Recent advances in dynamic monitoring of drug release of nanoparticle using Förster resonance energy transfer and fluorescence lifetime imaging

In this review, we summarized the recent advances in dynamic monitoring of drug release of nanoparticle using FRET and FLIM. Using FRET to understanding the dynamics of drug released from its nanocarrier within intracellular milieu provides high sensitivity and temporal information of the releasing profile. Such information is crucial for the design of drug carriers and validation of drug controlled release. This approach thus has been prevailingly used in monitoring of drug release from a variety of DDS, including quantum dot-, polymer-, and silica-based delivery systems. Alternatively, FLIM assessing changes of micro-environment of drug possesses great potential for use in profiling the intracellular drug release and subcellular drug distribution with various DDS. Our recent approach using FLIM for mapping the intracellular Dox released from pH-responsive MSN has exemplified the feasibility of delineating subcellular distribution of fluorescent drug with corresponding variation of fluorescence lifetime. Both FRET and FLIM are emerging as important techniques in assessing the efficiency of targeted delivery and controlled release of drug with different nanodelivery systems.