Contrast agents (CA) need to be applied for monitoring tissue-engineered implants by MR imaging. However, currently used CAs have limitations (i.e. negative contrast, label instability). In this study, Hemin-Lysine complex (HL) -as a naturally derived alternative CA- is used for active labeling of hybrid collagen-based templates. HL-labeled templates are clearly identified because of their bright signal in T1-weighted MR images. The signal of labeled templates and thus their integrity could be followed over time when subcutaneously implanted in a mouse model. Thus, loading collagen-based templates with HL appears to be a promising strategy to localize and monitor its fate upon implantation.