Protein adsorption/desorption dynamics on Ca-enriched titanium surfaces: biological implications

Abstract

Calcium ions are used in the development of biomaterials for the promotion of coagulation, bone regeneration, and implant osseointegration. Upon implantation, the time-dependent release of calcium ions from titanium implant surfaces modifies the physicochemical characteristics at the implant–tissue interface and thus, the biological responses. The aim of this study is to examine how the dynamics of protein adsorption on these surfaces change over time. Titanium discs with and without Ca were incubated with human serum for 2 min, 180 min, and 960 min. The layer of proteins attached to the surface was characterised using nLC-MS/MS. The adsorption kinetics was different between materials, revealing an increased adsorption of proteins associated with coagulation and immune responses prior to Ca release. Implant–blood contact experiments confirmed the strong coagulatory effect for Ca surfaces. We employed primary human alveolar osteoblasts and THP-1 monocytes to study the osteogenic and inflammatory responses. In agreement with the proteomic results, Ca-enriched surfaces showed a significant initial inflammation that disappeared once the calcium was released. The distinct protein adsorption/desorption dynamics found in this work demonstrated to be useful to explain the differential biological responses between the titanium and Ca-ion modified implant surfaces. Graphic abstract

Metal ions: the unfading stars of bone regeneration—from bone metabolism regulation to biomaterial applications

“…142 The Ca 2+ -modified implant surface not only enhances osseointegration but also reduces inflammatory responses and promotes vascularization. 43,143 Zhang et al 83 investigated the correlation among Ca 2+ , macrophage polarization, and new bone formation after implanting calcium phosphate-based biomaterials. The results revealed that Ca 2+ activated the Wnt/ β-catenin signaling pathway and then promoted the transcription of arginase-1 (Arg-1) and IL-10 (M2 marker genes) in macrophages.…”

Novel insights into nanomaterials for immunomodulatory bone regeneration

“…It is well known that calcium ions are essential for physiological bone metabolism and have the capability to suppress the expression of inflammatory cytokine TNF-α via activating the CaSR signalling cascade and inhibiting NF-κB pathway. 96 Silicon has also been reported to exhibit anti-oxidant and anti-inflammatory effects, which can inhibit the gene expression of TNF-α, COX-2, and iNOS and reduce the generation of NO and IL-6 in macrophages. 97 Recently, Chen et al 98 fabricated barrier collagen membrane coating nanometer-sized Ca 2 ZnSi 2 O 7 , and in vitro and in vivo models indicated that this material strengthened the expression of pro-inflammatory cytokines including TNF-α, IL-1β, IL-6, and IL-18 and activated BMP, canonical Wnt/β-catenin and OSM signaling to induce osteogenic differentiation of BMSCs.…”

Insight into the antibacterial mechanism of Cu-enriched sol–gel coatings employing proteomics

“…The adsorption/desorption patterns of key proteins associated with the coagulation system and the immune response could explain the differences between the in vitro blood clotting and inflammatory potential of the Ti- and Ca-modified implants. 20 Examining the Cu effects on the protein adsorption onto biomaterials should improve our understanding of the role of this element in tissue regeneration and its ability to prevent bacterial infections.…”