TY - JOUR
T1 - Enhancement of the Biological and Mechanical Performances of Sintered Hydroxyapatite by Multiple Ions Doping
AU - Sprio, Simone
AU - Dapporto, Massimiliano
AU - Preti, Lorenzo
AU - Mazzoni, Elisa
AU - Iaquinta, Maria Rosa
AU - Martini, Fernanda
AU - Tognon, Mauro
AU - Pugno, Nicola M.
AU - Restivo, Elisa
AU - Visai, Livia
AU - Tampieri, Anna
N1 - Funding Information:
The authors are grateful to Prof. R. Migliavacca (Department of Clinical-Surgical Diagnostic and Pediatric Sciences, Unit of Microbiology and Clinical Microbiology, University of Pavia, Italy), for providing E. coli and S. aureus bacteria. Funding. The experiments carried out at the University of Ferrara were supported by grants from FESR POR Regione Emilia Romagna Niprogen project, local unit MT and MIUR PRIN 2017 C8RYSS project, national unit FM, respectively. The study was supported by a grant of the Italian Ministry of Education, University and Research (MIUR) to the Department of Molecular Medicine of the University of Pavia under the initiative “Dipartimenti di Eccellenza (2018–2022).” NP is supported by the European Commission under the FET Proactive (“Neurofibres”) grant No. 732344, as well as by the Italian Ministry of Education, University and Research (MIUR) under the ARS01-01384-PROSCAN and the PRIN-20177TTP3S grants.
Publisher Copyright:
© Copyright © 2020 Sprio, Dapporto, Preti, Mazzoni, Iaquinta, Martini, Tognon, Pugno, Restivo, Visai and Tampieri.
PY - 2020/7/28
Y1 - 2020/7/28
N2 - In the present work, hydroxyapatite (HA) nanoparticles doped with Mg2+, Sr2+, and Zn2+ ions are developed by wet neutralization method and then sintered at 1,250°C to obtain bulk consolidated materials. Physicochemical and microstructural analyses show that the presence of doping ions in the HA structure induced the formation of βTCP as secondary phase, during the sintering process, and we found that this effect is depending on the stability of the various doping ions in the hydroxyapatite lattice itself. We also found that the formation of βTCP as secondary phase, in turn, confines the grain growth of HA induced by the high-temperature sintering process, thus leading to a strong increase of the flexural strength of the bulk materials, according to Hall-Petch-like law. Furthermore, we found that the doping ions enter also in the structure of the βTCP phase; besides the grain growth confinement, also the solubility and ion release ability of the final materials were enhanced. In addition to ameliorate the mechanical performance, the described phenomena also activate multiple biofunctionalities: (i) ability to upregulate various genes involved in the osteogenesis, as obtained by human adipose stem cells culture and evaluated by array technology; (ii) enhanced resistance to the adhesion and proliferation of Gram+ and Gram– bacterial strains. Hence, our results open a perspective for the use of sintered multiple ion-doped HA to develop ceramic biodevices, such as plates, screws, or other osteosynthesis media, with enhanced strength, osteointegrability, and the ability to prevent post-surgical infections.
AB - In the present work, hydroxyapatite (HA) nanoparticles doped with Mg2+, Sr2+, and Zn2+ ions are developed by wet neutralization method and then sintered at 1,250°C to obtain bulk consolidated materials. Physicochemical and microstructural analyses show that the presence of doping ions in the HA structure induced the formation of βTCP as secondary phase, during the sintering process, and we found that this effect is depending on the stability of the various doping ions in the hydroxyapatite lattice itself. We also found that the formation of βTCP as secondary phase, in turn, confines the grain growth of HA induced by the high-temperature sintering process, thus leading to a strong increase of the flexural strength of the bulk materials, according to Hall-Petch-like law. Furthermore, we found that the doping ions enter also in the structure of the βTCP phase; besides the grain growth confinement, also the solubility and ion release ability of the final materials were enhanced. In addition to ameliorate the mechanical performance, the described phenomena also activate multiple biofunctionalities: (i) ability to upregulate various genes involved in the osteogenesis, as obtained by human adipose stem cells culture and evaluated by array technology; (ii) enhanced resistance to the adhesion and proliferation of Gram+ and Gram– bacterial strains. Hence, our results open a perspective for the use of sintered multiple ion-doped HA to develop ceramic biodevices, such as plates, screws, or other osteosynthesis media, with enhanced strength, osteointegrability, and the ability to prevent post-surgical infections.
KW - antibacterial properties
KW - calcium phosphates
KW - ion doping
KW - magnesium
KW - mechanical properties
KW - osteogenic properties
KW - strontium
KW - zinc
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U2 - 10.3389/fmats.2020.00224
DO - 10.3389/fmats.2020.00224
M3 - Article
AN - SCOPUS:85089353043
SN - 2296-8016
VL - 7
JO - Frontiers in Materials
JF - Frontiers in Materials
M1 - 224
ER -