Behzadpour N, Sattarahmady N, Akbari N
MSc, Department of Medical Physics, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
MSc, Nanomedicine and Nanobiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
J Biomed Phys Eng. 2019 Dec 1;9(6):661-672. doi: 10.31661/jbpe.v0i0.1024. eCollection 2019 Dec.
Nowadays, it is needed to explore new routes to treat infectious bacterial pathogens due to prevalence of antibiotic-resistant bacteria. Antimicrobial photothermal therapy (PTT), as a new strategy, eradicates pathogenic bacteria.
In this study, the antimicrobial effects of a carbon nanoparticles-polypyrrole nanocomposite (C-PPy) upon laser irradiation were investigated to destroy the pathogenic gram-negative .
In this experimental study, the bacterial cells were incubated with 50, 100 and 250 µg mL concentrations of C-PPy and irradiated with a 808-nm laser at two power densities of 0.5 and 1.0 W cm. CFU numbers were counted for the irradiated cells, and compared to an untreated sample (kept in dark). To explore the antibacterial properties and mechanism(s) of C-PPy, temperature increment, reactive oxygen species formation, and protein and DNA leakages were evaluated. Field emission scanning electron microscopy was also employed to investigate morphological changes in the bacterial cell structures.
The results showed that following C-PPy attachment to the bacteria surface, irradiation of near-infrared light resulted in a significant decrement in the bacterial cell viability due to photothermal lysis. Slightly increase in protein leakage and significantly increase intracellular reactive oxygen species (ROS) were observed in the bacteria upon treating with C-PPy.
Photo-ablation strategy is a new minimally invasive and inexpensive method without overdose risk manner for combat with bacteria.
如今，由于抗生素耐药菌的普遍存在，需要探索治疗传染性细菌病原体的新途径。抗菌光热疗法（PTT）作为一种新策略，可根除病原菌。
在本研究中，研究了碳纳米颗粒-聚吡咯纳米复合材料（C-PPy）在激光照射下对革兰氏阴性病原菌的抗菌作用。
在本实验研究中，将细菌细胞与浓度为50、100和250μg/mL的C-PPy孵育，并以0.5和1.0W/cm的两种功率密度用808nm激光照射。对照射后的细胞进行菌落形成单位（CFU）计数，并与未处理的样品（置于黑暗中）进行比较。为了探索C-PPy的抗菌特性和机制，评估了温度升高、活性氧形成以及蛋白质和DNA泄漏情况。还采用场发射扫描电子显微镜研究细菌细胞结构的形态变化。
结果表明，C-PPy附着在细菌表面后，近红外光照射导致细菌细胞活力因光热裂解而显著降低。在用C-PPy处理的细菌中，观察到蛋白质泄漏略有增加，细胞内活性氧（ROS）显著增加。
光消融策略是一种新的微创且廉价的方法，在对抗细菌时无过量风险。
