Multifunctional effects of a modification of SLA titanium implant surface with strontium-containing nanostructures on immunoinflammatory and osteogenic cell function.

This study investigated the effects of surface modification of clinically available sandblasted/acid-etched (SLA) titanium oral implants with strontium (Sr)-containing nanostructures on both early immunoinflammatory macrophage cell functions and osteogenic stem cell functions. The goal was to provide insight for future surface engineering of titanium implants with multifunctional effects, that is, tissue healing capacity at both the nonosteogenic cell centered initial stage and the subsequent osteogenic cell-governed later stage-osseointegration process. The Sr-containing nanostructure was prepared in on the SLA-type implant surface by wet chemical treatment. The results showed that Sr modification is favorable for early macrophage cell functions and increases osteogenic capacity of the SLA surface. Surface Sr modification notably upregulated regenerative macrophage phenotype expression and anti-inflammatory cytokine IL10 production while suppressing inflammatory cytokine TNFα. Sr incorporation enhanced certain early cellular events of ST2 stem cells such as early cellular spreading and critical integrin gene expression, which in turn notably increased osteogenic differentiation (osteogenesis-related phenotype gene expression and osteocalcin production) when combined with the microstructured SLA implant surface. Surface modification of SLA-type implants with Sr-containing nanostructures demonstrated the ability to favorably influence early immunoinflammatory macrophage cell functions and the functionality of osteogenesis cells, resulting in an enhanced osseointegration outcome.