Intratumor injected gold molecular clusters for NIR-II imaging and cancer therapy.

Surgical resections of solid tumors guided by visual inspection of tumor margins have been performed for over a century to treat cancer. Near-infrared (NIR) fluorescence labeling/imaging of tumor in the NIR-I (800 to 900 nm) range with systemically administrated fluorophore/tumor-targeting antibody conjugates have been introduced to improve tumor margin delineation, tumor removal accuracy, and patient survival. Here, we show Au25 molecular clusters functionalized with phosphorylcholine ligands (AuPC, ~2 nm in size) as a preclinical intratumorally injectable agent for NIR-II/SWIR (1,000 to 3,000 nm) fluorescence imaging-guided tumor resection. The AuPC clusters were found to be uniformly distributed in the 4T1 murine breast cancer tumor upon intratumor (i.t.) injection. The phosphocholine coating afforded highly stealth clusters, allowing a high percentage of AuPC to fill the tumor interstitial fluid space homogeneously. Intra-operative surgical navigation guided by imaging of the NIR-II fluorescence of AuPC allowed for complete and non-excessive tumor resection. The AuPC in tumors were also employed as a photothermal therapy (PTT) agent to uniformly heat up and eradicate tumors. Further, we performed in vivo NIR-IIb (1,500 to 1,700 nm) molecular imaging of the treated tumor using a quantum dot-Annexin V (QD-P3-Anx V) conjugate, revealing cancer cell apoptosis following PTT. The therapeutic functionalities of AuPC clusters combined with rapid renal excretion, high biocompatibility, and safety make them promising for clinical translation.

Shortwave-infrared-light-emitting probes for the in vivo tracking of cancer vaccines and the elicited immune responses.

Tracking and imaging immune cells in vivo non-invasively would offer insights into the immune responses induced by vaccination. Here we report a cancer vaccine consisting of polymer-coated NaErF4/NaYF4 core-shell down-conversion nanoparticles emitting luminescence in the near-infrared spectral window IIb (1,500-1,700 nm in wavelength) and with surface-conjugated antigen (ovalbumin) and electrostatically complexed adjuvant (class-B cytosine-phosphate-guanine). Whole-body wide-field imaging of the subcutaneously injected vaccine in tumour-bearing mice revealed rapid migration of the nanoparticles to lymph nodes through lymphatic vessels, with two doses of the vaccine leading to the complete eradication of pre-existing tumours and to the prophylactic inhibition of tumour growth. The abundance of antigen-specific CD8+ T lymphocytes in the tumour microenvironment correlated with vaccine efficacy, as we show via continuous-wave imaging and lifetime imaging of two intravenously injected near-infrared-emitting probes (CD8+-T-cell-targeted NaYbF4/NaYF4 nanoparticles and H-2Kb/ovalbumin257-264 tetramer/PbS/CdS quantum dots) excited at different wavelengths, and by volumetrically visualizing the three nanoparticles via light-sheet microscopy with structured illumination. Nanoparticle-based vaccines and imaging probes emitting infrared light may facilitate the design and optimization of immunotherapies.

Phosphorylcholine-conjugated gold-molecular clusters improve signal for Lymph Node NIR-II fluorescence imaging in preclinical cancer models.

Sentinel lymph node imaging and biopsy is important to clinical assessment of cancer metastasis, and novel non-radioactive lymphographic tracers have been actively pursued over the years. Here, we develop gold molecular clusters (Au25) functionalized by phosphorylcholine (PC) ligands for NIR-II (1000-3000 nm) fluorescence imaging of draining lymph nodes in 4T1 murine breast cancer and CT26 colon cancer tumor mouse models. The Au-phosphorylcholine (Au-PC) probes exhibit 'super-stealth' behavior with little interactions with serum proteins, cells and tissues in vivo, which differs from the indocyanine green (ICG) dye. Subcutaneous injection of Au-PC allows lymph node mapping by NIR-II fluorescence imaging at an optimal time of ~ 0.5 - 1 hour postinjection followed by rapid renal clearance. Preclinical NIR-II fluorescence LN imaging with Au-PC affords high signal to background ratios and high safety and biocompatibility, promising for future clinical translation.

