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In the last decade, alginate-based microgels have gained relevant interest as three-dimensional analogues of extracellular matrix, being able to support cell growth and functions. In this study, core-shell microgels were fabricated by self-polymerization of dopamine (DA) molecules under mild oxidation and in situ precipitation of polydopamine (PDA) onto alginate microbeads, processed by electro fluid dynamic atomization. Morphological (optical, SEM) and chemical analyses (ATR-FTIR, XPS) confirmed the presence of PDA macromolecules, distributed onto the microgel surface. Nanoindentation tests also indicated that the PDA coating can influence the biomechanical properties of the microgel surfaces—i.e., σmaxALG = 0.45 mN vs. σmaxALG@PDA = 0.30 mN—thus improving the interface with hMSCs as confirmed by in vitro tests; in particular, protein adsorption and viability tests show a significant increase in adhesion and cell proliferation, strictly related to the presence of PDA. Hence, we concluded that PDA coating contributes to the formation of a friendly interface able to efficiently support cells’ activities. In this perspective, core-shell microgels may be suggested as a novel symmetric 3D model to study in vitro cell interactions.

In this work, the effect of different mixing techniques on thermal and mechanical properties of graphene nanoplatelets (GNPs) and graphene nanofibers (GANFs) loaded epoxy nanocomposites was investigated. Three dispersion methods were employed: a high shear rate (HSR), ultrasonication (US) and the fluidized bed method (FBM). The optical microscopy has revealed that the most suitable dispersion, in terms of homogeneity and cluster size, is achieved by implementing the US and FBM techniques, leading to nanocomposites with the largest increase of glass transition temperature, as supported by the DMA analysis data. The fracture toughness results show a general increase of both the critical stress intensity factor (KIC) and the critical strain energy release rate (GIC), likely due to the homogeneity and the low scale dispersion of the carbonaceous nanostructures. Based on the nanocomposite fracture toughness improvements and also assuming a potential large scale up production of the nanocomposite matrix, a single mixing technique, namely the FBM, was employed to manufacture the carbon fiber reinforced composite (CFRC). This method has resulted in being less time-consuming and is potentially most suitable for the high volume industrial production. The CFRCs were characterized in terms of tensile, flexural and interlaminar fracture toughness properties and the results were analyzed and discussed.

Despite type 1 diabetes' (T1D) potential influence on adolescents' physical development, the occurrence of body image problems of adolescents with diabetes remains unclear. No research synthesis has yet addressed this issue. This study aims to systematically evaluate the empirical evidence concerning body image in individuals with T1D in order to provide an overview of the existing literature. Using PRISMA methodology, 51 relevant studies that fulfilled the eligibility criteria were found, the majority of them (N = 48) involving youth. The findings varied across studies: 17 studies indicated that in youth with T1D, body dissatisfaction was common and that body concerns were generally greater in youth with T1D than in controls; nine studies did not find any differences in body image problems between participants with and without T1D; three studies described higher body satisfaction in youth with diabetes than in controls; and three studies reported mixed results. Body concerns in individuals with T1D were often found to be associated with negative medical and psychological functioning. The variability and limits in assessment tools across studies, the overrepresentation of female subjects, and the fact that most research in this field is based on cross-sectional data are stressed in the interpretation of these mixed findings. Future research directions that could improve the understanding of body image concerns and clinical implications are discussed.

Recent studies have proposed that the bioelectrical response of glial cells, called astrocytes, currently represents a key target for neuroregenerative purposes. Here, we propose the fabrication of electrospun nanofibres containing gelatin and polyaniline (PANi) synthesized in the form of nano-needles (PnNs) as electrically conductive scaffolds to support the growth and functionalities of primary astrocytes. We report a fine control of the morphological features in terms of fibre size and spatial distribution and fibre patterning, i.e. random or aligned fibre organization, as revealed by SEM- and TEM-supported image analysis. We demonstrate that the peculiar morphological properties of fibres - i.e., the fibre size scale and alignment - drive the adhesion, proliferation, and functional properties of primary cortical astrocytes. In addition, the gradual transmission of biochemical and biophysical signals due to the presence of PnNs combined with the presence of gelatin results in a permissive and guiding environment for astrocytes. Accordingly, the functional properties of astrocytes measured via cell patch-clamp experiments reveal that PnNs do not alter the bioelectrical properties of resting astrocytes, thus setting the scene for the use of PnN-loaded nanofibres as bioconductive platforms for interfacing astrocytes and controlling their bioelectrical properties.

