173 research outputs found
Synthesis of bio-functional nanoparticles from sono-responsive amino acids using high frequency ultrasound
A simple, one-pot high frequency ultrasonication (490 kHz) methodology to convert hydrophobic and amphipathic amino acids into nanostructures was investigated. The approach involved the oxidative coupling of aromatic amino acids (phenylalanine and tryptophan) in aqueous solutions to form high molecular weight dimers and oligomers. The role of cavitation bubble surface and ultrasonic power to trigger the out-of-equilibrium self-assembly of dimers and trimers to spherical and uniform nanostructures with controlled size has been discussed. The synthesized particles exhibited fluorescence in blue, green and red spectral regions and a strong antioxidant activity
Special issue on âUltrasound-assisted engineering of materials for biomedical usesâ
[no abstract available
A BBN-based Method to Manage Adaptive Behavior of a Smart User Interfaceâ
Abstract The present study proposes a new method to manage adaptation behaviour of adaptive system according to the output information provide by a user model based on Bayesian Belief Network (BBN). Such method has been applied in the development of smart interfaces for cooking and kitchen management, such as meal preparation and interaction with the major kitchen appliances, pandering the user's skills, expertise and disabilities. Nevertheless, this method is flexible and suitable enough to be used in other application contexts. The validity of the decision making algorithm has been tested through simulation of real user case scenarios
Genome Sequencing of <i>Pantoea agglomerans</i> C1 Provides Insights into Molecular and Genetic Mechanisms of Plant Growth-Promotion and Tolerance to Heavy Metals
Distinctive strains of Pantoea are used as soil inoculants for their ability to promote plant growth. Pantoea agglomerans strain C1, previously isolated from the phyllosphere of lettuce, can produce indole-3-acetic acid (IAA), solubilize phosphate, and inhibit plant pathogens, such as Erwinia amylovora. In this paper, the complete genome sequence of strain C1 is reported. In addition, experimental evidence is provided on how the strain tolerates arsenate As (V) up to 100 mM, and on how secreted metabolites like IAA and siderophores act as biostimulants in tomato cuttings. The strain has a circular chromosome and two prophages for a total genome of 4,846,925-bp, with a DNA G+C content of 55.2%. Genes related to plant growth promotion and biocontrol activity, such as those associated with IAA and spermidine synthesis, solubilization of inorganic phosphate, acquisition of ferrous iron, and production of volatile organic compounds, siderophores and GABA, were found in the genome of strain C1. Genome analysis also provided better understanding of the mechanisms underlying strain resistance to multiple toxic heavy metals and transmission of these genes by horizontal gene transfer. Findings suggested that strain C1 exhibits high biotechnological potential as plant growth-promoting bacterium in heavy metal polluted soils.6s
Ultrasonic transformation of antibiotic molecules into a selective chemotherapeutic nanodrug
Ultrasound-based engineering of carrier-free nanodrugs by supramolecular self-assembly has recently emerged as an innovative and environmentally friendly synthetic approach. By applying high-frequency sound waves (490 kHz) in aqueous solutions, the transformation of small chemotherapeutic and antibiotic drug molecules into carrier-free nanodrugs with anticancer and antimicrobial activities was recently achieved. The transformation of the antibiotic drug molecules, i.e., doxycycline, into stable nanodrugs (similar to 130 nm) with selective anticancer activity was achieved without requiring organic solvents, chemical agents, or surfactants. The obtained nanodrug exhibited reactive oxygen species (ROS)-mediated cytotoxicity on human breast cancer (MDA-MB 231 cells) but a negligible antiproliferative effect on healthy fibroblast cells. Imaging by super-resolution microscopy (STORM) provided insights into the intracellular trafficking and endosomal escape of the nanodrugs. Overall, these findings suggest that small antibiotic drugs can be transformed into chemotherapeutic nanodrugs with high selectivity against cancer cells
sono assembly of nanostructures via tyrosine tyrosine coupling reactions at the interface of acoustic cavitation bubbles
The reactive and oscillating surface of cavitation microbubbles acts as a catalytic binding site for the coupling of amphiphilic biomolecules
Sonosynthesis of nanobiotics with antimicrobial and antioxidant properties
Transforming small-molecule antibiotics into carrier-free nanoantibiotics represents an opportunity for developing new multifunctional therapeutic agents. In this study, we demonstrate that acoustic cavitation produced by high-frequency ultrasound transforms the antibiotic doxycycline into carrier-free nanobiotics. Upon sonication for 1 h at 10-15 W cm(-3), doxycycline molecules underwent hydroxylation and dimerization processes to ulti-mately self-assemble into nanoparticles of ~100-200 nm in size. Micrometer sized particles can be also obtained by increasing the acoustic power to 20 W cm(-3). The nanodrugs exhibited antioxidant properties, along with antimicrobial activity against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacterial strains. Our results highlight the feasibility of the ultrasound-based approach for engineering drug molecules into a nanosized formulation with controlled and multiple bio-functionalities
Consumers vs Internet of Things: A Systematic Evaluation Process to Drive Users in the Smart Worldâ
Abstract Smart Objects (SOs) market offers a wide variety of products apparently similar but characterized by different features that the average users fail to perceive. Consequently, their purchasing is often based on price and brand affection. In this context, users need a tool able to guide them in choosing the most suitable object to satisfy their expectations. To this purpose, this paper proposes a new systematic method to assess SOs in a comprehensive way: it allows to objectively assess and compare products and provides evaluation results tailored on users' needs. A first validation is carried out on three different SO typologies
The transdermal delivery of therapeutic cannabinoids
Recently, several studies have indicated an increased interest in the scientific community regarding the application of Cannabis sativa plants, and their extracts, for medicinal purposes. This plant of enormous medicinal potential has been legalised in an increasing number of countries globally. Due to the recent changes in therapeutic and recreational legislation, cannabis and cannabinoids are now frequently permitted for use in clinical settings. However, with their highly lipophilic features and very low aqueous solubility, cannabinoids are prone to degradation, specifically in solution, as they are light-, temperature-, and auto-oxidation-sensitive. Thus, plant-derived cannabinoids have been developed for oral, nasal-inhalation, intranasal, mucosal (sublingual and buccal), transcutaneous (transdermal), local (topical), and parenteral deliveries. Among these administrations routes, topical and transdermal products usually have a higher bioavailability rate with a prolonged steady-state plasma concentration. Additionally, these administrations have the potential to eliminate the psychotropic impacts of the drug by its diffusion into a nonreactive, dead stratum corneum. This modality avoids oral administration and, thus, the first-pass metabolism, leading to constant cannabinoid plasma levels. This review article investigates the practicality of delivering therapeutic cannabinoids via skin in accordance with existing literature
Michael-Type Addition Reactions for the In Situ Formation of Poly(vinyl alcohol)-Based Hydrogels
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