title: Controlled-release of bone morphogenetic protein-2 from a microsphere coating applied to acid-etched Ti6AL4V implants increases biological bone growth in vivo.
abstract: A central clinical challenge regarding the surgical treatment of bone and joint conditions is the eventual loosening of an orthopedic implant as a result of insufficient bone ingrowth at the bone-implant interface. We investigated the in vivo effectiveness of a coating containing recombinant human bone morphogenetic protein-2 (rhBMP-2)-loaded microspheres applied to acid-etched Ti6Al4V cylinders for implantation. Three groups of rabbits (24 per group) were used for implantation: (1) acid-etched Ti6Al4V implants coated with a mixture of rhBMP-2-loaded microspheres (125 ng rhBMP-2/mg microspheres) and α-butyl cyanoacrylate; (2) acid-etched, uncoated implants; and (3) bare, smooth uncoated implants. After implantation, 12 rabbits from each group were used for bone ingrowth determination at 4, 5, 6, 7, 8, and 12 weeks (2 rabbits per time point), while the remainder were used for histological analysis and push-out testing at 12 weeks. Scanning electron microscopy showed significant improvement in bone growth of the rhBMP-2 microspheres/α-butyl cyanoacrylate group compared with the other groups (p<0.01). Histological analysis and push-out testing also demonstrated enhanced bone growth of the rhBMP-2 group over that in the other two groups (p<0.01). The rhBMP-2 group showed the most significant bone growth, suggesting that coating acid-etched implants with a mixture of rhBMP-2-loaded microspheres and α-butyl cyanoacrylate may be an effective method to improve the osseointegration of orthopedic implants.
authors.affiliation: Department of Orthopedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Haidian District, Beijing, 100853, China.
authors.forename: Yangmu
authors.initials: Y
authors.lastname: Fu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Sun
authors.forename: Weixiong
authors.initials: W
authors.lastname: Liao
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Bai
authors.forename: Lili
authors.initials: L
authors.lastname: Zhang
authors.forename: Lina
authors.initials: L
authors.lastname: Du
authors.forename: Yiguang
authors.initials: Y
authors.lastname: Jin
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.forename: Zhongli
authors.initials: Z
authors.lastname: Li
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000497:Alloys; D000818:Animals; D001846:Bone Development / Q000187:drug effects*; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage*; D020099:Coated Materials, Biocompatible; D004659:Enbucrilate; D006801:Humans; D020007:Implants, Experimental; D008863:Microspheres; D016348:Osseointegration; D011817:Rabbits; D011994:Recombinant Proteins / Q000008:administration & dosage; D014025:Titanium; D016212:Transforming Growth Factor beta / Q000008:administration & dosage*
chemical_list: D000497:Alloys; D055396:Bone Morphogenetic Protein 2; D020099:Coated Materials, Biocompatible; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; C031462:titanium alloy (TiAl6V4); D014025:Titanium; D004659:Enbucrilate
keywords: Ti6Al4V; bone growth; microsphere; rhBMP-2; α-butyl cyanoacrylate