Selection of Patients Amenable to Nanomedicine Treatment

It is worth noting that patient selection is also advocated for passively targeted nanomedicines, due to the heterogeneity of EPR among patients [163]. 

A criterion was recently proposed by Ferrari and coworkers that relied on MMP9 and TIMPl (Tissue Inhibitor of Metalloproteinase 1) as biomarkers for the EPR effect to select patients amenable to treatment with nanomedidnes [164]. Using FDA-approved PEGylated Liposomal Doxorubidn (Doxil , PLD) as the model nanomedidne, they analyzed the prominent parameters governing PLD accumulation and anticancer activity 

Use of this strategy seems more accessible than the proposed imagery-based methods to evaluate the EPR effect after administration of fluorophore or contrast agent loaded formulations [163]. Indeed, it requires neither a sophisticated apparatus nor specialized personnel. Implementation of a localized imaging modality in this system could allow measurement of the EPR effect in the multitude of tumors frequently present at the time of patient presentation. The library of enzyme-activatable nanoprobes offers a great opportunity for rapid evaluation of the EPR effect based on this platform. 

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