Owing to the existence of the outer membrane barrier, most antibacterial agents cannot penetrate Gram-negative bacteria and are ineffective. Here, we report a general method for narrow-spectrum antibacterial Garcinia nanoparticles that can only be effective to kill Gram-positive bacteria, to effectively eliminate Gram-negative bacteria by creating transient nanopores in bacterial outer membrane to induce drug entry under microwaves assistance. In vitro, under 15 min of microwaves irradiation, the antibacterial efficiency of Garcinia nanoparticles against Escherichia coli can be enhanced from 6.73% to 99.48%. In vivo, MV-assisted GNs can effectively cure mice with bacterial pneumonia. The combination of molecular dynamics simulation and experimental results reveal that the robust anti-E. coli effectiveness of Garcinia nanoparticles is attributed to the synergy of Garcinia nanoparticles and microwaves. This work presents a strategy for effectively treating both Gram-negative and Gram-positive bacteria co-infected pneumonia using herbal medicine nanoparticles with MV assistance as an exogenous antibacterial auxiliary.

Both phototherapy via photocatalysts and physical puncture by artificial nanostructures are promising substitutes for antibiotics when treating drug-resistant bacterial infectious diseases. However, the photodynamic therapeutic efficacy of photocatalysts is seriously restricted by the rapid recombination of photogenerated electron–hole pairs. Meanwhile, the nanostructures of physical puncture are limited to two-dimensional (2D) platforms, and they cannot be fully used yet. Thus, this research developed a synergistic system of Ag 3 PO 4 nanoparticles (NPs), decorated with black urchin-like defective TiO 2 (BU–TiO 2-X /Ag 3 PO 4 ). These NPs had a decreased bandgap compared to BU-TiO 2-X , and BU-TiO 2-X /Ag 3 PO 4 (3:1) exhibited the lowest bandgap and the highest separation efficiency for photogenerated electron–hole pairs. After combination with BU-TiO 2-X , the photostability of Ag 3 PO 4 improved because the oxygen vacancy of BU-TiO 2-X retards the reduction of Ag + in Ag 3 PO 4 into Ag 0 , thus reducing its toxicity. In addition, the nanospikes on the surface of BU-TiO 2-X can, from all directions, physically puncture bacterial cells, thus assisting the hybrid's photodynamic therapeutic effects, alongside the small amount of Ag + released from Ag 3 PO 4 . This achieves synergy, endowing the hybrid with high antibacterial efficacy of 99.76 ± 0.15% and 99.85 ± 0.09% against Escherichia coli and Staphylococcus aureus , respectively, after light irradiation for 20 min followed by darkness for 12 h. It is anticipated that these findings may bring new insight for developing synergistic treatment strategies against bacterial infectious diseases or pathogenic bacterial polluted environments.

No abstract

No abstract

Medical tools and implants used in clinics can be contaminated with bacteria even with disinfection treatment. To avert this situation, titanium (Ti) plates modified with a MoS2(S)–Ag3PO4 coating were designed to kill Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) effectively under near-infrared (NIR) light irradiation. The introduction of Ag3PO4 nanoparticles (NPs) reduced the bandgap of MoS2 and suppressed the recombination of the photogenerated electron–hole pairs. Therefore, Ti–MoS2(S)–Ag3PO4 exhibited a higher photocatalytic performance, leading to the generation of more radical oxygen species (ROS). Furthermore, cooperating with the good photothermal performance of MoS2, the MoS2(S)–Ag3PO4 coating exhibited a high antibacterial efficacy of 99.76 ± 0.15% and 99.85 ± 0.09% against S. aureus and E. coli, respectively, for 15 min in vitro. Moreover, the MoS2(S)–Ag3PO4 coating had no apparent toxicity to cells. The proposed strategy may provide new insights for rapidly eradicating bacteria on medical tools and superficial implants.