Magnetic nanoparticles stimulate stem cells to regenerate bone
3 December 2014
Magnetic nanoparticles coated with targeting proteins can
stimulate stem cells to regenerate bone, according to research by
Keele University and Nottingham University.
Researchers were also able to deliver the cells directly to the
injured area, remotely controlling the nanoparticles by a magnetic
field to generate mechanical forces and maintain the regeneration
process through staged releases of a protein growth stimulant.
The current method for repairing bone that can’t heal itself is
through a graft taken from the patient. Unfortunately, this can be a
painful, invasive procedure, and when the area that needs repair is
too large or the patient has a skeletal disorder such as there can
sometimes be a lack of healthy bone for grafting.
For this reason, spurring the growth of new bone through injected
stem cells is an area of great interest to medical researchers. Much
progress has been made, but a major hurdle remains – finding an
appropriate means to stimulate the differentiation of the stem cells
so they become the quality of bone tissue needed in a quantity large
enough to treat patients effectively.
James Henstock, PhD led the Biotechnology and Biological Sciences
Research Council (BBSRC)-funded study, alongside Professor Alicia El
Haj, and colleagues at Keele University’s Research Institute for
Science and Technology in Medicine, as well as Kevin Shakesheff,
PhD, from the University of Nottingham’s School of Pharmacy.
James Henstock said: “Injectable therapies for regenerative medicine
show great potential as a minimally invasive route for introducing
therapeutic stem cells, drug delivery vehicles and biomaterials
efficiently to wound sites.”
“In our investigation we coated magnetic nanoparticles with
specific targeting proteins then controlled them remotely with an
external magnetic field to simulate exercise. We wanted to learn how
this might affect the injected stem cells and their ability to
restore functional bone.”
The team of researchers conducted their test using two models:
chicken foetal femurs and tissue-engineered collagen hydrogels. In
both instances the results showed an increase in bone formation and
density without causing any mechanical stress to the construct or
“This work demonstrates that providing the appropriate mechanical
cues in conjunction with controlled release of growth factors to
these injectable cell therapies can have a significant impact on
improving bone growth. It also could potentially improve tissue
engineering approaches for translational medicine” Dr Henstock said.