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Background: Many dyes or radioactive markers used for sentinel lymph node (SLN) have the shortcomings of false positive and radiation injury. Indocyanine green (ICG) seems to have a lower false positive rate and tissue damage, without a clear field of vision during the operation., Methods: For the shortcomings, we successfully synthesized three anionic pullulan materials, changed the degree of hydrophobic for size controlling (< 50nm) to prepare CHP nanoparticles (NPs) and changed the succinyl degree to prepare CHPC NPs with different negative surface potential., Results: The size of those NPs were less than 50nm under (transmission electron microscope) TEM, with hydrodynamic size of 90.67 ± 2.2 nm of CHP, 105.8 ± 1.7 nm of CHPC1 and 115.9 ± 2.3 nm of CHPC2. Moreover, the Zeta potential of CHP, CHPC1 and CHPC2 were -1.9 ± 0.2 mV, -9.6 ± 0.3 mV and -19.4 ± 0.7 mV. The size of ICG-loading CHP, CHPC1 and CHPC2 NPs increased to 109.4 ± 2.7 nm, 113.8 ± 1.2 nm and 30.6 ± 3.5 nm, as the zeta potential decreased to -2.7 ± 0.4 mV, -12.5 ± 1.6 mV and -23.1 ± 1.2 mV. With the increasing degree of succinyl, the size increased and the zeta potential decreased. At the same time, the higher degree of succinyl drug-loading NPs have lower release and have increased the stability of ICG. We found that the blank-NPs had no significant toxicity to normal cells (HSF), as the ICG@CHP group had larger toxicity than the CHPCs and control. Moreover, the cellular uptake was decreased with the increased degree of succinyl., Conclusion: In this study, we successfully prepared CHPC2 carriers with the maximum negative surface charge, for follow-up research and providing new ideas for SLN., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Developing dynamic and highly sensitive methods for imaging M2-type tumor-associated macrophages (TAMs) is vital for monitoring the tumor progression and assessing the therapeutic efficacy. Here, the fabrication and application of rationally designed Er-based rare-earth nanoprobes for the targeted imaging of M2-type TAMs in glioblastoma (GBM) through the second near-infrared (NIR-II) fluorescence beyond 1500 nm is reported. The NIR-IIb fluorescence of Er-based rare-earth nanoparticles can be remarkably enhanced by optimizing their core-shell structures and the shell thickness, which allows for in vivo imaging under excitation by a 980 nm laser with the lowest power density (40 mW cm -2 ). These bright Er-based nanoparticles functionalized with M2pep polypeptide show notable targeting ability to M2-type macrophages, which has been well tested in both in vitro and in vivo experiments by their up-conversion (UC) fluorescence (540 nm) and down-shifting (DS) fluorescence (1525 nm), respectively. The targeting capability of these nanoprobes in vivo is also demonstrated by the overlap of immunofluorescence of M2-type TAMs and Arsenazo III staining of rare-earth ions in tumor tissue. It is envisioned that these nanoprobes can serve as a companion diagnostic tool to dynamically assess the progression and prognosis of GBM., (© 2022 Wiley-VCH GmbH.)

Competing Interests: Conflict of interest The authors declare that they have no conflict of interest.

Revealing the anatomical structures, functions, and distribution of vasculature via contrast agent (CA) enhanced magnetic resonance imaging (MRI) is crucial for precise medical diagnosis and therapy. The clinically used MRI CAs strongly rely on Gd-chelates, which exhibit low T 1 relaxivities and high risks of nephrogenic systemic fibrosis (NSF) for patients with renal dysfunction. It is extremely important to develop high-performance and safe CAs for MRI. Herein, it is reported that ultra-small NaGdF 4 nanoparticles (UGNs) can serve as an excellent safe MRI CA via surface engineering with rationally designed novel hydrophilic block co-polymer (BP n ). By optimizing the polymer molecular weights, the polymer-functionalized UGNs (i.e., UGNs-BP 14 ) are obtained to exhibit remarkably higher relaxivity (11.8 mm -1 s -1 at 3.0 T) than Gd-DTPA (3.6 mm -1 s -1 ) due to their ultracompact and abundant hydrophilic surface coating. The high performance of UGNs-BP 14 enables us to sensitively visualize microvasculature with a small diameter of ≈0.17 mm for up to 2 h, which is the thinnest blood vessel and the longest time window for low field (1.0 T) MR angiography ever reported, and cannot be achieved by using the clinically used Gd-DTPA under the same conditions. More importantly, renal clearable UGNs-BP 14 show lower risks of inducing NSF in comparison with Gd-DTPA due to their negligible release of Gd 3+ ions after modification with the novel hydrophilic block copolymer. The study presents a novel avenue for boosting imaging-performance and systemic biosafety of UGNs as a robust MRI CA with great potential in precise diagnosis of vasculature-related diseases., (© 2022 Wiley-VCH GmbH.)