Polydopamine (PDA) coated SiO2 nanoparticles (SiO2@PDA) were considered as filler for an aeronautical graded epoxy matrix. The nanoparticles (NPs) were synthesized by a modified one-step procedure, based on the nucleation and growth of SiO2 NPs followed by the growth of a thin PDA layer on the silica surface. TEM observations have revealed that Core/Shell Nanoparticles (CSNPs) are characterized by a core with a diameter of 250 nm and a 15 nm thick PDA shell. Nanocomposites with different filler concentrations (0.1, 1 and 5 wt%) were manufactured. Preliminary fracture toughness results show an increase of both KIC and GIC with addition of 1 wt% of CSNPs. Further samples will be tested by thermal and mechanical techniques, with particular attention to the thermal stability and fracture toughness properties.

Background Recent research indicates that patients with type 1 diabetes (T1D) are at higher risk for disordered eating behaviors (DEBs) than their peers without diabetes. The present study aimed to explore the prevalence of DEBs in a sample of Italian children and adolescents with T1D and in matched-pair healthy controls during the COVID-19 lockdown. Methods In a cross-sectional study, 138 children and adolescents with T1D (aged 8.01–19.11 years, 65 boys) attending a Southern Italian diabetic service and 276 age- and gender-matched healthy peers voluntarily completed an online survey about eating behaviors (ChEAT and EAT-26), anthropometric characteristics, and clinical characteristics. Results 8.69% (N = 12) of participants with T1D and 13.4% (N = 37) of controls had ChEAT/EAT-26 scores indicating presence of DEBs, with no differences between patients—whether children (total ChEAT score F(1, 157) = .104, p = .748) or adolescents (total EAT-26 score F(1, 255) = .135, p = .731)—and healthy peers. zBMI values were lower than those measured in the latest diabetes visit (p p = .110). In both groups, adolescents had lower Oral Control scores than children (T1D: F(1, 138) = 20.411, p 2 = .132, controls: F(1, 276) = 18.271, p 2 = .063); additionally, gender (female) and age were found to be significant predictors of several ChEAT/EAT-26 scores. Conclusions This exploratory study suggested that children and adolescents with T1D did not experience more DEB symptoms during the COVID-19 lockdown compared to healthy controls. Results revealed DEBs as more of a female adolescent developmental issue rather than a result of the challenges of living with a chronic illness under quarantine measures. Possible effects of parental pressure on their children’s eating behaviors in the context of home confinement and of using a non-diabetes-specific measure to assess DEBs are discussed.

The aim of this paper is to study the effect of strain rate on the compressive behavior of the highly cross-linked RTM6 epoxy resin used in advanced aerospace composites. Dynamic compression tests were performed using a split Hopkinson pressure bar, along with reference quasi-static compression tests, to cover a strain rate range from 0.001 to 1035 s−1. Special attention was paid to the optimization of the test methodologies in order to obtain material data free of bias related to the use of different load introduction techniques and sample geometries over the considered strain rate range. In addition, the use of full-field 3D deformation measurements allowed the validation of traditional test and material assumptions. A novel self-alignment tool was developed to enable perfect interfacial contact during compression loading. The 3D digital image correlation technique was used to measure the instantaneous deformation of the sample during compression at different strain rates. Results showed a pronounced strain rate sensitivity of the RTM6 epoxy in compression. The peak yield strength increased with increasing strain rate, while the elastic modulus and Poisson’s ratio in compression were independent of the strain rate. The barreling of the sample in compression, quantified by the barreling ratio, showed an increase during the progression of the compression tests. However, the barreling ratio significantly decreased with the increasing strain rate. Finally, it was shown that neglecting the significant volume change in the yield stages gave rise to a non-negligible underestimation of the strength of the material.

Recent studies have proposed that the bioelectrical response of glial cells, called astrocytes, currently represents a key target for neuroregenerative purposes. Here, we propose the fabrication of electrospun nanofibres containing gelatin and polyaniline (PANi) synthesized in the form of nano-needles (PnNs) as electrically conductive scaffolds to support the growth and functionalities of primary astrocytes. We report a fine control of the morphological features in terms of fibre size and spatial distribution and fibre patterning, i.e. random or aligned fibre organization, as revealed by SEM- and TEM-supported image analysis. We demonstrate that the peculiar morphological properties of fibres – i.e., the fibre size scale and alignment – drive the adhesion, proliferation, and functional properties of primary cortical astrocytes. In addition, the gradual transmission of biochemical and biophysical signals due to the presence of PnNs combined with the presence of gelatin results in a permissive and guiding environment for astrocytes. Accordingly, the functional properties of astrocytes measured via cell patch-clamp experiments reveal that PnNs do not alter the bioelectrical properties of resting astrocytes, thus setting the scene for the use of PnN-loaded nanofibres as bioconductive platforms for interfacing astrocytes and controlling their bioelectrical properties.

