Biomedical Engineering Reference
In-Depth Information
12.5.5 Functional Deficit
Cellular loss or degeneration characterizes functional deficits such as liver cir-
rhosis, achalasia, Hirschprung's disease, gastroesophageal reflux, and anal
incontinence. The differentiation potential or the paracrine modulation of resident
SCs niches [
31
,
32
] would be the most useful properties.
12.5.6 Surgical Complications
The following may be amenable to SCs therapy:
Sepsis of abdominal origin: frequently the damage is perpetuated by immu-
nological mechanisms even when the original source of infection is controlled.
Immunomodulation properties could be useful.
Anastomotic dehiscences: many digestive surgical procedures (colonic, esophageal,
etc.) are taxed with high morbidity and mortality due to anastomotic complications.
Immunomodulatory and angiogenic properties might help reduce their incidence.
Peritoneal adherences: are the main cause of bowel obstruction and a frequent
cause of infertility and pain. Pathological inflammatory mechanisms play a fun-
damental role in their origin. Immunomodulatory properties may be beneficial.
12.6 General Considerations about Stem Cell Application
and Experience in Gastrointestinal System Disorders
Currently, SCs are considered as drugs and therefore, their application is subjected
to strict regulations and in many countries to specific laws (especially for ESCs
use). European regulatory agencies consider SCs as Advanced Therapy Medicinal
Products (EU Directive no. 1394/2007) and USA agencies as Human Cellular and
Tissue-based product. For these reasons, every new SC application should surpass
preclinical studies, quality controls and manufacturing recommendations, and
carefully designed clinical trials.
During stem cell therapy development, initial application ideas were frequently
in desperate conditions so we have contemplated than after the preliminary animal
results, SCs have been offered to single patients even before some important issues
have been fully clarified. Consequently preclinical and clinical experimentation
have run in parallel. Nevertheless we must not forget that SCs must surpass all
experimental steps before conclusions are obtained in order to prevent creating
society false expectations.
Related to gastrointestinal system, most studies to date (June 2011) have been
done in animal models and several approaches have been tested in humans (only a
few in controlled clinical trials). In the following sections, we will briefly describe
and analyze critically some of the most relevant applications.
