title: Nanogel-crosslinked nanoparticles increase the inhibitory effects of W9 synthetic peptide on bone loss in a murine bone resorption model.
abstract: We investigated the biological activity of W9, a bone resorption inhibitor peptide, using NanoClik nanoparticles as an injectable carrier, where acryloyl group-modified cholesterol-bearing pullulan (CHPOA) nanogels were crosslinked by pentaerythritol tetra (mercaptoethyl) polyoxyethylene. Thirty 5-week-old male C57BL/6J mice were fed a low calcium diet and received once-daily subcutaneous injections of the carrier alone, W9 24 mg/kg/day alone, W9 24 mg/kg/day incorporated in cholesterol bearing pullulan (CHP) nanogels, or W9 (8 and 24 mg/kg/day) incorporated in NanoClik nanoparticles for 4 days (n=5). Mice that received a normal calcium diet with NanoClik nanoparticle injections without W9 were used as a control group. Radiological analyses showed that administration of W9 24 mg/kg/day significantly prevented low calcium-induced reduction of bone mineral density in the long bones and lumbar vertebrae, but only when the NanoClik nanoparticles were used as a carrier. Histomorphometric analyses of the proximal tibiae revealed that W9 24 mg/kg/day incorporated in NanoClik nanoparticles prevented the increase in bone resorption indices induced by a low calcium diet, which was confirmed by measurement of serum bone resorption markers. These data suggest that NanoClik nanoparticles could be a useful carrier for peptide therapeutics, and also demonstrate that daily subcutaneous injections of the W9 peptide with the nanoparticles were able to inhibit bone loss in vivo. An osteoclastogenesis inhibition assay performed in vitro confirmed a slower release profile of W9 from NanoClik nanoparticles compared with conventional CHP nanogels.
authors.affiliation: Department of Bio-Matrix (Pharmacology), Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Toshimi
authors.initials: T
authors.lastname: Sato
authors.affiliation: Department of Bio-Matrix (Pharmacology), Graduate School, Tokyo Medical and Dental University, Tokyo, Japan ; Department of Biochemistry, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka.
authors.forename: Neil
authors.initials: N
authors.lastname: Alles
authors.affiliation: Department of Bio-Matrix (Pharmacology), Graduate School, Tokyo Medical and Dental University, Tokyo, Japan ; Department of Dental Pharmacology, City Dental College and Hospital, Dhaka, Bangladesh.
authors.forename: Masud
authors.initials: M
authors.lastname: Khan
authors.affiliation: Department of Bio-Matrix (Pharmacology), Graduate School, Tokyo Medical and Dental University, Tokyo, Japan ; Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Nagano
authors.affiliation: Department of Bio-Matrix (Pharmacology), Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Department of Bio-Matrix (Pharmacology), Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Tamura
authors.affiliation: Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura ; ERATO Akiyoshi Bio-Nanotransporter Project, Japan Science and Technology Agency, Katsura Int'tech Center Kyotodaigaku-Katsura, Nishikyo-ku, Kyoto, Japan.
authors.forename: Asako
authors.initials: A
authors.lastname: Shimoda
authors.affiliation: Department of Bio-Matrix (Pharmacology), Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Ohya
authors.affiliation: Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura ; ERATO Akiyoshi Bio-Nanotransporter Project, Japan Science and Technology Agency, Katsura Int'tech Center Kyotodaigaku-Katsura, Nishikyo-ku, Kyoto, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Akiyoshi
authors.affiliation: Department of Bio-Matrix (Pharmacology), Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Aoki
mesh_terms: D000818:Animals; D001862:Bone Resorption / Q000378:metabolism*; D004337:Drug Carriers / Q000737:chemistry*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D000080385:Nanogels; D053758:Nanoparticles / Q000737:chemistry*; D010012:Osteogenesis / Q000187:drug effects; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology; D011092:Polyethylene Glycols / Q000737:chemistry*; D011094:Polyethyleneimine / Q000737:chemistry*
chemical_list: D004337:Drug Carriers; D000080385:Nanogels; D010455:Peptides; C413692:polyethylene glycol polyethyleneimine nanogel; D011092:Polyethylene Glycols; D011094:Polyethyleneimine
keywords: cholesterol-bearing pullulan; controlled release; injectable drug carrier; nanocarrier; peptide drug; polyethylene glycol crosslinking