Molecularly targeted nanocarriers deliver the cytolytic peptide melittin specifically to tumor cells in mice, reducing tumor growth.
The in vivo application of cytolytic peptides for cancer therapeutics is hampered by toxicity, nonspecificity, and degradation. We previously developed a specific strategy to synthesize a nanoscale delivery vehicle for cytolytic peptides by incorporating the nonspecific amphipathic cytolytic peptide melittin into the outer lipid monolayer of a perfluorocarbon nanoparticle. Here, we have demonstrated that the favorable pharmacokinetics of this nanocarrier allows accumulation of melittin in murine tumors in vivo and a dramatic reduction in tumor growth without any apparent signs of toxicity. Furthermore, direct assays demonstrated that molecularly targeted nanocarriers selectively delivered melittin to multiple tumor targets, including endothelial and cancer cells, through a hemifusion mechanism. In cells, this hemifusion and transfer process did not disrupt the surface membrane but did trigger apoptosis and in animals caused regression of precancerous dysplastic lesions. Collectively, these data suggest that the ability to restrain the wide-spectrum lytic potential of a potent cytolytic peptide in a nanovehicle, combined with the flexibility of passive or active molecular targeting, represents an innovative molecular design for chemotherapy with broad-spectrum cytolytic peptides for the treatment of cancer at multiple stages.
Soman
Neelesh R
NR
Department of Biomedical Engineering, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Baldwin
Steven L
SL
Hu
Grace
G
Marsh
Jon N
JN
Lanza
Gregory M
GM
Heuser
John E
JE
Arbeit
Jeffrey M
JM
Wickline
Samuel A
SA
Schlesinger
Paul H
PH
D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D004337:Drug Carriers; D005260:Female; D006801:Humans; D008081:Liposomes; D008546:Melanoma, Experimental / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008555:Melitten / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000627:therapeutic use; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000008:administration & dosage / Q000648:ultrastructure; D014018:Tissue Distribution
D000970:Antineoplastic Agents; D004337:Drug Carriers; D008081:Liposomes; D008555:Melitten