As the primary malignant tumor in the brain, glioblastoma exhibits a high mortality due to the challenges for complete treatment by conventional therapeutic methods. It is of great importance to develop innovative therapeutic agents and methods for treatment of glioblastoma. In this work, the imaging and therapy of glioblastoma are reported by using dye sensitized core-shell NaYF 4 :Yb/Tm@NaYF 4 :Nd nanoparticles with strong up/down-conversion luminescence, of which the ultraviolet up-conversion emissions at 348 and 365 nm are significantly enhanced by nearly 28 times and used to control the release of SO 2 from 5-Amino-1,3-dihydrobenzo[c]thiophene 2,2-dioxide prodrug for gas therapy, and the second near-infrared (NIR-II) down conversion emission at 1340 nm is increased five times and applied for imaging. It is revealed that the released SO 2 molecules not only cause oxidative stress damage of tumor cells, but also induce their pro-death autophagy by down-regulating the expression of p62 and up-regulating the ratio of LC3-II/LC3-I, ultimately inhibiting tumor growth. The work demonstrates the great potential of rare earth nano-platform with functions of NIR-II imaging and photo-controlled gas therapy in the diagnosis and treatment of orthotopic glioblastoma., (© 2021 Wiley-VCH GmbH.)

The narrow absorption and emission bands, long fluorescence lifetime, and excellent stability of rare earth nanoparticles (referred to as RE NPs) make them very attractive for multimodal imaging and therapy of cancer. Their narrow absorption requires the careful selection of laser wavelength to achieve the best performance, particularly for RE NPs simultaneously having photothermal and photoluminescent properties (e.g., Nd-based nanoparticles), which has not been investigated. Herein, we prepared a series of different-sized NaNdF 4 nanoparticles (referred to as NNF NPs) (i.e., 4.7, 5.9, 12.8, and 15.6 nm) from ultrasmall nanoclusters and investigated their in vitro and in vivo size-dependent photothermal conversion and photoluminescence under irradiation by a 793 nm laser and an 808 nm laser, respectively. We find that all nanoparticles exhibited the better photothermal conversion performance under the irradiation of the 808 nm laser than under the 793 nm laser, of which 12.8 nm NNF NPs showed the best performance, and the temperature of their solution can be quickly increased from 30 °C to around 60 °C within 10 min under the irradiation of the 808 nm laser with a power intensity of 0.75 W/cm 2 . When we used the 793 nm laser to excite these NNF NPs, we found that all nanoparticles exhibited the stronger photoluminescence in the second near-infrared window (NIR-II) than under the excitation by the 808 nm laser, of which 15.6 nm NNF NPs possessed the strongest NIR-II luminescence. We then modified 12.8 nm NNF NPs with phospholipid carboxyl PEG and functionalized with RGD for actively targeted imaging of cancer. The NaNdF 4 @PEG@RGD nanoparticles (referred to as NNF-P-R NPs) have good biocompatibility, stability, and excellent targeting capability. The in vivo result show that 12.8 nm NNF NPs exhibited better photothermal conversion performance under the irradiation of the 808 nm laser, and stronger NIR-II fluorescence under irradiation of the 793 nm laser, which are consistent with the in vitro result. This work demonstrates the significance of selection of the proper laser wavelength for maximally taking advantage of RE nanoparticles for the diagnosis and treatment of cancer.

