Kidney Capsule Transplantation of Organoids

As previously described, a single HIO, matured in vitro for 28 d, was removed from Matrigel and then transplanted under the kidney capsule^{12 (link)}. Briefly, the mice were anesthetized with 2% inhaled isoflurane (Butler Schein) and 2.5–3 l min⁻¹ oxygen. The left side of the mouse was then prepped in sterile fashion with isopropyl alcohol and providine-iodine. A small left-posterior subcostal incision was made to expose the kidney. A subcapsular pocket was created in the kidney capsule and the HIO was then placed into the pocket. The kidney was then returned to the peritoneal cavity and the mice were given an intraperitoneal flush with 2–3 ml of piperacillin/tazobactam (100 mg kg⁻¹; Pfizer) to help prevent bacterial infection. The skin was closed in a double layer. For pain control, mice were then given a subcutaneous injection with buprenorphine (0.05 mg kg⁻¹; Midwest Veterinary Supply) or carprofen (4 mg kg⁻¹; Midwest Veterinary Supply) and were monitored for the next 48 h following surgery. Additional injections of pain medication were given if needed. At 12 and 16 weeks following engraftment, the mice were then euthanized and the tissues were collected and analyzed.