Feasibility of large experimental animal models in testing novel therapeutic strategies for diabetes

Table 1 Hurdles in clinical islet transplantation for type 1 diabetes mellitus

	Hurdles in clinical islet transplantation for type 1 diabetes mellitus
1	Poor access to human islets due to the scarcity of organ donors
2	Graft failure (e.g., metabolic pressure, oxidative stress caused by hypoxia or inflammation)
3	Continued autoimmunity and alloimmunity
4	Immunosuppressive drug therapy
5	Behavior of the transplanted cells in the growing body for transplantations performed in adolescents/children

Table 2 Use of pigs as biomedical research subjects

	Advantages
1	Similar body size, shape, and anatomy as that of humans
2	Human-relevant metabolic physiology and pathophysiology
3	Monogastric omnivore
4	Multiparity, short gestation, short generation interval, and long-life cycle
5	Pancreatic and islet architecture similar to that of humans
6	Can undergo the same surgical procedure as in humans
7	Tools for genetic alterations are available
8	High litter size makes the production of genetically modified pigs less time-consuming in comparison with other livestock species
	Disadvantages
1	Specialized facilities are required
2	Costly to maintain
3	Ethical issues associated with the use of pigs in biomedical research