A glassy hyperbranched polymer (HBPG) was synthesized and dispersed within an aeronautical graded epoxy matrix as toughening agent. This filler is a polyester characterized by a Tg higher then room temperature (∼90 °C) and obtained by means of bulk poly-condensation reaction starting from a diphenolic acid as precursor. HBPG/epoxy systems were prepared considering two concentration levels (0.1 and 5 wt%) and the effects on mechanical properties and fracture toughness were investigated. HBPG induces a limited reduction of the Tg along with an improvement of the fracture toughness performances as indicated by the increase KIC and GIC values.

Two different hyperbranched polymer (HBPs) fillers were synthesized and dispersed within an aeronautical graded epoxy matrix as toughening agents. The first typology, identified as HBPG (HBP Glassy) is a glassy polyester characterized by a higher glass transition temperature (Tg) then room temperature (∼90 °C) and obtained by means of bulk polycondensation reaction starting from a diphenolic acid as precursor. The second hyperbranched polymer, labelled HBPR (HBP Rubbery) was a polyamide ester with a Tg of about 20 °C and synthesized by bulk polycondensation of sebacic acid and diisopropanolamine. HBP/epoxy systems were prepared considering two concentration levels, respectively 0.1 and 5 wt%, and the effects on rheological, thermal stability, mechanical properties and fracture toughness were investigated and analyzed in respect to the corresponding neat epoxy. Rheological results revealed that the HBPG filler induces relevant effects on the viscosity of the epoxy matrix compared to HBPR limiting the potential usage of the system for composite manufacturing. Nevertheless, HBPG induces optimal results in term of thermal stability, mechanical and fracture performances, with a limited reduction of the Tg and a higher increase of degradation activation energy along with enhanced fracture behavior as indicated by an enhanced critical stress intensity factor (KIC) and critical strain energy value (GIC). The main result of this work suggests that the HBPG/RTM6 epoxy could be suitably used as polymer matrix for carbon-reinforced composites preserving the advantages of infusion process but at the same time enhancing the matrix-driven mechanical property.

Recent studies have proposed that the bioelectrical response of glial cells, called astrocytes, currently represents a key target for neuroregenerative purposes. Here, we propose the fabrication of electrospun nanofibres containing gelatin and polyaniline (PANi) synthesized in the form of nano-needles (PnNs) as electrically conductive scaffolds to support the growth and functionalities of primary astrocytes. We report a fine control of the morphological features in terms of fibre size and spatial distribution and fibre patterning

A preliminary design of customized antibiotic-loaded poly-methyl-methacrylate (ALPMMA) spacer characterized by an appropriate footprint according to the specific patient’s anatomy and a reliable mechanical response to severe functional loads (i.e., level walking and 45° bent knee) is reported. The targeted virtual prototyping process takes origin from a novel patented 3D geometrical conceptualization characterized by added customization features and it is validated by a preliminary FEM-based analysis. Mechanical and thermomechanical properties of the antibiotic-doped orthopedic PMMA cement, which will be used for the future prototype manufacturing, were measured experimentally by testing samples taken during a real day-running orthopedic surgery and manufactured according to the surgeon protocol. FEM analysis results indicate that small area is subjected to intensive stresses, validating the proposed geometry from the mechanical point of view, under the two loading scenarios, moreover the value of safety margins results positive, and this is representative of the lower stress magnitude compared to the critical material limits. The experimental data confirm that the presence of antibiotic will last during the surgeon period moreover, the temperature dependent modulus of the bone cement is slightly affected by the body range temperature whereas it will drastically drop for higher temperature out the range of interest. A complete customization, according to a patient anatomy, and the corresponding real prototype spacer will be manufactured by 3D printing techniques, and it will be validated by destructive testing during the second stage of this activity before commercialization.

The chemical modification of biomaterials (i.e., polyesters, polysaccharides) can offer the opportunity to develop multifunctional platforms characterized by a combination of suitable properties and useful for biomedical applications. Polydopamine (PDA) is a mussel-inspired polymer with excellent properties such as adsorption ability, high hydrophilicity, electrical properties and numerous functional groups for immobilizing biomolecules. Due to high adhesion properties to almost all kinds of substrates PDA it has been largely used as coating for surface modification of material to modulate cellular responses, including cell spreading, migration, proliferation, and differentiation. In order to develop bio-functionalized systems, PDA was proposed as coating of biomaterials differently processed in form of sub-micrometric fibres, microgels and foams. Starting by a dopamine precursor solution, PDA coating deposition on substrates was performed by exploring different methodologies. In particular, poly-e-caprolactone (PCL) electrospun fibres coated with PDA by electrofluidodynamic process was reported as possible bio-conductive interfaces. Preliminary results, in terms of synthesis conditions, structural characterization, and in vitro cell studies suggested that polymerization/oxidation reactions can be properly optimized to guide PDA self-assembly in order to control surface properties, and ultimately, influence cell materials interactions.

