Influence of the zinc concentration of sol–gel derived zinc substituted hydroxyapatite on cytokine production by human monocytes in vitro

Abstract

A possible complication associated with the implantation of hydroxyapatite (HA)-based prosthesis is the release of particles. These particles can be phagocyted by monocytes that are among the first cells to colonize the inflammatory site. The activated monocytes produce inflammatory mediators such as cytokines that cause osteoclasts activation. The present work, describes studies on the effect of sol-gel derived zinc-substituted HA particles with various zinc substitution percentages (0.5-2%) on cytokine production (TNF-alpha, IL-1beta, IL-6, IL-10, and IL-8) by both LPS-stimulated or unstimulated human monocytes. Our data demonstrates that the zinc has an effect on cytokines production. It decreases the production of TNF-alpha and increases the production of IL-8 by unstimulated cells. Using LPS-stimulated cells, it decreases the production of inflammatory cytokines and increases the production of anti-inflammatory cytokine (IL-10), indicating that zinc-substituted hydroxyapatite has favourable effects on the cytokines production by monocytes.

Glasses in bone regeneration: A multiscale issue

“…In particular our group has been very interested in the last few years in the substitution of MBGs by (i) up to 3.5% Ce2O3, because it was reported that Ce 3+ ions reduce the enamel demineralization, and are neuroprotective [19], (ii) up to 3.5% Ga2O3, because it was published that Ga 3+ ions increase the calcium content in bone, and are antimicrobial [20], and (iii) ZnO because, in addition to other biological functions, it was reported that Zn 2+ ions stimulates the bone formation and exhibit also a bactericide action [21,22]. In the …”

Characterization of calcium phosphate coating and zinc incorporation on the porous alumina scaffolds

“…By deposition of a coating with CaP/PVA suspension, we had obtained a layer with regular thickness, which resulted in a potential bioactive layer on macroporous alumina scaffold. In addition, the EDS analysis showed presence of zinc al low concentration level incorporated in the CaP/PVA coating of sample, which is an element that released at low concentration present pharmacological effect in bone metabolism 16,17 . In Figure 2a is presented the FTIR spectrum of calcium phosphate powder used in the suspension deposited on the surface of alumina scaffold, that identified bands corresponding to the vibration modes of PO 4 3-group (565, 599, 960 and 1041 cm -1 ) and to CO 3 2-group (871, 1414 and 1454 cm -1 ), characteristics of the apatites 13 .…”

“…It is important to point out that, due to very low concentration of Zn 2+ incorporated to the scaffold coated with CaP/PVA, the characteristic Zn(Kα) line fell in the background range of the spectra. Moreover, it has been recently reported in the literature 16,17 that using zinc associated with calcium phosphates has enhanced the bioactivity in bone tissue regeneration. However, Zn 2+ at an elevated level induces adverse reactions and must be released slowly from the implant.…”

Cytocompatibility evaluation of hydroxyapatite/collagen composites doped with Zn+2

“…The literature studies related that zinc released from the ZnCaP stimulates osteoblastic activities [6,7,9]. Nevertheless, zinc is known as a potent inhibitor of the crystal growth of apatite, which is a controversial issue.…”

“…It hold an inhibitory effect on osteoclastic bone resorption [6,7]. Several researchers have attempted to doper materials with Zn +2 at low concentrations increasing the bioactivity of bone cells [4,[6][7][8] and decreasing and regulating the inflammatory reaction [9].…”