The metastasis of breast cancer mainly occurs through the axillary lymph node and blood circulation systems. It is extremely difficult to know when the cancer cells start to metastasize; however, early detection of breast cancer metastasis is crucial and challenging to enable surgical removal of the primary tumor and perform a systematic lymphadenectomy to eliminate invasion of the tumor. Herein, we report real-time tracking of the metastasis of orthotopic breast cancer with background-free near-infrared long-persistent luminescence (NIR-PL) imaging, and its guidance for the surgical removal of lymph nodes. The NIR-PL imaging is based on Cr 3+ /Nd 3+ codoped ZnGa 2 O 4 (A-ZGCN) nanoparticles with a superlong afterglow time of more than 15 days. We show that the detection sensitivity of metastasis of cancer cells with the NIR-PL imaging is higher than the classic bioluminescence imaging. We find that the metastasis of breast cancer cells to lymph nodes occurred as early as on the third day after orthotopic inoculation of breast cancer cells and followed an order of the proper axillary lymph node (PALN, day 3) > accessory axillary lymph node (AALN, day 6) > accessory mandibular lymph node (AMLN, day 9) > mandibular lymph node (MLN, day 25). In addition, we show that the NIR-PL nanoprobes (i.e., A-ZGCN NPs) displayed 17% radioenhancement, which was used for radiotherapy of orthotopic breast cancer to further prevent and reduce its metastasis to other organs. The radiotherapy treatment is superior to surgery for removal of the tumor accompanied by a NIR-PL imaging-guided lymphadenectomy. Our work demonstrates the great potential of NIR-PL imaging and the corresponding nanoprobes for tracking metastasis of cancer cells and for radiotherapy.

Rare-earth nanoparticles (RE NPs) with narrow long wavelength emissions have been recently investigated for their potential application for fluorescence imaging in the second near-infrared window (NIR-II). Previously these RE NPs have a very limited application in the diagnosis and treatment of deep-seated tumors such as brain tumors, due to their weak fluorescence in the range of 1300-1700 nm. Herein, we report a significant enhancement of more than 10 times regular emission of NaNdF 4 nanoparticles at 1340 nm wavelength by coating them with an inert layer of NaLuF 4 , followed by sensitizing with a near-infrared dye (IR-808). We deliver these highly bright nanoparticles into the brain by using focused ultrasound to temporarily open the blood-brain barrier (BBB), and then detect the orthotopic glioblastoma by fluorescence imaging at 1340 nm. The images obtained from long wavelength fluorescence (i.e. 1340 nm) exhibited better resolution and contrast compared to the short wavelength fluorescence (i.e. 1060 nm). Our study not only provides insights for enhancing often overlooked emissions of rare-earth nanoparticles for NIR-II fluorescence imaging of deep-seated tumors, but also demonstrates great potential of focused ultrasound based technology in delivering nanotheranostic agents., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The treatment of malignant glioblastoma is a huge challenge due to the existence of the blood-brain barrier. Herein, we report the treatment of orthotopic malignant glioblastoma with imaging guided second near-infrared (NIR-II) photodynamic therapy and chemotherapy by using drug-loaded ultra-small Cu2-xSe theranostic nanoparticles (NPs). Ultra-small Cu2-xSe NPs possess a strong absorbance in the NIR-II window, and their absorption at 1064 nm is around 2 times that at 808 nm. Their strong NIR-II absorbance and the deeper-tissue penetration of NIR-II light ensure excellent photodynamic therapy performance under irradiation with a 1064 nm laser. We also demonstrate that ultra-small Cu2-xSe NPs can produce vast amounts of reactive oxygen species via electron transfer (for ˙OH generation) and energy transfer (for 1O2 generation) mechanisms under irradiation. In addition, these NPs can be effectively and locally transported into orthotopic malignant glioblastoma with the assistance of focused ultrasound. The deposited Cu2-xSe NPs can be used for photoacoustic imaging to guide the combined NIR-II photodynamic therapy and chemotherapy. The results show that the tumor growth can be significantly suppressed. This work demonstrates the great potential of drug-loaded ultra-small Cu2-xSe NPs as a promising therapeutic agent for the treatment of orthotopic malignant glioblastoma.

