Immune Cell‐Mediated Biodegradable Theranostic Nanoparticles for Melanoma Targeting and Drug Delivery

Although tremendous efforts have been made on targeted drug delivery systems, current therapy outcomes still suffer from low circulating time and limited targeting efficiency. The integration of cell‐mediated drug delivery and theranostic nanomedicine can potentially improve cancer management in both therapeutic and diagnostic applications. By taking advantage of innate immune cell's ability to target tumor cells, the authors develop a novel drug delivery system by using macrophages as both nanoparticle (NP) carriers and navigators to achieve cancer‐specific drug delivery. Theranostic NPs are fabricated from a unique polymer, biodegradable photoluminescent poly (lactic acid) (BPLP‐PLA), which possesses strong fluorescence, biodegradability, and cytocompatibility. In order to minimize the toxicity of cancer drugs to immune cells and other healthy cells, an anti‐BRAF V600E mutant melanoma specific drug (PLX4032) is loaded into BPLP‐PLA nanoparticles. Muramyl tripeptide is also conjugated onto the nanoparticles to improve the nanoparticle loading efficiency. The resulting nanoparticles are internalized within macrophages, which are tracked via the intrinsic fluorescence of BPLP‐PLA. Macrophages carrying nanoparticles deliver drugs to melanoma cells via cell–cell binding. Pharmacological studies also indicate that the PLX4032 loaded nanoparticles effectively kill melanoma cells. The “self‐powered” immune cell‐mediated drug delivery system demonstrates a potentially significant advancement in targeted theranostic cancer nanotechnologies.     

Solid lubricant formulations containing starch-soybean oil composites

Starch-oil composites comprising purified foodgrade corn starch (PFGS) and soybean oil (SBO) were investigated as potential ingredients for water-based solid lubricant formulations. Current solid lubricants are almost exclusively petroleumbased and are used for protecting sheet metal and/or as sheet metal forming lubricants. Starch-oil composites are preferred ingredients for formulating solid lubricants because they are based on renewable and abundantly available raw materials and also have superior environmental and health characteristics. Steel sheets coated with the PFGS-SBO containing solid lubricant were evaluated for boundary coefficient of friction (COF) and wear properties using ball-on-flat test geometry. The COF was highly dependent on the SBO to PFGS ratio in the composite. In the absence of SBO, the COF was high (≈0.8) and decreased sharply with increasing SBO content to a minimum value of 0.07. Wear evaluation showed no scratches or lubricant transfer on the ball. There were also no wear tracks observed on the flat sheet before or after the solid lubricant was washed off. It was concluded that waterbased solid lubricants formulated with the PFGS-SBO starch-oil composite have acceptable friction and wear properties and should be evaluated further for use in sheet metal forming.     

Antimicrobial poly(N‐vinyl‐2‐pyrrolidone‐alt‐maleic anhydride)/poly(ethylene imine) macrocomplexes

The antimicrobial polymer/polymer macrocomplexes were synthesized by radical alternating copolymerization of N‐vinyl‐2‐pyrrolidone with maleic anhydride [poly(VP‐alt‐MA)] with 2,2′‐azobis‐isobutyronitrile as an initiator at 65°C in dioxane solutions under nitrogen atmosphere, and interaction of prepared copolymer with poly(ethylene imine) (PEI) in aqueous solutions. The susceptibility of some Gram‐negative (Salmonella enteritidis and Escherichia coli) and Gram‐positive (Staphylococcus aureus and Listeria monocytogenes) bacteria to the alternating copolymer and its PEI macrocomplexes with different compositions in microbiological medium was studied using pour‐plate technique. All the studied polymers, containing biologically active moieties in the form of ionized cyclic amide, and macrobranched aliphatic amine groups and acid/amine complexed fragments, were more effective against L. monocytogenes than those for Gram‐positive S. aureus bacterium. This fact was explained by different surface layer structural architectures of biomacromolecules of tested bacteria. The resulting polymeric antimicrobial materials are expected to be used in various areas of medicine and food industry. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5841–5847, 2006     

