Transplantation of a tissue engineered cardiac pacemaker (TECP) may represent a novel therapy for cardiac sinus node dysfunction. We previously reported that cardiac progenitor cells (CPCs) derived from embryonic heart tubes could differentiate into cardiac pacemaking cells after endothelin-1 treatment. We aimed to examine the feasibility of TECP fabricated from CPCs-derived pacemaking cells and vascularization of TECP fabricated from CPCs-derived pacemaking cells and endothelial progenitor cells (EPCs) in vitro and in vivo implantation.Main methods:
TECP created using CPCs-derived pacemaking cells and vTECP created by mixing CPCs and EPCs in vitro were implanted into rat hearts. Sinus node damaged was induced by formaldehyde insult.Key results:
Spontaneous beating tissues, namely TECP, were obtained after seeding CPCs-derived pacemaking cells into Matrigel. ECG and epicardial multielectrode array (MEA) measurements confirmed implanted TECP have electrical activity. TECP implantation promoted individual survival in sinus node damage models (15/22 animals lived versus 0/17 control). vTECP fabricated by mixing the both EPCs and CPCs-derived pacemaking cells with Matrigel in equal proportions optimally formed pre-vascularization in vitro. The implantation of vTECP enhanced electrical activity in vivo, which may correlate with increased vascularization. PI3K-Akt-VEGF/VEGFR signaling was involved with vascular ingrowth in vTECP.Significance:
Our data supports the therapeutic potential of TECP fabricated with the CPCs-derived pacemaking cells for sinus node dysfunction. Vascularization by the addition of EPCs is an important factor to sustain viability of the TECP in vivo.