Regenerating tissue is such fiddly work that not even our best 3D printers can successfully construct capillary systems. But you know what can? Spinach! Its network of veins is surprisingly similar to that of a human heart, only covered in yucky green plant stuff. So scientists removed all the plant cells, took the remaining cellulose skeleton, and together with some human heart cells, they managed to create a surprisingly effective highway to health.
But why stop there? Ideally, we could get the entire vegetable garden involved in fixing our failing meat bodies. The scientists have also managed to decellularize parsley and other backyard herbs, and they speculate that broccoli or cauliflower could stand in for lung tissue. That means there could be a future in which we eventually become more plant than human -- especially once we start decellularizing cucumbers.