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High‐performing 2D electrical and optical devices can be realized by forming an ideal van der Waals (vdW) metal contact with weak interactions and stable interface states. However, the methods for applying metal contacts while avoiding damage from metal deposition present challenges in realizing a uniform, stable vdW interface. To overcome this problem, this study develops a method for forming vdW contacts using a sacrificial Se buffer layer. This study explores this method by investigating the difference in the Schottky barrier height between the vdW metal contact deposited using a buffer layer, a transferred metal contact, and a conventional directly deposited metal contact using rectification and photovoltaic characteristics of a Schottky diode structure with graphite. Evidently, the Se buffer layer method forms the most stable and ideal vdW contact while preventing Fermi‐level pinning. A tungsten diselenide Schottky diode fabricated using these vdW contacts with Au and graphite as the top and bottom electrodes, respectively, exhibits excellent operation with an ideality factor of ≈1, an on/off ratio of > 107, and coherent properties. Additionally, when using only the vdW Au contact, the electrical and optical properties of the device can be minutely modulated by changing the structure of the Schottky diode. [ABSTRACT FROM AUTHOR]

This article proposes an online maximum torque-per-Ampere (MTPA) control of an interior permanent-magnet synchronous motor (IPMSM) based on the square-wave voltage signal injection. Because the proposed method does not rely on a position sensor, it is applicable to sensorless IPMSMs. The proposed algorithm consists of a dynamic inductance estimator, frequency-adaptive flux observer, and an MTPA tracking controller. The proposed inductance estimation utilizes the pulsating square-wave voltage injection, which can maximize the injection frequency, and the dynamic performance can be preserved during the signal injection. Through the online flux and inductance estimation, the magnetic saturation of the IPMSM and the temperature variation can be fully considered in the MTPA control. The conventional rotor position estimator is replaced with the MTPA tracking controller, which does not rely on offline commissioning parameters. The proposed algorithm can operate under both the torque control and speed control mode, and accurate torque control on MTPA curve can be achieved. The simulation and experimental results demonstrate that the proposed method accurately tracks the MTPA point up to 200% of the rated torque in the mid- and high-speed region. [ABSTRACT FROM AUTHOR]

This article analyzes the effect of discretization in the frequency-adaptive flux observer (FAO). Although FAO has structural simplicity and ease of implementation, the discrete-time FAO has phase and gain errors in fundamental flux estimation. As a result, the estimated flux might be erroneous, especially in the high-speed region. For accurate flux estimation, this article analyzes how the voltage synthesis in the pulsewidth-modulation affects the stator flux. Through the analysis, the backward Euler method is selected for the primitive stator flux estimation. To mitigate the FAO's discretization error, the proposed FAO utilizes the integrators constructed at the rotor reference frame (RRF). Since the discretization error comes from the approximation error of the continuous-time integrator at the operating frequency, the proposed FAO conducts the fundamental flux extraction at the RRF, where the operating frequency components are treated as a dc signal. Thanks to the coordinate transformation, the FAO can be discretized with no error while keeping the structure of double integrators. The proposed method is verified through the computer simulation and experimental test. [ABSTRACT FROM AUTHOR]

[Display omitted] • High-quality PtSe 2 was synthesized on hBN using MBE. • PtSe 2 synthesized on hBN has higher crystallinity and less grain boundaries than that on SiO 2 /Si. • Fabricated a PtSe 2 -based photodetector on hBN shows a higher response to the illuminated light with a broadband wavelength. • The PtSe 2 -based photodetector fabricated on hBN shows higher photocurrent, faster response speed, and superior broadband detection range. Two-dimensional (2D) van der Waals materials are potential candidates for high-performance optoelectrical devices owing to the bandgap modulation, high on/off ratio, and ultra-stability. However, the challenge of synthesizing large-area, uniform, and high-quality 2D van der Waals materials should be addressed to manufacture large-scale and uniform optoelectrical devices using these materials. Although several previous studies investigated synthesis methods using chemical vapor deposition and molecular beam epitaxy (MBE), there are certain limitations such as the non-uniformity, lots of grain boundaries, and low carrier mobility. Here, by studying a method for synthesizing PtSe 2 on hBN buffer layer using MBE, we fabricated a PtSe 2 -based broadband photodetector. The high-quality PtSe 2 synthesized on hBN was evaluated using Raman spectroscopy and scanning transmission electron spectroscopy. These revealed that the synthesized PtSe 2 had a high quality and small grain boundary compared with PtSe 2 synthesized on SiO 2. Owing to the reduction in the carrier scattering and carrier recombination because of the high-quality and small grain boundaries, the photodetector using PtSe 2 synthesized on hBN displayed optoelectrical properties that were significantly better than those of PtSe 2 synthesized on SiO 2. Therefore, using hBN as a buffer layer for PtSe 2 growth, a remarkable performance of complex optoelectrical devices could be achieved. [ABSTRACT FROM AUTHOR]