Multiple primary pulmonary meningioma: A case report and literature review.

Lung cancer has become a leading cause of cancer-related deaths. With the conventional use of low-dose spiral computed tomography (CT) in physical examinations, an increasing number of small pulmonary nodules are screened. However, primary pulmonary meningiomas (PPMs) are rarely reported. Here, we report the case of a 64-year-old woman who had a CT scan during physical examination, which revealed three ground-glass-like opacity pulmonary nodules in both lungs. The patient underwent video-assisted thoracoscopic wedge resection of the right upper and lower lobes. Paraffin sections revealed pulmonary meningothelial-like and collagenous nodules in the right upper and lower lobes which stained as follows: EMA+, VIM+, SMA-, S-100-, CD34-, STAT6-, Ki-67+ (2%), and CgA-. Primary pulmonary meningiomas (PPMs) were finally diagnosed. PPM is a kind of rare and benign tumor. Surgery can provide a precise pathological examination, and patients can achieve an excellent prognosis after surgical resection.

In vivo non-invasive confocal fluorescence imaging beyond 1,700 nm using superconducting nanowire single-photon detectors.

Light scattering by biological tissues sets a limit to the penetration depth of high-resolution optical microscopy imaging of live mammals in vivo. An effective approach to reduce light scattering and increase imaging depth is to extend the excitation and emission wavelengths to the second near-infrared window (NIR-II) at >1,000 nm, also called the short-wavelength infrared window. Here we show biocompatible core-shell lead sulfide/cadmium sulfide quantum dots emitting at ~1,880 nm and superconducting nanowire single-photon detectors for single-photon detection up to 2,000 nm, enabling a one-photon excitation fluorescence imaging window in the 1,700-2,000 nm (NIR-IIc) range with 1,650 nm excitation-the longest one-photon excitation and emission for in vivo mouse imaging so far. Confocal fluorescence imaging in NIR-IIc reached an imaging depth of ~1,100 µm through an intact mouse head, and enabled non-invasive cellular-resolution imaging in the inguinal lymph nodes of mice without any surgery. We achieve in vivo molecular imaging of high endothelial venules with diameters as small as ~6.6 µm, as well as CD169 + macrophages and CD3 + T cells in the lymph nodes, opening the possibility of non-invasive intravital imaging of immune trafficking in lymph nodes at the single-cell/vessel-level longitudinally.

High-precision tumor resection down to few-cell level guided by NIR-IIb molecular fluorescence imaging.

In vivo fluorescence/luminescence imaging in the near-infrared-IIb (NIR-IIb, 1,500 to 1,700 nm) window under <1,000 nm excitation can afford subcentimeter imaging depth without any tissue autofluorescence, promising high-precision intraoperative navigation in the clinic. Here, we developed a compact imager for concurrent visible photographic and NIR-II (1,000 to 3,000 nm) fluorescence imaging for preclinical image-guided surgery. Biocompatible erbium-based rare-earth nanoparticles (ErNPs) with bright down-conversion luminescence in the NIR-IIb window were conjugated to TRC105 antibody for molecular imaging of CD105 angiogenesis markers in 4T1 murine breast tumors. Under a ∼940 ± 38 nm light-emitting diode (LED) excitation, NIR-IIb imaging of 1,500- to 1,700-nm emission afforded noninvasive tumor­to­normal tissue (T/NT) signal ratios of ∼40 before surgery and an ultrahigh intraoperative tumor-to-muscle (T/M) ratio of ∼300, resolving tumor margin unambiguously without interfering background signal from surrounding healthy tissues. High-resolution imaging resolved small numbers of residual cancer cells during surgery, allowing thorough and nonexcessive tumor removal at the few-cell level. NIR-IIb molecular imaging afforded 10-times-higher and 100-times-higher T/NT and T/M ratios, respectively, than imaging with IRDye800CW-TRC105 in the ∼900- to 1,300-nm range. The vastly improved resolution of tumor margin and diminished background open a paradigm of molecular imaging-guided surgery.

In vivo NIR-II structured-illumination light-sheet microscopy.

