Ji Shilu, Zhou Sensen, Zhang Xiaoke, Chen Weizhi, Jiang Xiqun
MOE Key Laboratory of High Performance Polymer Materials and Technology, and Department of Polymer Science & Engineering, College of Chemistry & Chemical Engineering, Nanjing University, Nanjing, 210093, P. R. China.
Biomater Sci. 2022 Apr 12;10(8):2054-2061. doi: 10.1039/d2bm00153e.
A small molecular probe (Ir-fliq) and a macromolecular optical probe (Ir-fliq-PVP) based on an iridium complex are designed for hypoxia imaging and antibacterial chemotherapy in this work. The existence of both isoquinoline and fluorene moieties in the probe structure extends the phosphorescence emission to the red-wavelength region. The rigid large conjugated structure of the ligand can also reduce the packing caused by intermolecular interactions and suppress the self-quenching, thus improving the phosphorescence efficiency. The hydrophilic Ir-fliq-PVP has a good ability to generate singlet oxygen and can be used for photodynamic antimicrobial chemotherapy (PACT). Moreover, the small molecular probe Ir-fliq is further cross-linked with carboxymethyl chitosan (CMCS) and sodium alginate (SA) to form a CSGI hydrogel. The biocompatibility, mechanical properties, antibacterial properties and hypoxic imaging ability of the CSGI hydrogel have been evaluated in chronic wound models of diabetic mice. It shows that the CSGI hydrogel can effectively inhibit the growth of bacteria in wounds through PACT under light irradiation, promote the healing of chronic wounds in diabetic mice, and record the hypoxia process of mouse wounds.
在本工作中，设计了一种基于铱配合物的小分子探针（Ir-fliq）和一种大分子光学探针（Ir-fliq-PVP）用于缺氧成像和抗菌化疗。探针结构中异喹啉和芴部分的存在将磷光发射扩展到了红色波长区域。配体的刚性大共轭结构还可以减少分子间相互作用引起的堆积并抑制自猝灭，从而提高磷光效率。亲水性的Ir-fliq-PVP具有良好的单线态氧生成能力，可用于光动力抗菌化疗（PACT）。此外，小分子探针Ir-fliq进一步与羧甲基壳聚糖（CMCS）和海藻酸钠（SA）交联形成CSGI水凝胶。在糖尿病小鼠慢性伤口模型中评估了CSGI水凝胶的生物相容性、力学性能、抗菌性能和缺氧成像能力。结果表明，CSGI水凝胶在光照下可通过PACT有效抑制伤口细菌生长，促进糖尿病小鼠慢性伤口愈合，并记录小鼠伤口的缺氧过程。
