Recent progress in the field of organ bioengineering based on decellularized organ scaffolds holds strong promise in addressing issues of donor organ shortage for transplantation in end-stage organ failure, biocompatibility of materials, continuous vascularisation and long-term functionality of regenerated tissues. This review highlights the key components in tissue engineering and approaches the perfusion-decellularization derived whole-organ scaffolds to serve as platforms in organ bioengineering. Important advances have occurred in small animal models, but the function exhibited by these designed organs has been rudimentary. In conclusion, this technology needs to be scaled up to human size to be of clinical relevance.
Tissue Engineering is defined as an multidisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain or improve the biological function of a tissue or whole organ.1 Although the idea of regeneration of organs or whole individuals has been well known through historical arts and literature of various cultures, in scientific research, the term tissue engineering was first used only recently in the 1980s, to employ living tissues and theoretically combine them with prosthetic materials. In addition, the actual generation of new tissue utilizing biological components, either alone or in combination with appropriate scaffolding material was further described in an article published in 1991 titled “Functional Organ Replacement: The New Technology of Tissue Engineering”.2 It was decided that with the emergence of innovative biocompatible materials it would be possible to generate new tissues successfully. Over the years, several attempts have been made by scientists to grow new tissues by seeding specialised cells on appropriately configured scaffolds; chondrocytes seeded on bone spicules, a collagen matrix to support the growth of dermal fibroblasts and keratinocyte sheets onto burn patients etc. A landmark experiment in this emerging field was in 1997 when chondrocytes were effectively seeded onto a scaffold made from poly (glycolic acid) and poly (lactic acid) cast from plastic replica of a human ear and implanted subcutaneously on the back of a mouse by Vacanti et. al. Since then, the fields of tissue engineering and regenerative medicine have increased their efforts in finding techniques necessary to develop functional tissue replacements of clinical relevance and complex organs such as the heart, lungs, kidney, liver and pancreas, remain the main challenge and goal.
The following image shows a simplified overview of the general methods used in tissue engineering: