Decellularized scaffolds for tissue engineering: Current status and future perspective.

Based on Organ Procurement and Transplantation Network data as of December 2019, more than 113 000 patients require an organ transplantation, yet, over the course of this past year, only 36 000 patients received a transplant. This discrepancy between those that need a donor organ and those that receive one remains one of medicine's biggest challenges. Multiple solutions, both biologic and artificial, have been proposed to mitigate this difference. One of the most promising approaches to generate bioartificial organs for transplantation involves re-seeding decellularized scaffolds with appropriate cells. Decellularization involves physical, chemical, or biological methods that typically require intimate contact of various decellularization solutions with each cell. Consequently, conventional submersion decellularization has been limited to simple tissues such as heart valves. The invention of perfusion decellularization was a breakthrough that allowed the generation of tissue-engineered scaffolds from tissues with higher structural organization and entire organs. Such scaffolds are composed of a myriad of extracellular matrix (ECM) components that include collagen, elastin, proteoglycans, and glycoproteins. Together, these components allow the scaffolds to fulfill specialized functions, such as structural functions as well as biological functions including the regulation of cellular processes and extracellular molecules. These specialized functions of decellularized scaffolds can increasingly be harnessed for applications in tissue engineering.