The journal Materialia has recently published
the outcome of research conducted by a group of researchers including several
from the Department of Physical Chemistry at the UPV-EHU's Faculty of Science
and Technology and BCMaterials, and others from centers at the University of
Minho (Portugal). In this work the research group developed a new composite
material that can be used for tissue engineering, specifically for regenerating
bone tissue. "The ultimate goal of this line of research would be to be
able to generate tissue that could then be implanted to treat bone
diseases," said José Luis Vilas-Vilela, head of the UPV/EHU's Department
of Physical Chemistry and one of the authors of this study.
The material developed comprises a scaffold or
matrix which in turn is made up of one of the main components of silk
(fibroin), a biocompatible material of natural origin, and which is loaded with
magnetic nanoparticles. The purpose of adding the nanoparticles was to make the
material "magnetoactive" so that they would respond when a magnetic
field is applied to them and thus transmit mechanical and electrical stimuli to
the cells. "The inserting of stimuli, which may be electrical, magnetic,
mechanical or of another type, has been proven to encourage cell growth and
differentiation, because this procedure in some way mimics the cellular
microenvironment and imitates the stimuli that occur in the environment in
which the cells carry out their functions," explained the researcher.
Positive in vitro study
This study was conducted in vitro, and two
methodologies were tested to obtain the fibroin matrix: in one, films were
created, and in the other, a kind of fabric was produced by interweaving the
fibers. "These are two pretty good methodologies for building this
scaffolding which simulates the extracellular matrix, the support to which the
cells can attach themselves in order to grow," specified the researcher.
The magnetoactive nanoparticles also form part of the structure as they have
been incorporated into the fibroin. So when we apply a magnetic field, we bring
about a response by these nanoparticles, which vibrate and thus deform the
structure, they stretch it and transmit the mechanical stress to the
cells," he said.
This Ph.D. holder in chemistry says that the
results have shown them that both types of matrix or scaffold "encourage
cell growth; the film type works better, the cells grow better, but more than
anything, we have confirmed, for the first time, that the magnetic stimulus
exerts a positive effect on cell growth."
This has signified a step forward in the line
of research of this research group in the quest for suitable materials and
methods for tissue fabrication. "We know that our aim is a long-term one
and now we are taking the first steps. We are developing various types of
materials, stimuli and processes so that we can have the means to achieve the
regeneration of different tissue. In addition, the idea would be to use the
stem cells of the patients themselves and be capable of differentiating them
towards the type of cell we want to form the tissue with, be it bone, muscle,
heart or whatever might be needed. That would be the ultimate goal towards
which we are already taking significant steps," he said.
To achieve that ultimate goal, this research
group needs to meet various challenges. The most immediate ones would be,
according to the expert, "to combine various stimuli and insert a
variation into the ones already applied, such as the direction in which the
deformation of the structure used is applied. We also need to explore cell
viability and functionality, how the cells are fed and how the waste they
produce is extracted. There are many factors where progress needs to be made,
but what has been achieved is spurring us on to continue," he concluded.