3D Printing of Composite Radiation Shielding for Broad Spectrum Protection of Electronic Systems.

The miniaturization of satellite systems has compounded the need to protect microelectronic components from damaging radiation. Current approaches to mitigate this damage, such as indiscriminate mass shielding, built-in redundancies, and radiation-hardened electronics, introduce high size, weight, power, and cost penalties that impact the overall performance of the satellite or launch opportunities. Additive manufacturing provides an appealing strategy to deposit radiation shielding only on susceptible components within an electronic assembly.

Magnitude Judgements Are Influenced by the Relative Positions of Data Points Within Axis Limits.

When visualising data, chart designers have the freedom to choose the upper and lower limits of numerical axes. Axis limits can determine the physical characteristics of plotted values, such as the physical position of data points in dot plots. In two experiments (total N=300), we demonstrate that axis limits affect viewers' interpretations of the magnitudes of plotted values.

Additive Manufacturing of Multimaterial Composites for Radiation Shielding and Thermal Management.

The harsh radiation environment of space induces the degradation and malfunctioning of electronic systems. Current approaches for protecting these microelectronic devices are generally limited to attenuating a single type of radiation or require only selecting components that have undergone the intensive and expensive process to be radiation-hardened by design. Herein, we describe an alternative fabrication strategy to manufacture multimaterial radiation shielding via direct ink writing of custom tungsten and boron nitride composites.

Dielectric and Mechanical Properties of 3D Printed Nanocomposites with Varied Particle Diameter.

3D printed nanocomposites provide a method for generating high-performance radio frequency devices. Limited work has been done to investigate the influence the nanoparticle diameter has on the performance of 3D printable nanocomposites. We describe here the development of a family of 3D printable nanocomposite inks formulated from nanoparticles with diameters ranging from 30 to 300 nm.

Solubilization of Hydrophobic Catalysts Using Nanoparticle Hosts.

A modular strategy for the solubilization and protection of hydrophobic transition metal catalysts using the hydrophobic pockets of water soluble gold nanoparticles is reported. Besides preserving original catalyst activity, this encapsulation strategy provides a protective environment for the hydrophobic catalyst and brings reusability. This system provides a versatile platform for the encapsulation of different hydrophobic transition metal catalysts, allowing a wide range of catalysis in water while uniting the advantages of homogeneous and heterogeneous catalysis in the same system.

Holographic aperture ladar with range compression.

Simultaneous range compression and aperture synthesis is experimentally demonstrated with a stepped linear frequency modulated waveform and holographic aperture ladar. The resultant three-dimensional (3D) data has high resolution in the aperture synthesis dimension and is recorded using a conventional low bandwidth focal plane array. Individual cross-range field segments are coherently combined using data driven registration and phase correction methods allowing range compression to be performed without the benefit of a coherent waveform.

Sensing by Smell: Nanoparticle-Enzyme Sensors for Rapid and Sensitive Detection of Bacteria with Olfactory Output.

We present here a highly efficient sensor for bacteria that provides an olfactory output, allowing detection without the use of instrumentation and with a modality that does not require visual identification. The sensor platform uses nanoparticles to reversibly complex and inhibits lipase. These complexes are disrupted in the presence of bacteria, restoring enzyme activity and generating scent from odorless pro-fragrance substrate molecules.

Enhanced Laser Desorption/Ionization Mass Spectrometric Detection of Biomolecules Using Gold Nanoparticles, Matrix, and the Coffee Ring Effect.

Nanomaterials have been extensively used as alternate matrices to minimize the low molecular weight interferences observed in typical MALDI but such nanomaterials typically do not improve the spot-to-spot variability that is commonly seen. In this work, we demonstrate that nanoparticles and low matrix concentrations (<2.5 mg/mL) can be used to homogeneously concentrate analytes into a narrow ring by taking advantage of the "coffee ring" effect.

Gradient and Patterned Protein Films Stabilized via Nanoimprint Lithography for Engineered Interactions with Cells.

Protein-based biomaterials provide versatile scaffolds for generating functional surfaces for biomedical applications. However, tailoring the functional and biological properties of protein films remains a challenge. Here, we describe a high-throughput method to designing stable, functional biomaterials by combining inkjet deposition of protein inks with a nanoimprint lithography based methodology.

Biocidal and Antifouling Chlorinated Protein Films.

Bacteria attach to the surfaces of medical devices and implants, resulting in life-threatening infections. Nonfouling coatings can be used to prevent adhesion of bacteria on the surface, while biocidal coatings kill the microbes. Combining nonfouling and biocidal properties can yield highly effective antimicrobial coatings.

Phase gradient algorithm method for three-dimensional holographic ladar imaging.

Three-dimensional (3D) holographic ladar uses digital holography with frequency diversity to add the ability to resolve targets in range. A key challenge is that since individual frequency samples are not recorded simultaneously, differential phase aberrations may exist between them, making it difficult to achieve range compression. We describe steps specific to this modality so that phase gradient algorithms (PGA) can be applied to 3D holographic ladar data for phase corrections across multiple temporal frequency samples.

Nanoparticle-dendrimer hybrid nanocapsules for therapeutic delivery.

Background: Nanocapsules can efficiently encapsulate therapeutic cargo for anticancer drug delivery. However, the controlled release of the payload remains a challenge for effective drug delivery.

Materials & Methods: We used dithiocarbamate-functionalized PAMAM dendrimer to cross-link the shell of arginine gold nanoparticles stabilized nanocapsule, and controlled the drug release from the nanocapsule.

Targeting bacterial biofilms via surface engineering of gold nanoparticles.

