The reversible thermosensitive hydroxypropyl chitin (HPCH) has been widely investigated for drug delivery, tissue engineering, wound repair and antibacterial hemostasis. To achieve non-invasive and real-time visualization of in vivo degradation of HPCH, aggregation-induced emission fluorogen (AIEgen) was introduced covalently in HPCH in water to obtain thermosensitive fluorescent hydroxypropyl chitin (FHPCH) avoiding using any organic solvent. The obtained fluorescent FHPCH hydrogel showed strong yellow-green fluorescence feature under UV irradiation, enabling visualization of the hydrogel with reversible thermosensitivity and reliable injectability. The in vitro enzymatic degradation study of FHPCH hydrogel showed that the attenuation of fluorescence intensity well matched with hydrogel weight loss. The injection through a 26-gauge needle for real-time fluorescence imaging in mice indeed indicated that AIE modified injectable thermosensitive FHPCH can be used for non-invasive, continuous and real-time visualization and quantitative analysis of in vivo degradation. This provides a new method for non-invasive real-time monitoring of similar implantable materials.

可逆热敏羟丙基甲壳素（HPCH）已被广泛研究用于药物输送、组织工程、伤口修复和抗菌止血。为了实现 HPCH 体内降解的无创和实时可视化，将聚集诱导发射荧光 (AIEgen) 共价引入水中的 HPCH，以获得热敏荧光羟丙基甲壳素 (FHPCH)，避免使用任何有机溶剂。获得的荧光 FHPCH 水凝胶在紫外线照射下显示出强烈的黄绿色荧光特征，使水凝胶具有可逆热敏性和可靠的可注射性可视化。FHPCH 水凝胶的体外酶降解研究表明，荧光强度的衰减与水凝胶的减重非常匹配。通过 26 号针头在小鼠体内进行实时荧光成像确实表明 AIE 修饰的可注射热敏 FHPCH 可用于无创、连续和实时可视化和定量分析体内降解。这为类似可植入材料的无创实时监测提供了一种新方法。