As shown in Figure 8A, the drug-loaded stent consisted of a three-layer, composite functional coating: the inner polytetrafluoroethylene membrane layer ensures the unidirectional release of drugs to the tumor tissue side to avoid fluctuating release and bile flow, leading to drug loss; the middle layer is loaded with two antitumor drugs, GEM and CIS, using PLCL as the carrier; and the outermost layer is a pure PLCL membrane to prevent the burst release of the loaded drugs. Here, PLCL1 is linked to in situ carcinoma.