Search results for " Light Scattering"

Investigation on the Possibility of Designing an Educational Dynamic Light Scattering Device for Sizing Particles Suspended in Air

2019

Abstract If a light beam meets a fluid that contains scattering centers randomly distributed in suspension, light is scattered by each of them. If the light source is coherent, the scattered waves will be also coherent, therefore they will interfere. The fluctuations of the far-field interference signal, once recorded and digitized, become a time series that can be later on analyzed to produce the average size of the suspended particles or the size distribution. The technique wears the name of Dynamic Light Scattering. We present the results of our investigation on the possibility of using an educational model, made of low-cost, conventional electronics, for recording the time signal of lig…

Glycerosomes: Use of hydrogenated soy phosphatidylcholine mixture and its effect on vesicle features and diclofenac skin penetration.

2016

In this work, diclofenac was encapsulated, as sodium salt, in glycerosomes containing 10, 20 or 30% of glycerol in the water phase with the aim to ameliorate its topical efficacy. Taking into account previous findings, glycerosome formulation was modified, in terms of economic suitability, using a cheap and commercially available mixture of hydrogenated soy phosphatidylcholine (P90H). P90H glycerosomes were spherical and multilamellar; photon correlation spectroscopy showed that obtained vesicles were ∼131nm, slightly larger and more polydispersed than those made with dipalmitoylphosphatidylcholine (DPPC) but, surprisingly, they were able to ameliorate the local delivery of diclofenac, whic…

Investigation of charge ratio variation in mRNA – DEAE-dextran polyplex delivery systems

2019

Biomaterials 192, 612 - 620 (2019). doi:10.1016/j.biomaterials.2018.10.020

Poly(ethylene oxide)-block-poly(n-butyl acrylate)-block-poly(acrylic acid) triblock terpolymers with highly asymmetric hydrophilic blocks: synthesis …

2013

The synthesis and aggregation behaviour in aqueous media of novel amphiphilic poly(ethylene oxide)-block-poly(n-butyl acrylate)-block-poly(acrylic acid) (PEO–PnBA–PAA) triblock terpolymers were studied. Terpolymers composed of two highly asymmetric hydrophilic PEO (113 monomer units) and PAA (10–17 units) blocks, and a longer soft hydrophobic PnBA block (163 or 223 units) were synthesized by atom transfer radical polymerisation (ATRP) of n-butyl acrylate and tert-butyl acrylate (tBA), followed by selective hydrolysis of the PtBA blocks. These terpolymers are not directly soluble in water but form defined spherical micelles by employing the dialysis method as confirmed by dynamic light scatt…

Targeted Hybrid Nanocarriers as a System Enhancing the Skin Structure

2021

The skin is constantly exposed to external and internal factors that disturb its function. In this work, two nanosystems-levan nanoparticles and a surfactin-stabilized nanoemulsion were preserved (tested for microbial growth) and characterized (size, polydispersity, Zeta potential, and stability). The nanosystems were introduced in the model formulations-cream, tonic, and gel, and confirmed by TEM. The analysis showed that nanoemulsion has a spherical morphology and size 220–300 nm, while levan nanoparticles had irregular shapes independently of the use of matrix and with particle size (130–260 nm). Additionally, we examined the antiradical effect of levan nanoparticles and nanoemulsion in …

Thermal aggregation of BSA in trehalose or saccharose solutions

2012

Lysozyme Aggregation Driven by Unfolding: the Role of Metal Ions

2007

Amyloid Fibrils Formation of Concanavalin A at Basic pH

2011

Mechanisms of partial unfolding and aggregation of proteins are of extreme interest in view of the fact that several human pathologies are characterized by the formation and deposition of protein-insoluble material, mainly composed of amyloid fibrils. Here we report on an experimental study on the heat-induced aggregation mechanisms, at basic pH, of concanavalin A (ConA), used as a model system. Thioflavin T (ThT) fluorescence and multiangle light scattering allowed us to detect different intertwined steps in the formation of ConA aggregates. In particular, the ThT fluorescence increase, observed in the first phase of aggregation, reveals the formation of intermolecular β-sheet structure wh…

(E)-2-Cyano-3-(5′-piperidin-1-yl-2,2′-bithien-5-yl)acrylic Acid: A Fluorescent Probe for Detecting Prefibrillar Oligomers

2013

The synthesis of (E)-2-cyano-3-(5′-piperidin-1-yl-2,2′-bithien-5-yl)acrylic acid, a novel amyloid aggregation fluorescent probe, is reported. This new probe is able to monitor soluble oligomeric aggregates after 24 h, at which time Thioflavin T emission, commonly used to monitor amyloid fibril formation, remains unchanged. Atomic force microscopy, native polyacrylamide gel electrophoresis, and dynamic light scattering confirm that the earlier stages of aggregation are prefibrillar oligomeric species not possessing the amyloid structure. This new molecular scaffold expands the toolbox of fluorescent probes for the identification of prefibrillar oligomers, which is needed in studies aimed at …

Observation of interaction forces by investigation of the influence of eluent additives on the retention behavior of aqueous nanoparticle dispersions…

2020

The investigation and subsequent understanding of the interactions of nanomaterials with components of their surrounding media is important to be able to evaluate both potential use cases as well as potential risks for human health and for the environment. To investigate such interactions, asymmetrical flow field-flow fractionation (AF4) is an interesting analytical tool. This statement grounds on the fact that interactions of the analyte with the membrane and with components of the eluent are crucial for the retention behavior of the analyte within the field-flow fractionation (FFF) channel. Therefore, the investigation of the retention behavior provides an insight in the nature of the int…