TY - JOUR
T1 - The polyethyleneglycol dilemma
T2 - Advantage and disadvantage of PEGylation of liposomes for systemic genes and nucleic acids delivery to tumors
AU - Hatakeyama, Hiroto
AU - Akita, Hidetaka
AU - Harashima, Hideyoshi
PY - 2013/6
Y1 - 2013/6
N2 - Gene and nucleic acid therapy is expected to play a major role in the next generation of agents for cancer treatment. We have recently developed a multifunctional envelope-type nano device (MEND) for use as a novel nonviral gene delivery system. The modification of polyethyleneglycol (PEG), i.e., PEGylation, is a useful method for achieving a longer circulation time for the delivery of MEND to a tumor via the enhanced permeability and retention (EPR) effect. However, PEGylation strongly inhibits cellular uptake and endosomal escape, which results in significant loss of activity of the delivery system. For successful nucleic acid delivery for cancer treatment, the crucial problem associated with the use of PEG, i.e., the "PEG dilemma" must be resolved. In this review, we describe the development and applications of MEND and discuss various strategies for overcoming the PEG dilemma based on the manipulation of both pharmacokinetics and intracellular trafficking of cellular uptake and endosomal release. To increase cellular uptake, target ligands including proteins, peptides, antibodies and aptamers that recognize molecules specifically expressed on tumors are first introduced. Second, cleavable PEG systems are described. The cleavage of PEG from carriers was achieved in response to the intracellular environment as well as the tumor microenvironment, which improvs cellular uptake and endosomal escape. Then, endosomal fusogenic peptides are discussed. Finally, pH-sensitive liposomes using pH-sensitive lipids are described.
AB - Gene and nucleic acid therapy is expected to play a major role in the next generation of agents for cancer treatment. We have recently developed a multifunctional envelope-type nano device (MEND) for use as a novel nonviral gene delivery system. The modification of polyethyleneglycol (PEG), i.e., PEGylation, is a useful method for achieving a longer circulation time for the delivery of MEND to a tumor via the enhanced permeability and retention (EPR) effect. However, PEGylation strongly inhibits cellular uptake and endosomal escape, which results in significant loss of activity of the delivery system. For successful nucleic acid delivery for cancer treatment, the crucial problem associated with the use of PEG, i.e., the "PEG dilemma" must be resolved. In this review, we describe the development and applications of MEND and discuss various strategies for overcoming the PEG dilemma based on the manipulation of both pharmacokinetics and intracellular trafficking of cellular uptake and endosomal release. To increase cellular uptake, target ligands including proteins, peptides, antibodies and aptamers that recognize molecules specifically expressed on tumors are first introduced. Second, cleavable PEG systems are described. The cleavage of PEG from carriers was achieved in response to the intracellular environment as well as the tumor microenvironment, which improvs cellular uptake and endosomal escape. Then, endosomal fusogenic peptides are discussed. Finally, pH-sensitive liposomes using pH-sensitive lipids are described.
KW - Drug delivery system
KW - Liposome
KW - Multifunctional envelope-type nano device
KW - Small interfering RNA
KW - Tumor
UR - http://www.scopus.com/inward/record.url?scp=84878836924&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84878836924&partnerID=8YFLogxK
U2 - 10.1248/bpb.b13-00059
DO - 10.1248/bpb.b13-00059
M3 - Review article
C2 - 23727912
AN - SCOPUS:84878836924
SN - 0918-6158
VL - 36
SP - 892
EP - 899
JO - Biological and Pharmaceutical Bulletin
JF - Biological and Pharmaceutical Bulletin
IS - 6
ER -