Finely tuned Prussian blue-based nanoparticles and their application in disease treatment

The Prussian blue (PB) based nanostructure is a mixed-valence coordination network with excellent biosafety, remarkable photothermal effect and multiple enzyme-mimicking behaviours. Compared with other nanomaterials, PB-based nanoparticles (NPs) exhibit several unparalleled advantages in biomedical applications. This review begins with the chemical composition and physicochemical properties of PB-based NPs. The tuning strategies of PB-based NPs and their biomedical properties are systemically demonstrated. Afterwards, the biomedical applications of PB-based NPs are comprehensively recounted, mainly focusing on treatment of tumors, bacterial infection and inflammatory diseases. Finally, the challenges and future prospects of PB-based NPs and their application in disease treatment are discussed.

Value of contrast-enhanced ultrasound in the diagnosis of breast US-BI-RADS 3 and 4 lesions with calcifications

AIM

To evaluate the diagnostic performance of contrast-enhanced ultrasound (CEUS) for Breast Imaging-Reporting and Data System for Ultrasound (US-BI-RADS) 3 and 4 lesions with calcifications.

MATERIALS AND METHODS

A retrospective study of 168 breast lesions with calcifications detected on both mammography and conventional ultrasonography (US) in 152 patients were categorised as US-BI-RADS 3-4 at US between June 2009 and June 2018. CEUS scores were obtained based on a CEUS five-point scoring system. The combination of US-BI-RADS and CEUS scores created the Rerated BI-RADS (referred to as CEUS-BI-RADS). All results were compared with the histological findings. The diagnostic performances of US and CEUS-BI-RADS were compared.

RESULTS

The diagnostic sensitivity, specificity, and accuracy of US were 81.8% (95% confidence interval [CI]: 71.6%, 92%), 85% (95% CI: 78.4%, 91.5%), and 83.9% (95% CI: 78.4%, 89.5%), respectively, while those for CEUS-BI-RADS were 98.2% (95% CI: 94.7%, 100%), 90.3% (95% CI: 84.8%, 95.7%), and 92.9% (95% CI: 89%, 96.8%), respectively. The diagnostic sensitivity and accuracy values of CEUS-BI-RADS greatly improved compared with those of US (p=0.003 and p=0.004, respectively). The areas under the receiver operating characteristic (ROC) curves for US and CEUS-BI-RADS were 0.888 (95% CI: 0.840, 0.936) and 0.963 (95% CI: 0.936, 0.989), respectively. The diagnostic efficacy of CEUS-BI-RADS was significantly higher than that of US alone (p=0.004).

CONCLUSION

CEUS-BI-RADS significantly improves the diagnostic accuracy for breast US-BI-RADS 3 and 4 lesions with calcifications compared with US.

Encapsulation of Methylene Blue in Zeolitic Imidazolate Framework-90 Nanoparticles to Protect Its Photodynamic Activity

Methylene blue (MB) is widely used as a photosensitizer in photodynamic therapy applications. However, it is easily reduced by reductases in biological environments, which hampers its further applications. Here, we developed a one-pot method to synthesize MB-encapsulated and poly(vinylpyrrolidone) (PVP)-modified zeolitic imidazolate framework-90 (ZIF-90) nanoparticles (MB@ZIF-90/PVP NPs). The NPs show intact crystalline structure with improved colloidal dispersity and stability both in water and in the medium for cell culture. The size of the enzymes is much larger than the pore size of ZIF-9; thus, the access of reductive enzymes to encapsulated MB is prohibited, resulting in the protection of MB's photodynamic activity. Furthermore, cell experiments confirm that MB@ZIF-90/PVP NPs have lower dark cytotoxity than equivalent free MB but can efficiently induce photodynamic damage to tumor cells even in the presence of reductive enzymes upon light irradiation.

