Described herein are biodegradable drug delivery conjugates for effectively delivering bioactive agents to a subject. The drug delivery conjugates comprise a water-soluble high molecular weight linear biodegradable polymer backbone comprising a plurality of linear water-soluble polymeric segments connected to one another by a first (main-chain) cleavable linker, wherein a bioactive agent is covalently bonded to at least one water-soluble polymeric segment, at least one cleavable linker, or a combination thereof. The conjugates possess numerous advantages over prior art delivery conjugates. Also described herein are methods for making and using the conjugates.
