title: Systematic strontium substitution in hydroxyapatite coatings on titanium via micro-arc treatment and their osteoblast/osteoclast responses.
abstract: This study attempts to enhance the osseointegration of titanium implants by adopting a micro-arc treatment (MAT) capable of replacing calcium (Ca) with different percentages of strontium (Sr) in order to fabricate strontium-containing hydroxyapatite (Sr-HAp) coatings. Sr, regarded as a significant therapy promoting bone mass and bone strength, has a dual mechanism, enhancing osteoblast differentiation and inhibiting osteoclast differentiation. This study also investigates how Sr content affects the microstructure of and osteoblast/osteoclast growth on the coatings. Experimental results indicate that an increase in the Sr content in the electrolyte bath results in a greater degree of Sr substitution at Ca sites within the HAp phase, facilitating the formation of Sr-HAp coatings with Sr fully solid soluble in the HAp phase. Irrespective of the Sr content, most coatings are similar in porous morphology and pore size. Additionally, the Sr-HAp coating shows higher osteoblast compatibility than raw titanium metal and the HAp coating. Moreover, cell adhesion and proliferation after 48 h was greater than that after 4 h, indicating that Sr can stimulate osteoblast adhesion and proliferation. Further, Sr significantly inhibits osteoclast differentiation when the Sr-HAp coatings exceed 38.9 at.% Sr.
authors.affiliation: Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, Beitun District, Taichung City 40601, Taiwan, ROC. cjchung@seed.net.tw
authors.forename: Chi-Jen
authors.initials: CJ
authors.lastname: Chung
authors.forename: Han-Yun
authors.initials: HY
authors.lastname: Long
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000737:chemistry*; D002448:Cell Adhesion; D002460:Cell Line; D049109:Cell Proliferation; D020099:Coated Materials, Biocompatible; D017886:Durapatite / Q000737:chemistry*; D008422:Materials Testing; D051379:Mice; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D010010:Osteoclasts / Q000166:cytology* / Q000378:metabolism; D013324:Strontium / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*
chemical_list: D018786:Bone Substitutes; D020099:Coated Materials, Biocompatible; D017886:Durapatite; D014025:Titanium; D013324:Strontium