Characterisation and immunogenicity of a decellularised skeletal muscle scaffold for laryngeal tissue engineering

Background Successful replacement of airways in patients has been done with tissue engineered constructs. However, replacing the larynx where active movement is crucial, requires functional muscle tissue. Methods Decellularised scaffolds were characterised with histological, immunohistochemical, and molecular techniques and xenogenically implanted to determine the effect of implantation on scaffold biodegradation time and immunogenicity in vivo. The cellular host immune response to the scaffold was quantified by stereology and by fluorescence activated cell sorting in vitro. Findings Decellularisation results in total DNA clearance and downregulation of MHC classes I/II and myosin heavy chain expression, with relative preservation of the scaffold's structural integrity (collagen, elastin, s-glycosaminoglycans content) and biomechanical properties. Decellularisation altered the host response to the scaffold in vivo, resulting in a prolonged degradation time and increased neoangiogenic potential relative to fresh tissue. In addition, we proved for the first time that decellularised scaffolds trigger a lower cellular mediated immune response, resulting in a reduced T-cell proliferative response in vitro, and alter the cellular immune profile towards the scaffolds in vivo, with a reduction in CD3+ cells and a shift towards the M2-macrophage phenotype. Interpretation Decellularised laryngeal muscles are non-immunogenic and may provide the optimum scaffold source for a tissue-engineered larynx. Funding UK Medical Research Council, Sparks Children's Charity, and Royal College of Surgeons of England.