Combined Use of Detergents and Ultrasonication for Generation of an Acellular Pig Larynx

The larynx is a fairly complex organ comprised of different muscles, cartilages, mucosal membrane, and nerves. Larynx cancer is generally the most common type of head and neck cancer. Treatment options are limited in patients with total or partial laryngectomy. Tissue-engineered organs have shown to be a promising alternative treatment for patients with laryngectomy. In this report we present an alternative and simple procedure to construct a whole pig larynx scaffold consisting of complete acellular structures of integrated muscle and cartilage. Larynges were decellularized (DC) using perfusion-agitation with detergents coupled with ultrasonication. DC larynges were then characterized to investigate the extracellular matrix (ECM) proteins, residual DNA, angiogenic growth factors, and morphological and ultrastructural changes to ECM fibers. After 17 decellularization cycles, no cells were observed in all areas of the larynx as confirmed by hematoxylin and eosin and DAPI (4 ',6-diamidino-2-phenylindole) staining. However, DC structures of dense thyroid and cricoid cartilage showed remnants of cells. All structures of DC larynges (epiglottis [p < 0.0001], muscle [p < 0.0001], trachea [p = 0.0045], and esophagus [p = 0.0008]) showed DNA <50 ng/mg compared with native larynx. Immunohistochemistry, Masson's trichrome staining, and Luminex analyses showed preservation of important ECM proteins and angiogenic growth factors in DC larynges. Compared with other growth factors, mostly retained growth factors in DC epiglottis, thyroid muscle, and trachea include granulocyte colony-stimulating factor, Leptin, fibroblast growth factor-1, Follistatin, hepatocyte growth factor, and vascular endothelial growth factor-A. Scanning electron microscopy and transmission electron microscopy analysis confirmed the structural arrangements of ECM fibers in larynges to be well preserved after DC. Our findings suggest that larynges can be effectively DC using detergent ultrasonication. ECM proteins and angiogenic growth factors appear to be better preserved using this method when compared with the native structures of larynges. This alternative DC method could be helpful in building scaffolds from dense tissue structures such as cartilage, tendon, larynx, or trachea for futurein vitrorecellularization studies orin vivoimplantation studies in the clinic. Impact statement This study successfully created decellularized porcine larynx using novel method of perfusion-agitation with detergents and ultrasonication, which maintained three-dimensional architecture of the larynx scaffold. Our method is devoid of harmful enzymes, which may prevent cellular repopulation or induce inflammatory response uponin vivoimplantation. We studied important aspect of preservation of extracellular matrix proteins in different structures of the larynx. Hence, our decellularization method could be used as an alternative method to decellularize various dense tissues such as cartilage or tendon.

Automated summary

The larynx is a complex organ consisting of various muscles, cartilages, mucosal membrane, and nerves, with larynx cancer being the most common type of head and neck cancer. Treatment options are limited for patients undergoing total or partial laryngectomy, but tissue-engineered organs have shown promise as an alternative. A novel decellularization method involving perfusion-agitation with detergents and ultrasonication was used to construct a pig larynx scaffold with preserved ECM proteins and angiogenic growth factors.