Accelerate bone regeneration
Bone tissue growth is a multi–stage process: stem cells differentiate into cartilage cells, which then turn into bone cells. In order for stem cells to become bone, they must experience some mechanical stress.
Researchers from the University of Illinois at Chicago, in collaboration with colleagues from the University of Pennsylvania and Case Western University, are developing a unique system that delivers stem cells to bone defects, also uses flexible fixators – spokes and rods that hold bones together and provide adjustable mechanical stress.
A group of researchers has discovered a way to ensure the timely release of two growth factors that mimic the natural process of bone formation during embryonic development.
A system of stem cells, flexible fixators and timely released growth factors in the future will be able to restore large bone defects or fractures in humans. Exposure to the right growth factors at the right time stimulates the development of bone from stem cells in the same way as it occurs during natural healing and bone development. In previous work, the authors developed flexible fixators and "condensates" of stem cells, which are a mass of stem cells connected to each other so that they can be moved in the form of plates or patches. The condensate form allows stem cells to be placed on certain areas of the body (in cracks or other bone defects) without the risk of their leaching, as often happens when stem cells are delivered by injection. When used together, condensates and flexible fixators have improved the healing of bone defects in rat models.
In the current study, it was decided to add another layer to the bone tissue repair system – several growth factors. One of them helps to transform stem cells into cartilage, this is the so-called transforming growth factor (TGF-β1). The second factor promotes the transformation of cartilage cells into bone cells and is called bone morphogenic protein (BMP-2).
In rats with femoral defects, the use of a new multicomponent healing system stimulated the growth of a new bone after 12 weeks with full restoration of function, the result exceeded the effect of using a system without growth factors or using only growth factors in isolation.
The achieved effect is comparable to the FDA-approved method of a BMP-2 impregnated collagen sponge, which is applied to spinal bone defects. The difference is that a collagen sponge can lead to the formation of bone where it is not needed, and the new system guarantees the growth of bone tissue only in those areas where condensate saturated with growth factors has been placed.
Article by S. Herberg et al. Combinatorial morphogenetic and mechanical cues to mimic bone development for defect repair is published in the journal Science Advances.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru according to the materials of UIC Today: Addition of growth factors to unique system helps new bone formation.