Biomedical Engineering Reference
In-Depth Information
Methods of Delivery of Cells to the Heart
Various cell delivery methods have been investigated for cell transplantation
treatment of cardiac infarcts. Cells may be injected directly into the area of the
myocardial infarct or various devices such as catheters may be used to deliver cells
into the coronary circulation. A rat model of ischemic cardiomyopathy was used to
compare the efficacy of intramyocardial and intracoronary angiogenic cell precur-
sors (ACP) implantation (Sun et al.
2008
). Human ACPs, delivered via intramyocar-
dial or intracoronary injection, engrafted into damaged cardiac tissue and improved
cardiac function within 4 weeks through effects on scar morphology and blood ves-
sel formation. Significant reductions in myocardial scar area were only observed in
the intramyocardial ACP group, although increases in blood vessel density were
greater in the intracoronary ACP group than in the intramyocardial delivery group.
Cellular Cardiomyoplasty
A very promising approach to reversal or stabilization of the postinfarct remodeling
process is the direct injection of regenerative cells into the myocardial infarct scar.
Such cell-based therapy for cardiac repair is called cellular cardiomyoplasty. This
procedure can be conducted with MyoCath
™
, Bioheart's proprietary catheter deliv-
ery system, to facilitate MyoCell
™
delivery into the myocardium via the retrograde
catheterization of the left ventricular cavity. Because implantation of autologous
skeletal myoblasts has been shown to lead to replacement of nonfunctioning myo-
cardial scar with functioning muscle and improvement in myocardial performance,
myoblast implantation at the time of coronary artery bypass graft or via the endoven-
tricular approach may lead to the same effects. In principle, myoblast implantation
by catheter delivery may offer the same therapeutic benefit. MYOHEART
(Myogenesis Heart Efficiency and Regeneration Trial) is a phase I, open-label, non-
randomized, dose escalation, multicenter study that is in progress to assess the safety
and cardiovascular effects of MyoCell
™
implantation by MyoCath
™
in congestive
heart failure (CHF) following myocardial infarction with previous placement of an
implantable cardioverter defibrillator.
IGF-1 Delivery by Nanofibers to Improve Cell Therapy for MI
Strategies for cardiac repair by injection of cells have been hampered by poor cell
engraftment, survival, and differentiation. To address these shortcomings for the pur-
pose of improving cardiac function after MI, a self-assembling peptide nanofibers
was designed for prolonged delivery of insulin-like growth factor 1 (IGF-1), a cardio-
myocyte growth and differentiation factor, to the myocardium, using a “biotin sand-
wich” approach (Davis et al.
2006
). Biotinylated IGF-1 was complexed with
Search WWH ::
Custom Search