Biomedical Engineering Reference
In-Depth Information
12.9 Future Perspectives
Over the last decade, SCs therapy for non-hematological diseases has grown
exponentially. Experimental studies have generated sufficient knowledge to allow
clinical research in the context of clinical trials and compassionate use.
SCs recognition as a drug and the legislation regulating their use will ensure
that SCs will probably arrive to the market (provided the phase III studies confirm
the promising results shown to date) in a safe and properly controlled way.
Allogeneic use (based mainly on the immune tolerance induced by some SCs) could
extend the applications to emergency conditions and could allow SCs banks creation.
The SCs obtaining process is very expensive so simplification of cell expansion
(probably with closed systems under development) and the creation of international
banks could make the access easier and cheaper for developing countries.
Nevertheless there are several main problems that hinder more extensive
application and need to be resolved. More animal data on safety, data on the choice
of SCs to use (one for all applications or disease-depending cell selection), the best
dosage, the most efficient application route and therapeutic mechanisms involved
are urgently required. SCs isolation must be standardized between different lab-
oratories and properly defined to produce a 'consistent product' and compare
results provided by different authors. Probably differentiation molecular pathways
knowledge must augment in order to ''direct'' SCs better to the treatment objec-
tive. Regarding safety, the interaction between cancer and SCs, despite the
numerous preclinical studies carried out, remains controversial. The possibility of
stem cell transformation in vivo must be clarified; SCs migration toward neo-
plasms is feared to be able to induce cancer progression (although some thera-
peutic progress has been obtained using this feature for local delivery of
chemotherapy reducing systemic toxicity) and several SCs are thought to be the
origin of some cancers. Actually, neoplastic disease is considered a major con-
traindication in the context of most ongoing clinical trials. As soon as this issue is
resolved, the number of possible applications would probably increase.
In the field of gastrointestinal system diseases (excluded liver and endocrine
pancreas), several phase I-II trials have been reported, there are numerous ongoing
phase II-III trials and probably some of them will report result soon revealing the
real benefit (or not) of these therapies. Nevertheless large randomized controlled
clinical trials are needed before firm conclusions can be drawn. Analyzing animal
models, if current trends with clinical trials persist, the spectrum of treated dis-
eases will increase.
Basic research must continue to obtain certain cells (for example mature
enterocytes) and cells perfectly able to integrate into and function within the organ,
thereby participating in the complex homeostasis of an organism. If this could be
achieved, the jump from reparative (substitution of a tissue by another—mainly
scar-) to regenerative (restitution of the original) therapy could be made. Today,
this may seem like science fiction, but the results obtained today would also have
seemed so a few years ago.
