Interrogating functional integration between injected pluripotent stem cell-derived cells and surrogate cardiac tissue.

Myocardial infarction resulting in irreversible loss of cardiomyocytes (CMs) remains a leading cause of heart failure. Although cell transplantation has modestly improved cardiac function, major challenges including increasing cell survival, engraftment, and functional integration with host tissue, remain. Embryonic stem cells (ESCs), which can be differentiated into cardiac progenitors (CPs) and CMs, represent a candidate cell source for cardiac cell therapy. However, it is not known what specific cell type or condition is the most appropriate for transplantation. This problem is exasperated by the lack of efficient and predictive strategies to screen the large numbers of parameters that may impact cell transplantation. We used a cardiac tissue model, engineered heart tissue (EHT), and quantitative molecular and electrophysiological analyses, to test transplantation conditions and specific cell populations for their potential to functionally integrate with the host tissue. In this study, we validated our analytical platform using contractile mouse neonatal CMs (nCMs) and noncontractile cardiac fibroblasts (cFBs), and screened for the integration potential of ESC-derived CMs and CPs (ESC-CMs and -CPs). Consistent with previous in vivo studies, cFB injection interfered with electrical signal propagation, whereas injected nCMs improved tissue function. Purified bioreactor-generated ESC-CMs exhibited a diminished capacity for electrophysiological integration; a result correlated with lower (compared with nCMs) connexin 43 expression. ESC-CPs, however, appeared able to appropriately mature and integrate into EHT, enhancing the amplitude of tissue contraction. Our results support the use of EHT as a model system to accelerate development of cardiac cell therapy strategies.

Diversity in public views toward stem cell sources and policies.

Studies of public views on stem cell research have traditionally focused on human embryonic stem cells. With more recent scientific research on developing other stem cell sources, a series of focus group studies was undertaken with Canadian adults to examine their views on different stem cell sources (adult, umbilical cord blood, human embryonic stem cells, somatic cell nuclear transfer or SCNT, and interspecies nuclear transfer, or iSCNT). Views on three different policy models--a permissive, middle-of-the-road and restrictive policy approach--were also explored. Participants were recruited from several different social groups including patients, young adults, seniors, members of two ethnic communities, and a mixed group of adults. Participants were generally supportive of the use of adult stem cell sources. While there was also majority support for the use of hESC and SCNT, this was conditional on strict regulatory oversight. There was also majority support for a permissive policy which allows research on hESC and SCNT. General themes that cut across different groups included the potential cost of new technologies to the health care system, issues around who would gain access to these technologies, and trust in the scientific establishment and regulatory systems. A diversity of viewpoints was found as participants justified their positions on stem cell sources and policy approaches, showing more complexity and nuance than has been generally portrayed.

Science communication reconsidered.

As new media proliferate and the public's trust and engagement in science are influenced by industry involvement in academic research, an interdisciplinary workshop provides some recommendations to enhance science communication.