DNA has been utilized to engineer the novel functionalized and networked nanostructures in this dissertation. Based on the anisotropicity and multivalency of branched DNA building blocks, a multifunctionalized nanocarrier platform, termed "DNAsomes", was constructed. These DNAsomes are liposome-like core-shell structures formed by the self-assembly of branched DNA-lipid hybrid molecules. The size and surface charge of self-assembled DNAsomes can be precisely manipulated. Importantly, DNAsomes were introduced as universal multi-functional drug carriers, particularly well-suited for small interfering RNA (siRNA) delivery due to the inherent base-pairing with DNA. X-shaped DNA (X-DNA) has four branched arms, providing multivalent functionalities that allow for simultaneous multiple crosslinking. By synthesizing four acrylate-functionalized X-DNA monomers, monodisperse and tunable DNA nanospheres were generated via photocrosslinking. The size and surface charge of these nanospheres were precisely controlled in a linear fashion, simply by adjusting the monomer concentration in the reaction. In addition, in vitro studies in mammalian cells revealed that these DNA nanospheres demonstrated significant efficacy in the delivery of a hydrophobic small molecule drug that intercalates DNA. These results highlight the potential of using DNA as a material building block to design novel nanocarriers with properties tailored for the delivery of drugs in general. New methods to construct functionalized DNA hydrogels were also demonstrated. Unlike traditional enzyme-catalyzed method, networked DNA gels were generated by remotely controlled photopolymerization of functionalized X-DNA building blocks. The gelling process was rapidly achieved within several minutes and the mechanical strength of gel matrixes was dramatically improved by adjustment with additional PEG monomers. Various types and shapes of photocrosslinked DNA hydrogels were prepared and further investigated for cell-free protein expression. Fine tuning of each system has its own benefits in terms of protein yield, format, and stability. These results highlight that DNA building blocks can be utilized as novel materials for bio-related applications, particularly in protein engineering.