The cardiac toxicity of PAMAM dendrimer drug delivery systems can be attenuated with the adjunct use of cardioprotective agents.

Polyamidoamine (PAMAM) dendrimer nanoparticles are efficient drug delivery vectors with potential clinical applications in nanomedicine. However, PAMAMs can compromise heart function, and strategies to mitigate cardiotoxicity would be beneficial. In this study, we investigated whether the adjunct use of three key cardioprotective agents could prevent cardiac injury induced by a seventh-generation cationic PAMAM dendrimer (G7). Isolated rat hearts were subjected to ischemia and reperfusion (I/R) injury in the presence or absence of G7 or the cardioprotective agents Losartan, epidermal growth factor (EGF), or S-nitroso-N-acetylpenicillamine (SNAP). I/R injury significantly compromised cardiac function, in terms of left ventricular (LV) hemodynamics, contractility, and vascular dynamics, which were markedly improved (P < 0.05) by the administration of Losartan, EGF, or SNAP alone, confirming their cardioprotective effects. The administration of G7 significantly worsened cardiac function recovery following I/R (P < 0.05). G7-induced impairments in cardiac and vascular dynamics were significantly improved by co-administration of Losartan, EGF, or SNAP. Treatment with G7 also significantly increased cardiac enzyme levels and infarct size, both of which were markedly reduced upon co-infusion of Losartan, EGF, or SNAP (P < 0.05). Thus, G7 deteriorates the recovery of cardiac function in isolated hearts subjected to I/R injury, which can be rescued by co-administration of Losartan, EGF, or SNAP. These findings enhance our understanding of PAMAM dendrimer nanotoxicology in the mammalian heart and suggest that the adjunct use of cardioprotective agents is an effective strategy for mitigating the cardiotoxicity of these dendrimers and potentially other drug delivery systems.