Osteoimmunomodulatory Effects of Enamel Matrix Derivate and Strontium Coating Layers: A Short- and Long-Term In Vivo Study

Abstract

Over the past few years, surface modification of implant surfaces has gained substantial attention as a promising solution to avoid the failure of biomaterials after implantation. Although researchers suggest several strategies for surface functionalization of titanium-based implants, only a few studies have compared the osteoimmunomodulatory effects of ionic nanostructures and biofunctionalization in the same biological model. Enamel matrix derivate (EMD) and strontium are both known for their positive influences on bone cell responses. In this study, we functionalized the titanium–zirconium implant surface with EMD and strontium using an electrochemical cathodic polarization method. Afterward, we evaluated the osteoimmunomodulatory effects of EMD or strontium coated titanium–zirconium implants in the tibia of eight Gray Bastard Chinchilla rabbits. We performed 2 and 3D micro-CT, wound fluid, histologic, and histomorphometric analyses on bone tissues after 4- and 8-weeks of implantation. Although the results could indicate some differences between groups regarding the bone quality, there was no difference in bone amount or volume. EMD stimulated higher ALP activity and lower cytotoxicity in wound fluid, as well as a lower expression of inflammatory markers after 8 weeks indicating its osteoimmunomodulatory effects after implantation. Overall, the results suggested that ionic nanostructure modification and biofunctionalization might be useful in regulating the immune responses to implants.

The response of soft tissue cells to Ti implants is modulated by blood-implant interactions

“…Optimizing implant surface properties to steer the immune response to an implant has been an area of increasing research focus [ 52 ]. The innate immune response to an implant involves different cells, including neutrophils, dendritic cells, NK cells, and macrophages.…”

Porous membranes of quaternized chitosan composited with strontium-based nanobioceramic for periodontal tissue regeneration

“…16 There is a study available, which compares the osteoimmunomodulatory effects of EMD-coated surface with strontium ion-coated implant surface. 17 Compared to EMD-coated surface, strontium-coated surface induced higher bone mineral density, bone surface-to-volume ratio, and bone surface/tissue volume, after 4 weeks of implantation.…”

Integrated osteoimmunomodulatory strategies based on designing scaffold surface properties in bone regeneration

“…In vivo study revealed that EMD-modified implants significantly increased ALP activity and reduced the expression of pro-inflammatory cytokines, suggesting an osteoimmunomodulatory effect of EMD. 176 In another study, a biomimetic glycopeptide hydrogel was designed by Wang et al to mimic the glycoprotein composition and the fibrous structure of a natural extracellular matrix and coated on a PCL/nHA scaffold for bone regeneration. In vitro study revealed that enhanced proliferation and osteogenic differentiation of BMSCs was found on the coated surface, which was further promoted by the M2 macrophage polarization induced by the glycopeptide hydrogel, in vivo study further confirmed the enhanced osteoimmunomodulatory effects of this hybrid scaffold developed here 170 (Fig.…”