The small difference between tumor and normal tissues in their responses to ionizing radiation has been a significant issue for radiotherapy of tumors. Herein, we report that dumbbell-shaped heterogeneous copper selenide-gold nanocrystals can serve as an efficient radiosensitizer for enhanced radiotherapy. The mean lethal dose of X-rays to 4T1 tumor cells can be drastically decreased about 40%, that is, decreasing from 1.81 to 1.10 Gy after culture with heterostructures. Due to the synergetic effect of heterostructures, the dose of X-rays is also much lower than those obtained from mixture of Cu 2- x Se + Au nanoparticles (1.78 Gy), Cu 2- x Se nanoparticles (1.72 Gy) and Au nanoparticles (1.50 Gy), respectively. We demonstrate that the sensitivity enhancement ratio of Cu 2- x Se nanoparticles was significantly improved 45% ( i. e., from 1.1 to 1.6) after the formation of heterostructures with gold. We also show that the heteronanocrystals exhibit an enhanced photothermal conversion efficiency, due to the synergetic interactions of localized surface plasmon resonance. These properties highly feature them as a multimodal imaging contrast agent (particularly for photoacoustic imaging, computed tomography imaging, and single photon emission computed tomography after labeled with radioisotopes) and as a radiosensitizer for imaging guided synergetic radiophotothermal treatment of cancer. The research provides insights for engineering low- Z nanomaterials with high- Z elements to form heteronanostructures with enhanced synergetic performance for tumor theranostics.

In-vivo intravital short wavelength infrared (SWIR, 1000-2300 nm) fluorescence imaging has attracted considerable attention in the imaging of tumor vasculature due to its low background, high sensitivity, and deep penetration. It can noninvasively provide dynamic feedback on the tumorigenesis, growth, necrosis and metastasis. Herein, monodisperse Nd 3+ -doped core-shell downconversion luminescent nanocrystals with strong emission in the second near-infrared (NIR II) window, strong temperature-dependent paramagnetism and fast attenuation to X-rays were prepared from ultra-small nanoclusters. The use of nanoclusters resulted in very uniform bright nanocrystals with a relative quantum yield comparable to the standard dye IR-26. These bright NIR nanocrystals were modified with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] to endow with excellent water-solubility, biocompatibility and a blood circulation half-life of 5.9 h. They were then successfully used to demonstrate the variation of tumor vasculature with tumor progression from tumorigenesis, growth, to necrosis in the subcutaneous breast tumor through the NIR II fluorescence imaging. They were also used as contrast agent of magnetic resonance imaging (MRI) and X-ray computed tomography (CT) imaging of tumor to provide complementary anatomic structure. Their great potential in NIR II imaging of tumor was further demonstrated with an orthotopic breast tumor. Their in-vivo biosafety was also investigated by hemanalysis and histological analyses., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Nanoscale ternary chalcogenides have attracted intense research interest due to their wealth of tunable properties and diverse applications in energy and environmental and biomedical fields. In this article, ultrasmall magnetic CuFeSe 2 ternary nanocrystals (<5.0 nm) were fabricated in the presence of thiol-functionalized poly(methacrylic acid) by an environmentally friendly aqueous method under ambient conditions. The small band gap and the existence of intermediate bands lead to a broad NIR absorbance in the range of 500-1100 nm and high photothermal conversion efficiency (82%) of CuFeSe 2 nanocrystals. The resultant CuFeSe 2 nanocrystals show superparamagnetism and effective attenuation for X-rays. In addition, they also exhibit excellent water solubility, colloidal stability, biocompatibility, and multifunctional groups. These properties enable them to be an ideal nanotheranostic agent for multimodal imaging [e.g., photoacoustic imaging (PAI), magnetic resonance imaging (MRI), computed tomography (CT) imaging] guided photothermal therapy of cancer.

