Download Artificial Organs in Animals…

Artificial organs in animals as a temporary bridge to transplantation
Taylor R. McConnell: Lincoln Memorial University-College of Veterinary Medicine, Harrogate, TN
ABSTRACT
METHODS
DISCUSSION
Artificial organs are currently being used
in animal models as a bridge to
transplantation. Some of the most
recently prepared models, which
including the Total Artificial Heart, the
AbioCor and Cardio West, and the Pulmonary Pediatric Pump-Lung
(Pedi-PL) are working to decrease clot formation and increase
blood flow to these organs. Immune responses vary depending on
the type of material used in each artificial organ, but as a
temporary means to transplantation, these organs are proving
successful in humans and animals.
Several studies were
performed for the total
artificial heart. The first one
was performed in 2015 which
included 2-3 month old calves
in which Carmat bioprosthetic
TAH were implanted. Another
device, the Cardio West TAH,
works by connecting to an outside power source and having
tubes that run through the abdomen, which control the
heart. A third device, the AbioCor, is powered through
batteries and is charged thorough an external charger
known as transcutaneous energy transmission (TET). The
Pedi-PL was placed in a sheep model temporarily until
transplantation between the right atria and descending
aorta in 8 sheep for 30 days. Flow rate and gas transfer was
measured continuously.. The Pedi-PL provided
cardiopulmonary support with reliability and
cardiocompatibility for the 30 day study in sheep. Tissue
engineering with the polystyrene scaffolding appeared
immunologically as expected as there was a persistent
immune response and became T-helper class two
dependent.
Although numerous artificial organs are successfully providing a
temporary solution until transplantation in animals and humans, there
is more research that must be conducted in this area. There are
numerous risks associated with the implantation itself, including
bleeding, infection, blood clots, and device malfunction. It is important
that the antigen and effector interaction is known before the transplant
is performed so that the host reaction is not overwhelming and harmful
to the host. The benefits to the transplant or artificial organ must
outweigh the risks, so this must be known. Blood transfusions and
antigen-effector interactions must be considered in special cases of
transplantation as errors in blood typing can result in severe
immunologic issues including graft rejection. Numerous studies are
currently being studied in these areas.
INTRODUCTION
The use of artificial organs in animals is becoming
more widely studied and its importance as a stable
bridge for transplantation is essential. This study
focuses mainly on the total artificial heart organs,
including the CardioWest and AbioCor, which
Pedi-Pump Lung ventricular
function as right and left ventricles, as well as the
assist device – biventricular
support
Cardiopulmonary Pediatric Pump-Lung (Pedi-PL),
which functions as a ventricular assist device with biventricular
support. The total artificial heart (TAH) models extend life
expectancy for months to years, though studies have shown there
have been challenges with implantation and post-surgery
complications including blood clots, bleeding, infection, and device
malfunction. The models were constructed through the use of
polystyrene and polylactic-glycolic acid microparticles and scaffolds
together with the model antigen, ovalbumin in a mouse model.
HYPOTHESIS
Artificial organs used as a temporary solution until tissue
transplantation can occur will be effective through the use of
synthetic tissues. Tissue engineering studies included polystryene
and polylactic-glycolic acid microparticles and scaffolding with a
model antigen, ovalbumin in a mouse model for 18 weeks.
Expected results would include an immune response with isotype
switching and helper t-cell dependent response to the tissues due
to antigenicity. Artifical organs may not be immune to responses
from the immune system.
RESULTS
Several studies were performed for the total artificial
heart. The first one was performed in 2015 which
included 2-3 month old calves in which Carmat
bioprosthetic TAH were implanted. Haematological values
were monitored. The Cardio West TAH works by
connecting to an outside power source and having tubes
that run through the abdomen, which control the heart.
AbioCor is powered through batteries and is charged
thorough an external charger known as transcutaneous
energy transmission (TET). The Pedi-PL was placed in a
sheep model temporarily until transplantation between
the right atria and descending aorta in 8 sheep for 30
days. Flow rate and gas transfer was measured
continuously. With the AbioCor and Cardio West artificial
hearts, devices proved successful, but several risks are
associated. The Pedi-PL provided cardiopulmonary
support with reliability and cardio-compatibility for the 30
day study in sheep. It had the ability to bridge pediatric
patients with end stage heart or lung disease to
transplantation. Tissue engineering with the polystyrene
scaffolding appeared immunologically as expected as
there was a persistent immune response and became Thelper class two dependent.
LITERATURE CITED
Animal studies with the Carmat bioprosthetic total artificial heart.
Latremouille C., Duveau D., Cholley B., Ziberstein L., Belbis G., Boughenou MF.,
Meleard D., Bruneval P., Adam C., Neuschwander A., Perles JC., Jansen P.,
Carpentier A.
Artificial organs as a bridge to transplantation. Famulari A., De Simone P.,
Verzaro R., Iaria G., Polisetti F., Rascente M., Aureli A.
Coronary artery disease from isolated non-H2-determined incompatibilities
in transplanted mouse hearts. Russell PS., Chase CM., Madsen JC., Hirohashi
T., Cornell LD., Sproule TJ., Colvin RB., Roopenian DC.
Effects of Cardiopulmonary Support With a Novel Pediatric Pump-Lung in a
30-Day Ovine Animal Model. Liu Y., Sanchez PG., Wei X., Watkins AC., Niu S.,
Wu ZJ., Griffith BP.
Surgical Transplant-The History Of Transplants, Transplantation And The
Immune System, Types of Transplants. Donor Organ And Tissue Networks.
<a href="http://science.jrank.org/pages/6939/TransplantSurgical.html">Surgical Transplant - The History Of Transplants,
Transplantation And The Immune System, Types Of Transplants, Donor Organ
And Tissue Networks</a>
The mechanical behavior and biocompatibility of polymer blends for Patent
Ductus Arteriosus (PDA) occlusion device. Huant Y., Wong YS., Wu J., Kong JF.,
Chan JN., Khanolkar L., Rao DP., Boey FY., Venkatraman SS.
Tissue Engineering & Artificial Organs. Bronzino JD., Peterson DR.
ACKNOWLEDGEMENTS
The author would like to give a special thank you to Dr. Nick Tataryn, post
doctoral veterinary mentor at Memorial Sloan Kettering Cancer Center,
the veterinary post-doc team, Dr. Heather Martin, Dr. Rodolfo Ricart, and
the veterinary team whom I met and allowed me to work with him/her
during my externship at Memorial Sloan Kettering Cancer Center and
Weill Cornell Medical College.
Another special thank you to the veterinary team at Lincoln Memorial
University-College of Veterinary Medicine, particularly Drs. Charles
Faulkner and John Dascanio for having this opportunity and another
special thank you to Dr. Ashutosh Verma for help with the preparation of
this presentation.