Green Eucalyptus leaf extract: A potent source of bio-active corrosion inhibitors for mild steel.

Eucalyptus leaves extract (ELE) inhibition impact toward mild steel (MS) corrosion in the HCl solution was examined by combined experimental and computational studies. The degree of inhibition was investigated by EIS and polarization test. The EIS analysis results showed that the increase of ELE concentration led to the significant increment of charge transfer resistance. An inhibition efficiency of ~88% was obtained using 800 ppm ELE after 5 h exposure. Polarization test results indicated the mixed inhibition effects of ELE with slight cathodic prevalence. The icorr values for the uninhibited and inhibited (800 ppm ELE) samples were 0.93 µA/cm2 and 0.25 µA/cm2, respectively. The ELE molecules adsorption on the surface of MS followed a Langmuir isotherm. Furthermore, the molecular simulation results evidenced the adsorption of ELE compounds on the iron surface.

Polyserotonin Nanoparticles as Multifunctional Materials for Biomedical Applications.

Serotonin-based nanoparticles represent a class of previously unexplored multifunctional nanoplatforms with potential biomedical applications. Serotonin, under basic conditions, self-assembles into monodisperse nanoparticles via autoxidation of serotonin monomers. To demonstrate potential applications of polyserotonin nanoparticles for cancer therapeutics, we show that these particles are biocompatible, exhibit photothermal effects when exposed to near-infrared radiation, and load the chemotherapeutic drug doxorubicin, releasing it contextually and responsively in specific microenvironments. Quantum mechanical and molecular dynamics simulations were performed to interrogate the interactions between surface-adsorbed drug molecules and polyserotonin nanoparticles. To investigate the potential of polyserotonin nanoparticles for in vivo targeting, we explored their nano-bio interfaces by conducting protein corona experiments. Polyserotonin nanoparticles had reduced surface-protein interactions under biological conditions compared to polydopamine nanoparticles, a similar polymer material widely investigated for related applications. These findings suggest that serotonin-based nanoparticles have advantages as drug-delivery platforms for synergistic chemo- and photothermal therapy associated with limited nonspecific interactions.

A Detailed Molecular Dynamics Simulation and Experimental Investigation on the Interfacial Bonding Mechanism of an Epoxy Adhesive on Carbon Steel Sheets Decorated with a Novel Cerium-Lanthanum Nanofilm.

The influences of steel surface treatment by a novel cerium-lanthanum (Ce-La) nanofilm on the adhesion mechanism of an epoxy adhesive were studied through experimental and modeling approaches. The surface morphology and microstructure of the film deposited were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The surface free energy and work of adhesion values were evaluated through contact angle analysis. Also, the interfacial adhesion strength between the epoxy adhesive and steel surface, together with failure forms, were examined through pull-off test, under dry and wet conditions, and Fourier transform infrared (FT-IR) spectroscopy. The results obtained from experiments revealed that depositing a Ce-La nanofilm on the steel surface increased its roughness and surface free energy, and strengthened the epoxy coating adhesion. It was also observed that the epoxy adhesion on the Ce-La treated steel was stronger, compared to the Ce-treated surface. Furthermore, the adhesion extent and surface bonding mechanism of aminoamide-cross-linked epoxy resin were computationally modeled by applying atomistic molecular dynamics (MD) and electronic density functional theory (DFT) methods. The modeling results evidenced that epoxy resin adhered more strongly to the conversion layer (represented by CeO2 and La2O3), compared to an untreated steel surface (i.e., pure and oxidized iron). The epoxy binding onto CeO2(111), La2O3(001), Fe2O3(110), and Fe3O4(100) almost occurred via electrostatic interactions, while its adhesion mechanism over FeO(100) and Fe(110) surfaces was based on van der Waals forces. The computations also demonstrated that the epoxy adsorption energy decreased in wet environments, because of solvent affinity toward the epoxy and the surface, but the rate of reduction was smaller over CeO2 and La2O3, compared to that observed with iron oxides. These modeling outcomes were consistent with our experiments and proposed the superior epoxy adhesion on modified steel sheets.

Microfluidic Manipulation of Core/Shell Nanoparticles for Oral Delivery of Chemotherapeutics: A New Treatment Approach for Colorectal Cancer.

A microfluidics approach to synthesize core-shell nanocarriers with high pH tunability is described. The sacrificial shell protects the core layer with the drugs and prevents their release in the severe pH conditions of the gastrointestinal tract, while allowing for drug release in the proximity of a tumor. The proposed nanoparticulate drug-delivery system is designed for the oral administration of cancer therapeutics.

On-chip synthesis of fine-tuned bone-seeking hybrid nanoparticles.

AIMS: Here we report a one-step approach for reproducible synthesis of finely tuned targeting multifunctional hybrid nanoparticles (HNPs). MATERIALS & METHODS: A microfluidic-assisted method was employed for controlled nanoprecipitation of bisphosphonate-conjugated poly(D,L-lactide-co-glycolide) chains, while coencapsulating superparamagnetic iron oxide nanoparticles and the anticancer drug Paclitaxel. RESULTS: Smaller and more compact HNPs with narrower size distribution and higher drug loading were obtained at microfluidic rapid mixing regimen compared with the conventional bulk method. The HNPs were shown to have a strong affinity for hydroxyapatite, as demonstrated in vitro bone-binding assay, which was further supported by molecular dynamics simulation results. In vivo proof of concept study verified the prolonged circulation of targeted microfluidic HNPs. Biodistribution as well as noninvasive bioimaging experiments showed high tumor localization and suppression of targeted HNPs to the bone metastatic tumor. CONCLUSION: The hybrid bone-targeting nanoparticles with adjustable characteristics can be considered as promising nanoplatforms for various theragnostic applications.

Enhanced osteogenic differentiation of stem cells via microfluidics synthesized nanoparticles.

Advancement of bone tissue engineering as an alternative for bone regeneration has attracted significant interest due to its potential in reducing the costs and surgical trauma affiliated with the effective treatment of bone defects. We have improved the conventional approach of producing polymeric nanoparticles, as one of the most promising choices for drug delivery systems, using a microfluidics platform, thus further improving our control over osteogenic differentiation of mesenchymal stem cells. Molecular dynamics simulations were carried out for theoretical understanding of our experiments in order to get a more detailed molecular-scale insight into the drug-carrier interactions. In this work, with the sustained intracellular delivery of dexamethasone from microfluidics-synthesized nanoparticles, we explored the effects of particle design on controlling stem cell fates. We believe that the insights learned from this work will lead to the discovery of new strategies to tune differentiation for in situ differentiation or stem cell therapeutics. FROM THE CLINICAL EDITOR: The use of mesenchymal stem cells has been described by many researchers as a novel therapy for bone regeneration. One major hurdle in this approach is the control of osteogenic differentiation. In this article, the authors described elegantly their microfluidic system in which dexamethasone loaded nanoparticles were produced. This system would allow precise fabrication of nanoparticles and consequently higher efficiency in cellular differentiation.