**A New Decellularization Protocol of Porcine Aortic Valves Using Tergitol to Characterize the Scaffold with the Biocompatibility Profile Using Human Bone Marrow Mesenchymal Stem Cells**

**Marika Faggioli 1,2 , Arianna Moro 2,3, Salman Butt 1,2, Martina Todesco 2,3 , Deborah Sandrin 2,4 , Giulia Borile 2,4 , Andrea Bagno 2,3 , Assunta Fabozzo 1,2 , Filippo Romanato 2,4 , Massimo Marchesan <sup>5</sup> , Saima Imran 1,2,\* and Gino Gerosa 1,2**


**Abstract:** The most common aortic valve diseases in adults are stenosis due to calcification and regurgitation. In pediatric patients, aortic pathologies are less common. When a native valve is surgically replaced by a prosthetic one, it is necessary to consider that the latter has a limited durability. In particular, current bioprosthetic valves have to be replaced after approximately 10 years; mechanical prostheses are more durable but require the administration of permanent anticoagulant therapy. With regard to pediatric patients, both mechanical and biological prosthetic valves have to be replaced due to their inability to follow patients' growth. An alternative surgical substitute can be represented by the acellular porcine aortic valve that exhibits less immunogenic risk and a longer lifespan. In the present study, an efficient protocol for the removal of cells by using detergents, enzyme inhibitors, and hyper- and hypotonic shocks is reported. A new detergent (Tergitol) was applied to replace TX-100 with the aim to reduce toxicity and maximize ECM preservation. The structural integrity and efficient removal of cells and nuclear components were assessed by means of histology, immunofluorescence, and protein quantification; biomechanical properties were also checked by tensile tests. After decellularization, the acellular scaffold was sterilized with a standard protocol and repopulated with bone marrow mesenchymal stem cells to analyze its biocompatibility profile.

**Keywords:** decellularization; Tergitol; valve bioprostheses; cardiac tissue engineering; mesenchymal stem cells; biocompatibility
