Dual-acting antibacterial porous chitosan film embedded with a photosensitizer

Abstract

This study proposes to develop a dual-acting antibacterial film of porous chitosan (Cs) embedded with small molecular compound, which possesses photosensitive characteristics with bactericidal efficacy, to promote the accelerated recovery of infectious wounds. The Cs/small molecular compound (Cs-cpd.2) dressing was prepared using the freeze-drying method. Characterization of the synthesized Cs-cpd.2 indicated that it has high porosity and moisture absorption effect, hence enhancing the absorption of wound exudate. Experimental results showed that Cs-cpd.2 dressing has good bactericidal and bacteriostatic effects on Staphylococcus aureus under visiblelight irradiation and has antibacterial effect in the dark. It was also found that the small molecular compound does not have cytotoxicity at a dose of 0-5 μM. Furthermore, Cs-cpd.2 that contained small molecular compound with a concentration of 0.3-1 μM has positive effect on both the cell viability rate and cell proliferation rate of human fibroblast CG1639. Cs-cpd.2 can significantly promote cell proliferation when the small molecular compound and the basic fibroblast growth factor bFGF were added together. Therefore, the proposed Cs-cpd.2 dressing is feasible for photodynamic therapy (PDT) and clinical wound dressing applications.

Photosensitizer‐loaded hydrogels: A new antibacterial dressing

“…Although chitosan is a common hydrogel material, the process of hydrogel synthesis can be innovated. A study proposed to develop a dual‐acting antibacterial film using porous chitosan containing small‐molecule compounds via the freeze‐drying method, which exhibited photosensitive properties and strong antibacterial efficacy 80 . In addition, owing to its high porosity and moisture absorption, the dressing made from these hydrogels increased the absorption of wound exudate.…”

The photosensitizer-based therapies enhance the repairing of skin wounds

“…Wound healing after skin injury involves complex interactions among multiple cells, primarily keratinocytes, vascular endothelial cells, fibroblasts, recruited immune cells, and the related extracellular matrix (ECM), and all of them are indispensable in the process ( Figure 2 ). The type and concentration of the PS and the light dose affect the effect of PDT on cells ( 54 , 55 ). With the increase concentration of 5-ALA and energy density, the viability of normal fibroblast cell decreases ( 56 ).…”

“…Different studies used different PS and irradiation. Low-level irradiation was shown to have a stimulating effect, while highlevel radiation could have an inhibitory effect on cells (54,55,104,105). This study used a relatively large irradiance.…”

Fabrication of Curcumin@Ag Loaded Core/Shell Nanofiber Membrane and its Synergistic Antibacterial Properties

“…One is photodynamic antibacterial therapy ( Wu et al, 2021 ), and the other is the use of metal nanoparticles ( Godoy-Gallardo et al, 2021 ) or antimicrobial peptides ( Qiu et al, 2021 ) to replace antibiotics. Photodynamic antimicrobial chemotherapy (PACT) kills bacteria through the combined action of light and photosensitizers ( Liu et al, 2020 ; Sun et al, 2021 ). The mechanism of PACT is that the chromophore of the photosensitizer generates singlet oxygen and other reactive oxygen species (ROS) under light irradiation ( Im et al, 2021 ; Xiao et al, 2021 ).…”