LANTHANUM DOPED DICALCIUM PHOSPHATE MIXED WITH GRAPHENE OXIDE BONE CEMENTS AS A POTENTIAL MATERIAL IN BIOMEDICAL APPLICATIONS

2021-9-06
Motameni, Ali
In this thesis, mesoporous particles of β-tricalcium phosphate (βTCP, βCa3(PO4)2) and lanthanum (La) doped βTCP were synthesized by wet precipitation method attached with a microwave refluxing system. Pure dicalcium phosphate (DCP) and La modified dicalcium phosphate (La-DCP) bone cements were prepared based on acid/base reaction between βTCP (or La- βTCP) and monocalcium phosphate monohydrate (MCPM) in the presence of water. DCP bone cements were also mixed with 1.5-3.5wt.% of graphene oxide (GO). The obtained materials were characterized by XRD, FTIR, SEM, ICP-OES, BET, and helium pycnometer. The loading /releasing analysis of proteins on/from βTCP and La- βTCP disks surfaces were evaluated using Fetal bovine serum (FBS) proteins. In vitro cell culture studies were performed with the human osteosarcoma cell line (Saos-2). Upon incorporating La3+ ions, expansion in lattice parameters of βTCP crystal was observed along with inhibition of growth rate. βTCP and La- βTCP materials were mesoporous in nature. Pore diameter and pore volume were expanded with the incorporation of La3+ ions. The outcomes confirmed that all La-βTCP materials were cytocompatible, and strict dose dependent effect of La3+ ions was observed on cell viability and alkaline phosphatase (ALP) activity. In DCP bone cements, the pure phase of brushite transformed into monetite with minimum addition of La3+ ions (0.090 mole), and the plate-like crystals of brushite turned into spheroid particles. The results of in vitro experiments on proliferation, adhesion, and osteogenic differentiation of Saos-2 cells indicated that the addition of 0.225 mole of La3+ ions promoted these properties compared to pure DCP. With the addition of GO to DCP bone cements, the mechanical properties of 2La-DCP cements improved. As the GO/2La-DCP bone cements were biocompatible, proliferation and differentiation properties of cells were significantly improved with the addition of GO.

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Citation Formats
A. Motameni, “LANTHANUM DOPED DICALCIUM PHOSPHATE MIXED WITH GRAPHENE OXIDE BONE CEMENTS AS A POTENTIAL MATERIAL IN BIOMEDICAL APPLICATIONS,” Ph.D. - Doctoral Program, Middle East Technical University, 2021.