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Non-lamellar lyotropic liquid crystalline nanocarriers such as hexosomes and cubosomes are relatively unexplored lipid-based nanoparticles in nanomedicine that can be specifically formulated to match specific medical applications, thus exploiting the majority of the possible routes of administrations. A growing number of papers demonstrate intriguing features that make them good candidates as nanocarriers for therapeutically active molecules or imaging probes. Yet, important aspects, including pharmacokinetics, hemocompatibility, toxicity, and delivery properties, are not completely clarified, so that their full potential as nanomedicines remains to be assessed. This article reviews recent advances in the field and suggests possible new routes forward.

In this work Nanoparticle Enhanced Laser Induced Breakdown Spectroscopy (NELIBS) has been employed for quantitative metal detection using amyloid fibrils coated with gold nanoparticles as enhancers. Amyloid fibrils represent, from one hand, an extremely interesting system for novel technologies, ranging from water purification to medical applications, and on the other hand, an ideal system for investigating the performance of laser-matter interaction in biological systems. The results obtained in this work show the potentiality of NELIBS for the quantification at sub-ppm (mg/kg) level of metallic elements (Cr, Pb, Tl and Cd) even in the protein and/or biological environment, employing amyloid fibrils with gold nanoparticles. Moreover, the single-shot measurements reveal the promising use of this technique in applications where high sensitivity and/or limitation in the sample amount are demanded.

While stimuli-responsive polymers have received a huge amount of attention in the literature, responsive lipid-based mesophase systems offer unique opportunities in biomedical applications such as drug delivery and biosensing. The different mesophase equilibrium structures enables dynamic switching between nanostructures to facilitate drug release or as a transducer for recognition events. In drug delivery, this behavior offers researchers the means to deliver a therapeutic payload at a specific rate and time i.e. 'on-demand'. This review summarizes the distinctive features of these multifaceted materials and aggregates the current state of the art research from our groups and others into the use of these materials as bulk gels and nanostructured dispersions for drug delivery, biosensing and diagnostics.

We characterized the sol–gel transition of positively charged fibrils composed of the model amphiphilic peptide RADARADARADARADA (RADA 16-I) using a combination of microscopy, light scattering, microrheology and rheology techniques, and we investigated the dependence of the hydrogel formation on fibril concentration and ionic strength. The peptide is initially present as a dispersion of short rigid fibrils with average length of about 100 nm. During incubation, the fibrils aggregate irreversibly into longer fibrils and fibrillar aggregates. At peptide concentrations in the range 3–6.5 g/L, the fibrillar aggregates form a weak gel network which can be destroyed upon dilution. Percolation occurs without the formation of a nematic phase at a critical peptide concentration which decreases with increasing ionic strength. The gel structure can be well described in the frame of the fractal gel theory considering the network as a collection of fibrillar aggregates characterized by self-similar structure with a fractal dimension of 1.34.

Nanoscale phase segregation in tailored graft copolymer electrolyte is probed by microscopy and small-angle scattering, and modeled by a stochastic technique. Based on stochastic modeling, we describe the percolation and connectivity of the ion-rich phase, and propose boundaries for the graft length and graft density to obtain favorable phase segregation potentially relevant for operation at low levels of hydration. The approach can be adapted for other copolymer systems, and points out new aspects in the structure–property relationships for polymer electrolytes.

We report on the network characterization of a series of hybrid nanocomposites consisting of integrated anisotropic nanoparticles (NPs) within a polyurea elastomeric matrix with low weight fractions ranging from 0.3 to 1.2 wt%. The grafting method employed to incorporate the silica-coated spindle-type hematite nanoparticles (SCH NPs), promotes the stability of the NPs in dispersion, and further enables their integration within the elastomeric polymer matrix, where the NPs are acting as multifunctional chemical crosslinkers and reinforcing fillers. The mechanical properties of these nanocomposite materials have systematically been investigated for both small and large deformations as a function of the particles concentration in the matrix. The results indicate that significant reinforcement of the hybrid nanocomposite is achieved even at very low NP loading with respect to the pristine elastomeric matrix.

Protein fibrils are a crucial subject of study in various research fields and disciplines. Amyloid fibrils are highly ordered fibrillar structures assembled from either peptides or unfolded proteins, which have a great importance in biology, medicine and recently have started to find an important role in many nanotechnology applications. Understanding the mechanisms of fibrillation, the structural features, and the physical and mechanical properties of these fibrils is an essential step to both unraveling their biological role and also their successful applications in nanotechnology and material science. Atomic force microscopy (AFM) is one of the most widely used single-molecule techniques to study the properties of amyloid fibrils. In this review we will discuss how the application of AFM during last few years has allowed moving considerably forward in the research of amyloid fibrils. We will review how AFM has rapidly evolved from a purely microscopic technique, providing important information about fibril structure and fibrillation processes, to a tool capable to probe also intrinsic properties of amyloid fibrils such as their strength and Young's moduli.

Food foams such as marshmallow, Chantilly and mousses have behavior and stability directly connected with their microstructure, bubble size distribution and interfacial properties. A high interfacial tension inherent to air/liquid foams interfaces affects its stability, and thus it has a direct impact on processing, storage and product handling. In this work, the interactions of egg albumin with various types of polysaccharides were investigated by drop tensiometry, interfacial rheology and foam stability. The progressive addition of egg albumin and polysaccharide in water induced a drop of the air-water surface tension which was dependent on the pH and polysaccharide type. At pH 4, that is below the isoeletric point of egg albumen (pI = 4.5) the surface tension was decreased from 70 mN/m to 42 mN/m by the presence of the protein, and from 70 mN/m to 43 mN/m, 40 mN/m and 38 mN/m by subsequent addition of xanthan, guar gum and κ-carrageenan, respectively. At pH 7.5 the surface tension was decreased from 70 mN/m to 43 mN/m by the simultaneous presence of the protein and κ-carrageenan. However, a higher surface tension of 48 and 50 mN/m was found when xanthan and guar gum were added, respectively, when compared with carrageenan addition. The main role on the stabilization of protein-polysaccharide stabilized interfaces was identified on the elasticity of the interface. Foam stability experiments confirmed that egg-albumin/κ-carrageenan at pH below the protein isoeletric point are the most efficient systems to stabilize air/water interfaces. These results clearly indicate that protein-polysaccharide coacervation at the air/water interface is an efficient process to increase foam stability.

