You need to determine which degradable material to use as a tissue engineering scaffold for repair of a critical-sized bone defect. (a critical-size defect is one that would not heal unaided). you are planning to seed the scaffold with cells then implant it into the defect. while the cells proliferate and generate bone, the scaffold will degrade and create void space into which the new tissue may grow. what degradation method would you prefer for this scaffold material and why? (hydrolytic vs. enzymatic degradation, bulk vs. surface degradation)