Polystyrene (PS)/gold (Au) core-shell nanocomposites with tunable size, high stability, and excellent catalytic activity have been synthesized by a facile method that combines the ionic self-assembly with the in situ reduction. The composition and stoichiometry, as well as its morphology and optical properties of these nanocomposites have been examined and verified by various characterization techniques. The size and the coverage of gold nanoparticles (NPs) can be simply tailored by changing the amount of 3-aminopropyltrimethoxysilane (APTES), the functionalization time, the protonation time, and the amount of chloroauric acid (HAuCl(4)). The continuous red shifts of the localized surface plasmon resonance absorption of the Au NPs on the PS spheres are observed. Importantly, the obtained Au NPs with controllable and uniform size on the surfaces of amino-functionalized PS spheres exhibit excellent size-dependent catalytic properties for the reduction of 4-nitrophenol (4-NP) by NaBH(4)., (Copyright © 2012 Elsevier Inc. All rights reserved.)

In this paper, highly selective core-shell molecularly imprinted polymers of 17β-estradiol on the surface of silica nanoparticles (SiO(2)@E2-MIPs) were prepared. The SiO(2)@E2-MIPs were characterized by Fourier transform infrared spectrometer (FT-IR), transmission electron microscope (TEM), dynamic adsorption and static adsorption tests. The sorption capacity of the SiO(2)@E2-MIPs were nearly 5 times that of the non-imprinted polymers (NIPs), and it only took 25 min to achieve the sorption equilibrium. It indicated that the SiO(2)@E2-MIPs exhibited a high selectivity, large adsorption capacity and fast kinetics. When the SiO(2)@E2-MIPs were used as dispersive solid-phase extraction (dSPE) absorbents to selectively enrich and determine estrogens in duck feed, the average recoveries of E2 and estriol (E3) were higher than 96.74% and 72.07%, respectively, and the relative standard deviations (RSD) of E2 and E3 were less than 1.61% and 3.28%, respectively. The study provides an effective method for the separation and enrichment of estrogens in the complex matrix samples by the SiO(2)@E2-MIPs., (Copyright © 2010 Elsevier B.V. All rights reserved.)

The development of lithium-niobate-on-insulator (LNOI) technology has sparked the advancement of numerous on-chip photonic devices for generating and manipulating light. However, the optical absorption of thin-film LNOI is very weak, especially in the near-infrared field, due to their extremely thin absorption layer and intrinsic band structure characteristics. Here, we propose a comprehensive framework to tackle these obstacles by means of ion implantation of Ag ions, which facilitates the encapsulation of plasmonic silver (Ag) nanoparticles within LNOI thin films. Through the incorporation of Ag nanoparticles, we have observed a tailored profile of optical nonlinear absorptions in LNOI thin films, transitioning from reverse saturable absorption to saturable absorption as well as optical-induced absorption to photobleaching behaviors. Moreover, the plasmonic effect elicited by the embedded Ag nanoparticles amplifies the third-order nonlinear coefficient by an order of magnitude. This work opens an avenue toward the development of high-performance on-chip photonic devices harnessing third-order nonlinearities of LNOI. [ABSTRACT FROM AUTHOR]

High-entropy oxide (HEO) nanoparticles have been regarded as a promising catalytic material system for oxygen evolution reaction in recent years. However, their traditional physical and chemical synthesis remains challenges due to the limitation of fabricating controllable small size HEO nanoparticles. Herein, a general and novel method of low-energy-recoil ion implantation and subsequent annealing is successfully developed to synthesize high-entropy oxide nanoparticles catalysts. By controlling the fluence of irradiation Ar+ ions, the size and the load of HEO nanoparticles can be accurately controlled. The obtained (FeCoNiCrAl)O HEO nanoparticles exhibit an overpotential of 295 mV at 10 mA cm−2, a small Tafel slope of 39 mV dec−1 and good stability in 1 M KOH, which is much better than the properties of binary and medium entropy oxide counterparts prepared by the same method, showing the good application prospect of low-energy-recoil ion implantation in the preparation of complicated multi-element-metal oxide nanoparticles. [ABSTRACT FROM AUTHOR]

