NIR-Triggered Multifunctional NO Nanoplatform for Conquering Thermal Resistance in Biofilms.

Photothermal treatment (PTT) has emerged as a promising avenue for biofilm elimination, yet its potential drawbacks, such as local hyperpyrexia and bacterial heat resistance, have posed challenges. To address these concerns, an innovative nanoplatform (Au@mSiO2 -arg/ICG) is devised that integrates phototherapeutic and gas therapeutic functionalities. This multifaceted nanoplatform is composed of mesoporous silica-coated Au nanorods (Au@mSiO2 ), supplemented with l-arginine (l-arg) and indocyanine green (ICG), and is engineered for mild temperature PTT aimed at biofilm eradication. Au@mSiO2 -arg/ICG nanoparticles (NPs) show excellent antibacterial effects through the generation of nitric oxide (NO) gas, heat, and reactive oxygen species (ROS) under 808 nm light irradiation. The ROS generated by ICG initiates a cascade reaction with l-arg, ultimately yielding NO gas molecules. This localized release of NO not only effectively curbs the expression of heat shock proteins 70 mitigating bacterial thermoresistance, but also reduces extracellular polymeric substance allowing better penetration of the therapeutic agents. Furthermore, this nanoplatform achieves an outstanding biofilm elimination rate of over 99% in an abscess model under 808 nm light irradiation (0.8 W·cm-2 ), thereby establishing its potential as a dependable strategy for NO-enhanced mild PTT and antibacterial photodynamic therapy (aPDT) in clinical settings.

Near-infrared light triggered upconversion nanocomposites with multifunction of enhanced antimicrobial photodynamic therapy and gas therapy for inflammation regulation.

Antibacterial photodynamic therapy (aPDT) is highly effective in killing bacteria, while the problem of hypoxia and limited light penetration in deep tissue has not been properly solved. In addition, few aPDT works take into account the regulation of inflammation, which is an important regulatory process after antimicrobial therapy and the final purpose of treatment. In this work, to address the above isssues, we have designed a multi-functional composite UCNPs-Ce6-Mn(CO)5Br@Silane (referred to as UCM@Si), which consists of several key components: Up-conversion nanoparticles (UCNPs: NaErF4:Tm3+@NaYF4:Yb3+), Chlorin e6 (Ce6) and Manganese pentacarbonyl bromide (Mn(CO)5Br). When exposed to near-infrared (NIR) light (980 nm), the UCNPs can emit strong red light at 655 nm which further trigger the aPDT of Ce6. The generated reactive oxygen (ROS) subsequently break the metal carbonyl bond of Mn(CO)5Br, leading to the production of carbon monoxide (CO) molecules as well as manganese ions (Mn2+), which further decomposes hydrogen peroxide (H2O2) in the microenvironment to oxygen (O2). Therefore, this simple nanocomposite not only provides substantial self-oxygen replenishment for enhanced aPDT, but also facilitates effective inflammation regulation via CO across a wide range of deep infections. This approach leverages the unique properties of these materials to combat bacterial infections by simultaneously killing bacteria, regulating inflammation, and enhancing the oxygen levels in the affected microenvironment. This O2 and CO gas based aPDT treatment system offers a promising approach to comprehensively address microbial-induced infectious diseases, particularly deep infections, holding the potential clinical applications.

Efficient and Stable Multicolor Emissions of the Coumarin-Modified Cs3LnCl6 Lead-Free Perovskite Nanocrystals and LED Application.

Lanthanide-based lead-free perovskite materials hold great promise for the development of high-resolution full-color displays in the future. Here, various Cs3LnCl6 perovskite nanocrystals (NCs) emitting light across the visible to near-infrared spectrum with remarkably high photoluminescence quantum yield (PLQY) are systemically prepared. Especially, by introducing multifunctional coumarin small molecules into Cs3EuCl6 NCs as an intermediate state, Cs3EuCl6 NCs can achieve an impressive PLQY of 92.4% with pure red emission and an exceptional energy transfer efficiency of nearly 93.2%. Furthermore, the lanthanide-based electroluminescent devices in red, green, and blue are successfully fabricated. Among them, the Cs3EuCl6-NC-based red light-emitting diode (LED) demonstrates a FWHM of 18 nm at 617 nm, an external quantum efficiency up to 5.17%, and a maximum brightness of 2373 cd m-2, which is the most excellent reported for lead-free narrowband (within 20 nm) emission devices. Notably, these devices exhibit an operating half-life of 440 h at a brightness level of 100 cd m-2, surpassing the performance of most reported lead-free perovskite LEDs (PLEDs). This work opens up exciting possibilities for the future commercialization of lanthanide-based PLEDs in the display industry, paving the way for more vibrant, energy-efficient, and long-lasting display technologies.