Monosize polystyrene latices carrying functional groups on their surfaces

In this study, monosized polystyrene (PS) latices were prepared by dispersion polymerization of styrene in isopropanol-water media using poly(acrylic acid) (PAA) as a steric stabilizer and 2,2′-azobisizobutyronitrile (AIBN) as an initiator. The effects of initiator and stabilizer concentrations, alcohol/water and monomer/dispersion medium ratio on the polymerization kinetics, and the size and monodispersity of PS latices were experimented with in a stirred reactor system. Monosize PS beads in the size range of 1.0–3.0 μm were obtained. The PS latex obtained in the first step having a diameter of 2.3 μm were used as the seed latex, and styrene/acrylate monomers, acrylic acid (AA), 2-hydroxyethyl methacrylate (HEMA), and dimethylaminoethyl methacrylate (DMAEMA) were copolymerized onto the PS latex particles. The incorporation of functional groups to the surface and bulk structure of PS was confirmed by IR, FTIR, XPS, and zeta potential measurements. © 1994 John Wiley & Sons, Inc.     

Characterization of monomers produced from thermal high-pressure conversion of meadowfoam and oleic acids into estolides

The monomers produced from thermal high-pressure conversion of meadowfoam or oleic acids into estolides were characterized as a complex mixture of fatty acids. Mild reaction conditions produced little change in the starting acids. However, vigorous reaction conditions,e.g. ≥3 h at 250°C with stirring, significantly altered the starting fatty acids.Cis/trans isomerization occurred readily, with the proportion oftrans isomers reaching 57%. In addition, the double bonds migrated throughout all positions of the hydrocarbon chain with concentrations diminishing outward from the starting double bond position. Branching was also observed to a small extent under these conditions and was even more pronounced in the absence of water. Lactones were also identified in the reaction mixture, with contents near 16% in the meadowfoam series. All products can be explainedvia carbocation rearrangement mechanisms that result from protonation of the starting olefins.     

Evaluation of partially hydrogenated methyl esters of soybean oil as biodiesel

Biodiesel, an alternative fuel derived from vegetable oils or animal fats, continues to undergo rapid worldwide growth. Specifications mandating biodiesel quality, most notably in Europe (EN 14214) and the USA (ASTM D6751), have emerged that limit feedstock choice in the production of biodiesel fuel. For instance, EN 14214 contains a specification for iodine value (IV; 120 g I₂/100 g maximum) that eliminates soybean oil as a potential feedstock, as it generally has an IV >120. Therefore, partially hydrogenated soybean oil methyl esters (PHSME; IV = 116) were evaluated as biodiesel by measuring a number of fuel properties, such as oxidative stability, low‐temperature performance, lubricity, kinematic viscosity, and specific gravity. Compared to soybean oil methyl esters (SME), PHSME were found to have superior oxidative stability, similar specific gravity, but inferior low‐temperature performance, kinematic viscosity, and lubricity. The kinematic viscosity and lubricity of PHSME, however, were within the prescribed US and European limits. There is no universal value for low‐temperature performance in biodiesel specifications, but PHSME have superior cold flow behavior when compared to other alternative feedstock fuels, such as palm oil, tallow and grease methyl esters. The production of PHSME from refined soybean oil would increase biodiesel production costs by US$ 0.04/L (US$ 0.15/gal) in comparison to SME. In summary, PHSME are within both the European and American standards for all properties measured in this study and deserve consideration as a potential biodiesel fuel.     

