Factors Influencing Retention of Injected Biomaterials to Treat Myocardial Infarction

Biomaterials that are commonly used for the attenuation of adverse remodeling or as regenerative treatment for myocardial infarction (MI), often have the capacity to release drugs in a sustained manner, providing strength and stability to the infarcted area, or mimic the extracellular matrix. Retention and redistribution of the injected biomaterials is a factor often overlooked, but plays a significant role in the effectiveness of the treatment. Wash-out of therapeutics from the cardiac area can lead to unwanted side-effects and can therefore add insult to injury. Here, the authors seek a deeper understanding on the mechanisms that play an important role in the retention of injected therapeutics, being: materials, drugs, or a combination thereof. Several factors influencing the therapeutic quantity retained at the target site are discussed; being the timing of injection after MI, cardiac pulsation, and injectate properties such as volume, mechanical properties, and tissue affinity. The importance of understanding is highlighted and these different parameters are taken into. More insight in these parameters can lead to an increase in therapeutic effectiveness, in addition to examination of indirect off-target effects.