For stable and efficient drives of interior permanent-magnet synchronous machines (IPMSMs), stator flux should be observed across a wide speed range. However, distortions such as a dc offset and low-order harmonics are contained in the estimated flux due to various reasons. In this paper, a distortion-minimizing flux observer is proposed to suppress the effects of dc offset and harmonics by implementing frequency-adaptive observers. The proposed frequency-adaptive flux observer is designed to extract a fundamental flux while keeping a simple structure even if the rotating speed of the IPMSM varies. The fundamental flux could be estimated by the proposed current- and voltage-model based flux observer, which is implemented with the frequency-adaptive observer and harmonic extractors. Moreover, parameter sensitivity and model transition are discussed to improve the performance of the proposed observers. The validity and effectiveness of the proposed methods are verified with simulation and experimental results. [ABSTRACT FROM AUTHOR]

This paper presents an online maximum torque per ampere (MTPA) control that considers both magnetic saturation and cross-magnetization effects of interior permanent-magnet synchronous machines (IPMSMs). For IPMSM drives, especially in torque-controlled applications, torque accuracy and high-efficiency operations are important issues. They can be dealt as a constrained optimization problem to satisfy both torque reference tracking and loss-minimizing operation. In this paper, nonlinear simultaneous equations are derived from Lagrange multiplier method, which could be solved by numerical algorithms. Among them, Levenberg–Marquardt algorithm (LMA) is employed to guarantee a robust calculation of optimal current references. It is optimized to alleviate calculation burden while maintaining the stability of the proposed algorithm. In addition, a torque reference limiter is implemented to satisfy a current limit in real time. The feasibility of the proposed method is verified under various operating conditions by simulation and experimental results. Through the proposed algorithms, accurate MTPA control is achieved under not only unsaturated but also highly saturated operating conditions. [ABSTRACT FROM AUTHOR]

State-space control could provide both high dynamic performance and sufficient stability margin to voltage source converters with LC filter. However, an inherent digital delay induced by a digital control system deteriorates performance and even induces instability. In this paper, a discrete-time voltage controller is proposed based on a discrete state-space model. First, a state feedback control with a reference feedforward path is designed in the discrete-time domain with consideration for the digital delay. Second, an output current decoupling path is augmented to minimize the effects of an output current disturbance. Controller gains are derived as the functions of system parameters and design specifications, which is based on a direct pole placement and pole-zero cancellation method in a rotating reference frame. Moreover, a parameter sensitivity and digital implementation are discussed to improve the performance and stability of the proposed controller. The effectiveness of the proposed controller is verified with various experimental results. It shows that a filter resonance is well damped out while maintaining wide voltage control bandwidth. [ABSTRACT FROM AUTHOR]

