PLGA-PTMC-Cultured Bone Mesenchymal Stem Cell Scaffold Enhances Cartilage Regeneration in Tissue-Engineered Tracheal Transplantation.

The treatment of long-segment tracheal defect requires the transplantation of effective tracheal substitute, and the tissue-engineered trachea (TET) has been proposed as an ideal tracheal substitute. The major cause of the failure of segmental tracheal defect reconstruction by TET is airway collapse caused by the chondromalacia of TET cartilage. The key to maintain the TET structure is the regeneration of chondrocytes in cartilage, which can secrete plenty of cartilage matrices. To address the problem of the chondromalacia of TET cartilage, this study proposed an improved strategy. We designed a new cell sheet scaffold using the poly(lactic-co-glycolic acid) (PLGA) and poly(trimethylene carbonate) (PTMC) to make a porous membrane for seeding cells, and used the PLGA-PTMC cell-scaffold to pack the decellularized allogeneic trachea to construct a new type of TET. The TET was then implanted in the subcutaneous tissue for vascularization for 2 weeks. Orthotopic transplantation was then performed after implantation. The efficiency of the TET we designed was analyzed by histological examination and biomechanical analyses 4 weeks after surgery. Four weeks after surgery, both the number of chondrocytes and the amount of cartilage matrix were significantly higher than those contained in the traditional stem-cell-based TET. Besides, the coefficient of stiffness of TET was significantly larger than the traditional TET. This study provided a promising approach for the long-term functional reconstruction of long-segment tracheal defect, and the TET we designed had potential application prospects in the field of TET reconstruction.

A new alternative for bony chest wall reconstruction using biomaterial artificial rib and pleura: animal experiment and clinical application.

OBJECTIVE: To evaluate a new method for chest wall reconstruction using porcine-derived artificial rib and pleura in an animal experiment. Further, the clinical application was performed in five patients with large defects in the chest wall as a preliminary observation. METHODS: In animal experiments, a full-thickness chest wall defect of 7 cm × 8 cm was created in 12 adult mongrel dogs. Six dogs underwent reconstruction with porcine-derived artificial ribs and pleura (test group), and six with methylmethacrylate and double polyester mesh in the form of traditional Marlex sandwich technique (control group). At follow-up of each for 3, 6, and 12 months postoperatively, a general performance assessment and thoracic radiography were performed. Gross and histopathological examinations were carried out following humane euthanasia at the time of last follow-up. In clinical application, five patients with wide tumor resection in the chest wall underwent reconstruction with porcine-derived artificial ribs and pleura as well. RESULTS: In animal experiment, no perioperative death or hyperpyrexia occurred and no difference in either infection or dyspnea was noted between the two groups. Postoperative radiography revealed good thoracic integrity with no evidence of collapse, deformation, or abnormal movement in the test group. In the control group, similar results were observed, except that two dogs had abnormal movement in the chest wall associated with respiration. Severe adhesions between the 'sandwich' complex and the host tissues were identified in the control group, but by contrast, only mild adhesions were noted in the test group. The non-degradable polyester mesh induced fibrous proliferation and rejection, whereas the artificial pleura was absorbed with mild fibrous hyperplasia after 12 months. In clinical application, no thoracic deformity, chronic pain, or respiratory discomfort were observed at 1 or 12 postoperative months. CONCLUSIONS: Porcine-derived ribs and pleura can be employed safely to create an artificial chest wall to repair bony chest defects. The clinical results corresponded well with those of animal experiments, and thus confirmed the safety and feasibility of this new alternative of chest wall reconstruction. However, a long-term study in a large number is needed due to the small number of animals in this study.