Long noncoding RNA CRNDE promotes proliferation, migration and invasion in prostate cancer through miR-101/Rap1A

Prostate cancer (Pca) is the second frequent malignancy in men. Long noncoding RNAs (lncRNAs) have been reported to play essential roles in the progression of cancers, including Pca. LncRNA colorectal neoplasia differentially expressed (CRNDE) has been found to affect tumorigenesis in many cancers. However, the exact role and mechanism of CRNDE in Pca remain poorly understood. 64 Pca patients were recruited in this study. PC3 and 22RV1 cells were used in vitro experiments. The expressions of CRNDE, microRNA-101 (miR-101), and Ras-related protein 1A (Rap1A) were detected in vivo and in vitro by quantitative real-time polymerase chain reaction and western blot, respectively. Cell proliferation, apoptosis, migration, and invasion were investigated through cell counting kit-8, flow cytometry, and Transwell assays, respectively. The interaction between miR-101 and CRNDE or Rap1A was explored by bioinformatics analysis and luciferase reporter assay. High expression of CRNDE was shown in Pca tissues and cells and predicted poor outcomes of patients. Overexpression of CRNDE promoted cell proliferation, migration, and invasion but decreased apoptosis in Pca cells, while its knockdown showed an opposite effect. CRNDE was a decoy of miR-101 and its effect on Pca progression was reversed by miR-101. Rap1A was identified as a target of miR-101 and it attenuated the effect of miR-101 on Pca development. Moreover, the Rap1A protein level was positively regulated by CRNDE, which was weakened by miR-101. CRNDE contributed to cell proliferation, migration, and invasion by regulating the miR-101/Rap1A axis in Pca, providing a novel strategy for Pca treatment.

Possible magnetic correlation above the ferromagnetic phase transition temperature in Cr2Ge2Te6

Cr₂Ge₂Te₆ has recently emerged as a new two-dimensional ferromagnetic semiconductor (2DFMS) that is promising for spintronic applications. The origin of the ferromagnetism is a debatable point. In this study, ac/dc susceptibility and electronic spin resonance (ESR) measurements are performed to explore the origin of the ferromagnetism in Cr₂Ge₂Te₆. Through the ac susceptibility scaling, the critical temperature T_C = 62.84 K and δ = 5.24 from the critical isotherm, γ + β = 1.78 from the temperature dependence of the crossover line and γ = 1.43 from the temperature dependence of the susceptibility along the same line. Unlike Cr₂Si₂Te₆ whose magnetism can be well described by the 2D-Ising model, Cr₂Ge₂Te₆ cannot be simply described by a single theory model. Meanwhile, the origin of the abnormal critical behavior has been explored and it may be related to the presence of the possible magnetic correlation around the high temperature T* ∼ 160 K, which is confirmed by different probing measurements. The magnetic correlation at high temperature accompanied by the strong magnetic-crystalline anisotropy at low temperature plays an important role in the origin of the abnormal ferromagnetism in Cr₂Ge₂Te₆. Our results may supply a typical reference to investigate the abnormal ferromagnetism of 2DFMSs.

Realization of linear-mapping between polarization Poincaré sphere and orbital Poincaré sphere based on stress birefringence in the few-mode fiber

Based on the spatial profiles and polarization states evolution process of the first-order modes resulted from stress-induced birefringence in the few-mode fiber (FMF), we analyze the mapping relationship between the input polarization states represented on polarization PS and the output spatial profiles represented on the orbital PS of the FMF with respect to the magnitude and orientation of birefringence. When the input mode lobe orientation and the phase differences between the four eigenmodes of FMF induced by the stress birefringence satisfy a given condition, the mapping relationship between the input polarization PS and the output orbital PS is linear. Thus, the arbitrary points on the orbit PS can be generated at the output of stressed FMF by controlling the polarization state of the input modes. Then we experimentally verify that, an electrical single-mode polarization controller, a mode converter for converting fundamental mode to higher-order mode, a polarization controller mounting a coil of two-mode fiber and a polarizer can be employed to generate arbitrary first-order spatial modes on the orbital PS by controlling the input single-mode polarization states. The positions on the orbital PS of the generated first-order modes, which are obtained by calculating the three normalized Stokes parameters of output modes, agree well with the simulation ones. The correlation coefficients between the theoretical mode profiles and the experimental ones are higher than 80%. Since the spatial profile evolutions depend on the variations of the input polarization states, a potential advantage of this method is high-speed switching among desired first-order modes by using the commercial devices switching the state of polarization.

Kernel mapping for mitigating nonlinear impairments in optical short-reach communications

Nonlinear impairments induced by the opto-electronic components are one of the fundamental performance-limiting factors in high-speed optical short-reach communications, significantly hindering capacity improvement. This paper proposes to employ a kernel mapping function to map the signals in a Hilbert space to its inner product in a reproducing kernel Hilbert space, which has been successfully demonstrated to mitigate nonlinear impairments in optical short-reach communication systems. The operation principle is derived. An intensity modulation/direct detection system with 1.5-µm vertical cavity surface emitting laser and 10-km 7-core fiber achieving 540.68-Gbps (net-rate 505.31-Gbps) has been carried out. The experimental results reveal that the kernel mapping based schemes are able to realize comparable transmission performance as the Volterra filtering scheme even with a high order.