[Display omitted] • Positive charge-mediated phase modulation of the crystal structure in 2D MoTe 2 synthesized by molecular beam epitaxy. • Structural phase of MoTe 2 is significantly influenced by the stoichiometric ratio of molybdenum to tellurium, and the tellurium adatoms make the 1T' phase more stable than the 2H phase. • Based on the energy difference and energy barrier between the two phases, the effects of doping on the structure during and after MoTe 2 synthesis were verified. Polymorphic phase transition between semi-conducting 2H and semi-metallic 1T′ in MoTe 2 has garnered significant interest due to its wide applicability for memory device. Recently, it has been reported that charge doping is a prospective method for facilitating practical application of phase transition. In particular, the positively doped system with lower energy barrier between two phases is more advantageous than the negatively doped system. However, although various methods for negative charge-mediated phase transition have been developed, study on positive charge-mediated phase transition is scarce due to the requirement of high charge density. Herein, we report positive charge-mediated phase modulation in MoTe 2 synthesized by molecular beam epitaxy. The structural phase of MoTe 2 is significantly influenced by the stoichiometric ratio of molybdenum to tellurium, and the tellurium adatoms make 1T' phase more stable than 2H phase. Photoelectron spectroscopy reveals that positive charge doping by electron transfer to tellurium adatoms is crucial in the determination of phase. Finally, based on the energy difference and energy barrier between two phases, the doping effects during and after synthesis are verified. This study on the structure modulation of MoTe 2 provides physical insight for phase transition as well as a basis for the development of nanoscale electronic devices. [ABSTRACT FROM AUTHOR]

The development of biologically targeted contrast agents for X-ray computed tomography (CT) imaging remains a major challenge. Here, we investigated a green chemistry-based synthesis of lymph node-targeted mannan-capped gold nanoparticles (M-GNPs) as a CT contrast agent. In this study, mannan was used as a reducing and stabilizing agent for gold nanoparticles (AuNPs). M-GNPs were readily internalized by antigen-presenting cells (APCs) through mannose receptors-mediated endocytosis. The M-GNPs, which had a spherical morphology, had an average diameter of 9.18 ± 0.71 nm and surface plasmon resonance (SPR) absorption spectra with maximal absorption at 522 nm. The M-GNPs displayed a concentration-based X-ray attenuation property with a maximum Hounsfield unit (HU) value of 303.2 ± 10.83. The local administration of M-GNPs led to significantly enhanced X-ray contrast for the imaging of popliteal lymph nodes. These findings demonstrated that M-GNPs can be used as biologically targeted contrast agents for CT imaging. [ABSTRACT FROM AUTHOR]

This paper addresses the inverter nonlinearity of a three-level T-type inverter. The main causes of the nonlinearity are pulse shaping, pulse skipping due to narrow pulses for the dead time, and voltage drop of the switching devices. Although the same causes have existed in two-level inverters, the pulse skipping phenomenon and results are quite different in the case of the three-level T-type inverter. The effects of pulse shaping and skipping have been investigated and discussed. In addition, the voltage drop of the switching devices has been considered in conjunction with the conduction path of the T-type inverter. Compensation methods based on the pulse width modulation (PWM) of T-type inverter to alleviate the inverter nonlinearity have been proposed from research results. The proposed methods could be easily implemented by adding appropriate offset voltages to the voltage references of the inverter in PWM. Furthermore, a neutral voltage balancing method of a three-level T-type inverter has been proposed in conjunction with the proposed PWM methods using offset voltage. Through extensive experimental tests, the fifth- and seventh-harmonic components of the current are conspicuously reduced along with the even harmonics. The neutral voltage of the inverter can be balanced effectively with the proposed offset voltage adjustments as well. [ABSTRACT FROM AUTHOR]

Autophagy is a self-degradation process that is important for balancing energy sources at critical times in development and in response to nutrient stress. Recently, it was report that autophagy is controlled by recognizing conserved pattern recognition receptors (PRRs), including toll-like receptors (TLRs). However, the molecular mechanism of TLRs in autophagy is not well understood. In this study, we found that serum starvation-dependent autophagy was associated with TLR9 activation in the absence of CpG-ODN, which is a specific TLR9 ligand. TLR9 was not only elevated but also colocalized with LC3 during autophagy by serum starvation or CPG-ODN treatment; however, these events did not occur simultaneously during autophagosome accumulation. Autophagy was even induced upon TLR9 activation after inhibiting recruitment of initial autophagy components by 3-MA, a specific inhibitor of class III PI3-kinase. Our data suggested that TLR9 may be promptly induced and recruit autophagy components from the endosome to autophagosome in response to stress. [ABSTRACT FROM AUTHOR]

