Strontium‐Substituted Hydroxyapatite‐Gelatin Biomimetic Scaffolds Modulate Bone Cell Response

Abstract

Strontium has a beneficial role on bone remodeling and is proposed for the treatment of pathologies associated to excessive bone resorption, such as osteoporosis. Herein, the possibility to utilize a biomimetic scaffold as strontium delivery system is explored. Porous 3D gelatin scaffolds containing about 30% of strontium substituted hydroxyapatite (SrHA) or pure hydroxyapatite (HA) are prepared by freeze-drying. The scaffolds display a very high open porosity, with an interconnectivity of 100%. Reinforcement with further amount of gelatin provokes a modest decrease of the average pore size, without reducing interconnectivity. Moreover, reinforced scaffolds display reduced water uptake ability and increased values of mechanical parameters when compared to as-prepared scaffolds. Strontium displays a sustained release in phosphate buffered saline: the quantities released after 14 d from as-prepared and reinforced scaffolds are just 14 and 18% of the initial content, respectively. Coculture of osteoblasts and osteoclasts shows that SrHA-containing scaffolds promote osteoblast viability and activity when compared to HA-containing scaffolds. On the other hand, osteoclastogenesis and osteoclast differentiation are significantly inhibited on SrHA-containing scaffolds, suggesting that these systems could be usefully applied for local delivery of strontium in loci characterized by excessive bone resorption.

Sintering of magnesium‐strontium doped hydroxyapatite nanocrystals: Towards the production of 3D biomimetic bone scaffolds

“…Substitution of Sr 2+ ions at Ca 2+ sites in HA lattice is well reported (Frasnelli et al, 2017;Lowry et al, 2018;Šupovà, 2015;Terra et al, 2009). In literature there are several studies demonstrating that the incorporation of Sr into biomaterials efficiently trades cell activity (Panzavolta et al, 2018) and induces bone regeneration. It was demonstrated that Sr stimulates bone formation by playing a stimulatory role in osteoblast cells and an inhibitory role in osteoclast cells (Capuccini et al, 2008;Capuccini et al, 2009).…”

“…are several studies demonstrating that the incorporation of Sr into biomaterials efficiently trades cell activity (Panzavolta et al, 2018) and induces bone regeneration.…”

Towards 3D Multi-Layer Scaffolds for Periodontal Tissue Engineering Applications: Addressing Manufacturing and Architectural Challenges

“…The composite scaffolds were developed by using a PCL polymeric matrix mainly for its good printability, biodegradability and for being an FDA approved biomaterial [ 49 ]. In relation to the ceramic phase, previous studies on Sr-containing biomaterials in various forms indicated that even small amounts of Sr (0.1 wt%) can enhance the osteoconductive properties of calcium phosphate, have a positive effect on bone mineralization, elevate the mechanical property of bone tissue and have crucial effects by inducing collagen type I synthesis [ 50 , 51 , 52 , 53 ]. Additionally, it has been reported that Sr can act via the calcium-sensing receptor and promote the transductions of the mitogen-activated protein kinase signaling.…”

Functionalization of Ceramic Coatings for Enhancing Integration in Osteoporotic Bone: A Systematic Review

“…This approach leads to a larger, effective functionalized area and 3D distribution of trace elements throughout the bulk material. Even small amounts of these ionic species substitutes in the structure of ceramics exert a significant effect on thermal stability, solubility, osteoclastic and osteoblastic responses, degradation and bone regeneration [53,54,[80][81][82][83][84].…”