The physics ruling the macroscopic behaviour of foods is discussed in a few selected examples in which the equilibrium/non-equilibrium nature can be directly related to the typical length scale of the food structure and the specific interaction strength, the latter describing the decrease in specific free energy (e.g., per mole of species or per single event) when going from a non-equilibrium to the equilibrium configuration. Liquid-crystalline phases in foods, such as those based on self-assembled lipids and water, are discussed as an example of equilibrium system, in which low correlation length scales (∼nm) enable very-short times to re-organize molecules into equilibrium configurations. High internal phase emulsions and dry foams where length scales are very large (∼10 1 –10 4 μm), are discussed as a typical example of non-equilibrium system, which however, can be stable for long times owing to the high free energy barrier and the large correlation lengths. Finally double emulsion systems are considered as an example where both interaction strength and correlation lengths have intermediate values. This allows tuning morphologies and making equilibrium behaviour to prevail over non-equilibrium by suitably tailoring the energetic interactions. In particular the case of osmotic pressure in the water phase of water/oil/water double emulsions is discussed as a viable route to control interaction strength in complex food systems.

Liquid crystalline foods based on self-assembly of lipids and water present rich phase diagrams, in which the hydrophilic and hydrophobic phases are organized in periodic three-dimensional nano-structures of different types, depending on temperature and composition. Since these systems constitute a rare example of food at local thermodynamic equilibrium, their structure can be predicted, in theory, based on the minimization of the total free energy. In the present work, we review past and recent attempts to predict the equilibrium structure of these materials, based on parametric, geometrical and physically inspired approaches. We also summarize our own efforts towards a general predictive simulation tool based on self-consistent field theory. For a specific lipid–water system, this approach allows predicting which liquid crystalline phases are present at equilibrium, but also the relevant topological parameters at a given temperature and composition, such as the radius of water channels or thickness of water lamellae and lipid bi-layers. Furthermore, the addition of guest molecules in either the hydrophobic or hydrophilic phase can also be accounted in the model. This approach should ultimately allow the design of complex liquid crystalline foods based on multiple components and functional molecules.

The evolution of surface tension during polymerization of three amine-cured epoxy systems was investigated. Due to the chemical reaction of the epoxy groups with primary and secondary amines, the energetic status of an epoxy-amine system increased during polymerization. At the same time, the polymerization process induced entropic variations, also contributing to the evolution of surface energetics. A simple relation expressing the surface tension as a function of the bulk energy, the entropy of the system, and the square gradient of the polymer density was derived. The bulk and surface energetics were expressed in terms of solubility parameter and surface tension, respectively. The former was predicted using the Van Krevelen group contribution method, while the latter was directly measured using the Wilhelmy wetting method. Results indicated that, in all the three epoxy-amine systems under investigation, a unique relationship combining the surface tension, the bulk energy, the entropy, and the density square gradient of the system could be used. On the basis of the present study, and taking into account all contributory factors, it was concluded that the enthalpy component to the surface energetics is the dominant contribution.

The amyloid aggregation of proteins is associated with a number of neurodegenerative diseases such like Alzheimer's, Huntington's and Parkinson's diseases, and also type-2 diabetes (T2D). Despite the physical and structural properties of the aggregating proteins, the corresponding amyloid aggregates feature some common characteristics including the formation of cross-β architecture and cytotoxicity to human cells, suggesting a common amyloid mechanism. Experimental studies have shown that several naturally-occurring small molecules, such as epigallocatechin gallate (EGCG), have an inhibitory effect on the aggregation of a wide range of those amyloid proteins, including islet amyloid polypeptide (IAPP, a.k.a.

The influence of cure temperature, composition and chemical structure on the morphology resulting from chemically induced phase separation has been investigated for different epoxy functionalized dendritic hyperbranched polymers blended with diglycydil bisphenol A and an aliphatic diamine. The cure temperature window chosen highlighted the influence of both the kinetics of phase separation and the thermodynamics of mixing on the final morphology. In relatively immiscible blends and at low cure temperatures, phase separation occurred immediately after mixing. However, increasing the miscibility by raising the temperature or modifying the chemistry of the dendritic hyperbranched polymers resulted in a homogeneous mixture prior to cure, and at low modifier contents, cure induced phase separation was thought to be associated with homogeneous nucleation of modifier rich spherical domains. Complete suppression of the phase separation could be achieved combining the effects of modifier solubility and reaction kinetics, by increasing the catalyst content in the most compatible blends.

We report temperature controlled release from thermo-responsive polystyrene-block-poly(N-isopropyl acrylamide)-block-polystyrene triblock copolymer hydrogel. The hydrogel swelling and release of water soluble methyl orange are studied as a function of temperature for bulk and for two nano-confinements: cylindrical electrospun nanofibres and spherical aerosol nanoparticles. The time for 80% release from bulk hydrogel is found to be dependent on temperature. At room temperature the 80% release takes in 3 h whereas at 40 °C the same release takes 60 h. The swelling was found to be dependent on temperature and polymer composition.