Purpose. Bacterial cancer therapy (BCT) research using engineered Salmonella typhimurium has increased in recent years. 2-Deoxy-2[18F] fluoro-D-glucose positron emission tomography (FDG PET) is widely used in cancer patients to detect cancer, monitor treatment responses, and predict prognoses. The aim of this pilot study was to investigate FDG uptake patterns in a mouse tumor model after BCT. Procedures. BCT was performed via the intravenous injection of attenuated S. typhimurium (SL Δ ppGpp/lux) into female mice bearing a tumor (derived from CT26 murine colon cancer cells) in the right thigh. 18F-FDG PET images acquired before BCT and at different time points after BCT. In vivo bioluminescence imaging confirmed bacterial presence in the tumor. The tumor volume, standardized uptake value (SUV) of FDG (SUVmax and SUVmean), early SUV reduction%, and normalized tumor volume change were analyzed. Results. Early after BCT (1 or 2 days post-injection (dpi)), FDG tumor uptake decreased in 10 out of 11 mice and then increased at later stages. FDG uptake before BCT was correlated with normalized tumor volume change after BCT. Early FDG reduction% after BCT was correlated with normalized volume change after BCT. Conclusions. Early after BCT, FDG tumor uptake decreased and then increased at later stages. The higher the FDG tumor uptake before BCT, the better the BCT response. FDG uptake patterns were related to tumor volume change after BCT. Therefore, FDG uptake was a good candidate for evaluating BCT. [ABSTRACT FROM AUTHOR]

A PtSe2-based edge-contact field-effect transistor (FET) incorporating PtSe2 as the channel material and PtTe2 as the contact metal is fabricated using tellurization on only a selected region. The higher on–off ratio of the PtSe2-based edge-contact device compared to other synthesized PtSe2-based FETs is successfully achieved by reducing the contact resistance. [Display omitted] One-dimensional (1D) edge contact is considered critical to reducing contact resistance between two-dimensional transition-metal dichalcogenides (TMDs) and contact metal and overcoming surface contact effects, such as surface damage and orbital hybridization. Although several studies have investigated edge contact, some problems such as inevitable etching damage and a limited area persist. Herein, a tellurization method is applied to a specific lateral region to fabricate PtTe 2 /PtSe 2 /PtTe 2 edge-contact field-effect transistors (FETs) without etching damage. High-resolution X-ray photoelectron spectroscopy and Raman spectroscopy are used to verify tellurization completion, which is evidenced by the complete transformation of PtSe 2 to PtTe 2 by the substitution of Se atoms with evaporated Te atoms. Furthermore, tellurization is applied to a specific lateral region by utilizing the hexagonal boron nitride to block the interdiffusion of evaporated Te atoms, which is confirmed by Raman spectroscopy and cross-sectional annular dark-field scanning transmission electron microscopy. Finally, the 1D edge-contact FETs fabricated by tellurization demonstrate a higher on–off ratio and carrier mobility than the surface-contact FET. Therefore, this method can be applied to various FETs based on TMDs for improving electrical performance through a reduction in contact resistance. [ABSTRACT FROM AUTHOR]

