title: Strontium and zoledronate hydroxyapatites graded composite coatings for bone prostheses.
abstract: Both strontium and zoledronate (ZOL) are known to be useful for the treatment of bone diseases associated to the loss of bone substance. In this work, we applied an innovative technique, Combinatorial Matrix-Assisted Pulsed Laser Evaporation (C-MAPLE), to deposit gradient thin films with variable compositions of Sr-substituted hydroxyapatite (SrHA) and ZOL modified hydroxyapatite (ZOLHA) on Titanium substrates. Compositional gradients were obtained by simultaneous laser vaporization of the two distinct material targets. The coatings display good crystallinity and granular morphology, which do not vary with composition. Osteoblast-like MG63 cells and human osteoclasts were co-cultured on the thin films up to 21 days. The results show that Sr counteracts the negative effect of relatively high concentration of ZOL on osteoblast viability, whereas both Sr and ZOL enhance extracellular matrix deposition. In particular, ZOL promotes type I collagen production, whereas Sr increases the production of alkaline phosphatase. Moreover, ZOL exerts a greater effect than Sr on osteoprotegerin/RANKL ratio and, as a consequence, on the reduction of osteoclast proliferation and activity. The deposition method allows to modulate the composition of the thin films and hence the promotion of bone growth and the inhibition of bone resorption.
authors.affiliation: Department of Chemistry "G. Ciamician", University of Bologna, 40126 Bologna, Italy. Electronic address: elisa.boanini@unibo.it.
authors.forename: Elisa
authors.initials: E
authors.lastname: Boanini
authors.affiliation: Laboratory of Preclinical and Surgical Studies, Codivilla-Putti Research Institute, Rizzoli Orthopaedic Institute, Bologna, Italy; Department Rizzoli RIT, Rizzoli Orthopedic Institute-IOR, Laboratory of Biocompatibility, Technological Innovations and Advanced Therapies, Bologna, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Torricelli
authors.affiliation: National Institute for Lasers, Plasma and Radiation Physics, P. O. Box MG 36, 77125 Bucharest-Magurele, Romania.
authors.forename: Felix
authors.initials: F
authors.lastname: Sima
authors.affiliation: National Institute for Lasers, Plasma and Radiation Physics, P. O. Box MG 36, 77125 Bucharest-Magurele, Romania.
authors.forename: Emanuel
authors.initials: E
authors.lastname: Axente
authors.affiliation: Laboratory of Preclinical and Surgical Studies, Codivilla-Putti Research Institute, Rizzoli Orthopaedic Institute, Bologna, Italy; Department Rizzoli RIT, Rizzoli Orthopedic Institute-IOR, Laboratory of Biocompatibility, Technological Innovations and Advanced Therapies, Bologna, Italy.
authors.forename: Milena
authors.initials: M
authors.lastname: Fini
authors.affiliation: National Institute for Lasers, Plasma and Radiation Physics, P. O. Box MG 36, 77125 Bucharest-Magurele, Romania.
authors.forename: Ion N
authors.initials: IN
authors.lastname: Mihailescu
authors.affiliation: Department of Chemistry "G. Ciamician", University of Bologna, 40126 Bologna, Italy.
authors.forename: Adriana
authors.initials: A
authors.lastname: Bigi
mesh_terms: D018786:Bone Substitutes / Q000737:chemistry* / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000378:metabolism; D018920:Coculture Techniques; D004164:Diphosphonates / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D006882:Hydroxyapatites / Q000737:chemistry* / Q000378:metabolism; D007093:Imidazoles / Q000737:chemistry* / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D010010:Osteoclasts / Q000166:cytology / Q000378:metabolism; D019736:Prostheses and Implants; D013324:Strontium / Q000737:chemistry* / Q000378:metabolism; D000077211:Zoledronic Acid
chemical_list: D018786:Bone Substitutes; D020099:Coated Materials, Biocompatible; D004164:Diphosphonates; D006882:Hydroxyapatites; D007093:Imidazoles; D000077211:Zoledronic Acid; D013324:Strontium
keywords: Co-cultures; Coatings; Combinatorial-MAPLE; Hydroxyapatite; Strontium; Zoledronate