3D functional organ printing: Promises and future challenges

Recent advancements in stem technology have been successfully adopted in tissue engineering and inspired biomanufacturing of biologically active 3D living organs. Although, 3D printing of a fully functioning organ has not been achieved for transplant yet, it is not far-fetched. Considering tremendous number of patients waiting for an organ transplant in the United States, of which approximately 17 people die a day waiting for an organ, organ printing will be a promising revolutionary technology saving human lives. Organ printing is layer-by-layer manufacturing of artificial functional organs, where living cells are deposited in a 3D spatially-oriented pattern by a robotically controlled platform. The technology is commercially available for skin, bone and cartilage tissue engineering; however, it further needs advancement to be clinically applicable for organs with complex physiological functionalities such as heart, pancreas and kidney. This paper reviews recent technologies in 3D organ printing for translational clinics and insights the concept of printing living cells and their 3D assembly. Current limitations including but not limited to tissue rejections, cell viability, 3D cellular assembly in a bioreactor environment, integration of blood vessels and need for multi-cellular non-homogeneous constructions are discussed and future challenges are highlighted.