In vitroinvestigations of bone remodeling on a transparent hydroxyapatite ceramic

Abstract

The light microscopic examination of cells directly on bioceramic materials in the transmission mode is impossible because many of these materials are opaque. In order to enable direct viewing of living cells and to perform time-lapse studies, nearly transparent bioceramic materials were developed. A dense and fine-grained transparent hydroxyapatite (tHA) was processed by a gel-casting route followed by low-temperature sintering (1000 degrees C). By virtue of its transparency, direct visualization of cellular events on this material is possible in transmitted light. In this study, the interaction of different bone cell types with the tHA ceramic was envisaged. Investigation of rat calvaria osteoblasts (RCO) cultured on tHA by means of transmission light microscopy indicated good cytocompatibility of tHA. Microscopic analysis of osteogenic-induced human bone marrow stromal cells (hBMSC) on tHA and quantitative analysis of their lactate dehydrogenase (LDH) activity at different time points of culture revealed favorable proliferation as well. An increase of the alkaline phosphatase (ALP) activity indicated the differentiation of osteogenic-induced hBMSC towards the osteoblastic lineage. In addition, the differentiation of human monocytes to osteoclast-like cells could also be demonstrated on tHA and was confirmed by fluorescent microscopy imaging of multinucleated cells on the transparent material.

Comparison of the Effects of Local Application of Hydroxyapatite Graft Soaked with Alendronate Solution and Pure Hydroxyapatite Graft in the Mandible of Ovariectomized Rats

“…in this study, we used hydroxyapatite (hA) as bone graft substitute because in vitro/vivo studies have reported favorable clinical results following surgical treatment of intrabony defects with hydroxyapatite graft materials (14,18,23,38). our results showed that the use of hA granules did not cause any undesirable reaction.…”

Medical Application of Calcium Orthophosphate Bioceramics

“…Furthermore, a release of factors by endothelial and osteoblast cells in co-culture supported proliferation and differentiation was suggested to ultimately result in microcapillary-like vessel formation and supported a neo-tissue growth within the scaffold [408]. More to the point, investigation of rat calvaria osteoblasts cultured on transparent HA bioceramics, as well as the analysis of osteogenic-induced human bone marrow stromal cells at different time points of culturing indicated to a good http://ccaasmag.org/BIO cytocompatibility of HA bioceramics and revealed favorable cell proliferation [368]. Positive results for other types of cells have been obtained in other studies [206,363,364,367].…”

“…Thus, transparent calcium orthophosphate bioceramics (Fig. 5) [361] have been prepared and investigated [204,206,289,292,[361][362][363][364][365][366][367][368][369][370]. They can exhibit an optical transmittance of ~ 66 % at a wavelength of 645 nm [370].…”

“…They can exhibit an optical transmittance of ~ 66 % at a wavelength of 645 nm [370]. The preparation techniques, for example, include a hot isostatic pressing [204,206], an ambient-pressure sintering [362], gel casting coupled with a low-temperature sintering [365,368], a pulse electric current sintering [366], as well as a spark plasma sintering [289,292]. Fully dense, transparent calcium orthophosphate bioceramics was obtained at temperatures above ~ 800 °C.…”

Towards Clinical Application of Mesenchymal Stromal Cells: Perspectives and Requirements for Orthopaedic Applications

“…Hydroxyapatite is a ubiquitous part of the vertebrate bone. Hydroxyapatite ceramics become easily integrated and also prove enough primary stability (John, Varma et al 2009;Nair, Bernhardt et al 2009;Nair, Varma et al 2009). Beta-tricalciumposphate is a completely resorbable scaffold with high purity.…”