Derivation and characterization of a cytocompatible scaffold from human testis

Is it possible to derive a scaffold from human testis for the purpose of tissue engineering and regenerative medicine? We developed a method to produce a cytocompatible decellularized testicular matrix (DTM) while maintaining the native tissue-specific characteristics and components. The potential benefits of tissue-specific scaffolds consisting of naturally-derived extracellular matrix (ECM) have been demonstrated using a wide variety of animal and human tissue sources. However, so far, testis scaffolds have never been considered for constructive remodelling purposes. Human cadaveric testicular tissue was exposed for 24 or 48 h to 1% Triton X-100 and/or 1% sodium dodecyl sulphate (SDS). Acellular samples were used for further scaffold characterization purposes. The extent of decellularization was evaluated by histology. Confirmation of cell removal in DTM was done by a DNA quantification technique. Retention of testicular tissue-specific characteristics was evaluated by mass spectrometry, immunohistochemistry, Alcian blue staining and scanning electron microscopy. Soluble toxicity and testicular cell attachment was assessed to check the cytocompatibility of DTM scaffolds. Histological analysis showed that DTM could be obtained by mechanical agitation in 1% SDS for 24 h. The resulting DTM was found to be clear of cells while retaining the typical three-dimensional structure and the major components of the native tissue scaffold, including collagen type I and IV, fibronectin, laminin and glycosaminoglycans. In addition, using proteomic analysis, we revealed numerous additional ECM proteins in DTM, indicating its complex nature. The mass spectrometry data were deposited to the ProteomeXchange with identifier PXD001524. Importantly, we demonstrated that DTM scaffolds are not cytotoxic, as evidenced by MTT assay not showing an aberrant fibroblast proliferation activity after indirect exposure, and support testicular cell attachment and infiltration. The functionality of human testicular cells in DTM needs to be investigated. Our results suggest that the insights into the molecular composition of the testicular ECM provide new clues for the unravelling of its important yet poorly understood role in regulating testicular function, and DTM-based bioscaffolds are promising components for the development of human in vitro spermatogenesis as a treatment for various types of male fertility disorders. This study is supported by a Ph.D. grant from the Agency for Innovation by Science and Technology (IWT) and research grants from the Flemish League Against Cancer-Public Utility Foundation (VLK), the Scientific Research Foundation Flanders (FWO), the Vrije Universiteit Brussel, the Swedish Research Council/ Finnish Academy of Science, Emil och Wera Cornells Stiftelse, the Swedish Childhood Cancer Foundation as well as through the regional agreement on medical training and clinical research (ALF) between Stockholm County Council and Karolinska Institutet. J.-B.S. was supported by the German Research Foundation (DFG-Grant No.: STU 506/3-1). E.G. and J.D.K. are postdoctoral fellows of the Scientific Research Foundation Flanders. The authors declare that no competing interests exist. Not applicable.