Nanoparticles with widely varying physical properties and origins (spherical versus irregular, synthetic versus biological, organic versus inorganic, flexible versus rigid, small versus large) have been previously noted to translocate across the cell plasma membrane. We have employed atomic force microscopy to determine if the physical disruption of lipid membranes, formation of holes and/or thinned regions, is a common mechanism of interaction between these nanoparticles and lipids. It was found that a wide variety of nanoparticles, including a cell penetrating pepide (MSI-78), a protein (TAT), polycationic polymers (PAMAM dendrimers, pentanol-core PAMAM dendrons, polyethyleneimine, and diethylaminoethyl-dextran), and two inorganic particles (Au-NH 2, SiO 2 -NH 2 ), can induce disruption, including the formation of holes, membrane thinning, and/or membrane erosion, in supported lipid bilayers.

We present the design of a concentric tube (CT) reactor for roll-to-roll chemical vapor deposition (CVD) on flexible substrates, and its application to continuous production of graphene on copper foil. In the CTCVD reactor, the thin foil substrate is helically wrapped around the inner tube, and translates through the gap between the concentric tubes. We use a bench-scale prototype machine to synthesize graphene on copper substrates at translation speeds varying from 25 mm/min to 500 mm/min, and investigate the influence of process parameters on the uniformity and coverage of graphene on a continuously moving foil. At lower speeds, high-quality monolayer graphene is formed; at higher speeds, rapid nucleation of small graphene domains is observed, yet coalescence is prevented by the limited residence time in the CTCVD system. We show that a smooth isothermal transition between the reducing and carbon-containing atmospheres, enabled by injection of the carbon feedstock via radial holes in the inner tube, is essential to high-quality roll-to-roll graphene CVD. We discuss how the foil quality and microstructure limit the uniformity of graphene over macroscopic dimensions. We conclude by discussing means of scaling and reconfiguring the CTCVD design based on general requirements for 2-D materials manufacturing.

Stochastic synthesis of a ligand coupled to a nanoparticle results in a distribution of populations with different numbers of ligands per nanoparticle. This distribution was resolved and quantified using HPLC, and is in excellent agreement with the ligand/nanoparticle average measured by 1H NMR, GPC, and potentiometric titration, yet significantly more disperse than commonly held perceptions of monodispersity. Two statistical models were employed to confirm that the observed heterogeneity is consistent with theoretical expectations.

Dendrimer conjugates for pharmaceutical development are capable of enhancing the local delivery of cytotoxic drugs. The ability to conjugate different targeting ligands to the dendrimer allows for the cytotoxic drug to be focused at the intended target cell while minimizing collateral damage in normal cells. Dendrimers offer several advantages over other polymer conjugates by creating a better defined, more monodisperse therapeutic scaffold. Toxicity from the dendrimer, targeted and nonspecific, is not only dependent upon the number of targeting and therapeutic ligands conjugated, but can be influenced by the repeating building blocks that grow the dendrimer, the dendrimer generation, as well as the surface termination.The narrow therapeutic index of many cytotoxic therapeutics, including doxorubicin, vincristine, cyclophophamide, and paclitaxel, often limits their effectiveness as they must be delivered in suboptimal dosages to prevent side effects in the patient. 1 To remedy this problem, targeted scaffolds can be used to deliver the drug the desired location in an increased, local concentration. As a result, the drug is effective only where it is needed and the undesired side toxicities are diminished. Examples of drug-targeting systems include nanoparticles, liposomes, micelles, linear polymers, branched polymers, and dendrimers. 2 Dendrimer-based platforms have achieved attention for use in pharmaceutical applications.3 -13 Similar to other polymeric carriers, dendrimers can be synthesized to avoid structural toxicity and immunogenicity. However, the unique branched structure of the dendrimer allows for the platform to overcome several significant challenges faced in the development of other polymeric carriers. Many polymers are highly heterogeneous, making characterization and batch reproducibility inherently difficult. Therapeutics with multiple drug or imaging moieties conjugated to a carry are heterogeneous populations that become more disperse as more functionalities are added. These problems often lead to unintended variations in biological activity, because the structural platform is not well understood and is difficult to reproduce. In contrast, the controlled synthesis and growth of dendrimers results in exceptionally low degrees of dispersity [polydispersity index (PDI) <1.1] 14, 15 with well-defined numbers of terminal groups for the conjugation of functional molecules, allowing for improved reproducibility. The dendrimer's ability to mimic the size, solubility, and shape of human proteins makes the

We demonstrate direct production of graphene on SiO2 by CVD growth of graphene at the interface between a Ni film and the SiO2 substrate, followed by dry mechanical delamination of the Ni using adhesive tape. This result is enabled by understanding of the competition between stress evolution and microstructure development upon annealing of the Ni prior to the graphene growth step. When the Ni film remains adherent after graphene growth, the balance between residual stress and adhesion governs the ability to mechanically remove the Ni after the CVD process. In this study the graphene on SiO2 comprises micron-scale domains, ranging from monolayer to multilayer. The graphene has >90% coverage across centimeter-scale dimensions, limited by the size of our CVD chamber. Further engineering of the Ni film microstructure and stress state could enable manufacturing of highly uniform interfacial graphene followed by clean mechanical delamination over practically indefinite dimensions. Moreover, our findings suggest that preferential adhesion can enable production of 2-D materials directly on application-relevant substrates. This is attractive compared to transfer methods, which can cause mechanical damage and leave residues behind.