Effects of Mn-doping on the structure and biological properties of beta-tricalcium phosphate

Abstract

Doping calcium phosphates with trace elements that exist in bone tissues is beneficial in terms of cell-material interactions and in vivo performance of the bone grafts made thereof. Manganese (Mn) is an essential element for normal growth and metabolism of bone tissues, but studies reporting the effects of Mn-doping calcium phosphates are scarce. The present study investigated the influence of Mn-doping on the structure, morphology and biological properties of beta-tricalcium phosphate [beta-Ca-3(PO4)(2)] (P-TCP). Mn-doped (MnTCP) powders, with Mn contents varying from 0 to 10 mol%, were obtained through an aqueous precipitation method followed by heat treatment at 800 degrees C. The successful incorporation of Mn into beta-TCP structure was proved through quantitative X-ray diffraction (XRD) phase analysis coupled with structural Rietveld refinement. Increasing Mn concentrations led to decreasing trends of a- and c-axis lattice parameters, and Mn-doping also significantly affected the morphology of beta-TCP powders. In vitro proliferation and differentiation assays of MC3T3-E1 osteoblastic-like cells, grown in the presence of the powders, revealed that the biological benefits of Mn-doped beta-TCP are limited to lower Mn incorporation levels and potentially related to their surface microstructure. The Mn1-beta TCP composition revealed the best set of bioactivity properties, potentially a good candidate for future applications of beta-TCP materials in osteoregeneration. (C) 2014 Elsevier Inc. All rights reserved.