title: Tendon-bone interface healing using an injectable rhBMP-2-containing collagen gel in a rabbit extra-articular bone tunnel model.
abstract: This study examines the hypothesis that injectable collagen gel can be an effective carrier for recombinant human bone morphogenetic protein-2 (rhBMP-2)'s localization to the healing tendon-bone interface. In 36 mature New Zealand White rabbits, the upper long digital extensor tendon was cut and inserted into the proximal tibial bone tunnel. Then a rhBMP-2-containing collagen gel was injected into the tendon-bone tunnel interface, using a syringe. Histological and biomechanical assessments of the tendon-bone interface were conducted at 3 and 6 weeks after implantation. In vitro testing showed that the semi-viscous collagen gel at room temperature was transformed into a firm gel state at 37°C. The rhBMP-2 release profile showed that rhBMP-2 was released from the collagen gel for more than 28 days. In vivo testing showed that fibrocartilage and new bone are formed at the interface at 6 weeks after injection of rhBMP-2. On radiography, spotty calcification appeared and enthesis-like tissue was produced successfully in the tendon at 6 weeks after injection of rhBMP-2. Use of the viscous collagen gel and rhBMP-2 mixture increased the fusion rate between the bone tunnel and tissue graft. This study demonstrates that viscous collagen gel can be an effective carrier for rhBMP-2 delivery into surgical sites, and that the injectable rhBMP-2-containing collagen gel may be applied for the enhancement of tendon-bone interface healing in the future. Copyright © 2015 John Wiley & Sons, Ltd.
authors.affiliation: Eulji University Hospital, Department of Orthopaedic Surgery, Seoul, Republic of Korea.
authors.forename: Kwang Won
authors.identifier: 0000-0002-6125-4827
authors.initials: KW
authors.lastname: Lee
authors.affiliation: Institute of Biomaterial and Medical Engineering, R & D, Cellumed Co., Ltd., Seoul, Republic of Korea.
authors.forename: Jung Soo
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Institute of Biomaterial and Medical Engineering, R & D, Cellumed Co., Ltd., Seoul, Republic of Korea.
authors.forename: Ju Woong
authors.initials: JW
authors.lastname: Jang
authors.affiliation: Institute of Biomaterial and Medical Engineering, R & D, Cellumed Co., Ltd., Seoul, Republic of Korea.
authors.forename: Young Bock
authors.initials: YB
authors.lastname: Shim
authors.affiliation: Institute of Biomaterial and Medical Engineering, R & D, Cellumed Co., Ltd., Seoul, Republic of Korea.
authors.forename: Kwang-Il
authors.initials: KI
authors.lastname: Lee
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000737:chemistry / Q000494:pharmacology*; D003094:Collagen / Q000737:chemistry / Q000494:pharmacology*; D004343:Drug Implants; D006801:Humans; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry / Q000494:pharmacology; D013708:Tendon Injuries / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D013710:Tendons / Q000378:metabolism* / Q000473:pathology; D013977:Tibia / Q000293:injuries / Q000378:metabolism*
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D004343:Drug Implants; D011994:Recombinant Proteins; D003094:Collagen
keywords: bone tunnel; enthesis; ligament injury; rhBMP-2; tendon