title: Biphasic calcium phosphate microparticles for bone formation: benefits of combination with blood clot.
abstract: Particulate forms of biphasic calcium phosphate (BCP) biomaterials below 500  μm are promising bone substitutes that provide with interconnected open porosity allowing free circulation of fluids and cells. Dispersion of the particles in the surrounding tissues at the time of implantation is a major drawback preventing from an easy use. We have asked whether blood clot could be a convenient natural hydrogel for handling BCP microparticles, and we hypothesized that blood clot might also confer osteoinductive properties to these particles. We show here that blood clotted around BCP microparticles constitutes a cohesive, moldable, and adaptable biomaterial that can be easily implanted in subcutaneous sites but also inserted and maintained in segmental bone defects, conversely to BCP microparticles alone. Moreover, implantation in bony and ectopic sites revealed that this composite biomaterial has osteogenic properties. It is able to repair a 6-mm critical femoral defect in rat and induced woven bone formation after subcutaneous implantation. Parameters such as particle size and loading into the clot are critical for its osteogenic properties. In conclusion, this blood/BCP microparticle composite is a moldable and osteoinductive biomaterial that could be used for bone defect filling in dental and orthopedic surgery.
authors.affiliation: GEPITOS, Université Nice Sophia-Antipolis, CNRS, UFR de Médecine, Nice, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Balaguer
authors.forename: Florian
authors.initials: F
authors.lastname: Boukhechba
authors.forename: Arnaud
authors.initials: A
authors.lastname: Clavé
authors.forename: Sébastien
authors.initials: S
authors.lastname: Bouvet-Gerbettaz
authors.forename: Christophe
authors.initials: C
authors.lastname: Trojani
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Michiels
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Laugier
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Bouler
authors.forename: Georges F
authors.initials: GF
authors.lastname: Carle
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Scimeca
authors.forename: Nathalie
authors.initials: N
authors.lastname: Rochet
mesh_terms: D000818:Animals; D001773:Blood Cells / Q000187:drug effects / Q000378:metabolism; D001777:Blood Coagulation / Q000187:drug effects*; D002130:Calcium Phosphates / Q000737:chemistry* / Q000494:pharmacology*; D005240:Feasibility Studies; D005269:Femur / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology; D051379:Mice; D010012:Osteogenesis / Q000187:drug effects*; D010316:Particle Size; D019919:Prosthesis Implantation; D011859:Radiography; D051381:Rats; D040521:Subcutaneous Tissue / Q000187:drug effects
chemical_list: D002130:Calcium Phosphates; C020243:calcium phosphate