Ultrafast lasers play important roles for scientific research and industrial applications. Saturable absorbers serve as crucial components for ultrafast laser generation. For decades, securing saturable absorbers with superior performance is one of the focuses in the field of advanced laser technology. In this work, the authors fabricate a new saturable absorption mirror (SAM) based on BK7 glass wafer, which is with a buried thin‐layer of silver (Ag) nanoparticles (NPs). The embedded Ag NPs‐based SAM (Ag‐NPs‐SAM) possesses excellent saturable absorption features due to the localized surface plasmon resonance (LSPR) effect of Ag NPs, and outstanding environmental stability owing to the protection of insulating dielectrics. In addition, benefiting from the ultrafast recovery time of Ag NPs, a continuous‐wave mode‐locking operation with the embedded Ag‐NPs‐SAM at 1037 nm is achieved in a Yb:KGW solid‐state laser system, obtaining pulses of a duration as short as 324 fs. The authors work offers a new strategy toward broadband response and high‐stability saturable absorbers for developing advanced ultrafast lasers. [ABSTRACT FROM AUTHOR]

Flower-like MoS nanoparticles (NPs) consist of ultra-thin MoS nanosheets are synthesized via a facile one-pot hydrothermal method. The MoS/ZnO p-n heterostructure is formed by coating n-type ZnO on the surface of flower-like MoS NPs through the seed-mediate route and post-annealing treatment. The effects for the dye removal and photocatalytic performances after ZnO coating are systematically investigated. The results demonstrated that the coating of ZnO nanoparticles has a positive promotion to the photodegrading properties while negative effect on the adsorption capacity of the MoS/ZnO heterostructures. The related mechanisms on the relationship of adsorption capacity and photocatalysis are discussed in detail. [ABSTRACT FROM AUTHOR]

We developed a dedicated computational framework by coupling the lattice-Boltzmann-method (LBM) modeling and the particle-swarm-optimization (PSO) algorithm to search optimal strategies of magnetic nanoparticle (MNP) injection for hyperthermia-based cancer treatment. Two simplified tumor models were considered: a circular model representing geometrically regular tumors and an elliptic model representing geometrically irregular tumors, both sharing the same area. The temperature distribution in the tumor and its surrounding healthy tissue was predicted by solving the Pennes' bio-heat transfer equation (PBHTE). Both single- and multi-site injection strategies were explored. The results suggest that the multi-site injection strategies generally work well, while the single-site injection strategy fails even on the simplest circular tumor model. The more the injection sites, the better the performance. In particular, when the number of injection sites reaches eight, all temperature requirements can be nearly 100% satisfied in both tumor models. Whether or not including the minimum dose requirement in the objective function only affects the optimization results by less than 2%. The thermal dose was also assessed by considering both temperature and heat exposure time. It was found that the optimal multi-site injection strategies perform reasonably well for both tumor models. Although the setting is only two dimensional and the optimization is on very simplified tumor models, the framework adopted in this present study works well and can provide useful insights into magnetic hyperthermia treatment. [Display omitted] • A dedicated computational framework has been developed to search optimal MNP injection strategies. • The framework was demonstrated on two tumor models. • The single-site injection strategy fails. • The more the injection sites, the better the performance. • Including the dose requirement in the optimization seems not necessary. [ABSTRACT FROM AUTHOR]

Embedded silver nanoparticles were produced in KTP single crystal by 200 keV Ag + ion implantation at fluence of 5 × 10 16 ions/cm 2 . The shape, size and spatial distribution of the formed silver nanoparticles were revealed by transmission electronic microscope (TEM) images. The embedded sphere silver nanoparticles with average diameters of 9.9 nm were along the projected range of Ag + ions, located at the depth between 35 nm and 80 nm from the surface. Both the measured and calculated absorption spectra of silver nanoparticles dispersed in KTP crystal indicate that the surface plasmon resonance (SPR) absorption peak was at ∼459 nm. [ABSTRACT FROM AUTHOR]

