A growing problem in cardiac drug toxicity has been blamed on the lack
of adequate testing prior to authorization for prescription use. This
study offers an effective alternative to the current method of in
vivo pharmaceutical testing, which is time and cost prohibitive. We
have accomplished this by developing the novel three-dimensional heart
tube model. At the “heart” of our model lies our patented
collagen scaffold that enables the cardiac myocytes to display an in
vivo–like architecture. The cardiac myocytes were cocultured
with the collagen tube for a period of 5 weeks, resulting in the heart
tubes. Our heart tubes were treated with specific drugs (nifedipine,
isoproterenol, and lidocaine) at varying concentrations. The percent of
apoptotic cells was calculated based on observing the number of cells that
labeled positive for caspase-3 via confocal microscopy. All three drugs
exhibited negative effects at high concentrations in that the number of
living cells decreased. Lidocaine showed an increase in apoptosis at
concentrations of 75 μM and above. This may indicate that certain
drugs have a minimum concentration level that must be reached before the
cells experience apoptosis from the toxic levels.