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[Display omitted] • NO exhibits the complementary advantage in enhancing the PDT antibacterial efficacy. • The system can avoid the shallow penetrability of short-wavelength light. • ROS/NO release can be controlled by single NIR, realizing on-demand sterilization. • The membrane can effective prevent inflammation and accelerate the wound healing. As an emerging bactericidal strategy, photodynamic therapy (PDT) exhibits great potential to combat various pathogenic infections, but its antibacterial efficacy may be compromised, generally owing to its shallow penetrability of short-wavelength (UV/Vis) light as well as short diffusion length and lifespan of the generated reactive oxygen species (ROS). Herein, we present a method for developing a nitric oxide (NO)-assisted PDT nanocomposite membrane with significantly enhanced bactericidal performances, upon a single near-infrared (NIR) light irradiation. Hierarchically structured nanoparticles (UCNP@PCN), composed of upconversion nanoparticles (UCNPs) and porphyrinic MOFs (PCN-224) are initially prepared. After being doped with l -arginine (LA), the nanoparticles are incorporated into polyvinylidene fluoride (PVDF) matrix to get electrospun nanocomposite membrane (UCNP@PCN@LA-PVDF). Upon NIR light irradiation (980 nm), this UCNP@PCN@LA-PVDF can generate sufficient ROS, which not only acts as main bactericidal agent in PDT but also induces the loaded LA to produce NO, eventually realizing the NO-assisted PDT antibacterial behavior. The generated NO exhibits a larger sterilization area as compared to that of the ROS, demonstrating a vital complementary advantage in facilitating PDT antibacterial efficacy as proven in vitro and in vivo tests. This type of nanocomposite membrane may find unique biomedical applications where both highly enhanced PDT antibacterial effects and deep penetration of NIR light are desired. [ABSTRACT FROM AUTHOR]

The periodic region with a helicoidal structure and the impact zone with a herringbone structure of the mantis shrimp's dactyl club, which makes it excellent in energy absorption. This biological structure gives us effective methods for making novel composite structures. In this paper, a dactyl-inspired sinusoidal-corrugated helicoidal sandwich-structural honeycomb (DSHSH) was manufactured with unidirectional basalt fiber and aluminum honeycomb based on periodic region and impact region of dactyl club. The DSHSH was compared with dactyl-inspired sinusoidal-corrugated plain-woven skin sandwich-structural honeycomb (DSPSH) and dactyl-inspired sinusoidal-corrugated unidirectional skin sandwich-structural honeycomb (DSUSH), dactyl-inspired helicoidal sandwich-structural honeycomb (DHSH), traditional plain-woven skin sandwich-structural honeycomb (TPSH), and traditional unidirectional skin sandwich-structural honeycomb (TUSH) in tests of impact and flexrual. The results exhibited that DSHSH that simulates multi-structures (periodic and impact regions) significantly improves peak load and energy absorption capabilities. [ABSTRACT FROM AUTHOR]

• Based on periodic region of dactyl club. • The dactyl-inspired structure has excellent mechanical properties. • It can be applied to many fields. The periodic region of mantis shrimp's dactyl club, composed of the helicoidal arrangement of mineralized fiber, has excellent energy absorption and damage tolerance. This structure, inspired by the dactyl club, has been proved effective to improve the mechanical properties of composites. In this paper, a novel dactyl-inspired sandwich honeycomb (DSH) was fabricated with unidirectional carbon fiber and aluminum honeycomb based on the periodic region of the dactyl club. The DSH was compared with plain-woven skin sandwich-structural honeycomb (PSH) and unidirectional skin sandwich-structural honeycomb (USH) in tests of impact and bending. As a result, the average impact contact force of DSH was 3514.6 N, which was increased by 60.9% and 106.0% compared with PSH (2184.7 N) and USH (1705.8 N), respectively. The bending energy absorption of DSH was 29556.5 N·mm, which was increased by 278.3% and 115.4% compared with PSH (7812.2 N·mm) and USH (13719.6 N·mm), respectively. The results exhibited that the quasi-isotropic helicoidal arrangement of carbon fiber was an effective way to improve the impact resistance and bending energy absorption of DSH. [ABSTRACT FROM AUTHOR]

• An antifogging/frost-resistant and self-healing coating is designed and developed. • Its antifogging property is ascribed to the appropriate water-absorbing capability. • Its frost-resistance relies on the existed non-freezing/intermediate status water. • The coating exhibits essential self-healing property under wet environment. Although many antifogging surfaces have been successfully developed, constructing a surface with both antifogging and frost resistance properties is still a great challenge since the condensed water inevitably turns into an ice layer under freezing conditions. Herein, an antifogging/frost-resistant polymeric coating consisting of poly(vinyl alcohol) and salicylic acid is developed on the basis of a hydrogen bond cross-linking strategy. Unlike conventional superhydrophilic antifogging surfaces, the excellent antifogging/frost resistance performance over a broad range of temperatures (ca. −196.6 to 85 °C), is ascribed to the water-absorbing capability of the coating. Moreover, the coating also exhibits efficient self-healing properties in a wet environment. Due to its simplicity and efficiency, this type of coating may serve as an excellent antifogging/frost-resistant platform for a broad range of applications in optics-related areas. [ABSTRACT FROM AUTHOR]

Many conventional bactericidal materials exhibit antibacterial activities by releasing biocides, which potentially trigger antibiotic resistance and cause environmental concerns. In the present work, we reported the development of antibacterial nanocomposite membrane containing upconversion nanoparticles (UCNPs) by electrospinning. The nanocomposite membrane itself was not bactericidal but exhibits strongly antimicrobial performance on demand as activated by near-infrared (NIR) light. Upon just 5 min of NIR irradiation, the UCNPs in the nanocomposite membrane could trigger the release of reactive oxygen species (ROS) from photosensitizers, which could kill both Gram-positive Staphylococcus aureus (94.5%) and Gram-negative Escherichia coli (93.2%) rapidly. Moreover, the bactericidal activity could be effectively maintained for at least four cycles. In addition, the nanocomposite membrane showed no adverse effects on the mammalian cells, as verified by a cytotoxicity assay. This work provided a new strategy in designing novel antibacterial materials that might be potentially applied in infection-resistant and wound healing. Upon NIR irradiation, the UCNPs in the nanocomposite membrane trigger the release of reactive oxygen species (ROS) from photosensitizers that rapidly killed both Gram-positive and Gram-negative bacteria. Unlabelled Image • The membrane itself is not bactericidal but becomes strongly antimicrobial on demand. • Upon NIR irradiation, the membrane demonstrates rapid bactericidal performances. • The bactericidal activity can be effectively maintained for multi-cycles. [ABSTRACT FROM AUTHOR]