Goal emulation and planning in perceptual space using learned affordances

In this paper, we show that through self-interaction and self-observation, an anthropomorphic robot equipped with a range camera can learn object affordances and use this knowledge for planning. In the first step of learning, the robot discovers commonalities in its action-effect experiences by discovering effect categories. Once the effect categories are discovered, in the second step, affordance predictors for each behavior are obtained by learning the mapping from the object features to the effect categories. After learning, the robot can make plans to achieve desired goals, emulate end states of demonstrated actions, monitor the plan execution and take corrective actions using the perceptual structures employed or discovered during learning. We argue that the learning system proposed shares crucial elements with the development of infants of 7–10 months age, who explore the environment and learn the dynamics of the objects through goal-free exploration. In addition, we discuss goal emulation and planning in relation to older infants with no symbolic inference capability and non-linguistic animals which utilize object affordances to make action plans.     

Oxidation behavior of electrically conductive α/β SiAlON composites with segregated network of TiCN

The oxidation behavior of novel electrically conductive α/β SiAlON composites with a continuous network of 2.5–10 vol% TiCN particulates was investigated. Composites, produced by coating spray dried granules with nano TiCN particles by a simple blending method, were gas pressure sintered at 1990 °C for 1 h under 10 MPa N₂ pressure. Oxidation tests were carried out between 800 °C and 1200 °C in air for 2 and 48 h in atmosphere of dry air. Below 1000 °C, the formation of TiO₂ crystals on the surfaces of TiCN particles was observed. Before the glass transition temperature of intergranular phase (T_g < 1000 °C), it was revealed that oxidation is controlled by the diffusion of oxygen into pre-formed TiO₂ particles. Above T_g, liquid glass dissolves the intergranular phase elements such as Ti, Y, and Si at the interface between TiCN and SiAlON particles. Migration of Ti towards the (opening point of the TiCN network) surface was found to be the main reason for the formation of subsurface porosity that slows down Ti diffusion through the surface. Moreover, it was detected that at high temperatures surface porosity filled by the intergranular glassy phase. Consequently, the oxidation rate was found to be decreased due to the slower oxygen diffusion.     

A design of cellular automata-based PUF and its implementation on FPGA

Since the number of networked devices increases continuously, ensuring the safety and reliability of these systems is growing at the same time. Today, a unique identity of a device can be obtained from physical unclonable functions (PUFs) and this identity as a trust anchor in higher-level security architectures. This article is exploring the cellular automaton (CA) paradigm to extract and magnify unique features of the underlying hardware to uniquely identify a device. The proposed PUF is based on a field-programmable gate arrays (FPGAs) implementation of CA with random memory (CARM) model. Implementation of the memory part of CARM is the challenge of the introduced PUF, and corresponding response is obtained from the introduced evolution figure metric. The uniqueness and reliability of the PUF hardware are compared with the results from the state-of-the-art PUF designs implemented on FPGA in the literature. The test results show that the introduced CA-based design is a promising and competitive candidate for PUF primitives.     

Structural Characterization of Asphaltenes and Ethyl Acetate Insoluble Fractions of Petroleum Vacuum Residues

Asphaltenes and insoluble fractions of vacuum residues (VRs) of two Indian crude oils (viz. Heera and Jodhpur) of different specific gravity were obtained by precipitation of VRs in n-hexane, n-heptane, and ethyl acetate, and also by subsequent reprecipitation of n-heptane and ethyl acetate soluble fractions by n-pentane. The effect of various solvents on average molecular structure of asphaltenes and insolubles was studied using nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FTIR), and size exclusion chromatography (SEC). The asphaltenes and insolubles of Jodhpur VR have higher amounts of high molecular weight species with a high concentration of condensed and substituted aromatic rings, branched and/or short alkyl side chains, oxygen and nitrogen functionalities, compared to that of Heera VR. Ethyl acetate insolubles comprise a higher number of substituted aromatic structures, branched aliphatic structures, complex average unit structures, nitrogen and oxygen functionalities, and high molecular weight (MW) species as compared to hexane and heptane asphaltenes. Heptane insolubles consist of more naphthenic rings condensed with aromatic rings than C6A and EAI.