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.

Novel soybean/gelatine-based bioactive and injectable hydroxyapatite foam: Material properties and cell response

“…However, it is worth noting that in the direct contact studies all cements and foams showed cell proliferation rates lower than that observed on the control TCPS. This result is coincident with previous studies on apatitebased ceramics and cements [5,[35][36][37][38][39]. It can be hypothesised that the relatively rougher surface topography of the cements may affect cell behaviour, directing cells towards a more differentiated phenotype rather than towards a proliferative one [40].…”

“…Currently, numerous synthetic scaffolds have been designed to favour cell attachment, cell growth and cell differentiation [3,4]. Some of the crucial characteristics of scaffolds are porosity and pore interconnectivity, which are necessary to allow tissue in-growth [5]. The ideal porosity of a scaffold should lie within a critical range to maintain its mechanical integrity, while undergoing resorption and sustaining cell proliferation and new extracellular matrix deposition [6][7][8].…”

Bone substitutes in the Netherlands – A systematic literature review

“…BoneSource Ò , composed of tetracalcium phosphate and dicalcium phosphate anhydrous, has a porosity of 46% [29,30] and a pore size of 2-50 lm [31]. Calcibon Ò consists of a-TCP, and has a porosity of 30-40% [32,33] with a pore size of <1 lm [33]. Calcibon Ò has a density of 1.84 g cm -3 [32], whereas Norian SRS Ò has a density of 1.3 g cm -3 [34].…”

The Significance of Gelatin in Calcium Phosphate Hybrid Bone Cement for Attachment and Differentiation of MG63 Cells

“…[1][2][3][4] Since 1983, calcium phosphate cements (CPCs) have gained much attention and have been used as injectable bone substitutes [4][5][6][7][8] that can be injected into bone cavities or defects. However, it is difficult to deliver a CPC to a complicated site and to compact it adequately due to brittleness.…”

“…Efforts have been made in recent years to overcome the disadvantages of these handling properties. Thus, several studies have focused on the addition of polymeric materials, such as chitosan, [9][10][11] alginate [3,7] and gelatin, [7,[12][13][14][15] into CPCs. Moreau and Xu [9] developed a fast-setting and anti-washout CPC-chitosan scaffold, with higher strength than the CPC control, in which chitosan lactate was mixed with water at a mass fraction of 15%.…”