There has been increasing interest in the development of pathological stimulus-activatable nanoplatforms with theranostic functions. Here, we report ketalized maltodextrin (KMD) nanoparticles which are able to deliver therapeutic and imaging functions to the acidic conditions simultaneously, as may be found in the site of inflammation. KMD was synthesized as a platform of the theranostic nanoparticles by conjugating acid-cleavable hydrophobic moieties to maltodextrin through carbonate bonds. KMD nanoparticles could undergo acid-triggered hydrolytic degradation to generate carbon dioxide (CO₂) bubbles, amplifying the ultrasound signal. The potential of KMD nanoparticles as a drug carrier was evaluated using silymarin as a model drug. KMD nanoparticles displayed significantly enhanced ultrasound contrast at acidic pH and released drug payloads in acid-triggered manners. The translational potential of silymarin-loaded KMD (s-KMD) nanoparticles as ultrasound contrast agents and therapeutic agents was thoroughly evaluated using cell culture models and mouse models of acetaminophen (APAP)-induced acute liver failure. s-KMD nanoparticles exhibited significantly enhanced ultrasound contrast in the APAP-intoxicated liver and also remarkably suppressed the hepatic damages by inhibiting the expression of pro-inflammatory cytokines. These results suggest that KMD nanoparticles hold tremendous potential as theranostic agents for various inflammatory diseases.

对具有治疗诊断功能的病理刺激可激活的纳米平台的开发越来越感兴趣。在这里，我们报告了缩酮化麦芽糖糊精（KMD）纳米颗粒，它能够同时向酸性条件下提供治疗和成像功能，这可能是在炎症部位发现的。通过将酸可裂解的疏水部分通过碳酸酯键缀合到麦芽糖糊精上，将KMD合成为治疗性纳米颗粒的平台。KMD纳米颗粒可能会发生酸触发的水解降解，从而生成二氧化碳（CO ₂）气泡，放大超声信号。使用水飞蓟素作为模型药物评估了KMD纳米颗粒作为药物载体的潜力。KMD纳米颗粒在酸性pH值下显示出明显增强的超声对比度，并以酸触发的方式释放了药物有效载荷。使用对乙酰氨基酚（APAP）诱导的急性肝衰竭的细胞培养模型和小鼠模型，彻底评估了水飞蓟素负载的KMD（s-KMD）纳米颗粒作为超声造影剂和治疗剂的翻译潜力。s-KMD纳米颗粒在APAP中毒的肝脏中显示出明显增强的超声对比度，并且还通过抑制促炎性细胞因子的表达显着抑制了肝损伤。