Noninvasive optical imaging with deep tissue penetration depth and high spatiotemporal resolution is important to longitudinally studying the biology at the single-cell level in live mammals, but has been challenging due to light scattering. Here, we developed near-infrared II (NIR-II) (1,000 to 1,700 nm) structured-illumination light-sheet microscopy (NIR-II SIM) with ultralong excitation and emission wavelengths up to ∼1,540 and ∼1,700 nm, respectively, suppressing light scattering to afford large volumetric three-dimensional (3D) imaging of tissues with deep-axial penetration depths. Integrating structured illumination into NIR-II light-sheet microscopy further diminished background and improved spatial resolution by approximately twofold. In vivo oblique NIR-II SIM was performed noninvasively for 3D volumetric multiplexed molecular imaging of the CT26 tumor microenvironment in mice, longitudinally mapping out CD4, CD8, and OX40 at the single-cell level in response to immunotherapy by cytosine-phosphate-guanine (CpG), a Toll-like receptor 9 (TLR-9) agonist combined with OX40 antibody treatment. NIR-II SIM affords an additional tool for noninvasive volumetric molecular imaging of immune cells in live mammals.

Cross-Link-Functionalized Nanoparticles for Rapid Excretion in Nanotheranostic Applications.

Most NIR-IIb fluorophores are nanoparticle-based probes with long retention (≈1 month or longer) in the body. Here, we applied a novel cross-linked coating to functionalize core/shell lead sulfide/cadmium sulfide quantum dots (PbS/CdS QDs) emitting at ≈1600 nm. The coating was comprised of an amphiphilic polymer followed by three crosslinked amphiphilic polymeric layers (P3 coating), imparting high biocompatibility and >90 % excretion of QDs within 2 weeks of intravenous administration. The P3 -QDs were conjugated to an engineered anti-CD8 diabody (Cys-diabody) for in vivo molecular imaging of CD8+ cytotoxic T lymphocytes (CTLs) in response to anti-PD-L1 therapy. Two-plex molecular imaging in combination with down-conversion Er nanoparticles (ErNPs) was performed for real-time in vivo monitoring of PD-L1 positive tumor cells and CTLs with cellular resolution by non-invasive NIR-IIb light sheet microscopy. Imaging of angiogenesis in the tumor microenvironment and of lymph nodes deep in the body with a signal-to-background ratio of up to ≈170 was also achieved using P3 -QDs.

Cross-Link-Functionalized Nanoparticles for Rapid Excretion in Nanotheranostic Applications.

Most NIR-IIb fluorophores are nanoparticle-based probes with long retention ( ≈ 1 month or longer) in the body. Here, we applied a novel cross-linked coating to functionalize core/shell lead sulfide/cadmium sulfide quantum dots (PbS/CdS QDs) emitting at ≈ 1600 nm. The coating was comprised of an amphiphilic polymer followed by three crosslinked amphiphilic polymeric layers (P3 coating), imparting high biocompatibility and > 90% excretion of QDs within 2 weeks of intravenous administration. The P3-QDs were conjugated to an engineered anti-CD8 diabody (Cys-diabody) for in vivo molecular imaging of CD8 + cytotoxic T lymphocytes (CTLs) in response to anti-PD-L1 therapy. Two-plex molecular imaging in combination with down-conversion Er nanoparticles (ErNPs) was performed for real-time in vivo monitoring of PD-L1 positive tumor cells and CTLs with cellular resolution by non-invasive NIR-IIb light sheet microscopy. Imaging of angiogenesis in the tumor microenvironment and of lymph nodes deep in the body with a signal-to-background ratio of up to ≈ 170 was also achieved using P3-QDs.

MXene (Ti3C2) Vacancy-Confined Single-Atom Catalyst for Efficient Functionalization of CO2.

