They can be opened without breaking, and can be reloaded and reused.
Actually the offical way to get 110 film out does not require opening the Cartridge. One uses a tool called a "Violator" (aptly named) to push on the backing paper through the Frame number window. This brings the film out through the exposure opening. When I used to do it, I used a Knitting needle.
Charles MacDonald firstname.lastname@example.org
I still live just beyond the fringe in Stittsville