A new decellularized tendon scaffold for rotator cuff tears - evaluation in rabbits.

BACKGROUND: Scaffolds have considerably advanced in recent years. In orthopaedic surgery, scaffolds have been used as grafts in procedures involving tendon and ligament reconstruction. This paper aimed to produce and evaluate decellularized tendon scaffolds (DTSs) from biomechanical, microscopic, macroscopic and in vivo perspectives. METHODS: Bilateral gastrocnemius muscle tendons from 18 adult New Zealand rabbits were collected. Of these 36 tendons, 11 were used as controls (Group A - control), and 25 were used in the decellularization protocol (Group B - DTS). The groups were subjected to histological, biomechanical and macroscopic analyses, and Group B - DTS was subjected to an additional in vivo evaluation. In the decellularization protocol, we used a combination of aprotinin, ethylenediamine tetraacetic acid (EDTA), sodium dodecyl sulfate (SDS) and t-octyl-phenoxypolyethoxyethanol (Triton X-100) for six days. During this period, the scaffolds were kept at room temperature on an orbital shaker with constant motion. RESULTS: The DTSs showed an increased cross-sectional area and inter-fascicular distance and no change in parallelism or matrix organization. The nuclear material was not organized in the DTSs as it was in the control. In the biomechanical analysis, no significant differences were found between the groups after analysing the ultimate tensile load, stiffness, and elongation at the ultimate tensile load. During the in vivo evaluation, mononuclear cell infiltration was noted. CONCLUSIONS: The evaluated decellularization protocol generated a tendon scaffold, maintained the most important biomechanical characteristics and permitted cell infiltration.