title: A theranostic agent to enhance osteogenic and magnetic resonance imaging properties of calcium phosphate cements.
abstract: With biomimetic biomaterials, like calcium phosphate cements (CPCs), non-invasive assessment of tissue regeneration is challenging. This study describes a theranostic agent (TA) to simultaneously enhance both imaging and osteogenic properties of such a bone substitute material. For this purpose, mesoporous silica beads were produced containing an iron oxide core to enhance bone magnetic resonance (MR) contrast. The same beads were functionalized with silane linkers to immobilize the osteoinductive protein BMP-2, and finally received a calcium phosphate coating, before being embedded in the CPC. Both in vitro and in vivo tests were performed. In vitro testing showed that the TA beads did not interfere with essential material properties like cement setting. Furthermore, bioactive BMP-2 could be efficiently released from the carrier-beads. In vivo testing in a femoral condyle defect rat model showed long-term MR contrast enhancement, as well as improved osteogenic capacity. Moreover, the TA was released during CPC degradation and was not incorporated into the newly formed bone. In conclusion, the described TA was shown to be suitable for longitudinal material degradation and bone healing studies.
authors.affiliation: Department of Biomaterials, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: Manuela
authors.initials: M
authors.lastname: Ventura
authors.affiliation: Department of Radiology, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands; Department of Urology, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: Yi
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Nano4Imaging GmbH, Zentrum für Biomedizintechnik (ZBMT), Pauwelsstrasse 17, 52074 Aachen, Germany.
authors.forename: Sjef
authors.initials: S
authors.lastname: Cremers
authors.affiliation: Nano4Imaging GmbH, Zentrum für Biomedizintechnik (ZBMT), Pauwelsstrasse 17, 52074 Aachen, Germany.
authors.forename: Paul
authors.initials: P
authors.lastname: Borm
authors.affiliation: Department of Tissue Regeneration, University of Twente, MIRA Institute for Biomedical Technology and Technical Medicine, PO Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Zeinab T
authors.initials: ZT
authors.lastname: Birgani
authors.affiliation: Department of Tissue Regeneration, University of Twente, MIRA Institute for Biomedical Technology and Technical Medicine, PO Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Pamela
authors.initials: P
authors.lastname: Habibovic
authors.affiliation: Department of Radiology, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: Arend
authors.initials: A
authors.lastname: Heerschap
authors.affiliation: Department of Rheumatology, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: Peter M
authors.initials: PM
authors.lastname: van der Kraan
authors.affiliation: Department of Biomaterials, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: John.Jansen@radboudumc.nl.
authors.forename: John A
authors.initials: JA
authors.lastname: Jansen
authors.affiliation: Department of Biomaterials, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: X Frank
authors.initials: XF
authors.lastname: Walboomers
mesh_terms: D000818:Animals; D001843:Bone Cements; D002130:Calcium Phosphates / Q000737:chemistry*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D010012:Osteogenesis; D051381:Rats; D055114:X-Ray Microtomography
chemical_list: D001843:Bone Cements; D002130:Calcium Phosphates
keywords: BMP (bone morphogenetic protein); Bone tissue engineering; Calcium phosphate cement; Drug delivery; MRI (magnetic resonance imaging)