Multimodal imaging probes play a crucial role in overcoming the limitations associated with single-mode imaging for clinical medical diagnosis. This study focuses on the development of a photoresponsive fluorine-containing water-soluble polymer (PF) through RAFT polymerization. Subsequently, a polymer–gadolinium(III) hybrid (PF-Gd) dual-modal probe capable of T₁-weighted ¹H MRI and ¹⁹F MRI was synthesized via postmodification of PF with a Gd-DOTA derivative. Under physiological conditions (pH = 7.4), the hybrids exhibit UV-activated ¹⁹F NMR/MRI and enhanced ¹H MRI. The inclusion of Gd³⁺ facilitates the acceleration of water molecule T₁ relaxation, leading to high-intensity ¹H MRI contrast. Leveraging the paramagnetic relaxation enhancement (PRE) effect between fluorine atoms and Gd³⁺, the restoration of Gd³⁺-accelerated ¹⁹F T₂ relaxation enables precise photoactivation of ¹⁹F MRI signals, transitioning from the “OFF” to the “ON” state. This study provides an important reference for the development of hybrid systems that function as real-time diagnostic tools and offers controlled activation for multimodal imaging probes.

中文翻译：

---

含氟聚合物-钆 （III） 杂化物，用于光激活双模式 T1 加权 1H MRI 和 19F MRI 造影剂


多模态成像探头在克服临床医学诊断中与单模成像相关的限制方面发挥着至关重要的作用。本研究的重点是通过 RAFT 聚合开发一种光响应性含氟水溶性聚合物 （PF）。随后，通过使用 Gd-DOTA 衍生物对 PF 进行后修饰，合成了能够进行 T₁ 加权 ¹H MRI 和 ¹⁹F MRI 的聚合物-钆 （III） 杂化 （PF-Gd） 双模态探针。在生理条件 （pH = 7.4） 下，杂交体表现出紫外线激活的 ¹⁹F NMR/MRI 和增强的 ¹H MRI。Gd³⁺ 的包含促进了水分子 T₁ 弛豫的加速，导致高强度 ¹H MRI 造影剂。利用氟原子和 Gd³⁺ 之间的顺磁弛豫增强 （PRE） 效应，恢复 Gd³⁺ 加速的 ¹⁹F T₂ 弛豫能够对 ¹⁹F MRI 信号进行精确的光激活，从“OFF”过渡到“ON”状态。本研究为开发混合系统提供了重要参考，该系统可作为实时诊断工具，并为多模态成像探头提供受控激活。