TITLE:
In Vivo Evaluation of Functionalized Biomimetic Hydroxyapatite for Local Delivery of Active Agents
AUTHORS:
Johan Forsgren, Ulrika Brohede, Sonya Piskounova, Albert Mihranyan, Sune Larsson, Maria Strømme, Håkan Engqvist
KEYWORDS:
Implant, titanium, hydroxyapatite, bisphosphonate, bone morphogenetic protein-2
JOURNAL NAME:
Journal of Biomaterials and Nanobiotechnology,
Vol.2 No.2,
February
15,
2011
ABSTRACT: This study was carried out to investigate the biological response in vivo to biomimetic hydroxyapatite implant coatings functionalized with bisphosphonates and bone morphogenetic proteins. The functionalization was carried out by a simple soaking procedure in the operating room immediately prior to surgery. Cylindrical titanium samples with and without coatings were implanted in the distal femoral epiphysis of sheep and retrieved after 6 weeks. The histological analysis proved that all samples were integrated well in the tissue with no signs of intolerance. Fewer osteoclasts were observed in the vicinity of bisphosphonate-functionalized samples and the bone was denser around these samples compared to the other samples. Samples functionalized with bone morphogenetic protein induced more bone/implant contact but showed a more inconsistent outcome with reduced bone density around the samples. This study demonstrates a simple method to functionalize implant coatings, which provides surgeons with an option of patient-specific functionalization of implants. The observed biological impact due to the delivery of active molecules from the coatings suggests that this strategy may also be employed to deliver antibiotics from similar coatings.