1. Osteogenic, anti-osteoclastogenic and immunomodulatory properties of a strontium-releasing hybrid scaffold for bone repair.
- Author
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Lourenço AH, Torres AL, Vasconcelos DP, Ribeiro-Machado C, Barbosa JN, Barbosa MA, Barrias CC, and Ribeiro CC
- Subjects
- Animals, Cell Adhesion drug effects, Cell Differentiation drug effects, Cell Fusion, Cell Polarity drug effects, Cell Proliferation drug effects, Cell Survival drug effects, Cells, Cultured, Female, Humans, Inflammation pathology, Leukocytes, Mononuclear cytology, Leukocytes, Mononuclear drug effects, Leukocytes, Mononuclear metabolism, Macrophages cytology, Macrophages drug effects, Macrophages metabolism, Male, Mesenchymal Stem Cells cytology, Mesenchymal Stem Cells drug effects, Mesenchymal Stem Cells metabolism, Mice, Inbred BALB C, Microspheres, Osteoclasts drug effects, Young Adult, Bone Regeneration drug effects, Osteoclasts cytology, Osteogenesis drug effects, Strontium pharmacology, Tissue Scaffolds chemistry
- Abstract
Strontium (Sr) is known to stimulate osteogenesis, while inhibiting osteoclastogenesis, thus encouraging research on its application as a therapeutic agent for bone repair/regeneration. It has been suggested that it may possess immunomodulatory properties, which might act synergistically in bone repair/regeneration processes. To further explore this hypothesis we have designed a Sr-hybrid system composed of an in situ forming Sr-crosslinked RGD-alginate hydrogel reinforced with Sr-doped hydroxyapatite (HAp) microspheres and studied its in vitro osteoinductive behaviour and in vivo inflammatory response. The Sr-hybrid scaffold acts as a dual Sr
2+ delivery system, showing a cumulative Sr2+ release of ca. 0.3 mM after 15 days. In vitro studies using Sr2+ concentrations within this range (0 to 3 mM Sr2+ ) confirmed its ability to induce osteogenic differentiation of mesenchymal stem/stromal cells (MSC), as well as to reduce osteoclastogenesis and osteoclasts (OC) functionality. In comparison with a similar Sr-free system, the Sr-hybrid system stimulated osteogenic differentiation of MSC, while inhibiting the formation of OC. Implantation in an in vivo model of inflammation, revealed an increase in F4/80+ /CD206+ cells, highlighting its ability to modulate the inflammatory response as a pro-resolution mediator, through M2 macrophage polarization. Therefore, the Sr-hybrid system is potentially an appealing biomaterial for future clinical applications., (Copyright © 2019. Published by Elsevier B.V.)- Published
- 2019
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