title: Fabrication of an rhBMP-2 loaded porous β-TCP microsphere-hyaluronic acid-based powder gel composite and evaluation of implant osseointegration.
abstract: Methods to improve osseointegration that include implantation of rhBMP-2 with various kinds of carriers are currently of considerable interest. The present study was conducted to evaluate if the rhBMP-2 loaded β-TCP microsphere-hyaluronic acid-based powder-like hydrogel composite (powder gel) can act as an effective rhBMP-2 carrier for implantation in host bone with a bone defect or poor bone quality. The release pattern for rhBMP-2 was then evaluated against an rhBMP-2-loaded collagen sponge as a control group. Dental implants were also inserted into the tibias of three groups of rabbits: an rhBMP-2 (200 µg) loaded powder gel composite implanted group, an implant only group, and a powder gel implanted group. Micro-CT and histology of the implanted areas were carried out four weeks later. The rhBMP-2 powder gel released less rhBMP-2 than the collagen sponge, but it continued a slow release for more than 7 days. The rhBMP-2 powder gel composite improved osseointegration of the dental implant by increasing the amount of new bone formation in the implant pitch and it improved the bone quality and bone quantity of new bone. The histology results indicated that the rhBMP-2 powder gel composite improved the osseointegration in the cortical bone as well as the marrow space along the fixture. The bone-to-implant contact ratio of the rhBMP-2 (200 µg) loaded powder gel composite implanted group was significantly higher than those of the implant only group and the powder gel implanted group. The powder gel appeared to be a good carrier and could release rhBMP-2 slowly to promote the formation of new bone following implantation in a bone defect, thereby improving implant osseointegration.
authors.affiliation: Department of Orthopedic Surgery, College of Medicine, SMG-SNU Boramae Medical Center, Seoul National University, 425 Shindaebang-2-Dong, Seoul, 156-707, Korea, spinelee@snu.ac.kr.
authors.forename: Jae Hyup
authors.initials: JH
authors.lastname: Lee
authors.forename: Jungju
authors.initials: J
authors.lastname: Kim
authors.forename: Hae-Ri
authors.initials: HR
authors.lastname: Baek
authors.forename: Kyung Mee
authors.initials: KM
authors.lastname: Lee
authors.forename: Jun-Hyuk
authors.initials: JH
authors.lastname: Seo
authors.forename: Hyun-Kyung
authors.initials: HK
authors.lastname: Lee
authors.forename: A-Young
authors.initials: AY
authors.lastname: Lee
authors.forename: Guang Bin
authors.initials: GB
authors.lastname: Zheng
authors.forename: Bong-Soon
authors.initials: BS
authors.lastname: Chang
authors.forename: Choon-Ki
authors.initials: CK
authors.lastname: Lee
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage*; D002130:Calcium Phosphates / Q000737:chemistry*; D005782:Gels; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry*; D008297:Male; D008863:Microspheres; D016348:Osseointegration; D011208:Powders; D019736:Prostheses and Implants; D011817:Rabbits; D011994:Recombinant Proteins / Q000008:administration & dosage; D055114:X-Ray Microtomography
chemical_list: D055396:Bone Morphogenetic Protein 2; D002130:Calcium Phosphates; D005782:Gels; D011208:Powders; D011994:Recombinant Proteins; C485817:beta-tricalcium phosphate; D006820:Hyaluronic Acid