Rapid and Detergent-Free Decellularization of Cartilage

The use of decellularized tissues or organs as cell culture scaffolds has proven to be a promising approach for tissue engineering and regenerative medicine, as these decellularized tissues can provide the instructive niche for cell differentiation and functions. Cartilage is a largely avascular tissue with limited regenerative capacity. Lesions caused by arthritis can lead to severe cartilage degeneration. Previous studies have indicated that decellularized cartilage can be used as scaffolds that support the chondrogenic differentiation of adult stem cells. However, these decellularization protocols all require the use of denaturing agents, such as high salt and detergents, that lead to the artifactual disruption of the chemical and physical integrity of the tissue microenvironment. Here, we established a new decellularization method for cartilage, through a combined effect of freezing-thawing, sectioning, and sonication in water. This protocol achieved the complete removal of cells within minutes, instead of hours or days required by existing procedures, and does not use any detergent. The resulting decellularized cartilage preserved the native ultrastructure and biochemical contents, including glycosaminoglycans, which is typically depleted by traditional decellularization methods. Human mesenchymal stem cells could readily adhere onto the decellularized cartilage. Together, this work unveils a simple new method for decellularizing cartilage, which will be useful in studying how tissue microenvironment supports chondrocyte growth and functions. Impact statement In this study, we develop a simple, fast cartilage decellularization method that does not require any detergent, so that the decellularized cartilage chemistry is preserved. Traditional detergent-based decellularization removes the tissue biochemical contents (i.e., glycosaminoglycans). In this new water decellularization protocol, the biochemical contents of cartilage can be preserved. This allows the study of biochemistry and physical content in extracellular matrix as a whole, and this protocol would definitely be useful for studying the effect of tissue microenvironment in supporting chondrocyte growth and functions.