Synthesis and applications of metal organic frameworks in photodynamic therapy

Abstract

Metal organic frameworks (MOFs) consist of metal atoms or clusters, coordinated to organic ligands to form macromolecular super structures, with pores large enough to host free drug molecules, including photodynamic therapy (PDT) photosensitizers. This review presents examples of applications in PDT of various types of MOFs. To contextualize the discussions of their PDT applications, general procedures of MOF synthesis are considered. Applications of MOFs in PDT are described using examples of several combination therapy innovations developed for the purpose of solving some of the key challenges in the clinical translation value chain of PDT. The review presents evidence to show that the explosion of research in MOFs is due to their capability for applications as carriers and delivery systems for PDT photosensitizers. It also shows their unique applications as platforms for combination therapies, for stimulus responsive release of photosensitizer and drug molecules, for cancer cell targeting, and for auxiliary enhancement of efficacy. Published literature on MOFs has been on the rise since the eighties. In Scopus, the applications of MOFs in PDT increased from 1 article in 2010, to 169 articles in 2023, whereas published literature on MOFs generally, increased from 878 to 11644 during this period. Research on the applications of MOFs in PDT has therefore increased more than that of MOFs generally. Literature on the applications of MOFs in PDT increased by between 0.7% to 1.45% relative to published literature on MOFs generally. Clearly, MOFs are researched to overcome challenges of and improve PDT efficacy, more than they are generally.