Biomedical Engineering Reference
In-Depth Information
will enhance the reliability of the trial's outcome. But while these tests may
indicate an improvement in the participant's healing and condition, they will
not inform us of the regenerative mechanisms behind these improvements. it
is equally important for tissue engineering that trials should not solely aim at
therapeutic goals, but that they should indeed contribute to a more profound
understanding of the working mechanisms of BTePs and of regeneration
in
situ
by answering some fundamentally new questions: is
there
regenerative
action
in vivo
, how does
it take place, and is the introduction of the active
construct and the interaction with the receiver's body safe? (roberts
et al
.,
2002; Hollander
et al
., 2006) To achieve these goals, criteria to determine
the extent, quality and mode of operation of the regeneration need to be
established. For the participants' wellbeing and to reduce the risks, it is
also advisable that this assessment uses non-invasive methods as much as
possible (Pancrazio
et al
., 2007).
one of the main challenges for trials with BTePs is therefore to
establish a fitting methodology that clearly sets the aims of the trial, tests
their achievement rigorously and allows us to define whether and how the
knowledge gained in one trial can be transferred to other domains of tissue
engineering and/or to therapeutic settings. standardisation of procedures
and of the analysis of results, definition and justification of inclusion and
exclusion criteria of both BTePs and participants are all necessary elements
(Jakobsen
et al
., 2005). The lack of a well developed methodology devalues
the validity of the research and raises questions concerning the respect for
and protection of participants. The inherent variability of the BTePs and
the dynamic generated by the BTeP may also have a negative effect on the
ability to generalise results and may limit their external validity. The small
number of participants that one can expect to be eligible for most trials
and the absence of long-term outcomes from the first BTEP-trials will also
preclude a confident extrapolation of trial results to a larger population. The
lack of acknowledged parameters will also hamper the determination of cut-
off points for the trial. The inherent variability of products and interactions
may also interfere with the interpretation of tests and trial results and of
adverse events: the cause of an adverse event and its importance for future
application of other BTePs may be hard to determine. Lastly, the surgeon's
skills (Lilford
et al
., 2004) as well as post-operative events and therapy can
influence the outcome of the whole process.
given these manifold variables and uncertainties, the development of
good methodologies, procedures and protocols with validated outcome
measurements will be essential to expand the domain of tissue engineering
further, especially but not exclusively in the domain of clinical trials with
BTePs.
