Amphiphilic Silane Modified Multifunctional Nanoparticles for Magnetically Targeted Photodynamic Therapy

Abstract

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.