Submit Manuscript | http://medcraveonline.com Abbreviations: CKD, chronic kidney disease; PEG, polye- thylene glycol; PCL, polycaprolactone; CAPs, cell adhesive proteins; DDR, discoidin domain receptors; LIFT, laser-induced forward trans- fer; CAD/CAM, computer-aided design and manufacturing; CKD, chronic kidney disease; MtoBS, multiple-head tissue/organ buil- ding systems; ATG, antithymocye globulin; BKV, BK virus; CMV, cytomegalo virus; DM, diabetes mellitus; EBV, epstein-barr virus; MMF, mycophenolate mofetil; mTOR, mammalian target of rapamy- cin; CAP, cell-adhesive peptide, ESP, enzyme-sensitive peptide, GF, growth factor Introduction Market size In the United States, approximately 400 billion dollars is spent annually on the treatment of patients who are suffering from end-stage organ failure, representing 50% of total healthcare costs. 1 According to Global Industry Analysts, Inc., it is expected that the market for organ preservation will reach 178.8 million US dollars by the year 2020 (Figure 1). 2 This market is showing a steady increase due to the high rate of end-stage organ failure, organ shortage and long wait times for organ transplantation. 2 The scarcity of available organs and organ donors is becoming a major problem as the need for organs increases. 3 As of January 2016, there are 100,791 individuals in the United States are waiting to receive a kidney transplant. 4 Currently, there are only 13,066 available organ donors, leaving 87% of patients without an available organ. 5 According to the United States Department of Health & Human Services, an organ recipient is being added every ten minutes to the waiting list and twenty-two patients die every day waiting for an organ transplant. 5 The large gap in supply and demand has even led to some organ donors seeking monetary compensation on the black market. 6 Moreover, even when a viable organ is available, it may be unusable due to lack of consent. 7 Although there is much awareness regarding the need for organ donors, individuals are unable to donate their organs unless they have provided written consent. 8 Although organ transplantation is the most viable option for treating CKD, it is clearly not a perfect solution. 9,10 Kidney transplantation methods When a CKD patient is ready to receive a new kidney, there are still many factors that come into play when considering the best path to successful treatment. In general, there are three types of kidney transplantation. 11,12 Iso-transplantation occurs between genetically- matched individuals, allo-transplantation occurs between non- genetically matched individuals and Xeno-transplantation occurs between two different species. 11,12 The lack of suffcient donor kidneys has lead to xeno-transplantation as a possible solution. 13 Most researchers consider pigs to be the most suitable source of organs due to the vast supply of available animal tissue. 14 Moreover, xeno- transplantation has the added beneft of being able to manipulate the organ to specifcally match the recipient’s needs. 14 Yet despite its potential, xeno-transplantation is still considered by many to be an unsafe form of transplantation. Xeno-transplantation carries a high probability of organ rejection and transmission of infectious agents from the donor tissue. 15 Lastly, the shorter life span of donor animals means that their organ would age at a faster rate than a human organ. 12 Iso and allo-transplantation remain safer alternatives over xeno- transplantation but they are still not guaranteed solutions, as they are still capable of eliciting an immune response to the donor tissue. 16 It is essential to monitor organ health to ensure long-term survival J Appl Biotechnol Bioeng. 2017;2(3):78‒86. 78 © 2017 Lobos et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and build upon your work non-commercially. Home-grown kidneys: challenges and mechanisms behind tissue engineering for the treatment of chronic kidney disease Volume 2 Issue 3 - 2017 Jezreel Lobos, Arpit Batish, Amandeep Sharma, Bill Tawil UCLA, USA Correspondence: Bill Tawil, UCLA, 420 Westwood Plaza, Room 5121, Engineering V, P.O. Box 951600, Los Angeles, CA 90095-1600, USA, Email btawil@seas.ucla.edu Received: January 01, 2016 | Published: February 24, 2017 Abstract Chronic kidney disease (CKD) is the leading cause of death for individuals suffering from end-stage kidney failure. While kidney transplantation is the most viable solution to CKD, it has many challenges and limitations. This review evaluates kidney transplant rejection and the various transplantation methods that may be employed to treat CKD. Kidney rejection and long-term transplant survival is the main concern regarding transplantation attempts. Thus, scientist must screen and strategize appropriately to ensure kidney transplant survival. Tissue engineering techniques are explored as means to improve upon transplantation attempts. Research into ensuring adequate organ scaffold design has become crucial in the field of regenerative medicine. Furthermore, the role of integrins is discussed as a central component for future tissue engineering techniques, by taking the study of scaffold design to the molecular level. Finally, a glimpse into the current advancements of three-dimensional bioprinting highlights the future of tissue engineering and shows how the field of regenerative medicine is taking another step closer to developing “home-grown” kidneys. With the prospect of generating a fully lab-created, personalized kidney, CKD may one day be treated without encountering any of the limitations that have hindered previous attempts. Keywords: home-grown, kidney transplantation, integrin, bioprinting, tissue engineering Journal of Applied Biotechnology & Bioengineering Review Article Open Access