Attenuation of Aggregatibacter actinomycetemcomitans virulence using curcumin-decorated nanophytosomes-mediated photo-sonoantimicrobial chemotherapy

This study aimed to focus on the simultaneous use of antimicrobial photodynamic therapy (aPDT) and sonodynamic antimicrobial chemotherapy (SACT), which is called photo-sonodynamic antimicrobial chemotherapy (PSACT) to attenuate the virulence of Aggregatibacter actinomycetemcomitans. Following the synthesis of Curcumin-decorated nanophytosomes (Cur-NPhs) as a novel photo-sonosensitizer, its particle size, polydispersity, zeta -potential surface morphology, physical stability, drug release, and entrapment efficiency were determined. In the Cur-NPhs-PSACT, the antimicrobial activities of Cur-NPhs against A. actinomycetemcomitans were investigated using cell viability, biofilm killing/degradation, metabolic activity, expression of quorum-sensing-associated qseB and qseC genes, and biofilm-associated rcpA gene under blue laser irradiation plus ultrasonic waves. Characterization tests showed the presence of a sphere-shaped vesicle and the self-closed structure of Cur-NPhs, resulting in a high drug-loading content and encapsulation efficiency. However, the antimicrobial effect of Cur-NPhs-PSACT was dose-dependent, PSACT using the high concentrations of Cur-NPhs (50x10(-4) g/L) showed significant reductions (P<0.05) in cell viability (13.6 log(10) CFU/mL), biofilm killing/degradation (65%), metabolic activity (89.6%,), and mRNA levels of virulence determinant genes (qseB; 9.8-fold, qseC; 10.2-fold, and recA; 10.2-fold). This study concludes that the Cur-NPhs-PSACT had antimicrobial activities against A. actinomycetemcomitans by downregulating the expression of virulence genes, and may attenuate this bacterium that decreases periodontal disease severity in patients.

Automated summary

This study focused on the use of photo-sonodynamic antimicrobial chemotherapy (PSACT) to attenuate the virulence of Aggregatibacter actinomycetemcomitans. The Cur-NPhs-PSACT showed dose-dependent antimicrobial effects, with high concentrations leading to significant reductions in cell viability, biofilm killing/degradation, metabolic activity, and expression of virulence determinant genes. This novel approach may have potential in decreasing periodontal disease severity in patients.