Relation between FET performance and initial growth stages of PtSe 2 film is analyzed for device application. In initial growth stages, platinum nucleus which degrade device performance co-exist in thin PtSe 2. Controlling growth kinetics, suppression of platinum nucleus and improvement of on–off ratio and mobility are achieved, which contribute to understand growth mechanism and optimize 2D TMD growth on three-dimensional substrate. [Display omitted] • PtSe 2 films with 1T structure were synthesized on SiO 2 /Si and sapphire (0 0 0 1) substrates using MBE. • Thickness- and substrate-dependent properties of synthesized PtSe 2 films using HR-XPS and STEM showed that metallic Pt co-existed in thin PtSe 2 films on SiO 2 /Si substrates. • Thickness- and substrate-dependent properties of synthesized PtSe 2 films showed that metallic Pt co-existed in thin PtSe 2 films on SiO 2 /Si substrates. • Electrical performance of thin PtSe 2 according to thicknesses and substrates was verified, which illustrating that co-existence of metallic Pt caused electrical degradation. • Suppression of metallic Pt by the change in interface energy between PtSe 2 and substrate affects the increased field effect mobility and on–off ratio of PtSe 2 -based electrical devices. Platinum diselenide (PtSe 2) is an emerging transition-metal dichalcogenide showing both strong interlayer coupling and remarkable electrical properties. Because field-effect transistors (FETs) recently fabricated using PtSe 2 films grown by various methods have not shown the high mobilities and on–off ratios compared with exfoliated PtSe 2 and predicted by theoretical calculations, the PtSe 2 growth mechanism must be better understood to prevent the degradation of electrical properties and improve the electrical performances of PtSe 2 -based devices. Therefore, molecular beam epitaxy is used in the current study to grow PtSe 2 films, and a correlation is demonstrated between the initial PtSe 2 growth kinetics and the electrical performances of PtSe 2 -based devices. X-ray photoelectron spectroscopy and annular dark field–scanning transmission electron microscopy show that metallic Platinum (Pt) is present in the thin PtSe 2 films, as explained by the density functional theory calculations comparing Pt–Pt bond with Pt–Se bond. Electrical measurements of the PtSe 2 -based FETs show that the electrical performances are closely correlated with the initial growth kinetics of the PtSe 2 films, indicating that removing Pt (which degrades device performance) is the most important aspect of growing thin PtSe 2 films to optimize device performance. [ABSTRACT FROM AUTHOR]

Purpose. Bacterial cancer therapy (BCT) research using engineered Salmonella typhimurium has increased in recent years. 2-Deoxy-2[18F] fluoro-D-glucose positron emission tomography (FDG PET) is widely used in cancer patients to detect cancer, monitor treatment responses, and predict prognoses. The aim of this pilot study was to investigate FDG uptake patterns in a mouse tumor model after BCT. Procedures. BCT was performed via the intravenous injection of attenuated S. typhimurium (SL Δ ppGpp/lux) into female mice bearing a tumor (derived from CT26 murine colon cancer cells) in the right thigh. 18F-FDG PET images acquired before BCT and at different time points after BCT. In vivo bioluminescence imaging confirmed bacterial presence in the tumor. The tumor volume, standardized uptake value (SUV) of FDG (SUVmax and SUVmean), early SUV reduction%, and normalized tumor volume change were analyzed. Results. Early after BCT (1 or 2 days post-injection (dpi)), FDG tumor uptake decreased in 10 out of 11 mice and then increased at later stages. FDG uptake before BCT was correlated with normalized tumor volume change after BCT. Early FDG reduction% after BCT was correlated with normalized volume change after BCT. Conclusions. Early after BCT, FDG tumor uptake decreased and then increased at later stages. The higher the FDG tumor uptake before BCT, the better the BCT response. FDG uptake patterns were related to tumor volume change after BCT. Therefore, FDG uptake was a good candidate for evaluating BCT. [ABSTRACT FROM AUTHOR]

In this paper, the characteristics of ripple current of a multimegawatt drive system fed by a pulse-width modulation (PWM) inverter are investigated. Based on the investigation, a novel PWM scheme is devised to reduce the switching loss of the inverter under an identical amount of torque ripple of a motor. The proposed PWM is composed of two parts. The first is minimum torque ripple PWM (MTRPWM), which is optimized in terms of the minimum torque ripple in high modulation index (MI). The second determines the minimum switching frequency while holding the average torque ripple less than the allowable value under various operating conditions. It is termed reduced switching frequency PWM (RSFPWM). Consequently, by simply changing the PWM method from conventional fixed switching frequency continuous PWM to the proposed PWM, MTRPWM and RSFPWM, simulation results show that the switching loss of the inverter driving a 3.5 MW induction motor is reduced to 51.6% while keeping the torque ripple in the allowable boundary, where MI is 1.12. This approach is applied to small-scale experimental sets consisting of an interior permanent magnet synchronous machine (IPMSM) motor-generator set, and an induction machine MG set in an effort to verify the validity and feasibility of the proposed method. Based on these experimental results, the cost indexes of the IPMSM and the induction machine, as defined in this paper, decrease by up to 66% and 77%, respectively, when the proposed method is applied when MI is 1.12 compared with the outcome with the conventional PWM. [ABSTRACT FROM AUTHOR]

