Stem Cell-Based Tissue-Engineered Laryngeal Replacement

Abstract

Patients with laryngeal disorders may have severe morbidity relating to swallowing, vocalization, and respiratory function, for which conventional therapies are suboptimal. A tissue‐engineered approach would aim to restore the vocal folds and maintain respiratory function while limiting the extent of scarring in the regenerated tissue. Under Good Laboratory Practice conditions, we decellularized porcine larynges, using detergents and enzymes under negative pressure to produce an acellular scaffold comprising cartilage, muscle, and mucosa. To assess safety and functionality before clinical trials, a decellularized hemilarynx seeded with human bone marrow‐derived mesenchymal stem cells and a tissue‐engineered oral mucosal sheet was implanted orthotopically into six pigs. The seeded grafts were left in situ for 6 months and assessed using computed tomography imaging, bronchoscopy, and mucosal brushings, together with vocal recording and histological analysis on explantation. The graft caused no adverse respiratory function, nor did it impact swallowing or vocalization. Rudimentary vocal folds covered by contiguous epithelium were easily identifiable. In conclusion, the proposed tissue‐engineered approach represents a viable alternative treatment for laryngeal defects. Stem Cells Translational Medicine 2017;6:677–687

Biomedical grafts for tracheal tissue repairing and regeneration “Tracheal tissue engineering: an overview”

“…It was found that natural scaffolds are biocompatible, less immunogenic, and biomimetic to the native tissue with all the essential functional group for better cell attachment and proliferation for neo‐tissue regeneration. And after getting preclinical studies and satisfactory verification from two formal clinical trials of partial laryngeal and tracheal replacement, porcine decellularized scaffolds seeded with human cells use started from 2015 for tissue engineering and preclinical study (Ansari et al, ; Liu et al, ). In another study, freeze‐dried collagenous biosheets implanted in rabbit model showed hyaline cartilage and mucosal layer regeneration (Komura et al, ; Satake et al, ).…”

In vivo feasibility study of the use of porous polyhedral oligomeric silsesquioxane implants in partial laryngeal reconstruction

“…We have previously shown that tissue engineered partial laryngeal replacements based on recellularised biological (decellularised donor tissue) scaffolds are safe and encourage functional laryngeal regeneration in pigs 13,14 . However, preparation of clinical products based on biologic scaffolds requires a dependable supply chain of organs of varying size and gender from human donors, intensive sterilisation, and means of controlling reproducible and sustainable biomechanical strength.…”

“…We and others have used two-stage procedures with pre-implantation of constructs into wellvascularised areas such as the forearm or muscle, in order to pre-vascularise implants and support tissue ingress into implants for use in airway reconstruction 14,23 . It is possible that this strategy might be applicable to implants based on polymeric scaffolds also and might be a more successful approach than the present direct, one-stage, protocol if improved formulations of POSS-PCU, other POSS family polymers, or other biomaterials, are explored for this purpose in future.…”

In vivo implantation of a tissue engineered stem cell seeded hemi‐laryngeal replacement maintains airway, phonation, and swallowing in pigs

“…We used our previously developed protocol for de‐cellularisation, which has been successfully applied to human and porcine trachea (Lange et al, ; Lange, Shah, Birchall, Sibbons, & Ansari, ) and porcine larynx (Ansari et al, ). Briefly, the thawed tissue (hemilarynges) was incubated in 50 nmol/L Latrunculin B (Sigma‐Aldrich, UK) in high‐glucose Dulbecco's modified Eagle's medium (Gibco, Paisley, Scotland) for 2 hr at 37°C.…”

“…Our previous study (Ansari et al, ) focused on the implantation of a de‐cellularised hemi‐larynx seeded with human bone marrow derived mesenchymal stem cells (BM‐MSC) and an oral mucosal sheet to assess potential safety (with respect to swallowing, feeding, and vocalisation) in a 6‐month large animal model. The implantation procedure was a two‐step approach; seeded scaffolds were initially placed in a muscle and fascia pocket to allow for vascularisation, followed by orthotopic implantation.…”