Fabrication of a dual stimuli-responsive magnetic nanohydrogel for delivery of anticancer drugs.

A dual stimuli-responsive magnetic nanohydrogel was fabricated as a potent drug delivery system (DDS) for 'smart' treatment of cancer by chemo/hyperthermia approach. For this objective, Fe3O4 nanoparticles (NPs) were produced via a co-precipitation approach and then modified by 3-(trimethoxysilyl) propylmethacrylate (MPS) moiety. The modified NPs were copolymerized with N,N'-(dimethylamino)ethyl methacrylate (DMAEMA), and maleic anhydride (MA) monomers by a free radical polymerization approach to afford a Fe3O4@P(DMAEMA-co-MA) core-shell NPs. Afterward, the NPs were shell crosslinked by the reaction of anhydride unites with neutralized cystamine (Cys). The fabricated pH- and reduction-responsive magnetic nanohydrogel was physically loaded with methotrexate (MTX), as an anticancer drug, and its drug loading efficiency (LE) was calculated as 64 ± 2.7%. The developed nanohydrogel/MTX exhibited proper stimuli-triggered drug release behavior that qualified it as an efficient DDS according to the abnormal micro-environment of cancerous tumors. The anticancer activity investigation using chemo/hyperthermia therapy approach by MTT-assay revealed that the nanohydrogel/MTX might show better clinical outcomes than those of the free MTX.

Acceptance of Full Driving Automation: Personally Owned and Shared-Use Concepts.

OBJECTIVE: This study aims to develop user acceptance models for two concepts of full driving automation: personally owned and shared use. BACKGROUND: Many manufacturers have been investing considerably in and actively developing full driving automation. However, factors influencing user acceptance of full driving automation are not yet fully understood. METHOD: This study consisted of two parts: focus group discussions and online surveys. A total of 30 potential users participated in focus groups to discuss their perception of full driving automation acceptance. Based on the findings from focus group discussions, theoretical foundations, and empirical evidence, we hypothesized the acceptance models for both personally owned and shared-use concepts. We tested the models with 310 and 250 participants, respectively, online. RESULTS: The results of focus groups indicated that users' concerns are centered around safety, usefulness, compatibility, trust, and ease of use. The survey results revealed the important roles of perceived usefulness and perceived safety in both models, whereas the direct impact of perceived ease of use was found to be insignificant. The indirect impact of perceived ease of use was less significant in the personally owned than in the shared-use model, whereas usefulness, trust, and compatibility played more important roles in the personally owned when compared with the shared-use model. CONCLUSION: The findings uncovered a chain of constructs that affect behavioral intention to use for both full driving automation concepts. APPLICATION: The framework and outcome of this study provide valuable guidelines that allow better understanding for government agencies, manufacturers, and automation designers regarding users' acceptance of full driving automation.

Synthesis of New Functionalized Citric Acid-based Dendrimers as Nanocarrier Agents for Drug Delivery.

INTRODUCTION: Citric acid-polyethylene glycol-citric acid (CPEGC) triblock dendrimers can serve as potential delivery systems. METHODS: In this investigation, CPEGC triblock dendrimers were synthesized and then imidazole groups were conjugated onto the surface of the G1, G2 and G3 of the obtained dendrimers. In order to study the type of the interactions between the functionalized dendrimers and a drug molecule, Naproxen which contains acidic groups, was examined as a hydrophobic drug in which the interactions would be of the electrostatic kind between its acidic groups and the lone pair electrons of nitrogen atom in imidazole groups. The quantity of the trapped drug and also the amount of its release were measured with UV spectrometric method in pH 1, 7.4 and 10. The average diameter of the nanocarriers was measured by Dynamic Light Scattering (DLS) technique. RESULTS: The size range of particles was determined to be 16-50 nm for different generations. The rate of the release increased in pH=10 in all generations due to the increases in Naproxen solubility and the hydrolysis of the esteric bonds in the mentioned pH. The results showed that the amount of the trapped drug increased with the increase in the generation of the dendrimer and pH. CONCLUSION: Based on our findings, we suggest CPEGC triblock dendrimers possess great potential to be used as drug/gene delivery system.