Table III.

Recent Chemistries Utilized in Direct Polymerization with Functional Initiators to Impart Bioresponsive Properties

Name and structure	Synthesis	Degradation	References
Disulfanediylbis(ethane-2,1-diyl) bis(2-bromo-2-methylpropanoate)	ATRP	Backbone cleaved intracellularly into two identical chains	54
2-((2-Hydroxyethyl)disulfaneyl)ethyl 2-bromo-2-methylpropanoate	ATRP/ROP	Backbone cleaved intracellularly into two unique chains	56
6-(2-((2-((2-Bromo-2-methylpropanoyl)oxy) ethyl)disulfaneyl)ethoxy)-6-oxohexyl 6-(1-(2-chloroethoxy)ethoxy)hexanoate	ATRP/ROP	Backbone cleaved intracellularly into multiple unique chains	63
PEG-SS-CPADNa	RAFT	Backbone cleaved intracellularly into PEG chain and polymer chain	48
CTA-peptide-PEGb RAFT	RAFT	Backbone cleaved extracellularly into PEG chain and polymer chain	61
3-Azidopropyl 2-((((3-oxo-3-(2-(pyridin-2-yldisulfaneyl) ethoxy)propyl)thio)carbonothioyl)thio)propanoate	RAFT	Backbone cleaved intracellularly into two unique chains	59
2-nPEG methyl ether (2-((2-aminoethyl) disulfaneyl)ethyl)carbamate	ROP	Backbone cleaved intracellularly into PEG chain and polymer chain	57

^aCPADN, 4-cyanopentanoic acid dithionaphthalenoate.

^bCTA, chain transfer agent.