title: Effect of inserted spacer in hepatic cell-penetrating multifunctional peptide component on the DNA intracellular delivery of quaternary complexes based on modular design.
abstract: A safe and efficient quaternary gene delivery system (named Q-complexes) was constructed based on self-assembly of molecules through noncovalent bonds. This system was formulated through the cooperation and competing interactions of cationic liposomes, multifunctional peptides, and DNA, followed by coating hyaluronic acid on the surface of the ternary complexes. The multifunctional peptide was composed of two functional domains: penetrating hepatic tumor-targeted cell moiety (KRPTMRFRYTWNPMK) and a wrapping gene sequence (polyarginine 16). The effect of spacer insertion between the two domains of multifunctional peptide on the intracellular transfection of Q-complexes was further studied. Experimental results showed that the formulations assembled with various peptides in the spacer elements possessed different intercellular pathways and transfection efficiencies. The Q-complexes containing peptide in the absence of spacer element (Pa) showed the highest gene expression among all samples. The Q-complexes containing peptides with a noncleavable spacerGA(Pc) had no ability of intracellular nucleic acid delivery, whereas those with a cleavable spacerRVRR(Pd) showed moderate transfection activity. These results demonstrated that the different spacers inserted in the multifunctional peptide played an important role in in vitro DNA transfection efficiency. Atomic force microscopy images showed that the morphologies of ternary complexes (LPcD) and Q-complexes (HLcPD) were crystal lamellas, whereas those of other nanocomplexes were spheres. Circular dichroism showed the changed configuration of peptide with spacerGAin nanocomplexes compared with that of its free state, whereas the Paconfiguration without spacer in nanocomplexes was consistent with that of its free state. The present study contributed to the structural understanding of Q-complexes, and further effective modification is in progress.
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, Shanghai.
authors.forename: Luchen
authors.initials: L
authors.lastname: Zhang
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, Shanghai.
authors.forename: Zhenbo
authors.initials: Z
authors.lastname: Li
authors.affiliation: School of Engineering, Zhejiang Agriculture and Forestry University, Lin'an, Zhejiang Province, People's Republic of China.
authors.forename: Fangli
authors.initials: F
authors.lastname: Sun
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, Shanghai.
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Xu
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, Shanghai.
authors.forename: Zixiu
authors.initials: Z
authors.lastname: Du
mesh_terms: D000595:Amino Acid Sequence; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000473:pathology; D002412:Cations / Q000737:chemistry; D057846:Cell-Penetrating Peptides / Q000737:chemistry*; D002942:Circular Dichroism; D004247:DNA / Q000008:administration & dosage* / Q000737:chemistry* / Q000235:genetics; D005434:Flow Cytometry; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D008081:Liposomes / Q000008:administration & dosage* / Q000737:chemistry; D008113:Liver Neoplasms / Q000235:genetics* / Q000473:pathology; D018625:Microscopy, Atomic Force; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D002412:Cations; D057846:Cell-Penetrating Peptides; D008081:Liposomes; D010455:Peptides; D049452:Green Fluorescent Proteins; C015462:polyarginine; D004247:DNA
keywords: Q-complexes; intracellular transfection; lipid component; multifunctional peptides; spacer elements