Bone is the second most grafted tissue after blood – however, autologous grafts are in short supply and allogeneic grafts are associated with problems including rejection by the body and post-transplant complications. For that reason, much work has been put into optimizing existing and finding new ways for creating induced bone grafts through tissue engineering, 3D printing and combinations of cell culture-based approaches.
Now, we can add vibrational forces to the list. A new study by Matthew Dalby at the College of Medical, Veterinary and Life Sciences at the University of Glasgow described the use of a laser interferometer, originally used for gravitational wave detection of astrophysical objects, to differentiate huma bone marrow-derived mesenchymal stem cells into bone tissue without the use of typical differentiation media.
The authors describe this approach as “nanokicking.” It is based on the principle of ultra-precise, nanoscale vibrations of cells entrapped in collagen matrices. The process of nanokicking inces the formation of a ‘bone putty’ that has potential to be used to heal bone fractures and fill bone.
To achieve induction of formation of bone-like tissue, the authors loaded between 40,000 and 200,000 osteosarcoma MG-63 cells/ml of collagen, which yielded gels with various stiffness properties. These cell-embedded collagen matrices were then to “nanokicking” – or nanoscale sinusoidal mechanotransduction – wherein bone-like tissue formation occurred.
With this approach, the cells are subjected to nanoscale vibrations at a paceof 10–14 nm displacements at 1 kHz frequency. In this way, the authors demonstrated successful osteogenesis independently of other environmental factors.
Immunofluorescence, PCR, and microarray was used to demonstrate the induction of osteogenesis. Finally, the authors argue that the approach’s scalability and flexibility allows this to be incorporated within other types of 3D scaffolds, making it possible to extend the approach to systems other than collagen gels, suich as electrospun nanofibers or Matrigel-like substrates.
The study, Stimulation of 3D osteogenesis by mesenchymal stem cells using a nanovibrational bioreactor, can be accessed here.