title: Osteogenic cell sheets reinforced with photofunctionalized micro-thin titanium.
abstract: Cell sheet technology has been used to deliver cells in single-sheet form with an intact extracellular matrix for soft tissue repair and regeneration. Here, we hypothesized that titanium-reinforced cell sheets could be constructed for bone tissue engineering and regeneration. Fifty-µm-thick titanium plates containing apertures were prepared and roughened by acid etching, some of which were photofunctionalized with 12 min of UV light treatment. Cell sheets were prepared by culturing rat calvarial periosteum-derived cells on temperature-responsive culture dishes and attached to titanium plates. Titanium-reinforced osteogenic cell sheet construction was conditional on various technical and material factors: cell sheets needed to be double-sided and sandwich the titanium plate, and the titanium plates needed to be micro thin and contain apertures to allow close apposition of the two cell sheets. Critically, titanium plates needed to be UV-photofunctionalized to ensure adherence and retention of cell sheets. Single-sided cell sheets or double-sided cell sheets on as-made titanium contracted and deformed within 4 days of incubation. Titanium-reinforced cell sheets on photofunctionalized titanium were structurally stable at least up to 14 days, developed the expected osteogenic phenotypes (ALP production and mineralization), and maintained structural integrity without functional degradation. Successful construction of titanium-reinforced osteogenic cell sheets was associated with increased cell attachment, retention, and expression of vinculin, an adhesion protein by photofunctionalization. This study identified the technical and material requirements for constructing titanium-reinforced osteogenic cell sheets. Future in vivo studies are warranted to test these titanium-reinforced cell sheets as stably transplantable, mechanically durable, and shape controllable osteogenic devices.
authors.affiliation: Laboratory of Bone and Implant Sciences (LBIS), The Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA Department of Partial Denture Prosthodontics, Nihon University School of Dentistry, Tokyo, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Ishijima
authors.affiliation: Laboratory of Bone and Implant Sciences (LBIS), The Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA.
authors.forename: Makoto
authors.initials: M
authors.lastname: Hirota
authors.affiliation: Laboratory of Bone and Implant Sciences (LBIS), The Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA.
authors.forename: Wonhee
authors.initials: W
authors.lastname: Park
authors.affiliation: Department of Anatomy, Nihon University School of Dentistry, Tokyo, Japan.
authors.forename: Masaki J
authors.initials: MJ
authors.lastname: Honda
authors.affiliation: Laboratory of Bone and Implant Sciences (LBIS), The Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA Department of Partial Denture Prosthodontics, Nihon University School of Dentistry, Tokyo, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Tsukimura
authors.affiliation: Department of Anatomy, Nihon University School of Dentistry, Tokyo, Japan.
authors.forename: Keitaro
authors.initials: K
authors.lastname: Isokawa
authors.affiliation: Department of Partial Denture Prosthodontics, Nihon University School of Dentistry, Tokyo, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Ishigami
authors.affiliation: Laboratory of Bone and Implant Sciences (LBIS), The Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA togawa@dentistry.ucla.edu.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ogawa
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001861:Bone Regeneration; D002478:Cells, Cultured; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010012:Osteogenesis; D010521:Periosteum / Q000166:cytology; D051381:Rats; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods; D014025:Titanium
chemical_list: D001672:Biocompatible Materials; D014025:Titanium
keywords: Ultraviolet light; bone engineering; hydrocarbon; hydrophilicity; periosteum; titanium mesh