Arcane Abeyance (p184 EGtW)Says:
…A creature holding the bead can use its action to release the spell within, whereupon the bead disappears. The spell uses your spell attack bonus and save DC, and the spell treats the creature who released it as the caster for all other purposes.
Find Familiar (p240 PHB) Says:
…In combat, it rolls its own initiative and acts on its own turn. A familiar can’t attack, but it can take other actions as normal.
Can a familiar accept the frozen spell bead and then use it to cast a spell, if so does the familiar concentrate on the spell instead of the original caster?