Long-period fiber gratings inscribed in few-mode fibers for discriminative determination

We successfully fabricated the long-period fiber gratings in few-mode fibers (FMF-LPFGs) with micro-tapered method, which are different from the traditional LPFGs that only couple the fundamental mode to different cladding modes to obtain multiple resonant dips. There are two resonant dips on the transmission spectrum of the FMF-LPFGs, which are induced by the coupling between the fundamental mode and the low-order cladding mode LP₀₃ (dip 1) and the coupling between the fundamental mode and the high-order core mode LP₁₁ (dip 2). Due to the difference of the coupling mechanism involved in two dips, the shift of resonant wavelengths has different characteristics with the variation of the external environment parameter. The corresponding wavelength of dip 1 exhibits a red shift as the temperature increased. But for dip 2, the resonant wavelength has a blue shift. In addition, the two dips have different temperature and strain sensitivities. Therefore, discriminative determination of temperature and strain is realized by establishing the cross coefficient matrix, and the relative measurement error is less than 3%. What's more, we theoretically analyzed the reason why the two resonant wavelengths shift toward opposite direction with the increase of temperature and toward the same direction with the increase of strain.

Kidney-targeted rhein-loaded liponanoparticles for diabetic nephropathy therapy via size control and enhancement of renal cellular uptake

The optimization of nanoparticle size for passing through glomerular filtration membrane, inefficient renal cellular uptake and rapid urinary excretion of nanoparticles are the major obstacles for renal disease treatment via a nanoparticle delivery system. Herein, we propose a concept of a two-step nanoparticular cascade of size control and enhancement of renal cellular uptake to overcome the renal delivery obstacles. Methods: We prepared kidney-targeted rhein (RH)-loaded liponanoparticles (KLPPR) with a yolk-shell structure composed by polycaprolactone-polyethyleneimine (PCL-PEI)-based cores and kidney targeting peptide (KTP)-modified lipid layers. The KLPPR size within the range of 30 ~ 80 nm allowed KLPPR distribute into kidney by passing through the glomerular filtration membrane and the KTP (sequence: CSAVPLC) decoration promoted the renal cellular uptake and endocytosis via a non-lysosomal pathway. Results: The KLPPR had an average size of 59.5±6.2 nm and exhibited high RH loading, sustained release, good stability and biocompatibility, rapid cellular uptake in HK-2 cells. In addition, intravenous administration of KLPPR resulted in excellent kidney-targeted distribution and low urinary excretion in mice with streptozocin-induced diabetic nephropathy (DN), lowered the parameters of urea nitrogen, serum creatinine and kidney index, as well as facilitated the recovery of renal physiological function in improving the levels of urinary creatinine and the creatinine clearance rate by suppressing secretion and accumulation of fibronectin and TGF-β1. Conclusion: Definitely, KLPPR were able to target the diseased kidney and improve the therapeutic effect of RH on DN by exploiting the two-step nanoparticular cascade of size control and enhancement of cellular uptake. This study offers a promising strategy for renal diseases treatment using liponanoparticle delivery system.

Supramolecular peptide constructed by molecular Lego allowing programmable self-assembly for photodynamic therapy

Peptide self-assemblies with multiple nanostructures have great potentials in functional biomaterials, and yet the tedious and costly covalent peptide modification and the lack of facile controllability on self-assembly morphology retard the peptide-related exploration. Here we report a simple approach to fabricate a supramolecular peptide that shows programmable self-assembly with multiple morphologies and application in photodynamic therapy. Pillar[5]arene-based host-guest recognition is used to construct a supramolecular peptide, which simplify the peptide modification and promote the controllability of the self-assembly behavior. Due to the ERGDS sequences on the exterior surfaces and hydrophobic cores of self-assemblies, the nanoparticles formed from the supramolecular peptide are suitable vehicles to encapsulate a photosensitizer for photodynamic therapy. In vitro and in vivo studies demonstrate that the inherent targeting capability and supramolecular strategy greatly boost its photodynamic therapeutic efficiency. This supramolecular peptide holds promising potentials in precise cancer therapy and perspectives for the peptide modification.

