Effect of cryopreservation on rhBMPª²2 induced regeneration of dog¬ðs tracheal cartilage

    YAN Xiaoª²Long,LI Xiaoª²Fei,LIU Yong,LU Qiang,WANG Lu

    Department of Thoracic Surgery, Tangdu Hospital,Fourth Military Medical University, Xi¬ðan 710038, China

    ¡¾Abstract¡¿ AIM: To confirm the validity and potential application of implanting the recombinant human bone morphogenetic proteinª²2 (rhBMPª²2) with collagen into the cryopreserved tracheal allografts to induce the regeneration of dog's tracheal cartilage. METHODS: Thirtyª²two mongrel dogs were randomly and equally divided into 4 groups. Fiveª²ring cervical tracheal segment was harvested as the alloraft and all the grafts were wrapped with pedicled omentum. Group A was subdivided into group A1, in which RhBMPª²2 with collagen as a carrier was injected into the soft tissues between cartilaginous rings of the grafts, and group A2 ¡ª¡ªthe blank group. Group B, in which the grafts were cryopreserved for two months before the operation, was also subdivided into group B1 and group B2. The animals were sacrificed 8 weeks postoperation. The postmortem specimens were examined grossly and histologically. Area of new cartilage was studied in each allografts. RESULTS: Structural integrity of the allografts was better in group B than in group A. In all the groups, new cartilage was induced in the rhBMPª²2 injected area and more new cartilage was observed in group B1 than in group A1. CONCLUSION: rhBMPª²2 has the ability to induce new cartilage formation in the cryopreserved racheal allografts. Cryopreserved tracheal allografts have better new cartilage inducing effect than noncryopreserved tracheal allografts. ......