MEDFORD/SOMERVILLE, Mass. (April 30, 2012, 3 PM EDT) -- Biomedical engineers at Tufts University's School of Engineering have demonstrated the first all-polymeric bone scaffold material that is fully biodegradable and capable of providing significant mechanical support during repair. The new technology uses micron-sized silk fibers to reinforce a silk matrix, much as steel rebar reinforces concrete. It could improve the way bones and other tissues are repaired following accident or disease.
The discovery is reported in the Proceedings of the National Academy of Sciences Online Early Edition the week of April 30-May 4, 2012.
In the U.S. an estimated 1.3 million people undergo bone graft surgeries each year, notes the paper.
Human bones are hard but relatively lightweight, able to withstand considerable pressure while being sufficiently elastic to withstand moderate torsion. Inside the hard, mineralized tissue is a matrix in which bone cells can proliferate and adhere. Natural bone is the obvious choice for grafts.
However autologous grafts mean putting the patient through additional surgery and the supply of self-donated tissue is, obviously, limited. Donor grafts pose risks of disease, graft rejection and other long-term complications.
A handful of all-polymeric biomaterials, such as collagen, are currently used for bone regeneration, but they lack strength. Incorporating ceramics or metals into polymers improves mechanical properties but such composites often sacrifice optimum bone remodeling and regeneration.
By bonding silk protein microfibers to a silk protein scaffold, the Tufts bioengineers were able to develop a fully biodegradable composite with high-compressive strength and improved cell responses related to bone formation in vitro.
The study found that silk microfiber-protein composite matrices mimicked the mechanical features of native bone including matrix stiffne
|Contact: Kim Thurler|