4.2. Diagnostic Efficiency of Fe3O4

4.2. Diagnostic Efficiency of Fe3O4-PPy for TumorMarkers in Diseased Gastric TissuesThe content of Fe3O4-PPy is much higher than that ofserum, which is helpful for screening patients and is noteasy to miss diagnosis. On the other hand, the content ofcore–shell nanocomposites in gastric cancer tissues has aslightly lower specificity for the diagnosis of gastric cancer. It should pay attention to combine with other teststo exclude false positives in our work. The sensitivity ofFe3O4-PPy in the diagnosis of gastric cancer is higherbecause the Fe3O4-PPy content in the tissue is significantlyhigher than that in serum (Fig. 5). The results of this study also show that CA242 is superior to CA19-9. The positive expression rates of various tumor markers are alsoinconsistent due to the location, type and tissue origin ofvarious tumors. Because the sensitivity and specificity ofindividual tumor markers are difficult to meet the clinical requirements for prognosis assessment of gastric cancer, patients with conditions should be tested for tumormarkers in combination [10]. Various tumor markers arenot unique to malignant tumors, and combined detectioncan increase the probability of false positives. Therefore,dynamic tracking, observation and combined detection oftumor markers, combined with clinical manifestations, can effectively improve the accuracy of tumor diagnosis andreduce the rate of missed diagnosis.Based on the analysis of clinical data of patients, itwas found that the levels of Fe3O4-PPy were signifi-cantly increased in patients with lymphatic invasion, nerveinvasion and lymph node metastasis. Relevant changes incancer tissue genes can be detected in body fluids or secretions, and changes in these body fluids can to some extentreflect changes in the same gene in tissues. Therefore, inorder to analyze the early noninvasive screening value ofcore–shell nanocomposite, this paper compares the diagnostic value of Fe3O4-PPy in gastric cancer tissues and plasma samples. It was found that in gastric cancer tissues,the AUC of Fe3O4-PPy level used to diagnose gastric cancer was 0.73, the sensitivity was 0.47, and the specificitywas 0.77. In plasma samples, the AUC of Fe3O4-PPy levelused to diagnose gastric cancer was 0.68 and the sensitivityis 0.75 and the specificity is 0.81. Core–shell nanocomposite levels have not been detected in plasma samples,and the clinical application of Fe3O4-PPy detection needsto be further expanded [11].At present, most of the gastric cancer test specimens areperipheral blood. Due to the effect of blood dilution andthe low content of markers in the early stage of the tumor,even less secretion into the peripheral blood, the positiverate is not high enough. Fe3O4-PPy is in direct contact withgastric mucosa, which can more sensitively reflect gastriclesions. The detection of tumor markers in gastric juice hasa higher diagnostic value than gastric serum. The CEA isa broad-spectrum tumor marker, it can reflect the existenceof a variety of tumors, and it is a good tumor markerto judge the efficacy, condition development, monitoringand prognosis of colorectal cancer, breast cancer and lungcancer. The test confirmed that the measured values ofCA72-4, CA19-9, and CEA were higher than the measuredvalues in serum with the statistically significant differences(P < 005). The positive expression rates of various tumormarkers are also inconsistent due to the location, type andtissue origin of various tumors.5. CONCLUSIONSThe magnetic material is an essential part of the magnetictargeted drug delivery system, and its performance willdirectly affect the therapeutic effect of the drug, in whichthe Fe3O4-Polypyrrole is commonly used for its most simple in its synthetic process and excellent biocompatibility.The Fe3O4-PPy is helpful for differential diagnosis andavoids misdiagnosis; changes in concentration can reflectthe actual situation of tumors in the body and can assist instaging and prognosis judgment. This study shows that thedetection sensitivity (82.17%, 80.32%, 79.48%, 84.63%,and 85.66%) and specificity (76.75%, 79.66%, 81.07%,83.47%, and 85.24%) of CA19-9, AFP, CA242, CEA,and CA72-4 in the tumor tissue of patients in observationgroup for the diagnosis of early gastric cancer are higherthan the sensitivity (78.66%, 79.25%, 76.18%, 82.11%,and 83.45%) and specificity (74.37%, 76.94%, 77.24%,81.22%, and 81.59%) of that in control group with statistically significant differences (P < 005). Therefore, itis believed that the Fe3O4-PPy is of great significance forthe detection of early gastric tumor markers in the tissuesof patients with early gastric cancer, and has certain value for the auxiliary diagnosis of early gastric cancer and theobservation of therapeutic effects. The results of this paperprovide a reference for the further researches of Fe3