An optimized non-destructive protocol for testing mechanical properties in decellularized rabbit trachea.

Successful tissue-engineered tracheal transplantation relies on the use of non-immunogenic constructs, which can vascularize rapidly, support epithelial growth, and retain mechanical properties to that of native trachea. Current strategies to assess mechanical properties fail to evaluate the trachea to its physiological limits, and lead to irreversible destruction of the construct. Our aim was to develop and evaluate a novel non-destructive method for biomechanical testing of tracheae in a rabbit decellularization model. To validate the performance of this method, we simultaneously analyzed quantitative and qualitative graft changes in response to decellularization, as well as in-vivo biocompatibility of implanted scaffolds. Rabbit tracheae underwent two, four and eight cycles of detergent-enzymatic decellularization. Biomechanical properties were analyzed by calculating luminal volume of progressively inflated and deflated tracheae with microCT. DNA, glycosaminoglycan and collagen contents were compared to native trachea. Scaffolds were prelaminated in vivo. Native, two- and four-cycle tracheae showed equal mechanical properties. Collapsibility of eight-cycle tracheae was significantly increased from -40 cmH2O (-3.9 kPa). Implantation of two- and four-cycle decellularized scaffolds resulted in favorable flap-ingrowth; eight-cycle tracheae showed inadequate integration. We showed a more limited detergent-enzymatic decellularization successfully removing non-cartilaginous immunogenic matter without compromising extracellular matrix content or mechanical stability. With progressive cycles of decellularization, important loss of functional integrity was detected upon mechanical testing and in-vivo implantation. This instability was not revealed by conventional quantitative nor qualitative architectural analyses. These experiments suggest that non-destructive, functional evaluation, e.g. by microCT, may serve as an important tool for mechanical screening of scaffolds before clinical implementation

Twenty years of experience with the rabbit model, a versatile model for tracheal transplantation research

Pathologies comprising more than half the length of the trachea are a challenge to the reconstructive surgeon. Innovative tracheal transplantation techniques aim to offer the patient a curative solution with a sustained improvement in quality of life. This review summarizes the authors’ experience with the rabbit as a versatile model for research regarding tracheal transplantation. Because of the segmental blood supply of the trachea, it is not feasible to transplant the organ together with a well-defined vascular pedicle. As such, the key element of successful tracheal transplantation is the creation of a new blood supply. This vascularized construct is created by prelaminating the rabbit trachea heterotopically, within the lateral thoracic fascia. After prelamination, the construct and its vascular pedicle are transferred to the orthotopic position in the neck. This model has become gold standard because of the advantages of working with rabbits, the anatomy of the rabbit trachea, and the reliability of the lateral thoracic artery flap. In this paper, the key elements of surgery in the rabbit are discussed, as well as the tracheal anastomosis and the harvest of the lateral thoracic artery flap. Practical tips and tricks are presented. The data described in this review represent the fundaments of ongoing translational research in the center over the past twenty years

Gene mapping in the river buffalo (Bubalus bubalis L)

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