Effect of recombinant human BMP-2 on the repair of cricoid cartilage defects in young and adult rabbits: A comparative study

• Published in: International journal of pediatric otorhinolaryngology 2005-09, Vol.69 (9), p.1239-1246
• Main Authors: Tcacencu, Ion, Carlsöö, Bengt, Stierna, Pontus
• Format: Article
• Language: English
• Subjects: Adult; Age; Age Factors; Animals; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins - administration & dosage; Bone Morphogenetic Proteins - pharmacology; Cell Proliferation - drug effects; Chondrogenesis - drug effects; Collagen Type I - biosynthesis; Collagen Type II - biosynthesis; Collagen Type X - biosynthesis; Cricoid Cartilage - drug effects; Cricoid Cartilage - injuries; Cricoid Cartilage - physiology; Growth factors; Humans; Immunohistochemistry; Ki-67 Antigen - biosynthesis; Larynx; Male; Medicin och hälsovetenskap; Osteogenesis - drug effects; Rabbits; Random Allocation; Recombinant Proteins - administration & dosage; Recombinant Proteins - pharmacology; Transforming Growth Factor beta - administration & dosage; Transforming Growth Factor beta - pharmacology; Wound healing; Wound Healing - drug effects; Wounds and Injuries - drug therapy
• ISSN: 0165-5876; 1872-8464
• DOI: 10.1016/j.ijporl.2005.03.026

The study evaluated the possible differences in the repair of cricoid cartilage defects treated with recombinant human BMP-2 in young and adult rabbits. A cricoid defect rabbit model was used. Thirty rabbits were randomly divided into eight groups. Two groups of young rabbits and two groups of adult rabbits were treated with rhBMP-2 delivered on an absorbable collagen sponge, while the other two groups of young rabbits and two groups of adult rabbits were used as controls. The rabbits were killed at 1 week or 4 weeks after surgery. A histomorphometric analysis and an evaluation of the expression of collagen types I, II, and X, and proliferating cell nuclear antigen as well as a study of distribution of calcified matrix, were performed. rhBMP-2 induced a marked chondrogenesis in both experimental age groups. However, in young rabbits the newly formed cartilage appeared more elongate, and the length of perichondrium involved was greater. The host cricoid cartilage of adult rabbits was calcified in large areas and displayed a strong matrix expression of collagen type X as well as collagen type I in the perichondrium, compared to the cricoid of young rabbits. In spite of these differences no immunohistochemical differences were found in the newly formed cartilage of both age groups treated with rhBMP-2. The cricoid cartilage defect was filled with new bone at 4 weeks in both age groups treated with rhBMP-2. New bone tissue had a well-defined trabecular structure. rhBMP-2 triggers appositional cartilage growth from the cricoid perichondrium of young rabbits more easily than from that of adult rabbits. The new bone induced by rhBMP-2 showed a similar immunohistochemical and morphological pattern in both age groups of rabbits.