A central topic in single-atom catalysis is building strong interactions between single atoms and the support for stabilization. Herein we report the preparation of stabilized single-atom catalysts via a simultaneous self-reduction stabilization process at room temperature using ultrathin two-dimensional Ti3- xC2T yMXene nanosheets characterized by abundant Ti-deficit vacancy defects and a high reducing capability. The single atoms therein form strong metal-carbon bonds with the Ti3- xC2T y support and are therefore stabilized onto the sites previously occupied by Ti. Pt-based single-atom catalyst (SAC) Pt1/Ti3- xC2T y offers a green route to utilizing greenhouse gas CO2, via the formylation of amines, as a C1 source in organic synthesis. DFT calculations reveal that, compared to Pt nanoparticles, the single Pt atoms on Ti3- xC2T y support feature partial positive charges and atomic dispersion, which helps to significantly decrease the adsorption energy and activation energy of silane, CO2, and aniline, thereby boosting catalytic performance. We believe that these results would open up new opportunities for the fabrication of SACs and the applications of MXenes in organic synthesis.

Multifunctional Self-Assembled Supernanoparticles for Deep-Tissue Bimodal Imaging and Amplified Dual-Mode Heating Treatment.

Developing multifunctional therapeutic and diagnostic (theranostic) nanoplatforms is critical for addressing challenging issues associated with cancers. Here, self-assembled supernanoparticles consisting of superparamagnetic Fe3O4 nanoparticles and photoluminescent PbS/CdS quantum dots whose emission lies within the second biological window (II-BW) are developed. The proposed self-assembled Fe3O4 and PbS/CdS (II-BW) supernanoparticles [SASNs (II-BW)] exhibit outstanding photoluminescence detectable through a tissue as thick as 14 mm, by overcoming severe light extinction and concomitant autofluorescence in II-BW, and significantly enhanced T2 relaxivity (282 mM-1 s-1, ca. 4 times higher than free Fe3O4 nanoparticles) due to largely enhanced magnetic field inhomogeneity. On the other hand, SASNs (II-BW) possess the dual capacity to act as both magnetothermal and photothermal agents, overcoming the main drawbacks of each type of heating separately. When SASNs (II-BW) are exposed to the dual-mode (magnetothermal and photothermal) heating, the thermal energy transfer efficiency is amplified 7-fold compared with magnetic heating alone. These results, in hand with the excellent photo- and colloidal stability, and negligible cytotoxicity, demonstrate the potential use of SASNs (II-BW) for deep-tissue bimodal (magnetic resonance and photoluminescence) in vivo imaging, while simultaneously providing the possibility of SASNs (II-BW)-mediated amplified dual-mode heating treatment for cancer therapy.

Iodide capped PbS/CdS core-shell quantum dots for efficient long-wavelength near-infrared light-emitting diodes.

PbS based quantum dots (QDs) have been studied in great detail for potential applications in electroluminescent devices operating at wavelengths important for telecommunications (1.3-1.6 µm). Despite the recent advances in field of quantum dot light-emitting diode (QLED), further improvements in near-infrared (NIR) emitting device performance are still necessary for the widespread use and commercialization of NIR emitting QLED technology. Here, we report a high-performance 1.51-µm emitting QLED with inverted organic-inorganic hybrid device architecture and PbS/CdS core-shell structured quantum dots as emitter. The resultant QLEDs show a record device performance for the QLEDs in 1.5 µm emission window, with a maximum radiance of 6.04 Wsr-1 m-2 and peak external quantum efficiency (EQE) of 4.12%, respectively.

In Vivo Ischemia Detection by Luminescent Nanothermometers.

There is an urgent need to develop new diagnosis tools for real in vivo detection of first stages of ischemia for the early treatment of cardiovascular diseases and accidents. However, traditional approaches show low sensitivity and a limited penetration into tissues, so they are only applicable for the detection of surface lesions. Here, it is shown how the superior thermal sensing capabilities of near infrared-emitting quantum dots (NIR-QDs) can be efficiently used for in vivo detection of subcutaneous ischemic tissues. In particular, NIR-QDs make possible ischemia detection by high penetration transient thermometry studies in a murine ischemic hindlimb model. NIR-QDs nanothermometers are able to identify ischemic tissues by means of their faster thermal dynamics. In addition, they have shown to be capable of monitoring both the revascularization and damage recovery processes of ischemic tissues. This work demonstrates the applicability of fluorescence nanothermometry for ischemia detection and treatment, as well as a tool for early diagnosis of cardiovascular disease.