The aim of this paper is to investigate the effect of strain rate and filler content on the compressive behavior of the aeronautical grade RTM6 epoxy-based nanocomposites. Silica nanoparticles with different sizes, weight concentrations and surface functionalization were used as fillers. Dynamic mechanical analysis was used to study the glass transition temperature and storage modulus of the nanocomposites. Using quasi-static and split Hopkinson bar tests, strain rates of 0.001 s−1 to 1100 s−1 were imposed. Sample deformation was measured using stereo digital image correlation techniques. Results showed a significant increase in the compressive strength with increasing strain rate. The elastic modulus and Poisson’s ratio showed strain rate independency. The addition of silica nanoparticles marginally increased the glass transition temperature of the resin, and improved its storage and elastic moduli and peak yield strength for all filler concentrations. Increasing the weight percentage of the filler slightly improved the peak yield strength. Moreover, the filler’s size and surface functionalization did not affect the resin’s compressive behavior at different strain rates.

Background: Recent research indicates that patients with type 1 diabetes (T1D) are at higher risk for disordered eating behaviors (DEBs) than their peers without diabetes. The present study aimed at examining the impact of the COVID-19 lockdown on DEBs in a sample of Italian children and adolescents with T1D and in matched-pair healthy controls.Methods: 138 children and adolescents with T1D (aged 8.01-19.11 years, 65 boys) attending a Southern Italian diabetic service and 276 age- and gender-matched healthy peers voluntarily completed a cross-sectional online survey of eating behaviors (ChEAT and Eat-26), anthropometric characteristics, and clinical characteristics. Results: 8.69% (N=12) of participants with T1D and 13.4% (N=37) of controls had ChEAT/EAT-26 scores indicating presence of DEBs, with no differences between patients—whether children (total ChEAT score F(1, 157)=.104, p=.748) or adolescents (total EAT-26 score F(1, 255)=.135, p=.731)—and healthy peers. zBMI values were lower than those measured in the latest diabetes visit (pp=.110). In both groups, adolescents had lower Oral Control scores than children (T1D: F(1, 138)= 20.411, p2 =.132, controls: F(1, 276)=18.271, p2 =.063); additionally, gender (female) and age were found to be significant predictors of several ChEAT/EAT-26 scores.Discussion: Psychological conditions in relation to DEB symptoms of children and adolescents with T1D were not aggravated by lockdown conditions. Results indicated DEBs as more of a female adolescent developmental issue rather than as a result of the challenges of living with a chronic illness aggravated by outbreak. Possible effects of parental pressure on their children’s eating behaviors in the context of home confinement and of using a non-diabetes-specific measure to assess DEBs are discussed.

ObjectiveTo examine body image problems and their associations with disordered eating behavior in adolescents with type 1 diabetes and well-matched healthy peers.MethodsUsing a cross-sectional design, 183 adolescents with type 1 diabetes (13.02–18.05 years) were recruited from diabetes centers in southern Italy and compared to healthy peers matched for age and gender. Participants completed self-report measures of disordered eating behaviors (DEPS-r and EDI-3RF) and a gender-specific body image problem questionnaire (SATAQ-4R). Socio-demographic and clinical data (zBMI, HbA1c, and disease duration) were also collected. Hierarchical multiple linear regression analyses were computed to determine the relative importance of diabetes variables and body image problems on participants’ disordered eating behaviors after controlling for demographic variables.ResultsAdolescents with type 1 diabetes showed diabetes-specific eating problems in 37.7% of cases and had more eating problem symptoms (assessed as drive for thinness and bulimia) than healthy peers. Male adolescents with type 1 diabetes did not display more body image problems (p > 0.05); females with type 1 diabetes compared to females in the control group were found to be more pressured by family (p = 0.025) but less by media (p = 0.022) to improve their appearance and attain a thin body. zBMI and body image problems contributed to a significant increase in disordered eating behavior risk both in male and female adolescents with diabetes and in healthy peers (zBMI 0.213 < β < 0.426, p < 0.05; body image 0.243 < β < 0.572, p < 0.05). None of the variables analyzed were found to significantly predict male bulimic symptoms (all β < 0.296, p > 0.05).ConclusionSince in adolescence type 1 diabetes and insulin therapy may increase the risk of weight gain and promote focus and attention on the body and thus contribute to the development of body image problems and disordered eating behaviors, continuity of medical, nutritional, and psychological care is needed.

