Effects of calcium ions on titanium surfaces for bone regeneration

• Published in: Colloids and surfaces, B, Biointerfaces B, Biointerfaces, 2015-06, Vol.130, p.173-181
• Main Authors: Anitua, Eduardo, Piñas, Laura, Murias, Alia, Prado, Roberto, Tejero, Ricardo
• Format: Article
• Language: English
• Subjects: Animals; Biocompatibility; Biomedical materials; Bone Regeneration; Bones; Calcium; Calcium - chemistry; Calcium ions; Cell Adhesion; Cell Differentiation; Cell Line; Cell Proliferation; Density; Durability; Humans; Implants; Implants, Experimental; Mass Spectrometry - methods; Microscopy, Electron, Scanning; Osseointegration; Osteoblasts - cytology; Osteoblasts - metabolism; Osteogenesis; Osteopontin - metabolism; Sheep; Surface Properties; Surfaces; Surgical implants; Tibia - pathology; Tibia - physiopathology; Tibia - surgery; Titanium; Titanium - chemistry; Titanium base alloys; X-Ray Microtomography
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/j.colsurfb.2015.04.006

•We analyze the physicochemistry of titanium surfaces modified with calcium ions.•We analyze the osteogenic potential of titanium surfaces modified with calcium ions.•The calcium adsorbate prevents the putative hydrocarbon adsorption on titania.•2/3 Ca release in burst mode, the rest is released progressively over 85 days.•Ca on titania enhances osteoblast response and bone-implant integration. The chemistry and topography of implant surfaces are of paramount importance for the successful tissue integration of load-bearing dental and orthopedic implants. Here we evaluate in vitro and in vivo titanium implant surfaces modified with calcium ions (Ca2+ surfaces). Calcium ions produce a durable chemical and nano-topographical modification of the titanium oxide interface. Time of flight secondary ion mass spectrometry examination of the outermost surface composition, shows that calcium ions in Ca2+ surfaces effectively prevent adventitious hydrocarbon passivation of the oxide layer. In aqueous solutions Ca2+ surfaces release within the first minute, 2/3 of the total measured Ca2+, the rest is released over the following 85 days. Additionally, Ca2+ surfaces significantly increase human fetal osteoblasts-like cell adhesion, proliferation and differentiation, as measured by the autocrine synthesis of osteopontin. Relevant for clinical application, after 12 weeks of healing in sheep tibia, microcomputer tomography and histomorphometric analysis show that Ca2+ surfaces develop significantly more bone contacts and higher bone density in the 1mm region around the implant. Consequently, titanium implants modified with calcium ions represent a valuable tool to improve endosseous integration in the clinical practice.