text: Numerous studies have been dedicated towards the development of effective methods to enable cardiac tissue regeneration in patients after ischemic heart disease. An emerging approach to answer the problems related to ischemic tissue repair is through the use of stem cell-based therapy. However, the actual mechanism due to which this stem cell-based therapy has generative effects on cardiac function is still under investigation. Even though numerous methods have been studied for cell administration, the efficiency of the number of cells retained in the beating heart after implantation is still very low. A promising approach to overcome this problem is through the use of cell microencapsulation therapy which has shown to enable a higher cell retention as compared to the injection of free stem cells into the heart.
  Another strategy to improve the impact of cell based encapsulation technique towards cardiac regenerative applications is through the use of genetically modified stem cells capable of secreting angiogenic factors such as vascular endothelial growth factor (VEGF) which stimulate neovascularization and restore perfusion in the damaged ischemic heart. An example of this is shown in the study by Zang et al. where genetically modified xenogeneic CHO cells expressing VEGF were encapsulated in alginate-polylysine-alginate microcapsules and implanted into rat myocardium. It was observed that the encapsulation protected the cells from an immunoresponse for three weeks and also led to an improvement in the cardiac tissue post-infarction due to increased angiogenesis.