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In this work, we study the mechanisms of X‐ray induced darkening in the Dy/Al/P co‐doped silica glasses at visible wavelengths and explore the role of P/Al ratio played in the enhancement of irradiation resistance. The absorption, emission spectra and lifetime, Raman, and electron paramagnetic resonance spectra of pristine and irradiated Dy‐silica glasses as a function of P/Al ratio were measured and analyzed. The Si‐related defects (Si‐E′ and non‐bridge oxygen hole center), Al‐related defects (Al‐E′ and Al‐related oxygen hole center), P‐related defects (P‐OHC and P2), and Dy2+ ions were studied and analyzed. Results demonstrate that increasing P/Al is efficient to suppress the photodarkening in Dy‐silica glasses at visible wavelengths. Results imply that Dy‐silica glasses with P/Al > 1 may be a promising candidate for efficient visible fiber lasers operated at around 575 nm wavelength. [ABSTRACT FROM AUTHOR]

Endoscopic submucosal dissection (ESD) is one of the most effective approaches for the minimally invasive treatment of early gastrointestinal cancers. Submucosal injections help safely and successfully remove lesions during ESD by elevating the mucosa and separating the submucosal muscle layer. Herein, we report dynamic injectable sodium alginate hydrogels (ISAHs) with shear-thinning for ESD surgery, which were easily fabricated by the sulfhydryl group of GSH-modified sodium alginate (SA-GSH) reacting with the aldehyde group of oxidized sodium alginate (OSA) at room temperature. ISAHs have advantageous self-healing abilities and antioxidant activity. Additionally, according to an in vitro test on porcine colorectal submucosal lifting, the submucosal elevation heights created by ISAHs were 13 % -18 % greater than those created by commercial ESD solutions (0.4 w / v % sodium hyaluronate). These properties and biocompatibility were confirmed in vitro and in vivo experiments. ISAHs will hopefully become a novel submucosal injectable hydrogel to assist ESD surgery. • ISAHs are shear-thinning and can be injected by an endoscopic injection needle. • ISAH have desirable self-healing properties and can effectively elevate lesions. • ISAHs with good antioxidant activity have the potential to reduce the inflammation. • ISAHs have more sustained submucosal lift than the commercial ESD solution. [ABSTRACT FROM AUTHOR]

Chronic wounds, especially diabetic wounds, involve abnormally long inflammatory periods due to their pathological microenvironment of high reactive oxygen species (ROS) levels and lack of blood vessels. Here, via a mild, simple and feasible fabrication approach, a sustained oxygenation system is proposed, consisting of MnO2 nanosheets and a dual-network hydrogel fabricated from natural biomaterials including silk fibroin (SF) and carboxymethyl cellulose (CMC). Compared with the initial value (61.09 kPa), the compression modulus of the dual-network hydrogel increased by 116.2% through the coordination of strong covalent bonds and sacrificial coordination bonds constructed by enzymatic crosslinking and UV-irradiation crosslinking; the intrinsic shear-thinning effect endows the dual-network hydrogel with satisfactory injectable properties to be customized as a predetermined shape to accommodate the irregular wounds of diabetes. The encapsulated MnO2 nanosheets can catalyze the excessive ROS into necessary O2in situ and, after co-incubating with the SF/CMC@MnO2 hydrogels, cells in oxidative stress show significantly lower ROS (3 times) and higher O2 (17 times) levels that are conductive to relieving oxidative stress, promoting angiogenesis and reducing inflammation in vivo. Meanwhile, these SF-based hydrogels can offset the overexpression of matrix metalloproteinases (MMPs) in diabetic wounds (more than 80%) and promote remodeling of the extracellular matrix. Eventually, wound healing rates >76% in 7 days and 100% in 14 days were achieved by the bio-fabricated nanocomposite hydrogel and are remarkably faster than the commercial dressing healing rates (<30% in 7 days and <80% in 14 days). These results indicate that this bio-fabricated hydrogel system with multiple and customizable functions has great promise in the personalized clinical care of chronic wounds. [ABSTRACT FROM AUTHOR]

