Table 4. UV-vis/NIR imaging agents with fluorescent dyes.

Imaging modality	Dye/contrast agent	Means of incorporation	Major polymer backbone	Responsive size change/degradability	Responsive imaging property	Formulation method a	Size (nm)	Targeting group	Cells/in vivo work	Therapeutics	Ref.
UV-vis	5-Aminofluorescein (5-AF), 7-amino-4-methyl coumarin (AMC), or QDs	Conjugation	Chitosan and PAA crosslinked with MBA	N/A	N/A	A + D	180	N/A	In vivo lymphatic node mapping of Balb/c mice	Doxorubicin, or Vascular endothelial growth factor C	117
UV-vis	Fluorescein isothiocyanate	Conjugation	Poly(amidoamine) dendrimers and alginate crosslinked with Ca2+	pH	N/A	E + B	433	N/A	Uptake and cytotoxicity on CAL-72 cells	Doxorubicin	118
UV-vis	8-Hydroxypyrene-1-carbaldehyde (HPC)	Encapsulation	Polyurethane	—	Change in emission wavelength as a function of pH	B	92	N/A	Uptake in NIH/3T3 fibroblast cells	N/A	19
UV-vis/NIR	DMDP-M	Encapsulation	Crosslinked Pluronic F127	—	Fluorescence turned “on” in presence of thiols	B	45	N/A	Uptake in NIH/3T3 fibroblasts	N/A	123
UV-vis	Self-fluorescent abietane	As part of polymer matrix	Poly(abietane methacrylate) crosslinked with PEGDA	N/A	N/A	A	90–135	Folic acid	Uptake in MCF-7 cells	Doxorubicin	120
UV-vis	Self-fluorescent ALC linker	Electrostatic encapsulation	Branched PEI crosslinked by aldehyde-l-cystine (ALC) linker	Thiols	Decrease in pH and presence of reducing agents lowers the fluorescence	B	200	N/A	Transfection in multiple cell lines	pDNA	121
UV-vis	Rhodamine B	As part of polymer matrix	P(NIPAM-co-RhBUA) crosslinked with MBA	Temperature	Increased in fluorescence in presence of Cr3+ and increased temperature	A	117 (20 °C) and 50 (40 °C)	N/A	N/A	N/A	122
NIR fluorescence	Cyanine dye	Conjugation	Azide-functionalized PEG methyl ether crosslinked with l-cystine-N-carboxy anhydride	Reducing environment	N/A	B	210	N/A	N/A	Doxorubicin	127
	NIR-797 isothiocyanate	Conjugation	Methacrylated carboxymethyl cellulose crosslinked with disulfide linkage-containing crosslinkers	Reducing environment	N/A	B	192	N/A	NIR fluorescence imaging of H22 tumor-bearing mice	Doxorubicin	126
	IRDye800	Conjugation	Amine-cholesteryl-group-bearing pullulan	N/A	N/A	C	30	N/A	SLN Mapping in mice and pigs	N/A	130 and 131
	ICG	Conjugation	ICG–HA conjugate	HAdase	Fluorescence turn “On” in presence of HAdase	C	189	HA	Tumor and SLN imaging of MDA-MB-231 tumor bearing mice	N/A	134
	ICG	Conjugation	Self-assembled ICG–HA conjugate with surface further crosslinked with disulfide linkage-containing crosslinkers	HAdase	Fluorescence turn “On” in presence of HAdase	C + B	293	N/A	Imaging of front paw of mice that are injected with nanogels pre-incubated with HAdase	N/A	135
	ICG	Conjugation	HA + poly(beta-amino)ester (PBAE) + ICG	pH	Fluorescence turn “On” in presence of HAdase	D	73 (pH 7.4) and 15 (pH 5.5)	HA	Uptake in MDA-MB-231 breast cancer cells	N/A	136
	Ga-porphyrin	As crosslinkers	α,ω-Diazide/hydroxyl PEG and α,ω-difolate/azidePEG crosslinked by Ga-TPPPP	N/A	—	B	110	Folate	—	N/A	137

^a Formulation methods: refer to Fig. 1.