Summary of layered metal hydroxides for optical imaging.

Optical imaging functions	Composition of materials	Imaging agent	In vitro/in vivo highlights	Reference
Fluorescent images	MgAl-FITC-LDH	FITC	Investigation of intercellular uptake mechanism for LDH nanovehicles using an MNNG/HOS osteosarcoma cell line	105
Fluorescent images	MgAl-FITC-LDH	FITC	Investigation of intracellular trafficking pathway for an LDH nanovehicle using an MNNG/HOS osteosarcoma cell line	109
Fluorescent images	MgAl-FITC-LDH	FITC	Drug-delivery carriers with a targeting function due to the chemical conjugation with a specific ligand	119
Fluorescent images	MgAl-FITC-LDH	FITC	In vitro or in vivo biocompatibility of LDH nanovehicles was evaluated on an MNNG/HOS osteosarcoma cancer model in vivo	110
	MgAl-RITC-LDH	RITC
SPECT	57CoMgAl-LDH	57Co	57Co-LDH NPs showed effective cellular uptake behaviour in vitro, which was proved by in vivo using a mouse colorectal cancer cell line, CT-26 tumor bearing mouse model	120
PET	64CuMgAl-LDH-BSA	64Cu	LDH NPs labelled with PET radioisotopes were selectively accumulated in tumor tissues via a passive targeting effect using a mouse mammary gland cancer cells line, 4T1 tumor model	121