Reductive activation of conformationally-constrained, anticancer drug delivery systems

Redox-active substituents were used to modulate reduction potentials in con formationally-constrained, drug delivery systems. The extent of drug delive ry was proportional to the degree of reductive activation, which was influe nced by the electronic properties of the substituents. Such reductively-act ivated carrier systems can be used to achieve controlled drug delivery to b ioreductive regions in hypoxic solid tumors.