Biocompatibility markers for the study of interactions between osteoblasts and composite biomaterials.
Biphasic calcium phosphate (BCP), a mixture of hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP), has attracted attention as an excellent bone graft substitute. Mixtures of ceramics with agarose, as natural biodegradable binder, have been recently performed in order to increase the flexibility of the ceramic component and to facilitate the biomaterial preparation. In previous studies we have evaluated the response of both L929 fibroblasts and Saos-2 osteoblasts to hydroxyapatite-betaTCP/agarose disks observing a higher sensitivity of osteoblasts to this biomaterial. In the present study, the use of specific fluorescent probes and antibodies has allowed to evaluate different cell function parameters as biocompatibility markers for the cell/biomaterial interaction of Saos-2 osteoblasts cultured for 7 days on hydroxyapatite-betaTCP/agarose disks. The cell cycle subG(1) fraction, the exposition of phosphatidylserine on the outside surface of the plasma membrane and the analysis of plasma membrane integrity versus cell size, indicate that the interaction with the biomaterial induces a light increase of apoptosis in osteoblasts without producing cell necrosis. The high percentage of viable cells on the biomaterial and the preservation of endothelial nitric oxide synthase (eNOS) expression, eNOS activity and mitochondrial membrane potential (Deltapsi(m)), demonstrate the good biocompatibility of hydroxyapatite-betaTCP/agarose disks and its potential utility for bone substitution and repair.
Alcaide
María
M
Department of Biochemistry and Molecular Biology I, Faculty of Chemistry, Universidad Complutense, 28040-Madrid, Spain.
Serrano
María-Concepción
MC
Pagani
Raffaella
R
Sánchez-Salcedo
Sandra
S
Vallet-Regí
María
M
Portolés
María-Teresa
MT
D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D001672:Biocompatible Materials / Q000494:pharmacology*; D015415:Biomarkers / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D009336:Necrosis; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D010006:Osteoblasts / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D010718:Phosphatidylserines / Q000378:metabolism
D017304:Annexin A5; D001672:Biocompatible Materials; D015415:Biomarkers; D010718:Phosphatidylserines; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III