The present invention relates to novel dendrimer compounds and methods of synthesizing the same. In particular, the present invention is directed to novel polyamidoamine (PAMAM) dendrimers, novel dendrimer branching units, methods for synthesizing such novel PAMAM dendrimers and functionalized dendrimers, as well as systems and methods utilizing the dendrimers (e.g., in diagnostic and/or therapeutic settings (e.g., for the delivery of therapeutics, imaging, and/or targeting agents (e.g., in disease diagnosis and/or therapy, etc.))).