Serum insensitive, intranuclear protein delivery by the multipurpose cationic lipid Saint-2

Delivery of antibodies to the cytosol

“…Often, β-galactosidase was detected or fluorescent proteins were analyzed via microscopy or flow cytometry as the readout for delivery efficiency. [41][42][43][44][45][46][47][48] As suggested by the numerous possible artifacts identified in our experiments or by others, these types of readout must be considered to be insufficient for indicating a true delivery to the cytoplasm. Another commonly used readout for protein delivery is cell death as an indicator for the delivery of toxic proteins.…”

Targeting antibodies to the cytoplasm

“…78 Many of the proposed protein transfection systems are lipidbased, such as TFA-DODAPL:DOPE, dioctadecylglycylspermine (DOGS), combinations of DOPE with CholCSper (a cationic surfactant consisting of cholesterol connected by a cysteine to carboxyspermine) or Saint-2 (N-methyl-4(dioleyl)methyl-pyridinium-chloride), as well as proprietary formulations. 50,62,76,81,91,92 Lipid-based protein transfection was improved by the development of delivery systems with prolonged intracellular release and compatibility with the presence of serum. 91,92 In addition to lipid-based transfection, other strategies for the intracellular delivery of proteins have been successfully employed.…”

“…50,62,76,81,91,92 Lipid-based protein transfection was improved by the development of delivery systems with prolonged intracellular release and compatibility with the presence of serum. 91,92 In addition to lipid-based transfection, other strategies for the intracellular delivery of proteins have been successfully employed. A polymerbased transfection that is similar to standard DNA-transfections and employs complexation of proteins with the cationic polymer polyethyleneimine (PEI) has been reported.…”

Intracellular Internalization Mechanism of Protein Transfection Reagents

“…Much effort has been therefore devoted to developing the excellent delivery systems, [1][2][3][4] and there are already several commercially-available protein transfection reagents; lipidbased, polymer-based, or peptide-based formulations. 5,6) One of the important factors for the protein delivery into cells is where the proteins are delivered. Depending on the purpose of the studies, proteins may be delivered to targeted organelles such as nuclei, cytoplasm, lysosomes, mitochondria, and so on.…”