Body parts are built up of composite tissues, which are organized in assembled tissue layers (e.g. skin and cartilage for the ear), each structured by a specific extracellular matrix (ECM). The ECM provides structural, mechanical and biochemical support for the cells. The ECM’s proper 3D architecture (i.e. morphology and organization) is fundamental for tissue homeostasis and function. For the regeneration of a damaged organ or body part, Tissue Engineering (TE) is envisioned as a promising solution. This approach makes use of TE constructs, combining cells with a matrix, either derived for native tissues with the decellularization process, or originated from synthetic biomaterials (i.e. with bioprinting or electrospinning). For the latest, this option remains hypothetical due to, amongst others, the lack of knowledge about the appropriate true ECM 3D-architecture and the right technology to reproduce it. The objective of this project is to develop antigen-specific stainings, comparable to immunohistochemistry, for different components of the ECM in whole tissues. We will leverage ex vivo high-resolution contrast-enhanced X-ray microfocus computed tomography (CECT) imaging to become a non-invasive quantitative 3D anatomical pathology tool that will allow unprecedented 3D characterization of the internal architecture and interdependency of the ECM components (i.e. neotissue and vascular network).