Optimizing Dynamic Interactions between a Cardiac Patch and Inflammatory Host Cells

Abstract

gineering modalities for cardiac repair, the host environment into which the repair cells are placed is largely overlooked. Within seconds of myocardial ischemia, hypoxia sets in in the myocardium and the inflammatory response starts, characterized by rapid deployment of circulating cells and the release of paracrine and autocrine signals. Therefore, the inflammatory conditions under which these interactions take place, the design of the scaffold material used, and the maturity of the implanted cells will determine the outcomes of any stem cell-based therapy. We discuss here the interactions between implanted and inflammatory cells of the host, which are critical for the design of effective heart repair therapies. AbstractDamaged heart muscle has only a minimal ability for regeneration following myocardial infarction in which cardiomyocytes are lost to ischemia. The most clinically promising approach to regeneration of cardiac muscle currently under investigation is that of injecting cardiogenic repair cells or implanting a preformed tissue-engineered patch. While major advances are being made in the derivation of functional human cardiomyocytes and the development of tissue-en-

A Comparison of Electrospun Polymers Reveals Poly(3-Hydroxybutyrate) Fiber as a Superior Scaffold for Cardiac Repair

“…Thus, a suitable polymeric scaffold for cardiac tissue engineering should demonstrate an appropriate biodegradation life-time while, at the same time, promote wall motion recovery and induce restorative processes (angiogenesis and accelerated healing). In this context, a BM that induces a shift in the balance of infiltrating macrophages to an M2 phenotype would be preferred, since the activation of an M1 macrophage response is typically associated with transplant rejection and chronic inflammation, while M2 macrophages are thought to participate in tissue remodeling and transplant tolerance [20].…”

Polymeric Electrospun Scaffolds: Neuregulin Encapsulation and Biocompatibility Studies in a Model of Myocardial Ischemia

“…Secretion of these factors over a short period of time can lead to device failure, limiting the beneficial effect of regenerative SCs. In fact, this reaction commonly occurs during the healing process after MI or following biomaterial implantation [27,28]. Thus, since our SCs demonstrated long-term structural integrity in the cardiac tissue, it may indicate that the immunological response was not damaging to the biomaterials and that prolonged cytokine release occurred.…”

A Regenerative Cardiac Patch Formed by Spray Painting of Biomaterials onto the Heart

“…To date, approaches to cardiac tissue engineering range from injectable hydrogel to construction of complex cardiac constructs. 16 Intramuscular injections have variable outcomes due to low biomaterials retention at the site of injection. 17 Implanting engineered cardiac patch represents a promising strategy for cardiac tissue engineering.…”