美科学家培育出可移植的老鼠肾脏

Bioengineered rat kidneys developed by Massachusetts General Hospital (MGH) investigators¹ successfully produced urine both in a laboratory apparatus²（装置） and after being transplanted into living animals. In their report, receiving advance online publication in Nature Medicine, the research team describes building functional³ replacement⁴ kidneys on the structure of donor⁵ organs from which living cells had been stripped, an approach previously⁶ used to create bioartificial hearts, lungs and livers. "What is unique about this approach is that the native organ's architecture is preserved, so that the resulting graft⁷ can be transplanted just like a donor kidney and connected to the recipient's vascular⁸（血管的） and urinary systems," says Harald Ott, MD, PhD, of the MGH Center for Regenerative Medicine, senior author of the Nature Medicine article. "If this technology can be scaled to human-sized grafts⁹, patients suffering from renal failure who are currently waiting for donor kidneys or who are not transplant candidates could theoretically receive new organs derived¹⁰ from their own cells."   Around 18,000 kidney transplants are performed in the U.S. each year, but 100,000 Americans with end-stage kidney disease are still waiting for a donor organ. Even those fortunate enough to receive a transplant face a lifetime of immunosuppressive drugs, which pose many health risks and cannot totally eliminate the incidence（发病率） of eventual¹¹ organ rejection¹².   The approach used in this study to engineer donor organs, based on a technology that Ott discovered as a research fellow at the University of Minnesota, involves stripping the living cells from a donor organ with a detergent¹³ solution and then repopulating the collagen scaffold that remains¹⁴ with the appropriate cell type -- in this instance human endothelial（内皮的） cells to replace the lining¹⁵ of the vascular system and kidney cells from newborn rats. The research team first decellularized rat kidneys to confirm that the organ's complex structures would be preserved. They also showed the technique worked on a larger scale by stripping cells from pig and human kidneys.   Making sure the appropriate cells were seeded into the correct portions of the collagen scaffold required delivering vascular cells through the renal artery¹⁶ and kidney cells through the ureter. Precisely^{17#p#分页标题#e#} adjusting the pressures of the solutions enabled the cells to be dispersed¹⁸ throughout the whole organs, which were then cultured in a bioreactor for up to 12 days. The researchers first tested the repopulated organs in a device that passed blood through its vascular system and drained off any urine, which revealed evidence of limited filtering of blood, molecular¹⁹ activity and urine production.