Copper-nanoparticle-embedded hydrogel for killing bacteria and promoting wound healing with photothermal therapy

J Mater Chem B. 2019 Apr 21;7(15):2534-2548. doi: 10.1039/c8tb03272f. Epub 2019 Mar 20.

Abstract

Bacterial infections at wound tissue sites usually delay the wound healing process and even result in severe life-threatening complications. Therefore, it is imperative to develop an efficient strategy to simultaneously enhance the antibacterial abilities and improve the wound healing process. Here, we report a composite hydrogel composed of methacrylate-modified gelatin (Gel-MA) and N,N-bis(acryloyl)cystamine (BACA)-chelated Cu nanoparticles (Cu NPs) via radical polymerization with a photoinitiator. The Cu NPs could effectively convert NIR laser irradiation (808 nm) energy into localized heat due to the localized surface plasmon resonance (LSPR) effect for effecting photothermal therapy. In vitro antimicrobial experiments revealed that the hybrid hydrogel exhibited predominant antibacterial efficacy against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, while Cu-NP-embedded hydrogel + laser group exhibited superior antibacterial capacity. The excellent antibacterial properties can be attributed to the synergistic effect of photothermal performance and rapid release of copper ions (Cu2+) because of the laser irradiation of Cu NPs. Moreover, the released Cu2+ could stimulate NIH-3T3 fibroblast proliferation without any inflammatory responses. Moreover, chronic wound healing process of S. aureus-infected model was significantly accelerated with prominent antibacterial ability, reduced inflammatory response, and promoted angiogenesis ability in vivo. In summary, Cu-NP-embedded hydrogels are a promising candidate for skin tissue regeneration and potentially valuable for clinical applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology
  • Anti-Bacterial Agents / therapeutic use
  • Cell Survival / drug effects
  • Copper / chemistry*
  • Escherichia coli / drug effects
  • Escherichia coli / metabolism
  • Hydrogels / chemistry*
  • Hydrogels / pharmacology*
  • Hydrogels / therapeutic use
  • Lipid Peroxidation / drug effects
  • Metal Nanoparticles / chemistry*
  • Mice
  • NIH 3T3 Cells
  • Phototherapy / methods*
  • Staphylococcus aureus / drug effects
  • Staphylococcus aureus / metabolism
  • Wound Healing / drug effects*

Substances

  • Anti-Bacterial Agents
  • Hydrogels
  • Copper