Mapping 3D Printability of Ionically Cross-Linked Cellulose Nanocrystal Inks: Architecting from Nano- to Macroscale Structures.

Engineering the rheological properties of colloidal inks is one of the main challenges in achieving high-fidelity 3D printing. Herein, we provide a comprehensive study on the rheological behavior of inks based on cellulose nanocrystals (CNCs) in the presence of given salts to enable high-quality 3D printing. The rheological properties of the CNC suspensions are tailored by considering the nature of the electrolyte (i.e., 10 types of salts featuring different ion sizes, charge numbers, and inter- and intra-molecular interactions) at various concentrations (25-100 mM). A high printing fidelity is achieved in a narrow CNC and salt concentration range, significantly depending on the salt type. The structure-property relationship is explored in a "3D-printing" space (2D map), introducing a guideline for researchers active in this field. To further unravel the effect of salt type on morphological properties, CNC aerogels are developed by freeze-drying the printed structures. The results illustrate that enhancing viscoelastic properties render a denser structure featuring smaller pores.

A dedicated electronic nose combined with chemometric methods for detection of adulteration in sesame oil.

Sesame oil (SO), one of the most popular and expensive edible oils, is prone to adulteration. In this study, the fatty acid profiles of pure sesame seed oil and samples adulterated with two less expensive edible oils (canola and sunflower) were analyzed using Gas Chromatography. A dedicated e-nose system was developed and tested on 15 mixtures of sesame-canola and sesame-sunflower samples. Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), and Multi-Layered Perceptron (MLP) methods were utilized to identify adulteration through the evaluation of Volatile Organic Compound. Result of chromatography showed that most samples of sesame oil containing impurities at levels less than 30% were recognized incorrectly in the standard range of SO fatty acids. This is while the developed e-nose system was able to detect adulteration at much lower levels. According to the results, PCA and LDA methods can describe the data set variance with precision of 95.6% and 97%, respectively. The MLP model had better results compared to PCA and LDA, with high determination coefficient (R2 = 0.981) and low RMSE (0.0178). Results indicate that the e-nose system provided an effective non-destructive method to detect SO adulteration at levels as low as 5%, which GC was unable to detect.

An electrochemical immunosensor using SARS-CoV-2 spike protein-nickel hydroxide nanoparticles bio-conjugate modified SPCE for ultrasensitive detection of SARS-CoV-2 antibodies.

As a promising approach for serological tests, the present study aimed at designing a robust electrochemical biosensor for selective and quantitative analysis of SARS-CoV-2-specific viral antibodies. In our proposed strategy, recombinant SARS-CoV-2 spike protein antigen (spike protein) was used as a specific receptor to detect SARS-CoV-2-specific viral antibodies. In this sense, with a layer of nickel hydroxide nanoparticles (Ni(OH)2 NPs), the screen-printed carbon electrode (SPCE) surface was directly electrodeposited to ensure better loading of spike protein on the surface of SPCE. The differential pulse voltammetry (DPV) showed signals which were inversely proportional to the concentrations of the antibody (from 1 fg mL-1 L to 1 µg mL-1) via a specific and stable binding reaction. The assay was performed in 20 min with a low detection limit of 0.3 fg mL-1. This biodevice had high sensitivity and specificity as compared to non-specific antibodies. Moreover, it can be regarded as a highly sensitive immunological diagnostic method for SARS-CoV-2 antibody in which no labeling is required. The fabricated hand-held biodevice showed an average satisfactory recovery rate of ~99-103% for the determination of antibodies in real blood serum samples with the possibility of being widely used in individual serological qualitative monitoring. Also, the biodevice was tested using real patients and healthy people samples, where the results are already confirmed using the enzyme-linked immunosorbent assay (ELISA) procedure, and showed satisfactory results.

Electrochemical immunosensor with Cu2O nanocube coating for detection of SARS-CoV-2 spike protein.

Severe acute respiratory syndrome SARS-CoV-2 has caused a global pandemic starting in 2020. Accordingly, testing is crucial for mitigating the economic and public health effects. In order to facilitate point-of-care diagnosis, this study aims at presenting a label-free electrochemical biosensor as a powerful nanobiodevice for SARS-CoV-2 spike protein detection. Utilizing the IgG anti-SARS-CoV-2 spike antibody onto the electrode surface as a specific platform in an ordered orientation through staphylococcal protein A (ProtA) is highly significant in fabricating the designed nanobiodevice. In this sense, the screen-printed carbon electrode modified with Cu2O nanocubes (Cu2O NCs), which provide a large surface area in a very small space, was applied in order to increase the ProtA loading on the electrode surface. Accordingly, the sensitivity and stability of the sensing platform significantly increased. The electrochemical evaluations proved that there is a very good linear relationship between the charge transfer resistance (Rct) and spike protein contents via a specific binding reaction in the range 0.25 fg mL-1 to 1 µg mL-1. Moreover, the assay when tested with influenza viruses 1 and 2 was performed in 20 min with a low detection limit of 0.04 fg mL-1 for spike protein without any cross-reactivity. The designed nanobiodevice exhibited an average satisfactory recovery rate of ~ 97-103% in different artificial sample matrices, i.e., saliva, artificial nasal, and universal transport medium (UTM), illustrating its high detection performance and practicability. The nanobiodevice was also tested using real patients and healthy samples, where the results had been already obtained using the standard polymerase chain reaction (PCR) procedure, and showed satisfactory results. Graphical abstract.

X-Chromosome Insufficiency Alters Receptive Fields across the Human Early Visual Cortex.

