Journal of Stem Cell Research & Therapy

Abstract

Gelatine Microspheres Support Direct Intramyocardial Delivery of Induced Pluripotent Stem Cell-Derived Cardiomyocytes

Raja Ghazanfar Ali Sahito, Carlos O Heras-Bautista, Benjamin Krausgrill, Martina Maass, Sven Baumgartner, Jurgen Hescheler, Agapios Sachinidis and Kurt Pfannkuche

Objective: Cardiac cell replacement therapy (cellular cardiomyoplasty) aims at restoring contractile function following cardiac infarction or cardiac myopathy and may add a new option to conventional treatments of cardiac failure in the future. Currently, this approach is hampered by the minor rate of cell engraftment and optimal strategies and routes of cell delivery need to be identified. Delivery of cardiomyocytes immobilized on biodegradable microspheres could support cell transfer. 

Methods: Murine induced pluripotent stem cell derived cardiomyocytes (iPS-CMs) expressing puromycinacetyltransferase and enhanced green fluorescent protein (eGFP) under control of the Acta-2 promotor were used. Macroporous gelatine microspheres were loaded with single cell suspensions of purified iPS-CMs and transplanted into healthy murine myocardial tissue. Single cell suspensions were transplanted for control. Persisting cells were determined by quantitative real-time PCR with Y-chromosome specific primers and histological analysis.
Results: Upon direct intramyocardial injection of iPS-CMs only 12.3 ± 4.4% of injected cells were detectable immediately after injection and this value further declined to 1.3 ± 0.5% at 24h. In contrast delivery of iPS-CMs on microspheres resulted in a persistence of 4.2 ± 1.2% at 24h (p<0.05 vs. iPS-CMs only). Histological analysis 24h after transplantation revealed the presence of eGFP+ iPS-CMs in the myocardiac tissue. However, one week after cell transfer no iPS-CMs were detectable.
Conclusion: Intramyocardial transfer of iPS-CMs bound to gelatin microspheres enhances cell retention in the early stage after transplantation significantly. However, the total cell loss remains high and long-term cell loss cannot be prevented by this approach. These findings support the conclusion that Anoikis is no major cause of cell loss during experimental cardiomyoplasty.