中国生物工程杂志

Objective: To construct ferritin nanoparticles modified with near-infrared fluorescent probes, and to study their bio-safety as an in vivo imaging system, biological distribution in mice, and tumor targeting. Methods: By artificially designing cysteine point mutation on the surface of ferritin, the surface of ferritin nanoparticles was functionalized with Dy731 fluorescent probe by sulfhydryl coupling of cysteine sulfhydryl groups and the maleimide group of the Dy731 dye. Ferritin nanoparticles (Dy731-Ft) modified with near-infrared fluorescent probes were mixed with 5% w/v agarose solution and cooled to form a gel. The gel was placed under the skin and abdominal muscle wall of mice to determine the ability of Dy731-Ft to penetrate skin and muscle tissue. Dy731-Ft protein nanoparticles were injected into mice through the tail vein to observe whether acute adverse reactions occurred in mice and to detect the in vivo near-infrared fluorescence intensity and observe the bio-distribution of Dy731-Ft as an in vivo imaging system in mice. U87-MG tumor xenograft models were constructed and the distribution of Dy731-Ft within the tissues and organs of tumor-bearing mice and its targeting to tumor tissues were verified by tail vein injection. Results: The results showed that no acute adverse reactions were observed during and after the injection of ferritin nanoparticles into mice, indicating that ferritin nanoparticles have good biocompatibility. Dy731-Ft accumulates mainly in the liver after in vivo injection. Conclusion: Near-infrared Dy731-Ft protein nanoparticles can target U87-MG tumor tissues, and its accumulation in tumor tissues may be related to the synergistic effect of the transferrin receptor 1 (TfR-1) mediated cellular endocytosis and enhanced permeability and retention effect (EPR) in tumor tissues.