Biomedical Engineering Reference
In-Depth Information
(Yamagata City, Japan) has transplanted H9C2 cells transfected with VEGF factor
gene to the infarcted myocardium in rats. After 2 weeks, the rats were sacrificed
and an analysis of their heart tissue was conducted. A monoclonal antibody (MAb)
cell marker showed profuse neovascularization around the transplanted cells in the
infarcted myocardium. The investigators concluded that H9C2 cells genetically
modified with the vascular endothelial growth factor gene and subsequently trans-
planted into the injured hearts of rats survived and created new areas of vascular
cell growth. This approach may hold promise for future clinical use.
Transplantation of Genetically Modified Bone
Marrow Stem Cells
Researchers at National University Hospital, Singapore have genetically modified
human bone marrow stem cells for cardiac transplantation. The modified cells were
implanted into live mice last year but the results of the study are not published as
yet. It is proposed that when surgeons open the chest cavity in a heart bypass opera-
tion, bone marrow from the breastbone can be collected, converted into heart
muscle cells in 4-6 h and then injected into the heart at the end of the operation.
This approach overcomes the drawback of using myoblasts from skeletal muscle
that are difficult to extract and take several days to grow in the laboratory prior to
transplantation.
Cell Transplantation for Congestive Heart Failure
Congestive heart failure (CHF) is a condition in which areas of the heart are failing
because of the presence of scarred, inelastic tissue. The human heart possesses a
CSC compartment, and CSC activation occurs in response to ischemic injury. The
loss of functionally competent CSCs in chronic ischemic cardiomyopathy may
underlie the progressive functional deterioration and the onset of terminal failure
(Urbanek et al.
2005
). CSC pool in the dog is characterized by undifferentiated
cells that are self-renewing, clonogenic, and multipotent. In experimental studies,
myocardial reconstitution resulted in a marked recovery of contractile performance
of the infarcted heart (Linke et al.
2005
). Thus, the activation of resident primitive
cells in the damaged dog heart can promote a significant restoration of dead tissue,
which is paralleled by a progressive improvement in cardiac function. These results
suggest that strategies capable of activating CSC pool, the growth reserve of the
myocardium, may be important in cardiac repair after ischemic injury.
The management of CHF is mostly medical. Current treatments for cardiovas-
cular disease prevent heart attack from occurring and/or alleviate its after-effects,
but they do not repair the damaged muscle that results, leaving sizably dead por-
tions of heart tissue that lead to dangerous scars in the heart resulting in heart
failure. Myoblast as well as SC transplants have been used to repair the damage.
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