Nanotechnology has been advanced since the last decades. Among all nanomaterials that have been developed, nanosilver is the most frequently used nanoparticles. Its release into natural water bodies is inevitable due to its broad applications. Nanosilver (nAg) was prepared via Tollens method using. The morphology, size distribution and average size of the obtained nAg was characterized using Transmission electron microscope (TEM) and Dynamic light scattering (DLS) technique. Stability of nanosilver was determined using UV-Vis spectroscopic method. Additionally, a time-resolved DLS technique was applied to confirm the UV-Vis spectroscopic results [ABSTRACT FROM AUTHOR]

Single layer monodisperse Ni nanoparticles were successfully prepared by reductive annealing of NiO films formed by magnetron sputtering. The spherical Ni nanoparticles had a monodisperse distribution on the substrate. The formation process of Ni nanoparticles was investigated, and the Ni nanoparticle size can be precisely controlled by the magnetron sputtering time. Morphology of these nanoparticles was observed with scanning electron microscopes and transmission electron microscopes. Magnetic properties of Ni nanoparticles have been confirmed by using a vibration sample magnetometer. The blocking temperature, particle size, and effective anisotropy constant were calculated by fitting the relationship between coercivity and temperature. [ABSTRACT FROM AUTHOR]

• Fine modulation of the second near-infrared-IIb (NIR IIb, 1500−1700 nm) emission of Er-based lanthanide nanoparticles. • Significant enhancement of NIR IIb fluorescence of Er-based lanthanide nanoparticles by 675 folds. • Efficient delivery of NIR IIb nanoparticles to tumor by using focused ultrasound sonication and active targeting strategy. • NIR IIb fluorescence imaging-guided surgery of orthotopic glioma. Highly sensitive and specific discrimination of brain tumor margins from the surrounding parenchyma remains a formidable challenge. Limited by the short of photostable probes with deep tissue penetration and high efficiency of crossing the blood-brain-barrier (BBB), the development of fluorescence-guided surgery (FGS) of brain tumors was markedly constrained. Herein, we report the capability of the strong second near-infrared-IIb (NIR IIb, 1500−1700 nm) fluorescence from Er-based lanthanide nanoparticles in imaging-guided surgery of orthotopic glioma. We designed an energy-cascaded Er3+-Ce3+-A3+ (A = Yb, Ho, Tm) system and prepared a series of NaErF 4 :Ce@NaAF 4 @NaLuF 4 down-conversion nanoparticles (DCNPs) for optimizing the influence of NaAF 4 interlayer and Ce3+ dopants. We modified the optimal NaErF 4 :2.5 %Ce@NaYbF 4 (0.9 nm)@NaLuF 4 DCNPs with Dye-brush polymer (Dye-BP) to facilitate 4I 13/2 →4I 15/2 transition, which leads to an impressive 675-fold enhancement of 1525 nm fluorescence in aqueous solution under 808 nm excitation due to the excellent energy-cascaded downconversion (ECD), in comparison with that of NaErF 4 nanoparticles. We further modified these highly bright nanoparticles with tumor-targeting angiopep-2 peptide, and efficiently delivered them to the glioma by using the focused ultrasound sonication (FUS) to temporarily open the BBB. We obtained the highest tumor-to-background ratio (TBR = 12.5) ever reported in the targeted NIR IIb fluorescence imaging of small orthotopic glioma (size < 3 mm, depth> 3 mm) through intact skull and scalp, which was drastically improved to ∼150 after cardiac perfusion and craniotomy to ensure the precise resection of tumor. More importantly, the size of glioma measured from the width of fluorescence profile is very close to that from T 2 -weighted MRI images. Our work provides the insights into engineering NIR IIb fluorescence of lanthanide nanoparticles, and demonstrates the great potential of NIR IIb fluorescence imaging-guided surgery of tumor. [ABSTRACT FROM AUTHOR]

