Wan Junshan, Yin Chuqiang, Chen Xiaotong, Wu Keying, Zhang Chonghui, Zhou Yu, Feng Yugong, Chang Jing, Wang Ting
Department of Clinical Medicine, Qingdao Medical College, Qingdao University, Qingdao 266071, China.
College of Marine Life Science, Ocean University of China, Qingdao 266003, China.
Bioengineering (Basel). 2025 Mar 15;12(3):296. doi: 10.3390/bioengineering12030296.
Bacterial infections remain a global healthcare challenge, requiring precise diagnostic modalities to guide therapeutic interventions. Current molecular imaging agents predominantly detect nonspecific hemodynamic alterations and lack pathogen-specific targeting capabilities for magnetic resonance imaging (MRI). Leveraging the selective bacterial uptake of maltotriose via the maltodextrin transport pathway, we engineered maltotriose-functionalized magnetic nanoparticles (Malt-MNPs) as a novel MRI contrast agent. Basic physicochemical characterization confirmed the nanosystem's colloidal stability, biocompatibility, and superparamagnetism (saturation magnetization > 50 emu/g). In a rat bacterial infection model, intravenously administered Malt-MNPs selectively accumulated at infection sites, inducing a >50% MRI signal change within 24 h while exhibiting minimal off-target retention in sterile inflammatory lesions (<10% signal change). This specificity enabled clear MRI-based differentiation between bacterial infections and noninfectious inflammation. These findings provide a promising strategy for clinical translation in infection imaging and treatment.
细菌感染仍然是全球医疗保健面临的挑战，需要精确的诊断方法来指导治疗干预。目前的分子成像剂主要检测非特异性血流动力学改变，并且缺乏用于磁共振成像（MRI）的病原体特异性靶向能力。利用麦芽三糖通过麦芽糖糊精转运途径的选择性细菌摄取，我们设计了麦芽三糖功能化磁性纳米颗粒（Malt-MNPs）作为一种新型MRI造影剂。基本的物理化学表征证实了该纳米系统的胶体稳定性、生物相容性和超顺磁性（饱和磁化强度>50 emu/g）。在大鼠细菌感染模型中，静脉注射的Malt-MNPs选择性地在感染部位积聚，在24小时内引起>50%的MRI信号变化，而在无菌性炎症病变中的非靶向滞留最小（<10%信号变化）。这种特异性使得基于MRI能够清晰地区分细菌感染和非感染性炎症。这些发现为感染成像和治疗的临床转化提供了一个有前景的策略。
