Tissue engineering rib with the incorporation of biodegradable polymer cage and BMSCs/decalcified bone: an experimental study in a canine model

Hua Tang,Zhifei Xu,Jim Kretlow,Xiong Qin,Bin Wu,Lu Zhang

doi:10.1186/1749-8090-8-133

Abstract

BackgroundThe reconstruction of large bone defects, including rib defects, remains a challenge for surgeons. In this study, we used biodegradable polydioxanone (PDO) cages to tissue engineer ribs for the reconstruction of 4cm-long costal defects.MethodsPDO sutures were used to weave 6cm long and 1cm diameter cages. Demineralized bone matrix (DBM) which is a xenograft was molded into cuboids and seeded with second passage bone marrow mesenchymal stem cells (BMSCs) that had been osteogenically induced. Two DBM cuboids seeded with BMSCs were put into the PDO cage and used to reconstruct the costal defects. Radiographic examination including 3D reconstruction, histologic examination and mechanical test was performed after 24 postoperative weeks.ResultsAll the experimental subjects survived. In all groups, the PDO cage had completely degraded after 24 weeks and been replaced by fibrous tissue. Better shape and radian were achieved in PDO cages filled with DBM and BMSCs than in the other two groups (cages alone, or cages filled with acellular DBM cuboids). When the repaired ribs were subjected to an outer force, the ribs in the PDO cage/DBMs/BMSCs group kept their original shape while ribs in the other two groups deformed. In the PDO cage/DBMs/BMSCs groups, we also observed bony union at all the construct interfaces while there was no bony union observed in the other two groups. This result was also confirmed by radiographic and histologic examination.ConclusionsThis study demonstrates that biodegradable PDO cage in combination with two short BMSCs/DBM cuboids can repair large rib defects. The satisfactory repair rate suggests that this might be a feasible approach for large bone repair.

Highlights

The reconstruction of large bone defects, including rib defects, remains a challenge for surgeons
Autogenous bone is often considered to be the best scaffold for bone tissue engineering [8,11,12], but concerns over the limited ability and donor site morbidity limit its use in the treatment of large defects, so allograft and xenograft bone often become the first choice in clinical applications
Gross observation All experimental dogs survived without any difficulty after surgery. No complications such as wound infection or paradoxical movement occurred after surgery

Summary

Introduction

The reconstruction of large bone defects, including rib defects, remains a challenge for surgeons. Tissue engineering has been demonstrated to be a viable technique for regenerating large segments of bone [6,7]; few attempts have been made to tissue engineer ribs where a complete segmental defect exists. Two important factors must be considered among many others—seed cell and scaffold. As for the scaffold, significant research has been performed to identify the best material for bone tissue engineering. Autogenous bone is often considered to be the best scaffold for bone tissue engineering [8,11,12], but concerns over the limited ability and donor site morbidity limit its use in the treatment of large defects, so allograft and xenograft bone often become the first choice in clinical applications

Methods

Results

Conclusion