Table 1.

Ligands utilized for exploiting active transport across the BBB.

Ligand	NP formulation	NP hydrodynami c size	NP zeta potential	Model	BBB integrity confirmation	Reference
Myristoylated polyarginine peptide	Cross-linked dextran coated superparamagnetic iron oxide (CLIO)	40 nm	Not reported	Intracranial implant of U-87 MG cells into mice	Intracranial implant of U-87 MG cells into mice	[87]
Chlorotoxin	Chitosan-g-PEG coated iron oxide NPs	33 nm	4.2 mV	Transgenic model of medulloblastom a	Brain tumor uptake compared to control NPs. Gd-DTPA used to confirm BBB integrity.	[96]
RI7217 (rat anti-mouse CD71 clone)	Liposome of EPC, cholesterol, EPG, and MPB-PE	116 nm	−14.8 mV	Balb/c mice	Brain uptake compared to control and other ligandcoupled liposomes	[89]
Lactoferrin	DMSA modified superparamagnetic iron oxide NPs	74.8 nm	−11.1 mV	Intracranial implant of C6 cells into rats	Brain tumor uptake compared to control NPs	[94]
Leptin30	Dendrigraft poly-l- lysine: DNA complexes	141 nm	1.15 mV	Nude mice	Permeability across BCEC monolayer assessed in vitro. Brain uptake compared to control NPs.	[277]
p- aminophenyl- α-D-manno- pyranoside	Daunorubicin loaded, Tf modified liposomes	122.8 nm	−6.37 mV	Intracranial implant of C6 cells into rats	Permeability across BMVEC monolayer assessed in vitro. Brain tumor uptake compared to control NPs.	[278]
OX26 monoclonal antibody	Chitosan-g-PEG NPs	636.69 nm	18.23 mV	Swiss albino mice	Brain uptake compared to control NPs.	[279]
OX26 monoclonal antibody	6-coumarin or NC- 1900 loaded PEG- PCL polymersomes	100 nm	−21.3 mV	Sprague– Dawley rats	Brain uptake compared to control NPs and NPs with varying amounts of OX26.	[280]
TAT	FITC or QD loaded cholesterol- terminated poly(ethylene glycol) NPs	190 nm	22 mV	Sprague– Dawley rats	Brain uptake compared to free FITC or QD	[281]
Cationic albumin	PEG-PLA NPs	82.1 nm	−12.19 mV	In vitro only	Permeability across BCEC	[282]