Proliferation and differentiation of human trabecular osteoblastic cells on hydroxyapatite

Abstract

In order to evaluate whether human osteoblastic cells differentiate normally on hydroxyapatite, we have compared the adhesion, proliferation, and differentiation of human trabecular (HT) osteoblastic cells on synthetic-dense hydroxyapatite and on standard plastic culture. We show here that initial HT cell attachment was 4-fold lower on hydroxyapatite than on plastic after 4 h of culture, and that normal cell attachment on hydroxyapatite was restored after 18 h of culture. HT cell proliferation was similar on the two substrates at 2-8 days of culture, but was lower on hydroxyapatite compared to plastic after 15 and 28 days of culture, as evaluated by DNA synthesis or cell number. HT cells cultured on both substrates produced an abundant extracellular matrix which immunostained for Type I collagen. The levels of carboxyterminal propeptide of Type I procollagen (P1CP) in the medium were lower in HT cell cultures on hydroxyapatite than on plastic. In addition, (3H)-proline incorporation into matrix proteins and the mean thickness of matrix layers were 52% and 26% lower, respectively, on hydroxyapatite compared to plastic after 4 weeks of culture, indicating that the total collagenous matrix synthesized by HT cells was lower on hydroxyapatite. However, (3H)-proline and calcium uptake expressed per cell was higher on hydroxyapatite than on plastic. The results show that human osteoblastic cells attach, proliferate, and differentiate on dense hydroxyapatite with a sequence similar to that of plastic. However, the growth of human osteoblastic cells is lower on hydroxyapatite in long-term culture, which results in a reduced amount of extracellular matrix, although matrix production per cell may be increased.

Effects of hydroxyapatite and PDGF concentrations on osteoblast growth in a nanohydroxyapatite-polylactic acid composite for guided tissue regeneration

“…This theory is in agreement with classical osteogenesis timelines and behaviours as shown by Stein and Lian [31]. Our results are also in support of various studies that the presence of HA can cause bone cells to differentiate and even to start to deposit mineral [32,33,34]. The presence of the HA should have a further advantage, PLA degradation products are acidic and therefore have been known to cause an adverse biological response.…”

Three-dimensional cultures of normal human osteoblasts: proliferation and differentiation potential in vitro and upon ectopic implantation in nude mice

“…These were based on the utilization of supports, as gels and sponges of collagen type I, PLGA foam, DegraPol, agarose, Matrigel, or methylcellulose. 7,10,15,16,18,20,22,25,26,30,32,34,37,39 Normal human osteogenic cells, osteoblasts from prepubertal-age donors, or bone marrow stromal fibroblasts adhering to scaffolding of HAP/ TC, 16,20,25,26,30,34 collagraft, 26 collagen sponges, 15,39 or bone chips 5 were utilized to produce specifically 3D structures designed for direct implantation in vivo.…”

Hydroxyapatite-Nanotube Composites and Coatings for Orthopedic Applications

“…It is also well understood that the new bone integration on an orthopedic surface is closely related and governed by bone cell (osteoblast) attachment, proliferation and differentiation, which predicts the mineralization of apatite on it [133]. Thus, the behavior of osteoblast is also very important to determine biocompatibility of orthopedic surface along with the apatite formability.…”

“…This is because a smaller amount of lateral force is required to push the detached cell along the scratched path/direction. Cell adhesion force is obtained by subtracting the lateral force contribution of the bare scratch from the height of the lateral force hump as explained in Moreover, a single osteoblast was found to synthesize more ECM with type I collagen and osteonectin on HA than on plastic [133][134], which may increase the attachment of the cell with the HA substrate. All these reports, along with the quantitative evaluation of adhesion force and energy presented in the present study, confirms that attachment of a single osteoblast is better on HA based surfaces than plastic.…”