A molecular theranostic agent designed for photodynamic therapy (PDT) treatment in the near-infrared and for imaging tissue tumors with magnetic resonance imaging (MRI) is reported. It consists of a linear π-conjugated Zn(II) porphyrin dimer linked at each extremity to a GdDOTA-type complex. This agent has shown very promising potential for PDT applications with good singlet oxygen generation in DMSO and high linear absorption in the near-infrared (λ_max = 746 nm, ε ≈ 10⁵ M^–1 cm^–1). Moreover, this molecule has a propensity for two-photon excited PDT with high two-photon cross sections (∼8000 GM in 880–930 nm range), which should allow for deeper tumor treatments and higher spatial precision as compared to conventional one-photon PDT. Regarding the MRI contrast agent properties, the molecule has shown superior relaxivity (14.4 mM^–1 s^–1 at 40 MHz, 298 K) in comparison to clinical contrast agents and the ability to be internalized in cells, thanks to its amphiphilic character. Irradiation of HeLa cells using either one-photon (740 nm) or two-photon excitation (910 nm) has led in both cases to important cell death.

中文翻译：

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卟啉二聚体-GdDOTA共轭物作为一剂和二剂光子光动力疗法和MRI的治疗手段

报道了设计用于近红外光动力疗法（PDT）治疗和磁共振成像（MRI）成像组织肿瘤的分子治疗剂。它由线性π-共轭的Zn（II）卟啉二聚体组成，在每个末端与GdDOTA型复合物相连。该剂在PDT中显示出非常有希望的潜力，在DMSO中产生良好的单线态氧并在近红外区域具有高线性吸收（_λmax = 746 nm，ε≈10 ⁵ M ^–1 cm ^–1）。此外，该分子倾向于具有高双光子截面（在880-930 nm范围内约为8000 GM）的双光子激发的PDT，与常规的单光子相比，这应允许更深的肿瘤治疗和更高的空间精度太平洋夏令时。关于MRI造影剂的特性，由于其具有两亲性，与临床造影剂相比，该分子显示出卓越的弛豫性（在40 MHz，298 K下为14.4 mM ^–1 s ^–1），并且具有被细胞内在化的能力。在两种情况下，使用单光子（740 nm）或双光子激发（910 nm）照射HeLa细胞都会导致重要的细胞死亡。