A simpler alternative: make a serrated spear, with hinged barbs that protrude when it's being pulled towards the entry point. Have it attached to a cable and draw the spear in once the monster has been impaled.
Even if the regenerative powers prevent the beast from bleeding out, it is now captured, and can be beheaded or otherwise 'taken apart'.
Pro's: no need for advanced tech, energy sources, or anticipating the regenerative powers.
Con: you need a powerful machine to power a heavy duty pulley. But that's likely easy to accomplish in an urban environment.