Objective To prepare the coating of dexamethasone-eluting intravascular stent and observe the features of its delayed release in vitro.Methods Spray painting and dipping coating were used respectively to prepare stent coating,and then high performance liquid chromatography(HPLC)was used to detect the drug loading.The stents prepared by dipping coating were set in a flow of 50 ml PBS buffer at a velocity of 20 ml/min,and 0.5 ml buffer was collected at 6 h and 1,2,4,6,8,10,12,15 d respectively with another 0.5 ml fresh PBS being added immediately.The drug content of the 0.5 ml buffer was detected by HPLC for drug sustained release in vitro.Results The drug loading of stents prepared by spray painting was(24.26?5.23)?g,while that stents prepared by dipping coating for 4 d was(93.15?7.83)?g.Drugs were released slowly and the release rate reached 84% at 15 d.Conclusion The dipping coating-prepared stents have evident effect of sustained release.

Purpose: This study aims to comprehensively evaluate the clinical efficacy of chemotherapy or endocrine therapy maintenance in metastatic breast cancer (MBC) patients. Materials and Methods: The meta-analysis of randomized clinical trials (RCTs) and propensity score matching of multicenter cohort study evaluated MBC patients who underwent first-line chemotherapy or endocrine therapy maintenance. This study is registered with PROSPERO: CRD42017071858 and ClinicalTrials.gov: NCT04258163. Results: A total of 2,867 patients from 15 RCTs and 760 patients from multicenter cohort were included. The results from meta-analysis showed that chemotherapy maintenance improved progression-free survival (PFS) (hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.54 to 0.73; p < 0.001; moderate-quality evidence) and overall survival (OS) (HR, 0.87; 95% CI 0.78 to 0.97; p=0.016; high-quality evidence) than observation. In the cohort study, for hormone receptor–positive MBC patients, chemotherapy maintenance improved PFS (HR, 0.67; 95% CI, 0.52 to 0.85; p < 0.001) and OS (HR, 0.55; 95% CI 0.42 to 0.73; p < 0.001) compared with observation, and endocrine therapy maintenance also improved PFS (HR, 0.65; 95% CI, 0.53 to 0.80; p < 0.001) and OS (HR, 0.55; 95% CI, 0.44 to 0.69; p < 0.001). There were no differences between chemotherapy and endocrine therapy maintenance in PFS and OS (all p > 0.05). Regardless of the continuum or switch maintenance therapy, showed prolonged survival in MBC patients who were response to first-line treatment. Conclusion This study provided evidences for survival benefits of chemotherapy and endocrine therapy maintenance in MBC patients, and there was no difference efficacy between chemotherapy and endocrine therapy maintenance for hormone receptor–positive patients.