Disclosed herein are crosslinked polycarbonates, composition thereof and methods thereof. The cross-linked polycarbonates can be prepared from allyl or epoxy polycarbonates. Described herein is the formation of functionalized poly(carbonate) particles with an established intermolecular cross-linking process. Six types of ‘nanosponges’ were prepared with the differentiation in crosslinking density and crosslinking chemistry. The intermolecular chain cross-linking process was investigated via the epoxide amine reaction and the thiol-ene click reaction.