Table 4.

Anionic amino acid derived polymers for pH-responsive drug release.

Type of AA	Payload	Target/pH	Polymer a	Ref.
Asp	DFS	Colon	pAsp-l-pNIPAm	[146]
	5-Fluoruracil	Intestine	Konjac glucomannan-pAsp hydrogel	[147]
	Ocular drug	Eye	Thiolated PAsp	[149]
	Glutathione or oxytocin	Colon	Succinic derivative of insulin cross linked pAspHz	[152]
	DTX	Drug resistant cancer cell	PEG-b-PAsp	[162]
Glu	Dox	Intracellular tumor	mPEG-b-p(LGA-co-CELG)	[182]
	Adriamycin hydrochloride	Tumor pH	Star-block-copolymer of PEI, PLGA and PEG	[183]
	Dox	Lysosome	PLGA-co-PLA-DPPE	[187]

^a See abbreviations for definitions of the terms used.