Host–guest supramolecular approach for the preparation of a 19F MRI-guided theranostic agent with long T2 relaxation times and its synergetic performances†
Abstract
The construction of highly efficient theranostic materials is critical for accurate lesion diagnosis and treatment. Among various diagnostic modalities, magnetic resonance imaging (MRI) is gaining attention due to its safety and precision. This study presents a novel theranostic agent, TPZ@TSF, that integrates 19F MRI for diagnostic imaging with photodynamic therapy (PDT) and hypoxia-activated tirapazamine (TPZ) as therapeutic modalities. TPZ@TSF is created through host–guest supramolecular interactions between β-cyclodextrin and adamantane, facilitating the development of complex functional materials. Investigations reveal that TPZ@TSF exhibits substantial intensity amplification in 19F NMR/MRI when exposed to glutathione (GSH), both in vitro and in vivo, achieving a long T2 relaxation time of 1267 ms, ensuring its excellent diagnostic profile. In vivo 19F MRI results indicate that TPZ@TSF accumulates in tumors within 8 hours after intravenous administration in mice, providing an ideal timeframe for starting PDT and chemotherapy. Furthermore, therapeutic evaluations suggest that TPZ@TSF enhances chemotherapy efficacy against tumor growth by reducing hypoxia levels through the consumption of oxygen molecules during PDT. This innovative work is anticipated to significantly advance 19F MRI-guided therapy and improve the development of advanced theranostic agents.