Evaluation of Acellular Bilayer Silk Fibroin Grafts for Onlay Tracheoplasty in a Rat Defect Model

Abstract

Objective To assess the efficacy of acellular bilayer silk fibroin (BLSF) grafts to repair full-thickness tracheal defects and to compare the performance with conventional porcine small intestinal submucosa (SIS) implants. Study Design A prospective controlled animal trial in a rat model of onlay tracheoplasty. Setting Pediatric medical center. Subjects and Methods Tracheal reconstruction of adult Sprague-Dawley rats was performed with BLSF (n = 38) or SIS (n = 32) matrices for up to 3 months of implantation. Functional evaluations of repaired conduits as well as histologic, immunohistochemical, and histomorphometric analyses of neotissues were assessed. Results Prior to scheduled euthanasia, survival rates of rats receiving BLSF or SIS grafts were ≥94%, with no clinical signs of airway obstruction observed over the course of the study. Micro–computed tomography analysis revealed that the mean percentage of stenosis was <20% in both implant groups. BLSF and SIS grafts supported formation of pseudostratified ciliated columnar epithelium by 1 week postoperatively; however, each matrix failed to promote de novo chondrogenesis by 3 months following repair. Conclusions BLSF scaffolds can be used for reconstruction of rat tracheal patch defects with functional outcomes comparable to those of SIS matrices.

The application of small intestinal submucosa in tissue regeneration

“…Animals that received BLSF or SIS biomaterials did not display any respiratory distress symptoms and were able to maintain a patent and unobstructed endotracheal tube, according to a necropsy assessment. SIS grafts encouraged the regeneration of airway mucosa at the implant site, and the majority of SIS implants degraded within a month of surgery [ 145 ]. A recent survey reported that SIS mesh treated with a vacuum system exhibited superior cell attachment and viability compared to the control group [ 146 ].…”

Engineered biomimetic micro/ nano-materials for tissue regeneration

“…In three-position scaffold materials, the use of high-molecularweight substances such as silk fibroin (SF) and chitosan (CTS) has been widespread. SF has a wide range of sources and good biological properties (Algarrahi et al, 2018;Galvez Alegria et al, 2019); thus, its increasing use in tissue engineering and has good prospects. The fast rate of breakdown of SF, however, limits its use (Chomchalao et al, 2013).…”

Preparation and characterization of a novel triple composite scaffold containing silk fibroin, chitosan, extracellular matrix and the mechanism of Akt/FoxO signaling pathway in colonic cancer cells cultured in 3D

“…In three-position scaffold materials, the use of high-molecular-weight substances such as silk fibroin (SF) and chitosan (CTS) has been widespread. SF has a wide range of sources and good biological properties ( Algarrahi et al, 2018 ; Galvez Alegria et al, 2019 ); thus, its increasing use in tissue engineering and has good prospects. The fast rate of breakdown of SF, however, limits its use ( Chomchalao et al, 2013 ).…”