The invention discloses a multi-layer
covered stent for unilateral
controlled release of immune drugs and a preparation method and application thereof. The multi-layer
covered stent comprises a substrate of a
stent covered with an inner layer membrane, and the substrate is sequentially covered with a middle layer
drug-loaded membrane and a blank pore membrane. The multi-layer
covered stent is stable in structure and uniform in
membrane layer distribution, the membrane
layers and the
stent are firmly combined, after the
stent enters a tumor
lesion site,
medicine on the surface of the middle-layer
medicine-carrying membrane is rapidly released to meet the treatment concentration, and after the outer-layer blank pore membrane absorbs
lesion exudate,
fiber network fusion occurs to generate small pores, so that the
treatment effect is improved. The
drug released by the middle-layer
drug-loading membrane passes through pores of the outer-layer membrane at a relatively stable rate, and finally, a small amount of drug is slowly released at a stable rate along with degradation of the inner-layer membrane material, so that immune drugs and radiotherapy can form a continuous and stable synergistic
treatment effect at a tumor part due to the zero-order release behavior; the
tumor microenvironment immunity and the far-
isolation effect are obviously improved, and the radiotherapy and
immunity combined treatment of the malignant tumor accompanied by lumen obstruction is more efficiently realized.