Oct. 4 (UPI) -- Because cells choose their own fate, tissues grown in the lab from stem cells may not offer therapeutic promise, according to a study.
Researchers from the King's College London, Imperial College London, University College London and the Francis Crick Institute wanted to determine why lab-grown tissues often fail to be fully effective as treatments when transplanted into patients, including for osteoarthritis or heart failure. The findings were published Wednesday in the journal Nature Communications.
In lab settings, stem cells -- those that can become any kind of cell -- have been placed in biodegradable 3-D structures, or "scaffolds."
They found that feedback between the cells and their scaffold may be why resulting signals altering the path the cells take as they grow and mature.
With the knowledge, the quality of lab-grown tissues could be modified to potentially improve outcomes for patients.
"Engineering tissues to replace damaged or diseased tissue could ultimately help patients with a variety of conditions, including cancer," author Dr. Holger Auner a blood cancer specialist from the Department of Medicine at the Imperial College London, said in a press release. "We hope that this insight will also help us to study how cancer cells interact with the tissue that surrounds them, which may lead to better therapies."
In engineered tissues, the 3-D scaffolds contain instructions to direct the stem cells inside how to differentiate. They are moved along the path from a "blank" template capable of becoming multiple cells types towards a final cell type.
They become ineffective because the stem cells quickly modify their 3-D scaffold, changing its composition and stiffness. They rely on this matrix to direct their own differentiation, rather than cues from the scaffold they were originally placed within.
In the 3-D scaffolds, the cells secreted proteins around themselves. They created stiff, nest-like structure or released factors that degrade and soften their surroundings. These modifications told the stem cells how to differentiate rather than from the initial cues from the scaffold.
With these findings, researchers need to figure out how to design 3-D scaffolds to create replacement tissues.
"The positive side of this discovery is that now we know cells make these modifications and it impacts their fate," researcher leader Dr. Eileen Gentleman of King's said. "When we provide stem cells with a 3-D structure to help them form a tissue, we have to remember that they will modify the environment we present to them.
"To really coax them to form the tissue we want, we have to find ways to harness this effect so that the local environment they create is one that will drive their differentiation down the correct path."