Industrial plant machines have a significantly lower frequency of defective data than the frequency of normal data. For this reason, machine learning is often applied using only some obtained state data. However, the low frequency of defect data does not guarantee that novel data occur, which is why detection of novelty class is required. This paper studies the novelty class detection method in multi-classification. Multi-class support vector machine was used for multi-classification. Cluster-based local outlier factor, histogram-based outlier score, outlier detection with minimum covariance deTerminant, isolation forest, and one-class support vector machine applied novelty class detection. Anomaly detection algorithms used the hard voting ensemble method. A feature engineering method that is advantageous for novelty class detection was confirmed by comparing the genetic algorithm (GA)-based feature selection and principal component analysis (PCA). Findings show that creating a model using GA-based feature selection for multi-classification and independent PCA for each class for novelty class detection is advantageous. With the use of an independent PCA, the problem was simplified to perform detection on a novelty class with a condition similar to the trained class. [ABSTRACT FROM AUTHOR]

This paper presents a carrier-based pulsewidth modulation (PWM) method that reduces the common-mode voltage (CMV) of a three-level four-leg converter. Based on an analysis of space vector PWM (SVPWM) and sinusoidal-PWM switching patterns, the fourth-leg pole voltage of a three-phase converter, known as the “f pole voltage,” is manipulated to reduce the CMV. To synthesize the f pole voltage for the suppression of the CMV, positive and negative pole voltage references of the f leg are calculated. In addition, the offset voltage to prevent distortion of the a, b, and c phase voltages regarding the neutral point is deduced. The proposed PWM strategy can be easily implemented in the software of a DSP-based converter control. The three-level four-leg converter with the proposed PWM algorithm results in a remarkable reduction in the peak-to-peak value of the CMV. From the simulation and the experimental results, the peak-to-peak value of the CMV when using the proposed PWM method is 33% compared to that when using the SVPWM method, while the number of CMV transitions during the switching period in the proposed PWM method is only 25% of that when using the SVPWM method. [ABSTRACT FROM PUBLISHER]

Single-step immunoassays have attracted much attention compared with conventional multi-step sandwich immunoassays, owing to their user-friendliness, minimization of potential errors (e.g., false signals) arising from multistep procedures, and reduced diagnosis time. However, developing a single-step immunoassay with high sensitivity and accuracy has remained challenging. In this study, we developed a single-step, digital immunoassay by applying an imaging technique to a typical sandwich immunoassay, leading to high sensitivity and accuracy. The imaging technology—composed of serial imaging of a sensing surface, stacking of the obtained images, and particle counting using an algorithm—enabled the differentiation of bound and unbound conjugates (detection antibody-conjugated polystyrene beads) without washing. Stationary bound conjugates became more distinct after stacking over 30 images, while randomly drifting unbound conjugates disappeared, enabling the counting of only individual bound labels. The platform efficiently detected SARS-CoV-2 nucleocapsid protein in the concentration range of 10 pg mL–1 to 1 ng mL–1 (limit of detection, 0.87 pg mL–1), which was 103 times more sensitive than that of a conventional lateral flow immunoassay. This immunoassay could be a promising method for highly sensitive and accurate point-of-care biosensors. [Display omitted] • A single-step, digital immunoassay was developed based on imaging techniques. • Serial imaging and image stacking enabled detecting only bound conjugates without washing steps. • Our single-step, digital immunoassay showed 103 times higher sensitivity than that of a conventional LFI platform. [ABSTRACT FROM AUTHOR]

