engineering construct for clinical application. MSCs hold great promise because of
their ability to adopt various differentiation lineages, for example, osteoblastic
or chondrogenic, which are relevant
especially to the orthopaedic field.1 For
translational strategies, they also have the
additional advantage of possessing immu-nomodulatory functionality.
It is interesting to observe how the life
sciences have influenced the engineering
and exact sciences (physics and chemistry)
employed in the biomaterials field. Twenty
years ago, cells in vitro tended to be used
mostly in simple cytotoxicity assays. This
is still an essential component of screen-
ing strategies and the guidelines are well
formulated in ISO 10993 Biological
Evaluation of Medical Devices. However,
today, complex co-culture systems using
primary human cells are being studied in
a variety of scenarios, including in three-
dimensional culture systems on biomate-
rial scaffolds or within hydrogels. 2 Where
once simple binary end-points such as
“cytotoxic/non-toxic” or “viable/non-
viable” were used, modern assay models
yield detailed information about cellular
functionality, which is studied with the
powerful toolbox of cell and molecular
biology. 3 It is evident that this technol-
ogy is required to give a differentiated
picture of cellular activity on biomateri-
als for tissue engineering applications. A
further significant development during
the past twenty years is the incorporation
of engineering principles into cell assays.
Advances in bioreactor systems mean that
cells can now be subjected to biomechani-
cal forces in a controlled environment
in which important parameters can be
measured on-line in a continuous fashion. 4
Developments in the
materials sciences
Parallel to these major advances in the life
sciences, the materials sciences have been
undergoing their own evolutionary pro-
cess, especially in the field of biodegrad-
able polymers, natural or synthetic, which
now have the ability to respond to small
changes in physical, chemical or even bio-
logical microenvironments. 5 Increasingly,
molecular self-assembly processes are
being employed to incorporate bioactive
signal moieties into polymeric systems that
not only have a structural component,
but also a suitable biochemical stimulus
to drive the regenerative process. 6 These
so-called responsive or interactive materi-
als are being developed to be injectable
and thus available for a minimally inva-
sive application in clinical medicine. Cell
encapsulation is also a strong focus of this
research activity. 7
THE ASSEMBLY SOLUTION
BORN FROM THE SAME STOCK AS THE SWISS WATCH MAKING INDUSTRY, MIKRON SHARES THIS SAME PASSION FOR PRECISION, RELIABILITY AND PERFECTION. ALL OVER THE WORLD, MORE THAN 2,000 OF OUR SYSTEMS ARE WORKING RIGHT NOW. JUST LIKE (SWISS) CLOCKWORK.
WWW.MIKRON.COM
AMERICA: DENVER (USA) - ASIA: SINGAPORE , SHANGHAI (CHINA) - EUROPE: BOUDRY (S WITZERLAND)
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June 2010 | 41
