Fibroblast activating protein (FAP) is an important biomarker of cancer associated fibroblasts and activated fibroblasts, which is highly expressed in activated fibroblasts of many tumor and fibrotic tissues, but not in normal tissues and non malignant lesions. Therefore, FAP has become an excellent target for diagnosis and treatment of tumors and other diseases. PET imaging and internal radiotherapy based on FAP inhibitor (FAPI) have been used in the diagnosis and treatment of many diseases, such as cancer and fibrosis. We first introduce the mechanism of disease occurrence and progression mediated by FAP and its clinical significance as a therapeutic target.Then,we systematically summarize the FAP probes labeled with 125I, 68Ga, 64Cu and other radionuclides, including their structural evolution, imaging, biodistribution and pharmacokinetic properties.After that, the reported strategies to improve the pharmacokinetic properties and target affinity of probes are summarized, including the use of squaramide linkers,modification with albumin binding agent,the development of dual-targeting probes.Finally, some suggestions for the future development of novel radioactive probes targeting FAP and the clinical application of classical probes are proposed.

Objective:To establish a simple, rapid and low-cost 2019 novel coronavirus (2019-nCoV) neutralizing antibody detection method.Methods:The 2019-nCoV RBD specific immunoglobulin G (RBD-IgG) detection method was established based on the principle of quantum dot immunochromatography(QDs), and the detection was evaluated by using of sera from coronavirus disease 2019 (COVID-19) convalescent patients ( N = 97), vaccinated donors ( N = 82) and healthy donors ( N = 299). The suitability of fingertip blood was evaluated by matching blood samples with peripheral blood ( N=54). Results:The 2019-nCoV RBD-IgG detection method based on QDs was successfully established. The detection result of QDSs had strong correlation ( Spearman r > 0.73, P < 0.000 1) and good consistency ( Kappa=0.93, P < 0.01) with the result of micro-neutralization test(MNT). The sensitivity and specificity were 92% and 99%, respectively. There was high correlation ( Spearman r =0.932 6, P < 0.000 1) and no significant difference ( P=0.102 6) between result of fingertip blood and peripheral blood. Fingertip blood can be used as a surrogate sample for testing. Conclusions:The 2019-nCoV neutralizing antibody detection method established in this study can provide an immediate, efficient and low-cost method selection for the assessment of herd immunity status, and provide technical support for the herd immunity monitoring of 2019-nCoV vaccinated population and the prevention and control of the epidemic.