Carbonic anhydrase IX is overexpressed in many solid tumors including hypoxic tumors and is a potential target for cancer therapy and diagnosis. Reported imaging agents targeting CA-IX are successful mostly in clear cell renal carcinoma as SKRC-52 and no candidate was approved yet in clinical trials for imaging of CA-IX. To validate CA-IX as a valid target for imaging of hypoxic tumor, we designed and synthesized novel [ 18 F]-PET tracer ( 1 ) based on acetazolamide which is one of the well-known CA-IX inhibitors and performed imaging study in CA-IX expressing hypoxic tumor model as 4T1 and HT-29 in vivo models other than SKRC-52. [ 18 F]-acetazolamide ( 1 ) was found to be insufficient for the specific accumulation in CA-IX expressing tumor. This study might be useful to understand in vivo behavior of acetazolamide PET tracer and can contribute to the development of successful PET imaging agents targeting CA-IX in future. Additional study is needed to understand the mechanism of poor targeting of CA-IX, as if CA-IX is not reliable as a sole target for imaging of CA-IX expressing hypoxic solid tumors. [ABSTRACT FROM AUTHOR]

Bilirubin (BR), a bile pigment that exerts potent antioxidant and anti-inflammatory effects, is also a major constituent of black pigment gallstones found in bile ducts under certain pathological conditions. Inspired by the intrinsic metal-chelating power of BR found in gallstones, herein we report a cisplatin-chelated BR-based nanoparticle (cisPt@BRNP) for use as a new photonic nanomedicine for combined photoacoustic imaging and photothermal therapy of cancers. The cisPt@BRNPs were prepared by simply mixing cisplatin with BRNPs, yielding ca. 150-nm-size NPs. Upon near-IR laser irradiation at 808 nm, cisPt@BRNPs generated considerable heat and induced clear death of cancer cells in vitro. Following intravenous injection into human colon cancer-bearing mice, cisPt@BRNPs allowed effective tumor visualization by photoacoustic imaging and remarkable antitumor efficacy by photothermal therapy, suggesting their potential for use as a new photonic nanomedicine for cancer therapy. [ABSTRACT FROM AUTHOR]

Bilirubin (BR), a bile pigment that exerts potent antioxidant and anti-inflammatory effects, is also a major constituent of black pigment gallstones found in bile ducts under certain pathological conditions. Inspired by the intrinsic metal-chelating power of BR found in gallstones, herein we report a cisplatin-chelated BR-based nanoparticle (cisPt@BRNP) for use as a new photonic nanomedicine for combined photoacoustic imaging and photothermal therapy of cancers. The cisPt@BRNPs were prepared by simply mixing cisplatin with BRNPs, yielding ca. 150-nm-size NPs. Upon near-IR laser irradiation at 808 nm, cisPt@BRNPs generated considerable heat and induced clear death of cancer cells in vitro. Following intravenous injection into human colon cancer-bearing mice, cisPt@BRNPs allowed effective tumor visualization by photoacoustic imaging and remarkable antitumor efficacy by photothermal therapy, suggesting their potential for use as a new photonic nanomedicine for cancer therapy. [ABSTRACT FROM AUTHOR]

In a previous study, we developed an E1 monobody specific for the tumor biomarker hEphA2 [PLoS ONE (2015) 10(7): e0132976]. E1 showed potential as a molecular probe for in vitro and in vivo targeting of cancers overexpressing hEphA2. In the present study, we constructed expression vectors for E1 conjugated to optical reporters such as Renilla luciferase variant 8 (Rluc8) or enhanced green fluorescent protein (EGFP) and purified such recombinant proteins by affinity chromatography in E. coli. E1-Rluc8 and E1-EGFP specifically bound to hEphA2 in human prostate cancer PC3 cells but not in human cervical cancer HeLa cells, which express hEphA2 at high and low levels, respectively. These recombinant proteins maintained >40% activity in mouse serum at 24 h. In vivo optical imaging for 24 h did not detect E1-EGFP signals, whereas E1-Rluc8 showed tumor-specific luminescence signals in PC3 but not in HeLa xenograft mice. E1-Rluc8 signals were detected at 4 h, peaked at 12 h, and were undetectable at 24 h. These results suggest the potential of E1-Rluc8 as an EphA2-specific optical imaging agent. [ABSTRACT FROM AUTHOR]