Abstract: Ternary platinum-ruthenium-nickel nanoparticles are prepared by water-in-oil reverse microemulsions of water/Triton X-100/propanol-2/cyclohexane. Nanoparticles formed in the microemulsions are characterized by transmission electron microscopy (TEM), electron diffraction (ED), X-ray diffractometry (XRD), energy dispersive X-ray analysis (EDX). These resulting materials showed a homogenous alloy structure, the mono-dispersion and an average diameter of 2.6±0.3nm with a narrow particle size distribution. The composition and particle size of ternary Pt-Ru-Ni nanoparticles can be controlled by adjusting the initial metal salt solution and preparation conditions. Pt-Ru-Ni ternary metallic nanoparticles showed an enhanced catalytic activity towards methanol oxidation compared to Pt-Ru bimetallic nanoparticles. [Copyright &y& Elsevier]

Abstract: The evolution of nanoparticles in sequentially ion-implanted Ag and Ag/Cu into silica glasses has been studied. The doses for implantation (×1016 ions/cm2) were 5Ag, 5Ag/5Cu and 5Ag/15Cu. Ag nanoclusters have been formed in the implanted 5Ag specimen. In the implanted 5Ag/5Cu specimen, some formed nanoclusters have brighter center features. With an increase of Cu ions dose, the nanoclusters with brighter center features become prevalent. The microstructural properties of the nanoparticles are characterized by transmission electron microscopy. Scanning transmission electron microscope high-angle annular dark field and high-resolution transmission electron microscopy are also utilized to study the formed nanoparticles. The results show that nanovoids have been induced into metal nanoparticles during the ion implanting process, not the core-shell nanoparticles as other workers believed. The nanovoids can be the aggregation of vacancies induced by irradiation. [Copyright &y& Elsevier]

• A high-performance Q-switched vortex laser has been realized on a waveguide platform. • The pulse width (28 ns) is the shortest ever reported for Q-switched vortex laser. • The near-field distributions of nanoparticles arrays have been simulated. Vortex beam, particularly pulsed vortex laser, has expanded the potential applications in optics due to their unique wave-front phase structure and the determined photon orbital angular momentum. In this study, we present a novel approach including the integration of fused silica embedded with silver nanoparticles (Ag:SiO 2) into the Nd:YAG waveguide platform for achieving nanosecond vortex pulses. Using a spiral phase plate for in-cavity phase modulation, we successfully demonstrate a Q-switched vortex laser with a high repetition rate in the megahertz range and short pulse width in the nanosecond regime. Additionally, we conduct a comprehensive analysis of the near-field distributions of Ag nanoparticles with varying sizes and distributions using COMSOL simulation. This study exemplifies the integration of silica-based photonic elements for realizing a high-stability and cost-effective nanosecond vortex laser system. [ABSTRACT FROM AUTHOR]

The ultrafast dynamics of electron transfer from Ag NPs to TiO 2 semiconductor plays an important role in the tailoring of optical nonlinearity and further photonic application. • Electrocatalysis by Ag/TiO 2 chip is enhanced by electron transfer (ET) process. • An improved transfer model is proposed to investigate the ET mechanism. • Optical nonlinearity of TiO 2 is tailored by the ET mechanism. • 1 μm mode-locked laser is achieved with reduced lasing threshold. The nanocomposite of titanium dioxide (TiO 2) with noble metallic nanoparticles (NPs) are widely used catalysis systems for various photonic applications owing to the well-known ultrafast dynamics process, electron transfer. In this work, the traditional electron transfer mechanism is further improved based on the nanocomposite chip with embedded Ag NPs in TiO 2 semiconductor (AgNP:TiO 2). Considering the increased absorption efficiency of Ag NPs, the delay time of electron-electron scattering and electron-phonon scattering are measured to indicate the evidence of electron transfer process. It is proved that the enhancement of optical nonlinearity is closely associated with the hot electron transfer between TiO 2 and Ag NPs. Benefiting from the electron transfer mechanism induced nonlinearity tailoring of TiO 2 , low-threshold mode-locked lasers have been realized with AgNP:TiO 2 as saturable absorber (SA) with low saturation intensity (decreased by 76.5%). This work not only fills the blank of optical nonlinearity modification by embedded Ag NPs in TiO 2 nanocomposites, but also build a bridge between hot electron transfer process and nonlinearity tailoring, suggesting potential applications in ultrafast dynamics and optoelectronics. [ABSTRACT FROM AUTHOR]