Abstract：
Liposomes have emerged as versatile nanocarriers, finding applications not only in drug delivery but also in pathogen detection and diagnostics. This study aimed to enhance the sensitivity of liposomes to Staphylococcus aureus by investigating the impact of lipid composition on liposomes loaded with 5(6)-carboxyfluorescein (CF). Liposomes were fabricated using various concentrations of cholesterol (10-40 mol%) combined with saturated phospholipids. Dynamic light scattering results revealed that higher cholesterol concentrations led to reduced liposome size, CF release (%), and entrapment efficiency (%). Liposome sensitivity towards S. aureus was evaluated by using CF-loaded liposomes with and without aptamer insertion. Liposomes with a higher cholesterol content (40 mol%) exhibited a strong ability to detect low bacterial concentrations down to 5 × 102 CFU/mL without relying solely on specific receptor-ligand recognition. However, functionalizing the liposome with an aptamer further improved the specificity and sensitivity of S. aureus detection at even lower concentrations, down to 80 CFU/mL, in the wide range of 80-107 CFU/mL. This study highlights the potential for optimizing the lipid composition of liposomes to improve their sensitivity for pathogen detection, particularly when combined with aptamer-based strategies.
摘要：
脂质体已经成为多功能纳米载体，不仅在药物递送中而且在病原体检测和诊断中找到应用。本研究旨在通过研究脂质组成对负载有5（6）-羧基荧光素（CF）的脂质体的影响来增强脂质体对金黄色葡萄球菌的敏感性。使用与饱和磷脂组合的各种浓度的胆固醇(10-40mol%)制备脂质体。动态光散射结果表明，较高的胆固醇浓度导致脂质体大小减小，CF释放（%），和截留效率(%)。通过使用具有和不具有适体插入的负载CF的脂质体来评估脂质体对金黄色葡萄球菌的敏感性。具有较高胆固醇含量（40mol％）的脂质体表现出强大的检测能力，可以检测低至5×102CFU/mL的低细菌浓度，而无需仅依靠特定的受体-配体识别。然而,用适体功能化脂质体进一步提高了在更低浓度下金黄色葡萄球菌检测的特异性和灵敏度，低至80CFU/mL，在80-107CFU/mL的宽范围内。这项研究强调了优化脂质体脂质组成以提高其病原体检测灵敏度的潜力，特别是当与基于适体的策略结合时。
