Deposition of Nanometric Polymer-Surfactant Complexes Formed by Cationic Dextran: A Path to Sustainable Formulations.

The home and personal care industry is evolving toward more sustainable and environmentally friendly ingredients. Rinse-off personal care products rely on formation of polymer-surfactant complexes to drive deposition of benefit agents (e.g.

Effect of Surfactant Concentration and Hydrophobicity on the Ordering of Water at a Silica Surface.

The performance of nonionic surfactants is mediated by the interfacial interactions at the solid-liquid interface. Here we applied sum frequency generation (SFG) vibrational spectroscopy to probe the molecular structure of the silica-nonionic surfactant solution interface in situ, supplemented by quartz crystal microbalance with dissipation monitoring (QCM-D) and molecular dynamics (MD) simulations. The combined studies elucidated the effects of nonionic surfactant solution concentration, surfactant composition, and rinsing on the silica-surfactant solution interfacial structure.

Protein Materials Engineering with DNA.

Proteins are a class of nanoscale building block with remarkable chemical complexity and sophistication: their diverse functions, shapes, and symmetry as well as atomically monodisperse structures far surpass the range of conventional nanoparticles that can be accessed synthetically. The chemical topologies of proteins that drive their assembly into materials are central to their functions in nature. However, despite the importance of protein materials in biology, efforts to harness these building blocks synthetically to engineer new materials have been impeded by the chemical complexity of protein surfaces, making it difficult to reliably design protein building blocks that can be robustly transformed into targeted materials.

Programming Protein Polymerization with DNA.

A strategy that utilizes DNA for controlling the association pathway of proteins is described. This strategy uses sequence-specific DNA interactions to program energy barriers for polymerization, allowing for either step-growth or chain-growth pathways to be accessed. Two sets of mutant green fluorescent protein (mGFP)-DNA monomers with single DNA modifications have been synthesized and characterized.

DNA-Encoded Protein Janus Nanoparticles.

Asymmetric functionality and directional interactions, which are characteristic of noncentrosymmetric particles, such as Janus particles, present an opportunity to encode particles with properties, but also a great synthetic challenge. Here, we exploit the chemical anisotropy of proteins, and the versatile chemistry of DNA to synthesize a protein-based Janus nanoparticle comprised of two proteins encoded with sequence-specific nucleic acid domains, tethered together by an interprotein "DNA bond". We use these novel nanoparticles to realize a new class of three-dimensional superlattice, only possible when two sides of the particle are modified with orthogonal oligonucleotide sequences.

DNA-Functionalized, Bivalent Proteins.

Bivalent DNA conjugates of β-galactosidase (βGal), having pairs of oligonucleotides positioned closely on opposing faces of the protein, have been synthesized and characterized. These structures, due to their directional bonding characteristics, allow for the programmable access of one-dimensional protein materials. When conjugates functionalized with complementary oligonucleotides are combined under conditions that support DNA hybridization, periodic wire-type superstructures consisting of aligned proteins form.

Modulating Nanoparticle Superlattice Structure Using Proteins with Tunable Bond Distributions.

Herein, we investigate the use of proteins with tunable DNA modification distributions to modulate nanoparticle superlattice structure. Using beta-galactosidase (βgal) as a model system, we have employed the orthogonal chemical reactivities of surface amines and thiols to synthesize protein-DNA conjugates with 36 evenly distributed or 8 specifically positioned oligonucleotides. When these are assembled into crystalline superlattices with gold nanoparticles, we find that the distribution of DNA modifications modulates the favored structure: βgal with uniformly distributed DNA bonding elements results in body-centered cubic crystals, whereas DNA functionalization of cysteines results in AB packing.

DNA-Mediated Cellular Delivery of Functional Enzymes.

We report a strategy for creating a new class of protein transfection materials composed of a functional protein core chemically modified with a dense shell of oligonucleotides. These materials retain the native structure and catalytic ability of the hydrolytic enzyme β-galactosidase, which serves as the protein core, despite the functionalization of its surface with ∼25 DNA strands. The covalent attachment of a shell of oligonucleotides to the surface of β-galactosidase enhances its cellular uptake of by up to ∼280-fold and allows for the use of working concentrations as low as 100 pM enzyme.