Mechanistic convergence of exercise and mesenchymal stem cell-derived exosome signaling in isoproterenol-induced myocardial injury

Table 1 Summary of interventions

Intervention	Mechanism/procedure	Benefit	Drawback	Ref.
Intramyocardial injection	Direct injection of stem cells into damaged myocardium	Direct targeted infusion of a large number of cells	Mechanical tissue damage; difficult infarct localization; higher arrhythmia incidence; suboptimal electromechanical coupling post-injection	[7]
Transendocardial intramyocardial injection	Percutaneous catheter-based, image-guided injections into endocardial surface targeting borderzone myocardium	Precise border zone access without open chest surgery; reported improvements in perfusion, EF, diastolic/LV function, and 6-minute walk metrics in preliminary work	Preliminary stage with inconsistent results	[7]
Epicardial intramyocardial injection	Surgical direct-visual injection into infarcted myocardium, typically adjunct during open-heart surgery	Direct visual access; described as not having coronary embolism risk	More invasive; leakage; dosing control challenges; inadequate donor-cell retention; studies limited to animals	[7]
Intrapericardial injection	Intrapericardial delivery of hydrogel compound containing MSCs; compared vs intramyocardial control; porcine feasibility/safety reported	Approximately 10 × higher viable cell retention vs intramyocardial in mice; increased exosome secretion and reduced myocardial apoptosis; no major adverse effects in mice; no abnormal cardiac events in pigs over 4 days	Follow-up in pigs only 4 days, so long-term effects not assessed	[21]
Intracoronary infusion	Catheter-based delivery into infarct-related artery by inflating the catheter and infusing cells during inflation; used during catheterization	Human trials described with EF increases, reduced scarred myocardium, and lack of arrhythmia post-procedure	Long-term effects not established; procedural blinding was limited; > 65 excluded; concern raised about potential bias in reporting/editorial handling; animal data suggest possible microvascular obstruction and myocardial injury	[12,28]
Embryoid body formation	Generate iPSC aggregates to drive spontaneous lineage commitment, then isolate MSC-like cells	Simple; cost-effective	Heterogeneity; scale-up challenges; limited microenvironment control	[19,24]
Specific differentiation	Predifferentiate iPSCs toward a lineage, then apply factors/conditions to yield iMSCs	Greater regenerative potential	More time-consuming; higher cost	[19,25]
Blood-based method	Culture iPSCs under blood-derived supplement conditions to promote iMSC phenotype	Low-cost; high proliferative potential	Potential immune reactivity if residual blood components/cell fragments persist	[25]
MSC switch method	Switch iPSC medium to MSC growth media; optional FACS to select subpopulations	Operationally straightforward; selection can improve consistency	Variability in signaling potency and paracrine profile; regulatory classification changes	[19,25]
Pathway inhibitor method	Use chemical pathway inhibitors to drive iPSC to iMSC differentiation	Can reduce heterogeneity via controlled signaling	Labor-intensive; scale-up/yield limitations	[19,25]
UTMD microbubble gene delivery	IV gene-loaded cationic microbubbles; ultrasound cavitation destroys bubbles to deliver genes	Enhances MSC homing; improved repair outcomes vs single-gene	Theoretical toxicity/embolism; transient gene expression	[8]
Targeted nanobubble-exosome delivery	IV nanobubble-antibody-exosome complex; LIPUS disrupts nanobubbles to drive exosome release/penetration	Improves myocardial retention/uptake vs controls; reduces non-cardiac sequestration	Preclinical window and assays limit safety claims; off-target biodistribution remains plausible	[10]
Dual-membrane phase-change nanoparticles	IV phase-change nanoparticles with MSC + macrophage membranes; miRNA-125b surface-adsorbed	Anti-apoptotic and anti-fibrotic effect	Short miRNA activity; repeat dosing	[14]

MSC: Mesenchymal stem cell; iPSC: Induced pluripotent stem cell; iMSC: Induced mesenchymal stem cell; EF: Ejection fraction; LV: Left ventricular; FACS: Fluorescence-activated cell sorting.