TY - JOUR
T1 - Understanding the impact of divalent cation substitution on hydroxyapatite
T2 - An in vitro multiparametric study on biocompatibility
AU - De Lima, Ingrid Russoni
AU - Alves, Gutemberg Gomes
AU - Soriano, Carlos Alberto
AU - Campaneli, Ana Paula
AU - Gasparoto, Thais Helena
AU - Ramos, Erivan Schnaider
AU - De Sena, Lídia Ágata
AU - Rossi, Alexandre Malta
AU - Granjeiro, José Mauro
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011/9/1
Y1 - 2011/9/1
N2 - Hydroxyapatite (HA), a stable and biocompatible material for bone tissue therapy, may present a variable stoichiometry and accept a large number of cationic substitutions. Such substitutions may modify the chemical activity of HA surface, with possible impact on biocompatibility. In this work, we assessed the effects of calcium substitution with diverse divalent cations (Pb 2+, Sr2+, Co2+, Zn2+, Fe 2+, Cu2+, or Mg2+) on the biological behavior of HA. Physicochemical analyses revealed that apatite characteristics related to crystallinity and calcium dissolution/uptake rates are very sensitive to the nature of cationic substitution. Cytocompatibility was evaluated by mitochondrial activity, membrane integrity, cell density, proapoptotic potential, and adhesion tests. With the exception of Zn-HA, all the substituted HAs induced some level of apoptosis. The highest apoptosis levels were observed for Mg-HA and Co-HA. Cu-HA was the only material to impair simultaneously mitochondrial activity, membrane integrity, and cell density. The highest relative cell densities after exposure to the modified HAs were observed for Mg-HA and Zn-HA, while Co-HA significantly improved cell adhesion onto HA surface. These results show that changes on surface dissolution caused by cationic substitution, as well as the increase of metal species released to biological media, were the main responsible factors related to alterations on HA biocompatibility.
AB - Hydroxyapatite (HA), a stable and biocompatible material for bone tissue therapy, may present a variable stoichiometry and accept a large number of cationic substitutions. Such substitutions may modify the chemical activity of HA surface, with possible impact on biocompatibility. In this work, we assessed the effects of calcium substitution with diverse divalent cations (Pb 2+, Sr2+, Co2+, Zn2+, Fe 2+, Cu2+, or Mg2+) on the biological behavior of HA. Physicochemical analyses revealed that apatite characteristics related to crystallinity and calcium dissolution/uptake rates are very sensitive to the nature of cationic substitution. Cytocompatibility was evaluated by mitochondrial activity, membrane integrity, cell density, proapoptotic potential, and adhesion tests. With the exception of Zn-HA, all the substituted HAs induced some level of apoptosis. The highest apoptosis levels were observed for Mg-HA and Co-HA. Cu-HA was the only material to impair simultaneously mitochondrial activity, membrane integrity, and cell density. The highest relative cell densities after exposure to the modified HAs were observed for Mg-HA and Zn-HA, while Co-HA significantly improved cell adhesion onto HA surface. These results show that changes on surface dissolution caused by cationic substitution, as well as the increase of metal species released to biological media, were the main responsible factors related to alterations on HA biocompatibility.
KW - apoptosis
KW - biocompatibility
KW - cytotoxicity
KW - hydroxyapatite
KW - metal ion release
UR - http://www.scopus.com/inward/record.url?scp=79960368787&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79960368787&partnerID=8YFLogxK
U2 - 10.1002/jbm.a.33126
DO - 10.1002/jbm.a.33126
M3 - Article
C2 - 21626666
AN - SCOPUS:79960368787
SN - 1549-3296
VL - 98 A
SP - 351
EP - 358
JO - Journal of Biomedical Materials Research - Part A
JF - Journal of Biomedical Materials Research - Part A
IS - 3
ER -