title: Identification of a boron nitride nanosphere-binding peptide for the intracellular delivery of CpG oligodeoxynucleotides.
abstract: CpG oligonucleotides (CpG ODNs) interact with Toll-like receptor 9 (TLR9), which results in the induction of immunostimulatory cytokines. We delivered CpG ODNs intracellularly using boron nitride nanospheres (BNNS). To enhance the loading capacity of CpG ODNs on BNNS, we used a phage display technique to identify a 12-amino acid peptide designated as BP7, with specific affinity for BNNS, and used it as a linker to load CpG ODNs on BNNS. The tyrosine residue (Y) at the eighth position from the N-terminus played a crucial role in the affinity of BP7 to BNNS. BNNS that bound BP7 (BNNS-BP7) were taken up by cells and showed no cytotoxicity, and CpG ODNs were successfully crosslinked with BP7 to create BP7-CpG ODN conjugates. Using BP7 as a linker, the loading efficiency of CpG ODNs on BNNS increased 5-fold compared to the direct binding of CpG ODNs to BNNS. Furthermore, the BP7-CpG ODN conjugate-loaded BNNS had a greater capacity to induce interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) production from peripheral blood mononuclear cells (PBMCs) than that of CpG ODNs directly loaded on BNNS. The higher amount of cytokine induction by BP7-CpG ODN conjugate-loaded BNNS may be attributed to a higher loading capacity and stronger binding to BNNS of the linker BP7. The greater functionality of BP7-conjugated CpG ODNs on BNNS expands the potential of BNNS for drug delivery applications.
authors.affiliation: Graduate School of Life Science, Hokkaido University, N10W8, Sapporo, 060-0812, Japan.
authors.forename: Huijie
authors.initials: H
authors.lastname: Zhang
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Yamazaki
authors.forename: Chunyi
authors.initials: C
authors.lastname: Zhi
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Hanagata
mesh_terms: D000595:Amino Acid Sequence; D001896:Boron Compounds / Q000737:chemistry / Q000378:metabolism*; D061505:Cell Surface Display Techniques; D015870:Gene Expression / Q000187:drug effects; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D008969:Molecular Sequence Data; D054118:Nanospheres / Q000737:chemistry*; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000493:pharmacokinetics* / Q000494:pharmacology; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014443:Tyrosine / Q000737:chemistry / Q000378:metabolism
chemical_list: D001896:Boron Compounds; C408982:CPG-oligonucleotide; D015850:Interleukin-6; D009838:Oligodeoxyribonucleotides; D010455:Peptides; D014409:Tumor Necrosis Factor-alpha; C017282:boron nitride; D014443:Tyrosine