and further promotes tumor response to PD-L1 monoclonal antibody. IR-780 has been proposed as a potential therapeutic small-molecule adjuvant to promote the effect of immunotherapy.

IR780-based diffuse fluorescence tomography for cancer detection.

IR780 iodide is a commercially available targeted near-infrared contrast agent for in vivo imaging and cancer photodynamic or photothermal therapy, whereas the accumulation, dynamics, and retention of IR780 in biological tissue, especially in tumor is still under-explored. Diffuse fluorescence tomography (DFT) can be used for localization and quantification of the three-dimensional distribution of NIR fluorophores. Herein, a homemade DFT imaging system combined with tumor-targeted IR780 was utilized for cancer imaging and pharmacokinetic evaluation. The aim of this study is to comprehensively assess the biochemical and pharmacokinetic characteristics of IR780 with the aid of DFT imaging. The optimal IR780 concentration (20 µg/mL) was achieved first. Subsequently, the good biocompatibility and cellar uptake of IR780 was demonstrated through the mouse acute toxic test and cell assay. In vivo, DFT imaging effectively identified various subcutaneous tumors and revealed the long-term retention of IR780 in tumors and rapid metabolism in the liver. Ex vivo imaging indicated IR780 was mainly concentrated in tumor and lung with significantly different from the distribution in other organs. DFT imaging allowed sensitive tumor detection and pharmacokinetic rates analysis. Simultaneously, the kinetics of IR780 in tumors and liver provided more valuable information for application and development of IR780.