Magnesium substitution in the structure of orthopedic nanoparticles: A comparison between amorphous magnesium phosphates, calcium magnesium phosphates, and hydroxyapatites

Maryam Nabiyouni; Yufu Ren; Sarit B Bhaduri

doi:10.1016/j.msec.2015.03.032

Magnesium substitution in the structure of orthopedic nanoparticles: A comparison between amorphous magnesium phosphates, calcium magnesium phosphates, and hydroxyapatites

Mater Sci Eng C Mater Biol Appl. 2015:52:11-7. doi: 10.1016/j.msec.2015.03.032. Epub 2015 Mar 24.

Authors

Maryam Nabiyouni¹, Yufu Ren², Sarit B Bhaduri³

Affiliations

¹ Department of Bioengineering, University of Toledo, Toledo, OH, USA. Electronic address: maryam.nabiyouni@rockets.utoledo.edu.
² Department of Mechanical, Industrial and Manufacturing Engineering, University of Toledo, Toledo, OH, USA.
³ Department of Mechanical, Industrial and Manufacturing Engineering, University of Toledo, Toledo, OH, USA; Department of Surgery (Dentistry), University of Toledo, Toledo, OH, USA.

PMID: 25953534
DOI: 10.1016/j.msec.2015.03.032

Abstract

As biocompatible materials, magnesium phosphates have received a lot of attention for orthopedic applications. During the last decade multiple studies have shown advantages for magnesium phosphate such as lack of cytotoxicity, biocompatibility, strong mechanical properties, and high biodegradability. The present study investigates the role of Mg(+2) and Ca(+2) ions in the structure of magnesium phosphate and calcium phosphate nanoparticles. To directly compare the effect of Mg(+2) and Ca(+2) ions on structure of nanoparticles and their biological behavior, three groups of nanoparticles including amorphous magnesium phosphates (AMPs) which release Mg(+2), calcium magnesium phosphates (CMPs) which release Mg(+2) and Ca(+2), and hydroxyapatites (HAs) which release Ca(+2) were studied. SEM, TEM, XRD, and FTIR were used to evaluate the morphology, crystallinity, and chemical properties of the particles. AMP particles were homogeneous nanospheres, whereas CMPs were combinations of heterogeneous nanorods and nanospheres, and HAs which contained heterogeneous nanosphere particles. Cell compatibility was monitored in all groups to determine the cytotoxicity effect of particles on studied MC3T3-E1 preosteoblasts. AMPs showed significantly higher attachment rate than the HAs after 1 day and both AMPs and CMPs showed significantly higher proliferation rate when compared to HAs after 7days. Gene expression level of osteoblastic markers ALP, COL I, OCN, OPN, RUNX2 were monitored and they were normalized to GAPDH housekeeping gene. Beta actin expression level was monitored as the second housekeeping gene to confirm the accuracy of results. In general, AMPs and CMPs showed higher expression level of osteoblastic genes after 7 days which can further confirm the stimulating role of Mg(+2) and Ca(+2) ions in increasing the proliferation rate, differentiation, and mineralization of MC3T3-E1 preosteoblasts.

Keywords: Amorphous magnesium phosphate; Calcium magnesium phosphate; Hydroxyapatite; Magnesium substituted calcium phosphate.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Animals
Calcium / pharmacology*
Cell Differentiation / drug effects
Cell Line
Cell Proliferation / drug effects
Hydroxyapatites / chemistry*
Magnesium / pharmacology*
Magnesium Compounds / chemistry*
Mice
Nanoparticles / adverse effects
Nanoparticles / chemistry*
Phosphates / chemistry*
Polymerase Chain Reaction

Substances

Hydroxyapatites
Magnesium Compounds
Phosphates
calcium magnesium phosphate
magnesium phosphate
Magnesium
Calcium