In recent years, mussel adhesive proteins have attracted much attention because they can form strong adhesive interface interactions with various substrates in a wet environment. Inspired by their catechol- and amine-based molecular structure, polydopamine (PDA), a dopamine derived synthetic eumelanin polymer, was recognized as a suitable bio-interface coating. PDA was successfully used to improve adhesion due to the availability of copious functional groups for covalently immobilizing biomolecules and anchoring reactive species and ions. Recently, it has been demonstrated that PDA and its derivatives can be successfully used for the surface modification of implants interfaces to modulate in vitro cellular responses in order to enhance the in vivo functionality of biomedical implants (i.e., prosthesis). Herein, we propose the development of multifunctional scaffolds based on poly&epsilon, &ndash, caprolactone (PCL) electrospun fibers coated with PDA via electro fluid dynamic methods, by optimizing polymerization/oxidation reactions capable of driving PDA self&ndash, assembly, and, ultimately, investigating the effects on cell response. Morphological analyses have confirmed the possibility to obtain different surface topographies as a function of the coating process while in vitro studies proved the ability of PDA coating to interact with cells no compromising in vitro viability. In perspective, in vitro conductive properties of fibers will be further investigated in order to validate their promising use as bioconductive interfaces for tissue engineering applications.

This paper describes the preparation and characterization of poly(2,6-dimethyl-1,4-phenylene)oxide (PPO) highly porous monolithic aerogels with a hydrophobic nanoporous–crystalline phase and a hydrophilic sulfonated amorphous phase. The sulfonated aerogels were obtained by the sulfonation of PPO physical gels, followed by the supercritical CO2 extraction of solvents. WAXD and FTIR analysis showed that the nanoporous–crystalline phase was preserved for a degree of sulfonation up to c.a. 35%, allowing a highly volatile organic compound (VOC) sorption capacity. The sulfonated PPO aerogels exhibited a high water sorption capacity, with a water uptake of up to 500 wt%, and faster VOC sorption kinetics from water with respect to unsulfonated aerogels.

The effects of the addition of an aromatic hyperbranched polyester (AHBP) on thermal, mechanical, and fracture toughness properties of a thermosetting resin system were investigated. AHBP filler, synthesized by using a bulk poly-condensation reaction, reveals a glassy state at room temperature. Indeed, according to differential scanning calorimetry measurements, the glass transition temperature (Tg) of AHBP is 95 &deg, C. Three different adduct weight percentages were employed to manufacture the AHBP/epoxy samples, respectively, 0.1, 1, and 5 wt%. Dynamical Mechanical Analysis tests revealed that the addition of AHBP induces a negligible variation in terms of conservative modulus, whereas a slight Tg reduction of about 4 &deg, C was observed at 5 wt% of filler content. Fracture toughness results showed an improvement of both critical stress intensity factor (+18%) and critical strain energy release rate (+83%) by adding 5 wt% of AHBP compared to the neat epoxy matrix. Static and dynamic compression tests covering strain rates ranging from 0.0008 to 1000 s&minus, 1 revealed a pronounced strain rate sensitivity for all AHBP/epoxy systems. The AHBP composites all showed an increase of the true peak yield compressive strength with the best improvement associated with the sample with 0.1 wt% of AHBP.

Conducting polymers have been largely used in biomedical field due to their peculiar properties in terms of electrical conductivity, biocompatibility, low density and versatile processability. Due to their particular mechanism of electrical conductivity similar to semiconductors, involving the mutual activity of electronic and ionic charge carriers, this polymers enable to successfully interface biological systems, improving signal transfer and cell communications. In this chapter, a classification of more commonly used conductive polymers will be provided, by highlighting the main advantages of their use in different applications fields, from tissue engineering to drug delivery, from cellular interfacing to biosensing.

Biosensing materials, with their peculiar abilities to feel and react to external stimuli by changing their properties, are rapidly diffusing in different application areas including healthcare, early diagnosis, and environmental monitoring. In particular, several efforts are currently focused on the development of new materials, able to change their structure, shape, color, or temperature through the application of external driving forces (acoustic, electrical, magnetic, luminous, mechanical, and/or thermal). In the last few decades, an enormous amount of research has been carried out for the realization of biosensing devices, through the synthesis of materials and an accurate engineering of the interfaces, leading to the development of micro- and nano-structured interfaces based on bottom-up approaches, suitable to confer to biosensing materials peculiar features in terms of reversibility, reactivity to external stimuli, and self-healing. In this context, the design of biosensing materials is a relevant issue that requires a multidisciplinary approach at the cutting edge of the chemistry, physics, biology and materials science. This Special Issue aims to describe the recent progress in the synthesis and processing of biosensing materials for the design of smart interfaces to be applied in, but not limited to, biomedical applications, bioengineering, and bioelectronics. Both original articles and reviews are welcome.

