Alternatives to wood joists
Other than engineered Joists, which are also made of wood products, the only alternative are steel I-beams with a wood nailer. That is of course you want to go complete commercial with steel and concrete panel floors.  You better have a very fat wallet and an engineer to sign off for the modification in Mass. Such a deviation from standard residential practice will require a permit and prior approval, accompanied with a engineered comfirmation of conformity. I have had to supply this type of documentation every time I replace wooden beams with steel beams to eliminate support posts or lalley columns . 

The other major consideration is how you plan to nest the steel, smaller joists into, or onto the lower supporting wall.