Transarterial radioembolization (TARE) is a widely utilized therapeutic approach for hepatocellular carcinoma (HCC), however, the clinical implementation is constrained by the stringent preparation conditions of radioembolization agents. Herein, we incorporated the superstable homogeneous iodinated formulation technology (SHIFT), simultaneously utilizing an enhanced solvent form in a carbon dioxide supercritical fluid environment, to encapsulate radionuclides (such as ¹³¹I,¹⁷⁷Lu, or ¹⁸F) with lipiodol for the preparation of radiolipiodol. The resulting radiolipiodol exhibited exceptional stability and ultra-high labeling efficiency (≥99%) and displayed notable intratumoral radionuclide retention and in vivo stability more than 2 weeks following locoregional injection in subcutaneous tumors in mice and orthotopic liver tumors in rats and rabbits. Given these encouraging findings, ¹⁸F was authorized as a radiotracer in radiolipiodol for clinical trials in HCC patients, and showed a favorable tumor accumulation, with a tumor-to-liver uptake ratio of ≥50 and minimal radionuclide leakage, confirming the feasibility of SHIFT for TARE applications. In the context of transforming from preclinical to clinical screening, the preparation of radiolipiodol by SHIFT represents an innovative physical strategy for radionuclide encapsulation. Hence, this work offers a reliable and efficient approach for TARE in HCC, showing considerable promise for clinical application (ChiCTR2400087731).

Objective To assess the imaging characteristics of 18F-Alfalide II in different tumorbearing mice and pharmacokinetics in Beagle dogs.Methods BALB/c nude mice(n-24)were used for subcutaneous tumor models(A549 and U87MG),orthotopic lung cancer models(A549)and orthotopic breast cancer models(MDA-MB-231)(n=6 in each group).18F-Alfatide II and 18F-fluorodeoxyglucose(FDG)microPET/CT images were compared in the 4 types of tumor-bearing nude mice models.18F-Alfatide II blocking experiment,biodistribution experiment and imaging studies in tumors of different growth cycles were performed in A549 subcutaneous tumor-bearing nude mice models.Pharmacokinetic experiments were carried out in Beagle dogs(n = 6)and CD-1 mice(n = 9).Two-sample t test was used to analyze the data.Results Compared with 18F-FDG,18F-Alfatide II microPET/CT images showed better imaging quality and contrast in subcutaneous A549,U87MG tumors and orthotopic A549(tumor/heart:4.50±1.17 vs 0.95±0.31;t = 4.125,P<0.01),orthotopic MDA-MB-231(tumor/muscle:6.60±1.53 vs 0.92±0.43;t = 3.984,P<0.01)transplantation nude mice models.18F-Alfatide II could specifically target A549 tumors,and the tumor uptake of 18F-Alfatide II was reduced by about 75% after pre-injection with cyclo(Arg-Gly-Asp-D-Tyr-Lys)(c(RGDyk)).18F-Alfatide II was rapidly cleared from the blood of Beagle dogs(T1/2 was(57.34±11.69)min).It was cleared in the form of prototype drug and(69.24±6.82)% of cumulative dose was excreted through the urine within 4 h after administration.Conclusions 18F-Alfatide II shows a higher target/non-target ratio than,18F-FDG in the imaging of A549,MDA-MB-231 and U87MG tumor-bearing nude mice models,which is more conducive to the diagnosis of tumor.18F-Alfatide II has excellent pharmacokinetic properties.

Objective To synthesize 18F-AlF-NOTA-G-TMTP1 and evaluate its potential for PET imaging on nude mice bearing high-metastatic potential hepatoma cells.Methods NOTA-G-TMTP1 was synthesized by the standard Fmoc-solid phase synthetic protocols and radiolabeled with 18F using NOTA-AlF chelation method.The nude mice models bearing low-metastatic potential HCC97L and high-metastatic potential HCCLM3 xenografts were established separately.The tumor-targeting characteristics of 18F-AlF-NOTA-G-TMTP1 were assessed by microPET/CT and biodistribution assay.Results NOTA-G-TMTP1 was labeled with 18F in one step with (25±6)％ labeling yield (n=5).The radiochemical purity of 18F-AlF-NOTA-G-TMTP1 was more than 95％ with a specific activity more than 11.1 GBq/μmol.The octanol/water partition coefficient (logP) for 18F-AlF-NOTA-G-TMTP1 was-3.166±0.022.The tumor to muscle ratios were 1.8± 0.4 and 4.7±0.2 at 35 min post injection for HCC97L and HCCLM3,respectively.The uptake of 18F-AlF-NOTA-G-TMTP1 in HCCLM3 tumor was inhibited (61.4％) by unlabeled G-TMTP1.Conclusion 18F-AlF-NOTA-G-TMTP1 has been successfully synthesized.It shows specific uptake by tumor induced by the high-metastatic potential hepatoma cells.