Fe-doped biodegradable dendritic mesoporous silica nanoparticles for starvation therapy and photothermal-enhanced cascade catalysis in tumor therapy.

Combination therapies have attracted significant attention because they address the limitations of monotherapy while improving overall efficacy. In this study, we designed a novel nanoplatform, named GOx@Fe-DMSN@PDA (GFDP), by integrating Fe2+ into dendritic mesoporous silica nanoparticles (DMSN) and selecting glucose oxidase (GOx) as the model drug loaded into the DMSN pores. Additionally, we coated the surface of the DMSN with polydopamine (PDA) to confer pH/near infrared (NIR) light-responsive controlled-release behavior and photothermal therapy (PTT). The introduction of Fe2+ into the DMSN framework greatly improved biodegradability and enhanced the peroxidase (POD)-like activity of GFDP. In addition, GOx could consume glucose and generate hydrogen peroxide (H2O2) within tumor cells to facilitate starvation therapy and enhance cascade catalysis. The PDA coating provided the DMSN with an intelligent response release ability, promoting efficient photothermal conversion and achieving the PTT effect. Cellular tests showed that under NIR light irradiation, GFDP exhibited a synergistic effect of PTT-enhanced starvation therapy and cascade catalysis, with a half-maximal inhibitory concentration (IC50) of 2.89 µg/mL, which was significantly lower than that of GFDP without NIR light irradiation (18.29 µg/mL). The in vivo anti-tumor effect indicated that GFDP could effectively accumulate at the tumor site for thermal imaging and showed remarkable synergistic therapeutic effects. In summary, GFDP is a promising nanoplatform for multi-modal combination therapy that integrates starvation therapy, PTT, and cascade catalysis.

1283-1460 nm continuously tunable, watt-level bismuth-doped phosphosilicate fiber laser and its frequency doubling to a visible laser.

We report, to the best of our knowledge, the first demonstration of an O + E-band tunable watt-level bismuth-doped phosphosilicate fiber laser and its frequency doubling to tunable red laser. Benefiting from the two types of bismuth active centers associated with silicon and phosphorus introduced in one fiber, an ultrabroad gain is available in the designed low-water-peak bismuth-doped phosphosilicate fiber (Bi-PSF) pumped by a self-made 1239 nm Raman fiber laser. The high-efficiency tunable lasing is achieved with a maximum output power of 1.705 W around 1320 nm and a slope efficiency of 33.0%. The wavelength can be continuously tuned from 1283 to 1460 nm over a 177 nm spectral range, almost covering the whole O+E-bands. We further employ a polarization beam splitter in the cavity to output an O + E-band linear-polarization laser for second-harmonic generation by a designed multi-period MgO2:PPLN crystal, and a 650-690-nm tunable visible laser is correspondingly obtained. Such an O+E-wideband tunable high-power laser and the SHG red laser may have great potential in the all-band optical communications, biophotonics, and spectroscopy.

Degradable iron-rich mesoporous dopamine as a dual-glutathione depletion nanoplatform for photothermal-enhanced ferroptosis and chemodynamic therapy.

Glutathione (GSH) is a crucial factor in limiting the effects of chemodynamic therapy (CDT) and ferroptosis, an iron-based cell death pathway. Based on this, we constructed iron-rich mesoporous dopamine (MPDA@Fe) nanovehicles with a dual-GSH depletion function by combining MPDA and Fe. Poly (ethylene glycol) (PEG) was further modified to provide desirable stability (PM@Fe) and glucose oxidase (GOx) was grafted onto PM@Fe (GPM@Fe) to address the limitation of hydrogen peroxide (H2O2). After the nanoparticles reached the tumor site, the weakly acidic microenvironment promoted the release of Fe. Then FeII reacted with H2O2 to generate hydroxyl radical (OH) and FeIII. The generated FeIII was reduced to FeII by GSH, which circularly participated in the Fenton reaction and continuously produced tumor inhibitory free radicals. Meanwhile, GOx consumed glucose to provide H2O2 for the reaction. MPDA had also been reported to deplete GSH. Therefore, dual consumption of GSH led to the destruction of intracellular redox balance and inhibition of glutathione-dependent peroxidase 4 (GPX4) expression, resulting in an increase in lipid peroxides (LPO) and further induction of ferroptosis. Additionally, MPDA-mediated photothermal therapy (PTT) raised the temperature of tumor area and produced photothermal-enhanced cascade effects. Hence, the synergistic strategy that combined dual-GSH depletion-induced ferroptosis, enhanced CDT and photothermal cascade enhancement based on MPDA@Fe could provide more directions for designing nanomedicines for cancer treatment.

Phase Unwrapping and Frequency Points Subdivision of the Frequency Sweeping Interferometry Based Absolute Ranging System.

Frequency sweeping interferometry (FSI) based absolute distance ranging has high precision and no ranging blind area. It can be used to realize large-scale and non-cooperative target measurement. However, the nonlinear frequency modulation of the laser seriously affects the ranging accuracy. In this manuscript, a measurement method assisted by Hilbert Transform (HT) and Chirp-z Transform (CZT) is proposed, which can realize the phase unwrapping of the beat signal, the length reduction in the delay fiber of auxiliary optical path, and the improvement of the frequency resolution. The narrow-band frequency suitable for HT is further studied. In the experiment, the ranging resolution is 70 µm and the standard deviation is 12.6 µm within a distance of 4005 mm.