Despite an increase in interested donors, the shortage of Organs has worsened. For example, about 80 000 persons in the United States awaiting an organ transplant from July 2000 to July 2001, with less than a third receiving one. The answer to this problem, like other big engineering challenges, necessitates long-term solutions involving the construction or manufacture of living organs from a person's own cells. Tissue engineering has evolved over the last three decades as a multidisciplinary subject comprising scientists, engineers, and clinicians with the goal of generating biological substitutes that replicate natural tissue to replace damaged tissues or restore organ function. Tissue engineering and regenerative medicine, which aim to create functioning tissue-constructs that mimic native tissue for the repair and/or replacement of damaged tissues or complete organs, have progressed quickly in recent decades. Traditional tissue engineering procedures, which use scaffolds, growth factors, and cells, have had little success in fabricating complicated 3D structures and in vivo organ regeneration, making them logistically and economically unsuitable for clinical use.