title: Peptide nanofiber complexes with siRNA for deep brain gene silencing by stereotactic neurosurgery.
abstract: Peptide nanofibers (PNFs) are one-dimensional assemblies of amphiphilic peptides in a cylindrical geometry. We postulated that peptide nanofibers (PNFs) can provide the tools for genetic intervention and be used for delivery of siRNA, as they can be engineered with positively charged amino acids that can electrostatically bind siRNA. The aim of this work was to investigate the use of PNFs as vectors for siRNA delivery providing effective gene knockdown. We designed a surfactant-like peptide (palmitoyl-GGGAAAKRK) able to self-assemble into PNFs and demonstrated that complexes of PNF:siRNA are uptaken intracellularly and increase the residence time of siRNA in the brain after intracranial administration. The biological activity of the complexes was investigated in vitro by analyzing the down-regulation of the expression of a targeted protein (BCL2), as well as induction of apoptosis, as well as in vivo by analyzing the relative gene expression upon stereotactic administration into a deep rat brain structure (the subthalamic nucleus). Gene expression levels of BCL2 mRNA showed that PNF:siBCL2 constructs were able to silence the target BCL2 in specific loci of the brain. Silencing of the BCL2 gene resulted in ablation of neuronal cell populations, indicating that genetic interventions by PNF:siRNA complexes may lead to novel treatment strategies of CNS pathologies.
authors.affiliation: Nanomedicine Lab, Institute of Inflammation and Repair, Faculty of Medical & Human Sciences, AV Hill Building, The University of Manchester , Manchester M13 9PT United Kingdom.
authors.forename: Mariarosa
authors.initials: M
authors.lastname: Mazza
authors.forename: Marilena
authors.initials: M
authors.lastname: Hadjidemetriou
authors.forename: Irene
authors.initials: I
authors.lastname: de Lázaro
authors.forename: Cyrill
authors.initials: C
authors.lastname: Bussy
authors.forename: Kostas
authors.initials: K
authors.lastname: Kostarelos
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D001692:Biological Transport; D001921:Brain / Q000378:metabolism* / Q000601:surgery; D045744:Cell Line, Tumor; D004337:Drug Carriers / Q000737:chemistry / Q000378:metabolism; D020868:Gene Silencing; D006801:Humans; D008297:Male; D057139:Nanofibers / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000172:deficiency / Q000235:genetics; D034741:RNA, Small Interfering / Q000737:chemistry* / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013238:Stereotaxic Techniques
chemical_list: C000595707:BCL2 protein, human; D004337:Drug Carriers; D010455:Peptides; D019253:Proto-Oncogene Proteins c-bcl-2; D034741:RNA, Small Interfering
keywords: CNS; brain; gene therapy; nanomedicine; neurodegeneration