Physics and Materials Science Department, São Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil.
Hagler Fellow, Texas A&M University, College Station, Texas, USA.
J Biophotonics. 2022 Feb;15(2):e202100189. doi: 10.1002/jbio.202100189. Epub 2021 Dec 11.
Pneumonia is responsible for high mortality rates around the world, and its major treatment is based on antibiotic treatment. Antimicrobial resistance has been increasing in the last years, resulting in relevant public health concern. A promising alternative for pneumonia is antimicrobial photodynamic therapy. The purpose of this study was to investigate whether 808 nm wavelength is able to be transmitted through the biological tissues of the thoracic wall and be delivered in enough energy inside the cage to activate indocyanine green and promote photodynamic response. A light source panel was developed composed of 200 lasers centered at 808 nm with an irradiance of 77.8 ± 10.0 mW/cm and tested in an ex vivo thoracic cage model. Monte Carlo simulations were used to understand the photon migration through all the tissues at the thoracic wall. It was observed that tissues responsible for the major absorption of photons are the skin and subcutaneous fat. Experimental measurement of the irradiance was obtained after the light pass-through ex vivo pig thoracic cage, obtaining 3% to 5% of the emitted irradiance. Finally, it was observed that even with 3% of the initial irradiance, a 99.9% reduction of the Streptococcus pneumoniae was successfully achieved after 42.6 minutes of irradiation.
肺炎在全球范围内导致高死亡率，其主要治疗方法基于抗生素治疗。近年来，抗菌药物耐药性不断增加，引起了相关的公共卫生关注。抗菌光动力疗法是一种有前途的替代方法。本研究旨在探讨 808nm 波长是否能够穿透胸壁的生物组织，并在笼内输送足够的能量激活吲哚菁绿并促进光动力反应。开发了一个由 200 个中心波长为 808nm 的激光组成的光源面板，辐照度为 77.8±10.0mW/cm，并在离体猪胸模型中进行了测试。蒙特卡罗模拟用于了解光子在胸壁所有组织中的迁移。观察到主要吸收光子的组织是皮肤和皮下脂肪。在离体猪胸模型中透光后，对辐照度进行了实验测量，得到了 3%至 5%的发射辐照度。最后，即使初始辐照度为 3%，经过 42.6 分钟的照射，也成功地实现了肺炎链球菌的 99.9%减少。