Towards understanding the unusual photoluminescence intensity variation of ultrasmall colloidal PbS quantum dots with the formation of a thin CdS shell.

In this study, we report anomalous size-dependent photoluminescence (PL) intensity variation of PbS quantum dots (QDs) with the formation of a thin CdS shell via a microwave-assisted cation exchange approach. Thin shell formation has been established as an effective strategy for increasing the PL of QDs. Nonetheless, herein we observed an unusual PL decrease in ultrasmall QDs upon shell formation. We attempted to understand this abnormal phenomenon from the perspective of trap density variation and the probability of electrons and holes reaching surface defects. To this end, the quantum yield (QY) and PL lifetime (on the ns-µs time scales) of pristine PbS QDs and PbS/CdS core/shell QDs were measured and the radiative and non-radiative recombination rates were derived and compared. Moreover, transient absorption (TA) analysis (on the fs-ns time scale) was performed to better understand exciton dynamics at early times that lead to and affect longer time dynamics and optical properties such as PL. These experimental results, in conjunction with theoretical calculations of electron and hole wave functions, provide a complete picture of the photophysics governing the core/shell system. A model was proposed to explain the size-dependent optical and dynamic properties observed.

Hybrid nanostructures for high-sensitivity luminescence nanothermometry in the second biological window.

Hybrid nanostructures containing neodymium-doped nanoparticles and infrared-emitting quantum dots constitute highly sensitive luminescent thermometers operating in the second biological window. They demonstrate that accurate subtissue fluorescence thermal sensing is possible.

Anti-proliferation effects of isorhamnetin on lung cancer cells in vitro and in vivo.

BACKGROUND: Isorhamnetin (Iso), a novel and essential monomer derived from total flavones of Hippophae rhamnoides that has long been used as a traditional Chinese medicine for angina pectoris and acute myocardial infarction, has also shown a spectrum of antitumor activity. However, little is known about the mechanisms of action Iso on cancer cells. OBJECTIVES: To investigate the effects of Iso on A549 lung cancer cells and underlying mechanisms. MATERIALS AND METHODS: A549 cells were treated with 10~320 µg/ml Iso. Their morphological and cellular characteristics were assessed by light and electronic microscopy. Growth inhibition was analyzed by MTT, clonogenic and growth curve assays. Apoptotic characteristics of cells were determined by flow cytometry (FCM), DNA fragmentation, single cell gel electrophoresis (comet) assay, immunocytochemistry and terminal deoxynucleotidyl transferase nick end labeling (TUNEL) . Tumor models were setup by transplanting Lewis lung carcinoma cells into C57BL/6 mice, and the weights and sizes of tumors were measured. RESULTS: Iso markedly inhibited the growth of A549 cells with induction of apoptotic changes. Iso at 20 µg/ml, could induce A549 cell apoptosis, up-regulate the expression of apoptosis genes Bax, Caspase-3 and P53, and down-regulate the expression of Bcl-2, cyclinD1 and PCNA protein. The tumors in tumor-bearing mice treated with Iso were significantly smaller than in the control group. The results of apoptosis-related genes, PCNA, cyclinD1 and other protein expression levels of transplanted Lewis cells were the same as those of A549 cells in vitro. CONCLUSIONS: Iso, a natural single compound isolated from total flavones, has antiproliferative activity against lung cancer in vitro and in vivo. Its mechanisms of action may involve apoptosis of cells induced by down-regulation of oncogenes and up-regulation of apoptotic genes.

Interferon-γ and celecoxib inhibit lung-tumor growth through modulating M2/M1 macrophage ratio in the tumor microenvironment.