The aim of this work was to reveal the moisture absorption&ndash, desorption&ndash, resorption characteristics of epoxy and epoxy-based nanocomposites filled with different multiwall carbon nanotubes (MWCNTs) by investigating the reversibility of the moisture effect on their thermomechanical properties. Two types of MWCNTs with average diameters of 9.5 and 140 nm were used. For the neat epoxy and nanocomposite samples, the moisture absorption and resorption tests were performed in atmospheres with 47%, 73%, and 91% relative humidity at room temperature. Dynamic mechanical analysis was employed to evaluate the hygrothermal ageing effect for unconditioned and environmentally &ldquo, aged&rdquo, samples. It was found that moisture sorption was not fully reversible, and the extent of the irreversibility on thermomechanical properties was different for the epoxy and the nanocomposite. The addition of both types of MWCNTs to the epoxy resin reduced sorption characteristics for all sorption tests, improved the hygrothermal and reduced the swelling rate after the moisture absorption&ndash, desorption.

The following data describe the thermal properties of two different typologies of Hyperbranched Polymers (HBPs): the first one is a polyester (HBPG – Hyperbranched Polymer Glassy) with a glass transition temperature (Tg) higher than room temperature (∼90 °C) whereas the second one is a polyamide ester (HBPR – Hyperbranched Polymer Rubbery) characterized by Tg of about 20 °C. The nanocomposites manufactured using these HBPs as filler were characterized using Optical Microscopy and Differential Scanning Calorimetry. The raw data for the evaluation of fracture toughness properties are reported for the listed materials. This article provides data related to “The effect of Glassy and Rubbery Hyperbranched Polymers as Modifiers in Epoxy Aeronautical Systems” (Zotti et al.). Keywords: Thermosetting matrix, Polymer matrix composites (PMC), Hyperbranched polymers (HBPs), Thermal stability, Fracture toughness

The growing interest in the use of polysaccharides nanoparticles for biomedical applications is related to the recent progresses on the synthesis of cellulose-based polymers with the specific functionalities. In particular, cellulose graft copolymers are emerging as amphiphilic materials suitable to fabricate smart nanoparticles for drug delivery applications. In this work, a cellulose-graft-poly(e-caprolactone) (cell-g-PCL) was synthetized and characterized by FTIR, TGA and DSC in order to validate the synthesis process. We demonstrated that fast evaporation processes promoted cell-g-PCL self-assembly to form nanomicellar structures with hydrodynamic radius ranged from 30 to 60 nm as confirmed by TEM analysis. Moreover, the application of controlled electrostatic forces on solvent evaporation – namely electrospraying - allowed generating round-like nanoscaled particles, as confirmed by SEM supported via image analysis. We demonstrated also that sodium diclofenac (DS) drastically influenced the mechanism of particle formation, favoring the deposition of erythrocyte-like particles with highly concave surfaces, not penalizing the encapsulation efficiency of nanoparticles (>80%). The release profile showed a fast delivery of DS - about 60% during the first 24 h - followed by a sustained release - about 20% during the next 6 days – strictly related to the peculiar weak interactions among amphiphilic polymer segments and water molecules, thus suggesting a successful use of electrosprayed cell-g-PCL nanoparticles for therapeutic treatments in nanomedicine.

Synthesized silicon oxide (silica) nanoparticles were functionalized with a hyperbranched polymer (HBP) achieving a core/shell nanoparticles (CSNPs) morphology. CSNPs were characterized by Fourier Transform Infrared (FTIR) spectroscopy, Transmission Electron Microscopy (TEM), and Thermogravimetric Analysis (TGA). A core diameter of about 250 nm with a 15 nm thick shell was revealed using TEM images. An aeronautical epoxy resin was loaded with the synthesized CSNPs at different percentages and thermal properties, such as thermal stability and dynamic mechanical properties, were investigated with the use of different techniques. Although the incorporation of 2.5 wt% of CSNPs induces a ~4 &deg, C reduction of the hosting matrix glass transition temperature, a slight increase of the storage modulus of about ~10% was also measured. The Kissinger Method was employed in order to study the thermal stability of the nanocomposites, the degradation activation energies that resulted were higher for the sample loaded with low filler content with a maximum increase of both degradation step energies of about ~77% and ~20%, respectively. Finally, fracture toughness analysis revealed that both the critical stress intensity factor (KIC) and critical strain energy release rate (GIC) increased with the CSNPs content, reporting an increase of about 32% and 74%, respectively, for the higher filler loading.

