CHICAGO » A 2-year-old girl who was implanted with a windpipe grown from her own stem cells has died, three months after she became the youngest person to receive the experimental treatment.

Hannah Warren died Saturday at Children’s Hospital of Illinois in Peoria, hospital spokeswoman Shelli Dankoff said. The hospital said in a statement that Hannah couldn’t "overcome additional health issues that were identified as her care progressed."

Her family asked for privacy, but expressed their sorrow in a fundraising blog updated Sunday: "She is a pioneer in stem-cell technology and her impact will reach all corners of our beautiful Earth. Her new trachea was performing well, but her lungs went from fairly good, to weak, to poor."

Hannah’s treatment was part of an ongoing scientific effort to develop lab-grown tissues and organs. Similar methods have been used to grow bladders, urethras and last year a girl in Sweden got a lab-made vein using her own stem cells and a cadaver vein.

In Hannah’s case, the stem cells came from her bone marrow. They were seeded in a lab onto a plastic scaffold, where it took a few days for them to multiply and create a new windpipe, which was implanted April 9.

Hannah was born in South Korea and traveled to Illinois for the surgery. A pediatric surgeon in Peoria had met Hannah’s family while on a business trip to South Korea and helped connect them with Dr. Paolo Macchiarini, an Italian surgeon based in Sweden who pioneered the technique.

Hannah’s parents, Darryl Warren and Lee Young-mi, had read about Macchiarini’s success using stem-cell based tracheas, but they couldn’t afford to pay for the operation at his center in Stockholm. Dr. Mark Holterman, the Illinois doctor, helped the family arrange to have the procedure at his hospital with Macchiarini leading the surgical team. Children’s Hospital waived the cost.

The hospital is part of OSF Saint Francis Medical Center, a Roman Catholic system that considers the operation part of its mission to provide charity care and a way to champion a type of stem-cell therapy that doesn’t involve human embryos, the surgeons said in April. The Catholic church opposes using stem cells derived from human embryos in research or treatment.

Hannah wasn’t able to leave the hospital after the operation, Dankoff said. The girl’s family and her caregivers believe the knowledge gained from her surgery will benefit other patients.

Hannah would have been 3 years old on Aug. 22.

"We will forever miss her infectious personality and miraculous strength and spirit," her family wrote on their blog.

AP Medical Writer Lindsey Tanner contributed to this report.