Our fat tissue could be used to make our bones regrow, with scientists successfully using adipose cells to repair spinal compression fractures. It could change how breaks are treated and improve bone strength in diseases such as osteoporosis.
Researchers from Osaka Metropolitan University (OMU) have used stem cells taken from fat tissue – adipose-derived stem cells (ADSCs) – and partially developed them to mature into bone cells. Then, these pre-differentiated cells were assembled into spherical clusters known as spheroids, a formation that scientists have found aids tissue repair and regeneration.
The spheroidal ADSCs were then combined with β-tricalcium phosphate – a biocompatible compound commonly used in bone grafts and dental implants – and delivered to an internal target, which in this case was the L4 and L5 vertebrae of rats with osteoporosis spinal fractures. Micro-CT scans, histology and biomechanical testing was performed at four and eight weeks to gauge bone regeneration and injury healing.
"The osteogenic spheroid group showed significantly higher bone mass, fusion score and mechanical strength than the control group did," the researchers noted. "Histological analysis revealed enhanced new bone formation and β-tricalcium phosphate integration.
"Further, adipose-derived stem cell survival was confirmed at the repair site," they continued. "These results indicate that adipose-derived stem cells contribute to both paracrine and direct osteogenesis."
Basically, the new bone corrected the injury and bone strength was significantly improved in the rats that received the treatment, compared with the control group. What's more, it wasn't a superficial fix – the genes driving bone formation and regeneration had also been switched on.
“This study has revealed the potential of bone differentiation spheroids using ADSCs for the development of new treatments for spinal fractures,” said Yuta Sawada, a researcher in the Graduate School of Medicine at OMU. “Since the cells are obtained from fat, there is little burden on the body, ensuring patient safety.”
The researchers began this journey with a focus on Japan's aging population, a demographic across the world that's at higher risk of brittle bones and fractures. Age-related spinal fractures – known as osteoporotic vertebral fractures – are both common and result in a serious decline of quality of life. Collecting ADSCs, however, even in older age, is relatively easy, and the treatment is far less invasive than traditional fracture surgery.
There are nonetheless some limitations to the research, including that the rats' vertebral defects were by design, so don't replicate a human fracture, and the animals are quadrupedal, so spinal load is different to what we experience as bipeds. And, of course, there's little long-term data on such novel therapies – in any species, let alone humans.
Still, stem-cell therapy for bone regeneration is a huge topic of interest for scientists. In 2022, an Australian team used sound waves to differentiate stem cells into bone-producing mesenchymal stem cells (MSCs), which are normally difficult to harvest as they are largely found in bone marrow. The Osaka researchers hope that in the future we'll be using such techniques that use our body to heal or strengthen our bones at any age.
“This simple and effective method can treat even difficult fractures and may accelerate healing,” Dr. Shinji Takahashi from OMU. “This technique is expected to become a new treatment that helps extend the healthy life of patients.”
The research was published in the journal Bone & Joint Research.
Source: Osaka Metropolitan University