This work aimed to investigate the effect of hybrid carbon nanofillers (e.g., carbon nanotubes/carbon nanofibers in the ratio 1:1 by mass) over the electrical and flexural properties for an epoxy matrix and corresponding basalt fibre reinforcing composite (BFRC) subjected to full-year seasonal water absorption. Hydrothermal ageing was performed by full immersion of the tested materials into distilled water according to the following model conditions (seasons). The mechanical properties were measured in three-point bending mode before environmental ageing and after each season. Upon environmental ageing, the relative change of flexural strength and elastic modulus of the epoxy and NC was within 10–15%. For nanomodified BFRCs, the slightly higher effect (approx. by 10%) of absorbed moisture on flexural characteristics was found and likely attributed to higher defectiveness (e.g., porosity, the formation of agglomerates etc.). During flexural tests, electrical resistance of the nanocomposites (NC) and BFRC/NC samples was evaluated. The electrical conductivity for UD BFRC/NC, before and after hydrothermal ageing, was by 2 and 3 times higher than for the NC, accordingly, revealing the orientation of electrically conductive nanoparticles and/or their agglomerates during lay-up manufacturing which was evaluated by the rules of the mixture. Based on all results obtained it can be concluded that the most potentially applicable for damage indication was UD BFRC/NC along fibres since full-year hydrothermal ageing improved its electrical conductivity by approx. 98% and, consequently, the ability to monitor damages was also enhanced.

We report an innovative fiber optic nano-optrode based on Long Period Gratings (LPGs) working in reflection mode for the detection of human Thyroglobulin (TG), a protein marker of differentiated thyroid cancer. The reflection-type LPG (RT-LPG) biosensor, coated with a single layer of atactic polystyrene (aPS) onto which a specific, high affinity anti-Tg antibody was adsorbed, allowed the label-free detection of Tg in the needle washouts of fine-needle aspiration biopsies, at concentrations useful for pre- and post-operative assessment of the biomarker levels. Analyte recognition and capture were confirmed with a parallel on fiber ELISA-like assay using, in pilot tests, the biotinylated protein and HRP-labeled streptavidin for its detection. Dose-dependent experiments showed that the detection is linearly dependent on concentration within the range between 0 and 4 ng/mL, while antibody saturation occurs for higher protein levels. The system is characterized by a very high sensitivity and specificity allowing the ex-vivo detection of sub ng/ml concentrations of human Tg from needle washouts of fine-needle aspiration biopsies of thyroid nodule from different patients.

The effects of temperature and moisture on flexural and thermomechanical properties of neat and filled epoxy with both multiwall carbon nanotubes (CNT), carbon nanofibers (CNF), and their hybrid components were investigated. Two regimes of environmental aging were applied: Water absorption at 70 &deg, C until equilibrium moisture content and thermal heating at 70 &deg, C for the same time period. Three-point bending and dynamic mechanical tests were carried out for all samples before and after conditioning. The property prediction model (PPM) was successfully applied for the prediction of the modulus of elasticity in bending of manufactured specimens subjected to both water absorption and thermal aging. It was experimentally confirmed that, due to addition of carbon nanofillers to the epoxy resin, the sorption, flexural, and thermomechanical characteristics were slightly improved compared to the neat system. Considering experimental and theoretical results, most of the epoxy composites filled with hybrid carbon nanofiller revealed the lowest effect of temperature and moisture on material properties, along with the lowest sorption characteristics.

The aim of this work was to establish the effect of environmental factors (moisture and temperature) on some mechanical, electrical and thermal properties of epoxy-based composites filled with carbon nanofillers: nanotubes (CNT), nanofibers (CNF) and hybrid nanofiller (nanotubes/nanofibers in the ratio 1:1) and to reveal the most environmentally stable NC. First, the nanocomposites (NC) containing different nanofiller contents were prepared to evaluate electrical percolation threshold and to choose NC at certain electrical conductivity for further characterization of the physical properties in initial state and during/after environmental ageing. The environmental ageing consisted of water absorption at 70 °C until equilibrium moisture content reached all samples in 4 weeks and 2) heating at 70 °C for the same time, and 3) freezing at -20 °C for 8 weeks. Two concurrent factors, temperature and moisture, led to post-curing of all materials studied without significant plastization. Some positive nanofiller effects were found for sorption, mechanical and thermophysical characteristics of RTM6 epoxy resin. Based on experimental results, the most environmentally stable NC was epoxy filled with 0.1 wt. % of CNT/CNF hybrid, which had the lowest effect of temperature and moisture on thermal and electrical conductivities, along with the lowest equilibrium water content and diffusivity.The aim of this work was to establish the effect of environmental factors (moisture and temperature) on some mechanical, electrical and thermal properties of epoxy-based composites filled with carbon nanofillers: nanotubes (CNT), nanofibers (CNF) and hybrid nanofiller (nanotubes/nanofibers in the ratio 1:1) and to reveal the most environmentally stable NC. First, the nanocomposites (NC) containing different nanofiller contents were prepared to evaluate electrical percolation threshold and to choose NC at certain electrical conductivity for further characterization of the physical properties in initial state and during/after environmental ageing. The environmental ageing consisted of water absorption at 70 °C until equilibrium moisture content reached all samples in 4 weeks and 2) heating at 70 °C for the same time, and 3) freezing at -20 °C for 8 weeks. Two concurrent factors, temperature and moisture, led to post-curing of all materials studied without significant plastization. Some positive nanofiller e...