Bacterial biofilms are associated with persistent infections that are resistant to conventional antibiotics and substantially complicate patient care. Surface engineered nanoparticles represent a novel, unconventional approach for disruption of biofilms and targeting of bacterial pathogens. Herein, we describe the role of surface charge of gold nanoparticles (AuNPs) on biofilm disruption and bactericidal activity towards and which are important ventilator associated pneumonia (VAP) pathogens.

Immunomodulatory effects of coated gold nanoparticles in LPS-stimulated and murine model systems.

The ability of nanoparticle surface functionalities to regulate immune responses during an immunological challenge (i. e. inflammation) would open new doors for their use in non-prophylactic therapeutics.

Enhanced Laser Desorption/Ionization Mass Spectrometric Detection of Gold Nanoparticles in Biological Samples Using the Synergy between Added Matrix and the Gold Core.

Laser desorption/ionization mass spectrometry (LDI-MS) has been used to detect gold nanoparticles (AuNPs) in biological samples, such as cells and tissues, by ionizing their attached monolayer ligands. Many NP-attached ligands, however, are difficult to ionize by LDI, making it impossible to track these NPs in biological samples. In this work, we demonstrate that concentrations of matrix-assisted LDI (MALDI) matrices an order of magnitude below the values typically used in MALDI can facilitate the selective detection of AuNPs with these ligands, even in samples as complex as cell lysate.

The Interplay of Size and Surface Functionality on the Cellular Uptake of Sub-10 nm Gold Nanoparticles.

Correlation of the surface physicochemical properties of nanoparticles with their interactions with biosystems provides key foundational data for nanomedicine. We report here the systematic synthesis of 2, 4, and 6 nm core gold nanoparticles (AuNP) featuring neutral (zwitterionic), anionic, and cationic headgroups. The cellular internalization of these AuNPs was quantified, providing a parametric evaluation of charge and size effects.

A Multichannel Biosensor for Rapid Determination of Cell Surface Glycomic Signatures.

Cell surface glycosylation serves a fundamental role in dictating cell and tissue behavior. Cell surface glycomes differ significantly, presenting viable biomarkers for identifying cell types and their states. Glycoprofiling is a challenging task, however, due to the complexity of the constituent glycans.

Fabrication of Robust Protein Films Using Nanoimprint Lithography.

A nanoimprint-lithography-based fabrication method to generate stable protein films is described. The process is environmentally friendly and generalizable with respect to the protein building blocks. These non-fouling surfaces are readily patternable, incorporate intrinsic protein charge into the film, and able to control cellular adhesion.

Bacteriophage-based nanoprobes for rapid bacteria separation.

The lack of practical methods for bacterial separation remains a hindrance for the low-cost and successful development of rapid detection methods from complex samples. Antibody-tagged magnetic particles are commonly used to pull analytes from a liquid sample. While this method is well-established, improvements in capture efficiencies would result in an increase of the overall detection assay performance.

Inkjet-printed gold nanoparticle surfaces for the detection of low molecular weight biomolecules by laser desorption/ionization mass spectrometry.

Effective detection of low molecular weight compounds in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is often hindered by matrix interferences in the low m/z region of the mass spectrum. Here, we show that monolayer-protected gold nanoparticles (AuNPs) can serve as alternate matrices for the very sensitive detection of low molecular weight compounds such as amino acids. Amino acids can be detected at low fmol levels with minimal interferences by properly choosing the AuNP deposition method, density, size, and monolayer surface chemistry.

Supramolecular regulation of bioorthogonal catalysis in cells using nanoparticle-embedded transition metal catalysts.

Bioorthogonal catalysis broadens the functional possibilities of intracellular chemistry. Effective delivery and regulation of synthetic catalytic systems in cells are challenging due to the complex intracellular environment and catalyst instability. Here, we report the fabrication of protein-sized bioorthogonal nanozymes through the encapsulation of hydrophobic transition metal catalysts into the monolayer of water-soluble gold nanoparticles.

Nanoparticle-Stabilized Capsules for the Treatment of Bacterial Biofilms.

Bacterial biofilms are widely associated with persistent infections. High resistance to conventional antibiotics and prevalent virulence makes eliminating these bacterial communities challenging therapeutic targets. We describe here the fabrication of a nanoparticle-stabilized capsule with a multicomponent core for the treatment of biofilms.

Co-delivery of protein and small molecule therapeutics using nanoparticle-stabilized nanocapsules.

Combination therapy employing proteins and small molecules provides access to synergistic treatment strategies. Co-delivery of these two payloads is challenging due to the divergent physicochemical properties of small molecule and protein cargos. Nanoparticle-stabilized nanocapsules (NPSCs) are promising for combination treatment strategies since they have the potential to deliver small molecule drugs and proteins simultaneously into the cytosol.

Regulating exocytosis of nanoparticles via host-guest chemistry.

Prolonged retention of internalized nanoparticulate systems inside cells improves their efficacy in imaging, drug delivery, and theranostic applications. Especially, regulating exocytosis of the nanoparticles is a key factor in the fabrication of effective nanocarriers for chemotherapeutic treatments but orthogonal control of exocytosis in the cellular environment is a major challenge. Herein, we present the first example of regulating exocytosis of gold nanoparticles (AuNPs), a model drug carrier, by using a simple host-guest supramolecular system.

Direct cytosolic delivery of siRNA using nanoparticle-stabilized nanocapsules.

The use of nanoparticle-stabilized nanocapsules (NPSCs) for the direct cytosolic delivery of siRNA is reported. In this approach, siRNA is complexed with cationic arginine-functionalized gold nanoparticles by electrostatic interactions, with the resulting ensemble self-assembled onto the surface of fatty acid nanodroplets to form a NPSC/siRNA nanocomplex. The complex rapidly delivers siRNA into the cytosol through membrane fusion, a mechanism supported by cellular uptake studies.