PDF(Pubmed)
Abstract：
Antimicrobial Photodynamic Therapy (aPDT) is an innovative and promising method for combating infections, reducing the risk of antimicrobial resistance compared to traditional antibiotics. Squaraine (SQ) dyes can be considered promising photosensitizers (PSs) but are generally hydrophobic molecules that can self-aggregate under physiological conditions. To overcome these drawbacks, a possible solution is to incorporate SQs inside nanoparticles (NPs). The present work deals with the design and development of innovative nanophotosensitizers based on poly lactic-co-glycolic acid (PLGA) NPs incorporating a brominated squaraine (BrSQ) with potential application in aPDT. Two designs of experiments (DoEs) based on the single emulsion and nanoprecipitation methods were set up to investigate how different variables (type of solvent, solvent ratio, concentration of PLGA, stabilizer and dye, sonication power and time) can affect the size, zeta (ζ)-potential, yield, entrapment efficiency, and drug loading capacity of the SQ-PLGA NPs. SQ-PLGA NPs were characterized by NTA, FE-SEM, and UV-Vis spectroscopy and the ability to produce reactive oxygen species (ROS) was evaluated, proving that ROS generation ability is preserved in SQ-PLGA. In vitro antimicrobial activity against Gram-positive bacteria in planktonic state using Staphylococcus aureus was conducted in different conditions and pH to evaluate the potential of these nanophotosensitizers for aPDT in the local treatment of infections.
摘要：
抗微生物光动力疗法（aPDT）是一种创新且有前途的抗感染方法，与传统抗生素相比，降低了抗生素耐药性的风险。方酸(SQ)染料可以被认为是有前途的光敏剂(PS),但通常是在生理条件下可以自聚集的疏水性分子。为了克服这些缺点，一种可能的解决方案是在纳米颗粒(NPs)中加入SQs。本工作涉及基于聚乳酸-乙醇酸（PLGA）NP的创新纳米光敏剂的设计和开发，该纳米光敏剂掺入了溴化方酸（BrSQ），具有在aPDT中的潜在应用。建立了基于单乳液和纳米沉淀方法的两种实验设计(DoE)，以研究不同的变量(溶剂类型、溶剂比,PLGA浓度,稳定剂和染料，超声处理功率和时间)会影响大小，zeta(ζ)-电位,产量，截留效率，SQ-PLGANP的载药能力。SQ-PLGANP以NTA为特征，FE-SEM，和紫外可见光谱和产生活性氧（ROS）的能力进行了评估，证明在SQ-PLGA中保留了ROS生成能力。在不同的条件和pH下使用金黄色葡萄球菌对浮游状态的革兰氏阳性细菌进行体外抗菌活性，以评估这些纳米光敏剂对aPDT在局部治疗感染中的潜力。
