Human mesenchymal stromal cells response to biomimetic octacalcium phosphate containing strontium

Abstract

The incorporation of bioinorganics into synthetic biomaterials is a promising approach to improve the biological performance of bone graft substitutes, while still retaining their synthetic nature. Among these bioinorganics, strontium ions (Sr(2+) ) have reported enhanced bone formation, and a reduced risk of bone fractures. While previous results have been encouraging, more detailed studies are needed to further develop specific applications. This study demonstrates the effects of Sr(2+) on the osteogenic differentiation of human mesenchymal stromal cells (hMSCs) when introduced as either a dissolved salt, or incorporated into biomimetic calcium phosphate (CaP) coatings. Upon attachment, hMSCs seeded in the presence of higher Sr(2+) concentrations presented with a more elongated shape as compared to the controls without Sr(2+) . Both Sr(2+) as a dissolved salt in the medium, or incorporated into CaP coatings, positively influenced hMSC alkaline phosphatase (ALP) activity in a dose-dependent manner. At the mRNA level, the expression of osteogenic markers ALP, bone sialoprotein, bone morphogenetic protein 2, osteopontin, and osteoclacin were increased in the presence of Sr(2+) , independent of the delivery method. Overall, this study demonstrates the positive effects of strontium on the osteogenic differentiation of human MSCs, and supports the use of strontium-incorporated CaPs for bone regeneration applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1946-1960, 2016.

Continuous release of bone morphogenetic protein-2 through nano-graphene oxide-based delivery influences the activation of the NF-κB signal transduction pathway

“…Loading of carriers such as calcium phosphate cements, 31 titanium, 32 collagen, 33 silk, 34 and polylactic acid-polyglycolic acid 35 through simple adsorption merely resulted in an abrupt release of biological activity, which is apparently physiologically insufficient in resolving …”

Bibliographic review on the state of the art of strontium and zinc based regenerative therapies. Recent developments and clinical applications

“…In another study, electrolytes with different proportions of Sr: Sr-0M, Sr-0.05M, Sr-0.1M and Sr-0.15M were analysed using MC3T3E1 cells. 80 Calcium phosphate (CPS) coated titanium sheets, adding Sr 2+ by vertical immersion to reach varying concentrations of Sr 2+ in CPS (0, 10, and 1000 mM), were tested on hMSCs looking for osteogenic differentiation; 82 a SrO layer on a sandblasted large grit double acid etched (SLA) surface produced by hydrothermal treatment using a Sr containing solution was implanted into New Zealand white rabbits; 83 and lastly, titanium implants were induced to release Sr (Sr-Ti) or Mg (Mg-Ti) ions in Japanese white rabbits. 84 Sodium alginate (SA) is a promising and efficient biomaterial for bone formation and healing, 85,86 and its utility in bone tissue regeneration has been studied as a coating with Sr and dopamine (DOPA) on a titanium (Ti) surface, which are well-known for their potential characteristics for bone tissue engineering; five samples were made: Ti, Ti/DOPA, Ti/DOPA/SA, Ti/DOPA/SA/Sr1 (1 wt% Sr) and Ti/DOPA/SA/Sr5 (5 wt% Sr) and tested using MG-63 cells.…”

Biomineralization‐Inspired Material Design for Bone Regeneration

“…One study mentioned that the addition of strontium to the mineralization solution “strongly disrupted the [PILP] process,” although no data were provided . Strontium is known to decrease osteoclast‐resorbing activity and differentiation, while promoting osteoblast differentiation, which makes it attractive for bone regeneration strategies. Another study focused on the interference of copper that was included in the mineralization solution by dissolution from TEM grids.…”