What if humans could regrow tissue? Texas A&M study moves science closer
Published in Bioprinting.
Researchers have successfully regenerated skeletal and connective tissue — even if not perfectly formed — demonstrating the next, critical step in limb regeneration.
For centuries, the inability to regrow lost body parts has been considered a defining limitation of humans and other mammals. While animals like salamanders can regenerate entire limbs, humans are left with scar tissue.
But new research from the Texas A&M College of Veterinary Medicine and Biomedical Sciences (VMBS) suggests that this limitation may not be permanent. Instead, the capacity for regeneration may still exist — hidden within the body’s normal healing process.
“Why some animals can regenerate and others, particularly humans, can’t is a big question that has been asked since Aristotle,” said Dr. Ken Muneoka, a professor in the VMBS’ Department of Veterinary Physiology & Pharmacology (VTPP). “I’ve spent my career trying to understand that.”
In their study, published in Nature Communications, Muneoka and his colleagues detail a newly developed two-step treatment that led to the regeneration of bone, joint structures and ligaments. While the results were imperfect, the team believes this approach could be used more immediately to reduce scarring and improve tissues repair after amputations.
Redirecting the body’s natural response
In mammals, injuries typically trigger fibrosis, a process in which fibroblast cells rapidly close the wound and form scar tissue. This response prioritizes survival by sealing the injury quickly, but also limits the body’s ability to rebuild missing structures.
In regenerative species, like salamanders that can regrow lost limbs, those same types of cells organize into a blastema, a temporary structure that enables tissue regrowth.
“It’s as if these cells can move in two different directions,” Muneoka said. “They could either make a scar or make a blastema. Our research focused on redirecting the behavior of fibroblasts already present at the injury site.”
To test whether mammalian healing could be shifted toward regeneration, researchers developed a sequential treatment using two well-studied growth factors.
The first step involved applying fibroblast growth factor 2 (FGF2) after a wound had already closed. This timing allowed the body to complete its typical healing response, and then the team “changed what happens next,” Muneoka said.
FGF2 stimulated the formation of a blastema-like structure — something that does not normally occur in mammals following this type of injury; several days later, a second treatment — using bone morphogenetic protein 2 (BMP2) — was applied, triggering those cells to begin forming new structures.
“This is really a two-step process,” Muneoka said. “You first shift the cells away from scarring, and then you provide the signals that tell them what to build.”