Superabsorbent polymers (SAPs) are organic materials possessing high capacity to absorb and retain large volumes of water, saline and physiological solutions (at least 10–20 times their weight). The most commonly used SAPs are acrylated-based polymers that are not biodegradable or recyclable. To overcome these limits, carboxymethylcellulose (CMC) with hydroxyethylcellulose (HEC) hydrogels were synthetized in this work and dried using a supercritical assisted process at 200 bar and 45 °C. The solvent exchange procedure influenced the final aerogel morphology and, thus, the aerogel swelling ratio (SR). A solvent exchange starting from 50 % v/v ethanol, preserved the native gel nanofibrous morphology, producing a SR up to 20 times larger than the ones reported in the literature using the same process, corresponding to a water uptake larger than 500 times the weight of the dried aerogel.

In this work, basalt microfiber reinforced poly(lactic acid) (PLA) composites filled with talc nanoplatelets (2D) and sepiolite nanofibers (1D) were prepared at different compositions and tested to assess the effects of filler geometry. Thermal analysis results show that crystallinity of amorphous PLA can be enhanced up to 24% by adding basalt and talc. Thermal stability of PLA is increased by basalt microfibers whereas talc and sepiolite prompted early degradation in binary composites. In ternary systems, i.e. PLA/basalt/talc and PLA/basalt/sepiolite, thermal stability was further increased. Mechanical tensile and flexural properties were remarkably increased for a specific composition basalt (30 wt%) and talc (10 wt%) with a final enhancement of 176% and 261% for modulus and 46% and 43% for strength respectively in tensile and bending configuration. For the composition, the coefficient of thermal expansion is significantly reduced up to 54% of the corresponding pristine PLA value. The increase of thermal conductivity is mainly related to the presence of 1D sepiolite, with a variation of ∼54% for the 10 wt% PLA/sepiolite binary system. Finally, a significant increment of impact property was observed by unnotched Charpy impact tests for talc (+97%) and basalt (+140%) composites.

Summary Syndiotactic polystyrene films and aerogels with nanoporous crystalline phase and sulfonated amorphous phase have been prepared and characterized. The nanoporous nature of the crystalline phase confers to these materials a high solubility of volatile organic compounds (VOCs) from aqueous solutions even at low VOC concentrations while the sulfonation of the amorphous phase enhance the VOC sorption kinetics. These combined properties make these materials particularly interesting for a potential use as a sorption medium to remove traces of pollutants from water. Different aspects relative to the preparation, the structure and the transport properties of these innovative polymeric materials are described.

Metal nanoparticles (NPs) were prepared from acrylamide complex of iron and nickel nitrates by controlled thermolysis at constant temperature in a self-generated atmosphere and used to fabricate epoxy resin nanocomposites. X-ray diffraction performed on the nanoparticles revealed a metal core/polymeric shell structure for the nanoparticles thermolysed at higher temperature as also confirmed by cross analysis of thermo-gravimetrical and vibrating magnetometer data. Optical microscopy was used to investigate the achieved dispersion of the nanoparticles within the uncured resin and transmission electronic microscopy was used to analyse the morphology and the average dimensions of the nanoparticles. Thermal stability of manufactured nanocomposites was studied by thermo-gravimetric analysis in inert and oxidative conditions, reporting that negligible variations are induced by the presence of nanofillers. A complete thermo-mechanical and fracture characterization was carried out to assess the effect of nanoparticles on final nanocomposite system. A slight increase of the modulus is recorded at room temperature whereas a significant variation is induced for higher temperature. The presence of nanoparticles induces a global increase in the fracture energy of nanocomposite associated to different failure mechanisms. Magnetic data indicate that iron particles based nanocomposites display room-temperature ferromagnetic behaviour with saturation magnetization and coercivity depending on the diameter of the metal core.

The aim of this paper was to estimate the effect of moisture and temperature on the flexural properties of the epoxy filled with single and hybrid carbon nanofillers (CNTs and CNFs) and to reveal the most environmentally stable NC. Water absorption at 70 °C until equilibrium moisture content and heating at 70 °C for 4 weeks were followed by freezing at -20 °C for 8 weeks. Microstructural characterization of optical images revealed homogeneous dispersion of all carbon nanofillers in the epoxy resin at microscale. Positive nanofiller effects were found for sorption, flexural and thermophysical characteristics of the epoxy resin. The most environmentally stable NC was epoxy filled with 0.1 wt. % of CNTs/CNFs hybrid, which had the lowest effect of temperature and moisture on mechanical characteristics, along with the lowest equilibrium water content and diffusivity.