Highly hydrostable and flexible opal photonic crystal film for enhanced up-conversion fluorescence sensor of COVID-19 antibody.

Efficient detection of related markers is significant for the early screening of COVID-19. Near infrared (NIR) light excited up-conversion fluorescence probes are ideal for biosensing but limited by the low luminescence efficiency. In this work, a novel highly stable opal photonic crystal (OPC) structure was designed to provide an OPC effect for up-conversion fluorescence enhancement, and sensitive Novel Coronavirus IgG up-conversion FRET-based sensor was further constructed. For the problems of water stability and mechanical stability of polymer OPC which cannot be solved for a long time, polymer spray combined with a flipped OPC film strategy is presented. Fragmented size OPC film was firmly fixed by polymer modification layer, which gave large size OPC film great water stability, mechanical stability and bending performance without affecting the fluorescence enhancement property. On this basis, the up-conversion emission intensity was enhanced significantly, and fluorescence resonant energy transfer (FRET) based Novel Coronavirus IgG antibody sensor was constructed. Monolayer up-conversion nanoparticles (UCNPs) on the surface of the polydopamine (PDA)/OPC film can make the fluorescent signal more sensitive, and effectively reduce the detection limit. The test device integrating NIR excitation and mobile phone realized the visual fast detection, showing remarkable sensing performance for COVID-19 antibodies with the limit of detection (LOD) of 0.1 ng mL-1. This detection platform will provide a more effective tool for early detection of the novel coronavirus.

Antibacterial PDT nanoplatform capable of releasing therapeutic gas for synergistic and enhanced treatment against deep infections.

Antibacterial photodynamic therapy (aPDT) has emerged as an attractive treatment option for efficient removal of pathogenic bacteria. However, aPDT in deep tissue will encounter difficulties such as limited light penetration depth, insufficient oxygen (O2) supply and inability to eliminate inflammation introduced by bacteria, which hinders its clinical application. Herein, the near infrared (NIR) strategy of simultaneously generating O2 and CO was developed for aPDT based antibacterial therapy and mitigation of deep infection inflammation. Methods: We prepared NIR-mediated multifunctional aPDT nanoplatform (POS-UCNPs/ICG) producing therapeutic gas of O2 and CO. The CO, O2 and ROS generation of the nanoplatform were characterized by dye probes, respectively. The antibacterial activity and anti-inflammation of POS-UCNPs/ICG were demonstrated in vitro and in vivo. In addition, the therapeutic effects in vivo were serially analyzed by immunofluorescence staining, Masson's staining, hematoxylin and eosin staining, colony formation units (CFU) and so on. Results: NIR-mediated multifunctional aPDT nanoplatform was realized by combining the up-conversion nanoparticles (UCNPs) and partially oxidized SnS2 (POS) nanosheets (NSs) as well as indocyanine green (ICG). Using a single 808 nm light, aPDT can be achieved via ICG molecules, meanwhile, O2/CO can be generated by POS NSs through upconversion light excitation. During the aPDT process, O2 can enhance aPDT, while CO can regulate inflammation through the PI3K/NF-κB pathway. Therefore, POS-UCNPs/ICG groups had a highest percentage of healing area up to 91.55±1.26% in mouse abscess model. Conclusion: Due to enhanced aPDT and anti-inflammatory collaborative therapy, the POS-UCNPs/ICG composites showed remarkably accelerated recovery in animal abscess models. Such NIR light responsive nanoplatform with optimized antibacterial capacity and immunomodulatory functions is promising for clinical therapeutics of bacteria-induced infections.

Ni2+ and Pr3+ Co-doped CsPbCl3 perovskite quantum dots with efficient infrared emission at 1300 nm.

Lead halide perovskite quantum dots (PQDs) show great prospects in the field of optoelectronic applications. Although having high efficiency and narrow-band emission performance in the visible light region, the infrared multicolor luminescence performance of perovskite nanocrystals is still highly desired. In this work, in order to increase the luminescence intensity and extend the infrared multicolor luminescence, transition metal and rare earth ions are co-doped into PQDs. Herein, PQDs emitting at 1300 nm are realized by Pr3+ doping, which has not been reported in previous literature. The luminescence and kinetic process of Ni2+ and Pr3+ co-doped CsPbCl3 PQDs are studied, which exhibit considerably enhanced emission intensity at 400 nm and 1300 nm, with an overall quantum efficiency of photoluminescence (PLQY) of 89% and the highest infrared PLQY of 23%.