Covalent organic frameworks (COFs) have emerged as a transformative class of porous crystalline materials with exceptional potential in biomedical applications, particularly in targeted drug and radionuclide delivery. Their tunable pore architecture, high surface area, and modular functionalization make them ideal candidates for advanced theranostic platforms. In this study, we report the development of a PEGylated nanoscale COF system—PEG-COF-Ag—specifically designed for efficient loading and stable retention of radioactive iodine-125. The framework is constructed from a keto-form 2,2′-bipyridine-based COF that features nitrogen-rich coordination sites capable of binding silver ions (Ag⁺) with high affinity. This Ag⁺ serves as a nucleation point for subsequent iodination via strong Ag–I interaction, preventing deiodination under physiological conditions. Through stepwise modification, including ultrasonic exfoliation and polyethylene glycol (PEG) conjugation, the material achieves a uniform particle size of approximately 150 nm, enhancing biocompatibility and tumor penetration. Radiolabeling experiments demonstrate near-complete incorporation of 125I within 30 seconds, reaching a yield of 94%, which surpasses many existing nanocarriers. Stability assessments confirm that over 95% of the radioactivity remains intact after 24 hours in PBS and serum, with more than 90% retained after seven days. In vitro studies show that PEG-COF-Ag-125I effectively induces apoptosis in PC-3 cancer cells, with significant dose-dependent cytotoxicity. In vivo biodistribution analysis via SPECT/CT imaging reveals prolonged tumor accumulation: at 10 hours post-injection, the radiolabelled COF maintains an average retention rate of 61.7%, significantly outperforming free 125I, which is rapidly cleared. Therapeutic evaluation in tumor-bearing mice shows that repeated intratumoral administration of 125I-COF leads to a 62.HDAC3 Antibody In Vitro 9% reduction in tumor volume over nine days, while control and free 125I groups exhibit minimal response.Acetyl-Histone H3 Antibody manufacturer No adverse weight loss or organ damage is observed, indicating low systemic toxicity.PMID:35212695 Histological and immunohistochemical analyses further validate the efficacy, showing extensive necrosis and reduced Ki67 expression in treated tumors. These findings highlight the robustness and versatility of the PEG-COF-Ag platform, which integrates rapid radiolabeling, long-term stability, and potent therapeutic outcomes. The system not only addresses key limitations in current brachytherapy approaches but also opens avenues for future applications with other isotopes such as 131I, offering a new generation of injectable, site-specific radiotherapeutics with enhanced precision and safety.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
