A Thin Layer of Decellularized Porcine Myocardium for Cell Delivery

Abstract

Decellularized porcine myocardium has shown many benefits as a cell delivery scaffold for cardiac therapy. However, using full thickness decellularized myocardium as cardiac patch may lead to poor viability and inhomogeneous distribution of delivered cells, due to perfusion limitations. In this study, we explored the feasibility of decellularized porcine myocardial slice (dPMS) to construct a vascularized cardiac patch for cell delivery. Decellularized porcine myocardium was sliced into thin layers (thickness~300 µm). Adipose-derived Stem cells (ASCs) obtained from rat and pig were seeded on dPMS. The viability, infiltration, and differentiation of seeded ASCs were examined. The mechanical properties of dPMSs of various thickness and native myocardium were tested. We noticed dPMS supported attachment and growth of rat and pig ASCs. Both rat and pig ASCs showed high viability, similar patterns of proliferation and infiltration within dPMS. Rat ASCs showed expression of early-endothelial markers followed by mature-endothelial marker without any additional inducers on dPMS. Using rat myocardial infarction model, we delivered ASCs using dPMS patched to the infarcted myocardium. After 1 week, a higher number of transplanted cells were present in the infarcted area when cells were delivered using dPMS versus direct injection. Compared with MI group, increased vascular formation was also observed.

Cardiac tissue-derived extracellular matrix scaffolds for myocardial repair: advantages and challenges

“…Vessel formation was demonstrated as shown by immunofluorescence staining with vascular markers α-SMA and vWF. Source: Adapted with permission from Shah et al through open access policy [38]…”

“…For example, when patched on the acute rat MI model, the cardiac dECM generated by seeding a mixture of human iPSC-derived CMs and iPSC-derived CD90 + cells, has shown to reduce infract size, increase wall thickness and promote vascularization as indicated by positive staining of vWF and α-SMA, leading to improve the heart function compared to the control group [26]. Similarly, when used to deliver rASCs on a rat MI model, recellularized cardiac dECM resulted in the presence of higher number of transplanted cells at the infracted area compared to direct injection seeding method, leading to increased vascular formation within the patch [38]. These findings demonstrated the importance of recellularization for therapeutic benefits of cardiac dECM.…”

“…For instance, decellularized porcine myocardial slices (dPMSs) (300 µm thick), when seeded with neonatal rat ventricular cells (NRVCs) on top of the scaffold using static seeding method, has resulted inhomogeneous distribution of NRVCs as indicated by the presence of high cell density near the surface (∼3 µm below periphery) compared to the core of dECM (∼30 µm below periphery) [43]. When seeded on top of dPMSs using static seeding technique, our previous studies have also shown limited infiltration of hMSCs and rASCs on 300, 600 and 900 µm scaffolds [38, 52]. Cell injection seeding method involves seeding of cells with a small gauge needle by multiple injections throughout the different regions of dECM scaffold [47].…”

Tissue-engineered human embryonic stem cell-containing cardiac patches: evaluating recellularization of decellularized matrix

“…In contrast, other researchers have reported increased stiffness after decellularization. Disparities in these data are mainly related to different physiological and chemical characteristics of xeno-derived scaffolds 36 and to decellularization protocols that result in incomplete cellular DNA removal 37 or that leave behind significant cell residue. 35 Given the key role of myocardium micro-elasticity in the ejection fraction, restoring the elastic properties is fundamental to reestablishing the function of the ventricle in tissue-engineered products.…”

Main histological parameters to be evaluated in an experimental model of myocardial infarct treated by stem cells on pigs

“…Different types of cells have been used in experimental assays on pigs (Castro et al., 2019; Johnson & Singla, 2017; Mohsin & Houser, 2019; Shah et al., 2018; Van der Spoel et al., 2011; Wang et al., 2017). The types of cells that have been tested in various clinical trials (http://www.clinicaltrials.gov) with disappointing results have included bone marrow mononuclear cells (BMNCs), bone marrow mesenchymal stem cells(BMSCs), mesenchymal cells derived from adipose tissue (ASCs) and, more recently, pre-derived embryonic cells (ESCs), induced pluripotent stem cells (iPSCs) and cardiac progenitor cells (CSCs) (Higuchi et al., 2017).…”