Abstract: The present invention relates to novel therapeutic and diagnostic dendrimer based modular platforms (e.g., drug delivery platforms). In particular, the dendrimer based modular platforms are configured such that two or more dendrimers (e.g., PAMAM dendrimers) are coupled together (e.g., via a cycloaddition reaction) wherein each of the coupled dendrimers is functionalized (e.g., functionalized for targeting, imaging, sensing, and/or providing a therapeutic or diagnostic material and/or monitoring response to therapy). In some embodiments, the present invention provides dendrimer based modular platforms having coupled dendrimers (e.g., two or more coupled dendrimers) wherein each dendrimer is conjugated to one or more functional groups (e.g., therapeutic agent, imaging agent, targeting agent, triggering agent) (e.g., for specific targeting and/or therapeutic use of the dendrimer based modular platform).