Protocol for In Utero Fetal-to-Fetal Kidney Transplantation in Rats.

Area of Science:

• Developmental Biology
• Regenerative Medicine
• Fetal Surgery

Background:

• Congenital renal disorders, like Potter sequence, stem from renal dysgenesis.
• Current research lacks protocols for whole-organ transplantation during gestation.
• Prenatal therapeutic approaches are needed for fetal kidney insufficiency.

Purpose of the Study:

• To establish a step-by-step protocol for in utero whole-organ fetal kidney transplantation.
• To enable longitudinal assessment of graft maturation in a fetal environment.
• To create a model for studying developmental organogenesis and fetal immunology.

Main Methods:

• Grafting donor fetal kidneys (embryonic day 14.0-16.5) into allogeneic rat fetuses (embryonic day 18.0-18.5).
• Utilizing transuterine needle insertion for subcutaneous deposition of the donor kidney.
• Natural delivery of term pups for postnatal evaluation and observation.

Main Results:

• Successful transplantation of whole fetal kidneys into recipient fetuses.
• Grafts were retained postnatally in term neonates.
• The protocol allows for real-time visualization using GFP-expressing donor tissue.

Conclusions:

• This is the first protocol for successful whole-organ transplantation directly into fetuses in utero.
• The model is valuable for studying organogenesis, fetal immunology, and regenerative strategies.
• The protocol is adaptable for xenotransplantation and immunological tolerance studies.