Tumor-associated macrophages play an important role in tumor growth and progression. These macrophages are heterogeneous with diverse functions, eg, M1 macrophages inhibit tumor growth, whereas M2 macrophages promote tumor growth. In this study, we found that IFNγ and/or celecoxib (cyclooxygenase-2 inhibitor) treatment consistently inhibited tumor growth in a mouse lung cancer model. IFNγ alone and celecoxib alone increased the percentage of M1 macrophages but decreased the percentage of M2 macrophages in the tumors, and thus the M2/M1 macrophage ratio was reduced to 1.1 and 1.7 by IFNγ alone and celecoxib alone, respectively, compared to the M2/M1 macrophage ratio of 4.4 in the control group. A combination of IFNγ and celecoxib treatment reduced the M2/M1 macrophage ratio to 0.8. Furthermore, IFNγ and/or celecoxib treatment decreased expression of matrix metalloproteinase (MMP)-2, MMP-9, and VEGF, as well as the density of microvessels in the tumors, compared to the control group. This study provides the proof of principle that IFNγ and/or celecoxib treatment may inhibit lung-tumor growth through modulating the M2/M1 macrophage ratio in the tumor microenvironment, suggesting that IFNγ and celecoxib have potential to be further optimized into a new anticancer therapy.

Temporary transection of innominate vein in surgery of midtracheal tumor.

In this case, a patient presented with a large primary midtracheal tumor posterior to the innominate vein and brachiocephalic artery. The left innominate vein (LIV) was temporarily transected to attain proper access to the tumor. After complete removal of the tumor, the vessel was reanastomosed. The operation was uneventful, and the patient recovered well. Temporary transection of the LIV appears to be a reasonable alternative to surgical resection in such a large cross-border midtracheal tumor.

Microwave-assisted cation exchange toward synthesis of near-infrared emitting PbS/CdS core/shell quantum dots with significantly improved quantum yields through a uniform growth path.

In this study, we develop a reproducible and controllable microwave-assisted cation exchange approach, for the first time, to quickly synthesize high-quality, near-infrared emitting PbS/CdS core/shell quantum dots (QDs). These monodisperse QDs, emitting in the range of 1300-1600 nm, show a quantum yield as high as 57% that is ~1.4 times higher than that achieved by the same QDs prepared using conventional heating in an oil bath. To the best of our knowledge, it is the highest reproducible value reported to date for PbS-based QDs in this emission range. More importantly, the as-synthesized PbS/CdS QDs can self-assemble nearly perfectly and easily at the micrometer scale as a result of their uniform shape and narrow size distribution.

Interleukin-17 and prostaglandin E2 are involved in formation of an M2 macrophage-dominant microenvironment in lung cancer.

INTRODUCTION: Tumor-associated macrophages (TAMs) are divided into M1 and M2 macrophages. M1 macrophages inhibit tumor growth, whereas M2 macrophages promote tumor growth and metastasis. The aim of this study was to examine the possible causes leading to the formation of an M2-macrophage-dominant tumor microenvironment in non-small-cell lung cancer. METHODS: Forty-eight archived lung tumor samples were examined for the expression of interleukin-17 (IL-17) receptors, IL-17 receptor A (IL-17RA) and IL-17 receptor C (IL-17RC), and the number of TAMs using immunohistochemical staining. Twenty fresh lung tumors and matched normal lung tissues were examined for expression of IL-17, cyclooxygenase-2, and prostaglandin E2 (PGE2), using enzyme-linked immunosorbent assay and Western blot analysis. Macrophage-migration assays were performed using fresh lung tumor tissues and IL-17 as chemoattractants. Induction of M2-macrophage differentiation was analyzed using real-time quantitative polymerase chain reaction. RESULTS: TAMs expressed IL-17RA and IL-17RC. Lung tumors expressed higher levels of IL-17, cyclooxygenase-2, and PGE2, compared with normal lung tissues. Lung tumor tissues attracted migration of mouse RAW264.7 macrophages and primary peritoneal macrophages through IL-17, which was mediated by IL-17RA and IL-17RC. IL-17 did not induce either M1- or M2-macrophage differentiation. However, human lung cancer A549 cells strongly induced M2-macrophage differentiation of RAW264.7 macrophages when the two cell lines were cocultured. The inductive factor secreted by A549 cells was identified to be PGE2. CONCLUSIONS: IL-17 recruits macrophages, and PGE2 induces M2-macrophage differentiation, hence the increased levels of IL-17 and PGE2 in lung cancer contribute to the formation of an M2-macrophage-dominant tumor microenvironment.