Biological implants have an electroplated surface wherein a substantial portion of the electroplated surface is covered with dendrites. The dendrites assist in maintaining the implant in location. When the metal is a radioactive metal or the surface of the electroplated is coated with a radioactive material, the dendrites increase surface area thereby increasing radiation dosage and further extend the radioactive surface farther away from the surface of the implant, further enhancing radioactive emission. This is particularly useful for a cholangiocarcinoma stent which can be implanted into the biliary stent to treat cholangiocarcinoma.