Stimuli-sensitive drug linkers in polymer prodrugs obtained by RDRP techniques via the “grafting from” or “drug-initiated” strategy.

Linker	Drug	Polymerization method	Nanocarrier	Cleavageconditions	Release	Ref.
	CdA (ester) (diglycolate)	NMP	PI	Human serum	Ester: <1% after 24 h	235
					Diglycolate: 20% after 24 h
	Ptx (diglycolate)	NMP	PI	Human serum	3–5% after 24 h	237
	Ptx (diglycolate)	RAFT	POEGMA	Human serum	30% after 24 h	237
	CdA (ester) (diglycolate)	RAFT	PSqMA	Human serum	Ester: 25% after 24 h	236
					Diglycolate: 28% after 24 h
	Ptx	RAFT (initiator + DHP) (initiator + DEGVE)	PDMA	pH 4	DHP: <10% after 96 h	234
					0% after 96 h
				pH 5	DEGVE: 30% after 96 h
					< 10% after 96 h
	Gem	RAFT	Gem-PMMA	pH 5.5 + cathepsin B	71.6% after 72 h	231
	Gem (amide) (amide + diglycolate)	NMPrROP	Gem-P(MMA-co-MPDL)	Human serum	Amide: <2% after 24 h	238
					Amide/diglycolate: <7–13% after 24 h
			Gem-P(OEGMA-co-MPDL)		Amide: <8–25% after 24 h
	Gem	NMP	PI	Human serum	6.1% after 24 h	230
	Gem (amide) + Dox/Lap (succinate) (diglycolate)	NMP	PI	Human serum	Gem: <2% after 24 h	239
					Dox/Lap: no release