In this work, we revealed the possible mechanisms of the photodarkening in Pr3+ ions singly doped and Pr3+/Ce3+ co‐doped silicate glasses and fibers induced by X‐ray and 488‐nm laser radiations and studied the role of Ce3+ in increasing radiation resistance in Pr3+‐doped silicate glasses and fibers. The absorption, emission, electron paramagnetic resonance (EPR), radiation induced attenuation spectra, and X‐ray photoelectron spectroscopy (XPS) of Pr3+ singly doped and Pr3+/Ce3+ co‐doped silicate glasses before and after X‐ray radiation were measured and analyzed. The fluorescence intensity and photoinduced attenuation of Pr3+ singly doped and Pr3+/Ce3+ co‐doped silicate fibers at visible wavelengths pumped by 488‐nm laser were measured and analyzed. The influence of Ce3+ ions co‐doping on the spectroscopic properties of Pr3+ ions as well as the radiation‐induced defects in silicate glasses was studied. Results demonstrate that both X‐ray and 488‐nm laser radiations will induce photodamage in Pr3+ ions‐doped silicate glasses and fibers. Co‐doping Ce3+ (by up to 1 mol%) is efficient to suppress the darkening induced by both X‐ray and 488‐nm laser radiations without influence on the luminescence behavior of Pr3+ ions in silicate glasses and fibers. Our studies demonstrate the promising potential of Pr3+/Ce3+ co‐doped silicate glasses for visible lasing applications. [ABSTRACT FROM AUTHOR]

In this work, we systematically study the spectroscopic properties of Tb3+/Dy3+ co‐doped phosphate glasses in the visible spectral region and explore the sensitization role of Dy3+ in the enhancement of visible fluorescence of Tb3+ ions. Judd‐Ofelt parameters Ω2 and Ω4/Ω6 of the phosphate glass as host for Tb3+ are calculated as 21.60 × 10‐20 cm2 and 0.73, respectively, based on the measured spectral absorption. Multiple energy transfer (ET) routes from Dy3+ to Tb3+ and their efficiencies are characterized, and the enhanced fluorescence properties of Tb3+ are investigated, including the emission spectral strength and the spontaneous emission lifetime as functions of Dy3+ doping concentration. The efficient nonradiative ET processes between Dy3+ and Tb3+ allow a moderate concentration level of Tb3+ to achieve favorably stronger spectral absorption at blue and ultraviolet wavelengths. Tb3+/Dy3+ co‐doped phosphate glass shows promising potential for phosphors and lasing operation at visible wavelengths. [ABSTRACT FROM AUTHOR]

One‐pot transformation of monomer mixtures into block copolymers remains a key challenge. Herein, a metal‐free route to prepare block copolymers from monomer mixtures by a hydroxyl functionalized ionic liquid of 3‐(2‐hydroxyl‐ethyl)‐1‐methylimidazolium bromide (HEMIMB) is described. HEMIMB can bridge two catalytic cycles including ring‐opening alternating copolymerization (ROAC) of phthalic anhydride (PA) with epoxides and ring‐opening polymerization (ROP) of L‐lactide (LA), and enable a selective copolymerization from PA, LA, and epoxides. The selective copolymerization depends on the presence of PA in mixed feedstocks, exhibits the first ROAC of PA with epoxides and then ROP of LA to the formation of block polyesters in one‐pot strategy. This work is beneficial to the development of metal‐free catalysts for sequence‐controlled polymerization that enable block architectures from mixtures of monomers. [ABSTRACT FROM AUTHOR]

The infection-prone wound pathology microenvironment leads to ulceration and difficult healing of diabetic wounds, which seriously affects the quality of survival of patients. In this study, natural polymer materials gelatin and polylysine were used as substrates. By introducing iron/tannic acid (FeIIITA) composite nanoparticles with excellent photothermal properties into the system, the glutamine residues of gelatin were crosslinked with the primary ammonia of polylysine by glutamine aminotransferase. A nanocomposite hydrogel with excellent antibacterial ability and NO production was constructed it was used to improve the clinical problems of diabetes wounds that were difficult to vascularize and easy to be infected. Under the premise of maintaining its structural stability, the hydrogel can be customized to meet the needs of different mechanical strengths by adjusting the ratios to match different diabetic wounds. Meanwhile, the photothermal effect of FeIIITA nanoparticles can synergize with the endogenous antibacterial ability of polylysine to improve the antibacterial efficacy of hydrogels. The potential of hydrogel to promote intracellular NO production was confirmed by fluorescent staining. Microneedle patches prepared from hydrogel can be applied to diabetic wounds, which can achieve NO deep release. Its anti-inflammatory and angiogenic abilities are also useful in achieving effective healing of diabetic wounds. [Display omitted] • A hydrogel-forming microneedle was designed for diabetic wound healing. • Enzyme-regulated for programmed NO sustained release • Endogenous/photodynamic synergistic and efficient antibacterial • Hydrogel-forming microneedles for deep subcutaneous release of NO • Microneedles promoted collagen deposition, vascular renewal, and anti-inflammatory. [ABSTRACT FROM AUTHOR]