Amphiphilic Silane Modified Multifunctional Nanoparticles for Magnetically Targeted Photodynamic Therapy.

Efficient targeting is a major challenge in practical photodynamic therapy (PDT). Though the "enhanced permeability and retention" (EPR) effect is a widely used tumor targeting method, magnetic targeting strategy is more promising considering the issue of high targeting efficiency and reducing concentration-dependent toxicity. Herein, magnetic targeting and highly effective Fe3O4@Ce6/C6@silane NPs are reported as a class of precisely controlled photosensitizers (PS) for PDT. On the basis of the amphiphilic silane encapsulation, PS chlorin e6 (Ce6) and Coumarin 6 (C6) as well as Fe3O4 NPs were coloaded into the inside hydrophobic environment of amphiphilic silane, forming a theranostic agent for dual-mode imaging guided and magnetic targeting enhanced in vivo PDT agent. To solve the problem of over-irradiation, the coloaded design of C6 and Ce6 molecules can afford the real time PDT monitoring by ratio emissions with same excitation wavelength. When Fe3O4@Ce6/C6@silane and Ce6/C6@silane NPs are compared in in vitro and in vivo experiments, the introduction of Fe3O4 in the composite does not affect the PDT efficiency, whereas, in contrast, it brings MRI imaging and magnetic targeting functions. Fe3O4@Ce6/C6@silane injection followed with magnetic field (MF) and light irradiation is important in generating an effective PDT process, showing great potential in tumor therapy.