The Cytocompatibility and Early Osteogenic Characteristics of an Injectable Calcium Phosphate Cement

Abstract

In this study, the cytocompatibility and early osteogenic characteristics of rat bone marrow cells (RBMCs) on injectable calcium phosphate (CaP) cement (Calcibon) were investigated. In addition to unmodified CaP cement discs, 2 other treatments were given to the discs: preincubation in MilliQ and sintering at different temperatures. After primary culture, RBMCs were dropwise seeded on the discs and cultured for 12 days. The samples were evaluated in terms of cell viability, morphology (live and dead assays and scanning electron microscopy (SEM)), cell proliferation (deoxyribonucleic acid (DNA) analyses), early cell differentiation (alkaline phosphatase (ALP) activity), and physicochemical analyses (xray diffraction (XRD)). The live and dead, DNA, and SEM results showed that Calcibon discs without any additional treatment were not supporting osteoblast-like cells in vitro. There were fewer cells, and cell layers were detached from the disc surface. Therefore, different preincubation periods and sintering temperatures were evaluated to improve the cytocompatibility of the CaP cement. Preincubating discs in MilliQ for periods of 1, 4, 8, and 12 weeks resulted in the hydrolysis of a-tri calcium phosphate (TCP) into an apatite-like structure with some b-TCP, as shown with XRD, but the material was not cytocompatible. Sintering the discs between 8008C and 11008C resulted in conversion of a-TCP to b-TCP with some hydroxyapatite and an increase in crystallinity. Eventually, the discs sintered at 11008C achieved better cell attachment, more-abundant cell proliferation, and earlier differentiation than other sintered (6008C, 8008C, and 10008C), preincubated, and unmodified specimens. On basis of our results, we conclude that in vivo results with CaP-based cements do not guarantee in vitro applicability. Furthermore, unmodified Calcibon is not cytocompatible in vitro, although preincubation of the material results in a more-favorable cell response, sintering of the material at 11008C results in the best osteogenic properties. In contrast to in vivo studies, the Calcibon CaP cement is not suitable as a scaffold for cellbased tissue-engineering strategies.

Self-Setting Calcium Orthophosphate Formulations: Cements, Concretes, Pastes and Putties

“…For example, the data on cytocompatibility and early osteogenic characteristics are available in literature [475]. The ratio of the cases determined to be "effective" or "better" among the 74 cases we found to be 97.3 % [476].…”

Human Embryonic Stem Cell-Derived Mesenchymal Stem Cell Seeding on Calcium Phosphate Cement-Chitosan-RGD Scaffold for Bone Repair

“…Previous studies showed that human stem cell attachment to CPC was relatively poor. 40,41 The tripeptide RGD sequence can promote the attachment of cells because it is recognized by the adhesion receptors on the cell membrane. Thus, the affinity between cells and biomaterials could be improved by the immobilization of RGD, which can mimic the natural extracellular matrix.…”

“…However, previous studies showed that human stem cell attachment to CPC was relatively poor. 40,41 Therefore, there is a need to improve the cell attachment to CPC. Two hypotheses were tested: (1) hESC-derived MSCs can successfully undergo osteogenic differentiation on the CPC-chitosan scaffold; (2) RGD incorporation will greatly enhance hESC-derived MSC attachment, osteogenic differentiation, and synthesis of bone minerals on the CPC-chitosan scaffold.…”

Self-Setting Calcium Orthophosphate Formulations

“…For example, the data on cytocompatibility and early osteogenic characteristics are available in literature [543]. The ratio of the cases determined to be -effective‖ or -better‖ among the 74 cases we found to be 97.3% [544].…”