Have you tried cleaning and oiling?
First clean it, just warm water and soap should work, scrubbing into the pivot a bit, too, use an old toothbrush or something like that. Then oil with a lube of your preferance. If that doesn't work, more oil, and just open and close the blade a few hundred times (no exact number, just, open and close the blade while watching tv or something)
After washing, make sure you dry the tool well as Leatherman's are known for rust-issues, sometimes.
I don't know of significantly different blades like you ask.