We are interested in the design and syntheses of mainly two classes of macromolecules, viz., dendrimers and polymers. The design of these macromolecules is inspired by specific applications that our group is interested in and sometimes by the sheer beauty of the structures that one can generate using organic syntheses as a tool box. The structures that we imagine are often inspired by the intricacies of the nature's nature macromolecules such as proteins and nucleic acids. Dendrimers, derived from the Greek word dendron (tree), are highly branched molecules that are built using iterative synthetic strategies. One of the most attractive aspects of dendrimers is that these molecules can be built as a pure single molecule even at very high molecular weights. Another interesting aspect of dendrimer is that they become globular at high molecular weights and therefore are useful as supramolecular hosts. We have developed a new design strategy to functionalize the interiors of these globular dendrimers to enhance the versatility of these molecules as hosts. In addition, we have also reported three different synthetic strategies to introduce sequences in dendrimers, i.e. these methodologies afford the capability to vary each monomer unit within a dendron or dendrimer. We are now working on several projects that demonstrate the capabilities of dendrimers in host-guest binding, catalysis, drug delivery, and other biological applications.