Ultrasonic irradiation enhanced the efficacy of antimicrobial photodynamic therapy against methicillin-resistant Staphylococcus aureus biofilm.
Ultrason Sonochem
; 97: 106423, 2023 Jul.
Article
in En
| MEDLINE
| ID: mdl-37235946
ABSTRACT
Antimicrobial photodynamic therapy (aPDT) is a non-pharmacological antimicrobial regimen based on light, photosensitizer and oxygen. It has become a potential method to inactivate multidrug-resistant bacteria. However, limited by the delivery of photosensitizer (PS) in biofilm, eradicating biofilm-associated infections by aPDT remains challenging. This study aimed to explore the feasibility of combining ultrasonic irradiation with aPDT to enhance the efficacy of aPDT against methicillin-resistant staphylococcus aureus (MRSA) biofilm. A cationic benzylidene cyclopentanone photosensitizer with much higher selectivity to bacterial cells than mammalian cells were applied at the concentration of 10⯵M. 532â¯nm laser (40â¯mW/cm2, 10â¯min) and 1â¯MHz ultrasound (500â¯mW/cm2, 10â¯min, simultaneously with aPDT) were employed against MRSA biofilms in vitro. In addition to combined with ultrasonic irradiation and aPDT, MRSA biofilms were treated with laser irradiation only, photosensitizer only, ultrasonic irradiation only, ultrasonic irradiation and photosensitizer, and aPDT respectively. The antibacterial efficacy was determined by XTT assay, and the penetration depth of PS in biofilm was observed using a photoluminescence spectrometer and a confocal laser scanning microscopy (CLSM). In addition, the viability of human dermal fibroblasts (WS-1 cells) after the same treatments mentioned above and the uptake of P3 by WS-1 cells after ultrasonic irradiation were detected by CCK-8 and CLSM in vitro. Results showed that the percent decrease in metabolic activity resulting from the USâ¯+â¯aPDT group (75.76%) was higher than the sum of the aPDT group (44.14%) and the US group (9.88%), suggesting synergistic effects. Meanwhile, the diffusion of PS in the biofilm of MRSA was significantly increased by 1â¯MHz ultrasonic irradiation. Ultrasonic irradiation neither induced the PS uptake by WS-1 cells nor reduced the viability of WS-1 cells. These results suggested that 1â¯MHz ultrasonic irradiation significantly enhanced the efficacy of aPDT against MRSA biofilm by increasing the penetration depth of PS. In addition, the antibacterial efficacy of aPDT can be enhanced by ultrasonic irradiation, the USâ¯+â¯aPDT treatment demonstrated encouraging in vivo antibacterial efficacy (1.73 log10 CFU/mL reduction). In conclusion, the combination of aPDT and 1â¯MHz ultrasound is a potential and promising strategy to eradicate biofilm-associated infections of MRSA.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Photochemotherapy
/
Methicillin-Resistant Staphylococcus aureus
/
Anti-Infective Agents
Limits:
Animals
/
Humans
Language:
En
Journal:
Ultrason Sonochem
Journal subject:
DIAGNOSTICO POR IMAGEM
Year:
2023
Document type:
Article
Affiliation country:
China