Femtosecond laser enabled selective micro-holes drilling on the multicore-fiber facet for displacement sensor application

We experimentally demonstrate a femtosecond laser enabled selective micro-holes drilling technique on the multicore-fiber facet. The precise position of individual cores at the seven-core fiber facet is initially locked by the image processing algorithm, and then six micro-holes are successfully fabricated after the pulse energy of femtosecond laser is optimized. Meanwhile, the use of fabricated seven-core fiber for the application of reflective intensity-modulated fiber optics displacement sensor (RIM-FODS) is comprehensively investigated. By using the beam propagation method (BPM), we theoretically investigate the effect of micro-hole depth on the RIM-FODS performance, in terms of both dead zone and measurement range. We identify that, with the increase of micro-hole depth, the dead zone range can be substantially reduced at the expense of measurement range reduction. However, multiple micro-holes with a successive depth difference can overcome such problem. When the micro-holes with depths of 5, 10, 15, 20, 25, 30 μm are fabricated on the seven-core fiber facet, and the dead zone range can be substantially reduced from 150 μm to 20 μm, together with an extension of measurement range from 250 μm to 400 μm.

Construction of Microreactors for Cascade Reaction and Their Potential Applications as Antibacterial Agents

Enzymatic cascade reactions in confined microenvironments play important roles in cellular chemical transformation. They also have important biotechnological and therapeutic applications. Here, enzymatic cascade microreactors (MRs) coupling glucose oxidase (GOx) and hemoglobin (Hb) (GOx-Hb MRs) were successfully fabricated by co-precipitation of GOx and Hb into a MnCO₃ template, followed by the assembly of a multilayer film on a template surface, slight cross-linking, and final removal of MnCO₃. In the presence of glucose with blood-relevant concentration, the GOx-Hb MRs exhibited a higher cascade reaction activity under mild acidic conditions than that under neutral conditions at physiological temperature. The GOx-Hb MRs effectively consumed glucose to generate HO^· at pH = 5, which significantly inhibited bacterial growth and biofilm formation. This kind of enzymatic cascade microreactors might be useful for applications in biomedical fields.

Performance enhancement of free-space optical communications under atmospheric turbulence using modes diversity coherent receipt

This paper numerically and experimentally investigates the performance of free-space optical receiver using modes diversity coherent receipt under moderate-to-strong turbulence. By utilizing a three-mode photonic lantern with digital maximum ratio combining, a 40 Gbps QPSK optical signal is received. The turbulence strength is measured by the ratio of beam diameter to atmospheric coherence length, D/r0. The larger the D/r0, the stronger the turbulence is, and vice versa. Compared with conventional single mode fiber based receipt, the required transmitted power can reduce by 4.6 dB and 4 dB at 10% interruption probability under turbulence strength D/r0 = 8 and 16. The required transmitted power at bit error ratio of 2.2 × 10^-2 can relax by 4.2 dB and 5 dB under turbulence strength D/r0 = 8 and 16.

All-fiber orbital angular momentum mode multiplexer based on a mode-selective photonic lantern and a mode polarization controller

We demonstrate for the first time, to the best of our knowledge, an all-fiber orbital angular momentum (OAM) multiplexer that multiplexes both OAM modes of -l and +l up to the second order by using a mode-selective photonic lantern and a mode polarization controller. The experimentally obtained mode profiles are close to the theoretical results, and the mode purities are higher than 89% for all the OAM modes at 1550 nm. The losses for all mode generations are less than 3.8 dB in the C-band.

Link optimized few-mode fiber Raman distributed temperature sensors

A link optimized few-mode fiber-based Raman distributed temperature sensor is proposed to enhance the temperature resolution of the long-distance sensing system. Comprehensive theoretical analysis and experimental validation in contrast with the traditional single-mode fiber-based sensing link have been conducted to reveal the benefits provided by the optimization scheme. The temperature resolutions are about 3.8°C for the proposed fiber link at 20 km distance, leading to about 6.2°C improvement compared with the single-mode fiber (SMF) link. The total measurement is completed within 80 s over 20 km with a spatial resolution of 3 m.

