Multifunctional ORMOSIL and PAA nanoparticles

Various problems arising during molecular imaging of different fluoroprobes and metabolites used in PDT can be circumvented by focusing on multifunctional therapy agents. Thus an effective photo sensitizer coupled with other useful roles to play in PDT treatment make nanoparticles as a good vehicle for different delivery assuming multifunctional roles not only in PDT but also as therapeutic agents for targeted delivery. A new approach is the involving use of 100 nm NPs as photo sensitizers and/or imaging agents. In our Lab., we employ two such NPs and are ORMOSIL (organically Modified Silica) and PAA (Polyacrylamide) which are found to be biologically very safe without disturbing the therapeutic value. The size of the nanoparticles determined by TEM and Dynamic Light Scattering are ~30 nm. These NPs are taken up in conjunction with cyanine dye at near infra red as it has been reported in literature that encapsulated NPs shows very low singlet oxygen production compared with the post-loaded NPs though the reasons are not yet clear. Therefore, we investigated the idea of post-loading or adsorbing vis-a-vis encapsulation.