Design of highly mode group selective photonic lanterns with geometric optimization

Highly mode group selective photonic lanterns (PLs) are desired for mode-division multiplexing transmission systems. Usually, mode selectivity is achieved by using input fibers with different core diameters or refractive indices to break degeneracy between mode groups. We demonstrate that mode group selectivity can be greatly improved by optimizing core geometry of PLs. For three-mode PLs with optimized core geometry, based on beam propagation method (BPM) simulation results, mode selectivity is improved from 23.8 dB to 43.9 dB for LP₀₁ mode, and mode selectivity of LP₁₁ mode is improved from 26.8 dB to 45.5 dB. The reason is the optimized core geometry can significantly slow down the changing of mode profile along the taper of the PL; thus adiabatic tapering requirement can be greatly alleviated. It can also be observed that the simulation results by the BPM are in good agreement with calculation of coupled-mode theory.

Long-range Raman distributed temperature sensor with high spatial and temperature resolution using graded-index few-mode fiber

We designed and fabricated a graded-index few-mode fiber (GI-FMF) with large effective mode area and low intermodal dispersion for Raman distributed temperature sensor (RDTS) to simultaneously achieve high spatial and temperature resolution over long distance. In experiment, we measured the spatial and temperature resolution of the RDTS using different types of fibers under different launch conditions based on a commercially available RDTS system. By using the GI-FMF under the overfilled launch condition, we achieved a 1 °C temperature resolution with a spatial resolution of 1.13 m at the distance of 25 km. The spatial resolution using the standard MMF degraded to 2.58 m with only a 0.3 °C higher temperature resolution in comparison. As a result, the GI-FMF under the few-mode operation condition can provide a desirable temperature resolution comparable with that of the MMF with a negligible degradation on spatial resolution. Moreover, the RDTS using the GI-FMF under the quasi-single mode operation condition achieved a temperature resolution of 4.7 °C at the distance of 25 km with a 2.2 °C improvement and no degradation on spatial resolution compared with that using the standard SMF.

Few-mode multicore fiber enabled integrated Mach-Zehnder interferometers for temperature and strain discrimination

We proposed and experimentally demonstrated paralleled Mach-Zehnder interferometers (MZIs) in few-mode multicore fiber (FM-MCF) for temperature and strain discriminative sensing. A section of FM-MCF is sandwich-spliced between two single-mode multicore fiber (SM-MCF) with a rotational offset. The arbitrarily controlled angular misalignment generates intentional intermodal interferences in outer cores of the FM-MCF thus multiple MZI structures are implemented. Experimental results show that the temperature sensitivities are 105.8 pm/°C and 223.6 pm/°C for two outer cores, strain sensitivity is 13.96 pm/με for the outer core 1 and 11.7 pm/με for the outer core 2, respectively. Due to the low condition number of the cross coefficient matrix dependent on the temperature and strain response indexes, the temperature-strain cross sensitivity can be efficiently eliminated. In addition, the structure's fabrication process is simple, cost effective, and repeatable. The sensing structure can be applied to a wide range of measurements and is expected to develop potentials by building a higher dimensional matrix with more cores.

Review article: therapeutic bile acids and the risks for hepatotoxicity

BACKGROUND

Bile acids play important roles in cholesterol metabolism and signal through farnesoid X receptor and G protein-coupled receptors. Given their importance in liver biology, bile acid therapy enables therapeutic applications beyond the treatment of cholestatic liver disease. However, predicting hepatotoxicity of bile acids in humans is obscured due to inconsistent extrapolations of animal data to humans.

AIM

To review the evidence that could explain discordant bile acids hepatotoxicity observed in humans and animals.

METHOD

Literature search was conducted in PubMed using keywords "bile acid," "transporter," "hepatotoxicity," "clinical study," "animal study," "species difference," "mechanism," "genetic disorder." Relevant articles were selected for review.

RESULTS

Clinically significant hepatotoxicity was reported in response to certain bile acids, namely chenodeoxycholic acid, which was given a boxed warning for potential hepatotoxicity. The chemical structure, specifically the number and orientation of hydroxyl groups, significantly affects their hydrophobicity, an important factor in bile acid toxicity. Experimental studies show that hydrophobic bile acids can lead to liver injury through various mechanisms, such as death receptor signalling, mitochondrial dysfunction and inflammation. Although animal studies play a central role in investigating bile acid safety, there are considerable differences in bile acid composition, metabolism and hepatobiliary disposition across species. This does not allow appropriate safety inference, especially for predicting hepatotoxicity in humans. Exploring evidences stemming from inborn errors, genetic models of disease and toxicology studies further improves an understanding of bile acid hepatotoxicity.

CONCLUSION

Species differences should be considered in the development of bile acid related therapeutics. Although the mechanism of bile acid hepatotoxicity is still not fully understood, continued mechanistic studies will deepen our understanding.