Here, we investigated processing by receptive fields, a fundamental property of neurons in the visual system, using fMRI and population receptive field (pRF) mapping in 20 human females with monosomic Turner syndrome (TS) (mean age, 10.3 ± 2.0 years) versus 22 age- and sex-matched controls (mean age, 10.4 ± 1.9 years). TS, caused by X-chromosome haploinsufficiency in females, is associated with well-recognized effects on visuospatial processing, parieto-occipital cortical anatomy, and parietal lobe function. However, it is unknown whether these effects are related to altered brain structure and function in early visual areas (V1-V3) versus downstream parietal cortical regions. Results show that girls with TS have the following: (1) smaller volume of V1-V3, (2) lower average pRF eccentricity in early visual areas, and (3) sparser pRF coverage in the periphery of the visual field. Further, we examined whether the lower volume of early visual areas, defined using retinotopic mapping, in TS is due to smaller surface area or thinner cortex. Results show that girls with TS had a general reduction in surface area relative to controls in bilateral V1 and V2. Our data suggest the possibility that the smaller cortical surface area of early visual areas in girls with TS may be associated with a lower number of neurons, which in turn, leads to lesser coverage of the peripheral visual field compared to controls. These results indicate that X-chromosome haploinsufficiency associated with TS affects the functional neuroanatomy of early visual areas, and suggest that investigating pRFs in TS may shed insights into their atypical visuospatial processing.SIGNIFICANCE STATEMENT Turner syndrome is caused by the absence of one of the two X-chromosomes in females. Using functional neuroimaging and population receptive field mapping, we find that chromosome dosage variation (X-monosomy) associated with Turner syndrome affects the functional neuroanatomy of the visual cortex. Specifically, girls with Turner syndrome have smaller early visual areas that provide lesser coverage of the peripheral visual field compared with healthy controls. Our observations provide compelling evidence that the X-chromosome affects not only parietal cortex, as described in previous studies, but also affects early visual areas. These findings suggest a paradigm change in understanding the effect of X-monosomy on the development of visuospatial abilities in humans.

A new hypothesis for foregut and heart tube formation based on differential growth and actomyosin contraction.

For decades, it was commonly thought that the bilateral heart fields in the early embryo fold directly towards the midline, where they meet and fuse to create the primitive heart tube. Recent studies have challenged this view, however, suggesting that the heart fields fold diagonally. As early foregut and heart tube morphogenesis are intimately related, this finding also raises questions concerning the traditional view of foregut formation. Here, we combine experiments on chick embryos with computational modeling to explore a new hypothesis for the physical mechanisms of heart tube and foregut formation. According to our hypothesis, differential anisotropic growth between mesoderm and endoderm drives diagonal folding. Then, active contraction along the anterior intestinal portal generates tension to elongate the foregut and heart tube. We test this hypothesis using biochemical perturbations of cell proliferation and contractility, as well as computational modeling based on nonlinear elasticity theory including growth and contraction. The present results generally support the view that differential growth and actomyosin contraction drive formation of the foregut and heart tube in the early chick embryo.

Promoter methylation, transcription, and retrotransposition of LINE-1 in colorectal adenomas and adenocarcinomas.

BACKGROUND: The methylation of the CpG islands of the LINE-1 promoter is a tight control mechanism on the function of mobile elements. However, simultaneous quantification of promoter methylation and transcription of LINE-1 has not been performed in progressive stages of colorectal cancer. In addition, the insertion of mobile elements in the genome of advanced adenoma stage, a precancerous stage before colorectal carcinoma has not been emphasized. In this study, we quantify promoter methylation and transcripts of LINE-1 in three stages of colorectal non-advanced adenoma, advanced adenoma, and adenocarcinoma. In addition, we analyze the insertion of LINE-1, Alu, and SVA elements in the genome of patient tumors with colorectal advanced adenomas. METHODS: LINE-1 hypomethylation status was evaluated by absolute quantitative analysis of methylated alleles (AQAMA) assay. To quantify the level of transcripts for LINE-1, quantitative RT-PCR was performed. To find mobile element insertions, the advanced adenoma tissue samples were subjected to whole genome sequencing and MELT analysis. RESULTS: We found that the LINE-1 promoter methylation in advanced adenoma and adenocarcinoma was significantly lower than that in non-advanced adenomas. Accordingly, the copy number of LINE-1 transcripts in advanced adenoma was significantly higher than that in non-advanced adenomas, and in adenocarcinomas was significantly higher than that in the advanced adenomas. Whole-genome sequencing analysis of colorectal advanced adenomas revealed that at this stage polymorphic insertions of LINE-1, Alu, and SVA comprise approximately 16%, 51%, and 74% of total insertions, respectively. CONCLUSIONS: Our correlative analysis showing a decreased methylation of LINE-1 promoter accompanied by the higher level of LINE-1 transcription, and polymorphic genomic insertions in advanced adenoma, suggests that the early and advanced polyp stages may host very important pathogenic processes concluding to cancer.

Neural signature of developmental coordination disorder in the structural connectome independent of comorbid autism.

Children with autism spectrum disorders (ASD) often exhibit motor clumsiness (Developmental Coordination Disorder, DCD), i.e. they struggle with everyday tasks that require motor coordination like dressing, self-care, and participating in sport and leisure activities. Previous studies in these neurodevelopmental disorders have demonstrated functional abnormalities and alterations of white matter microstructural integrity in specific brain regions. These findings suggest that the global organization of brain networks is affected in DCD and ASD and support the hypothesis of a 'dys-connectivity syndrome' from a network perspective. No studies have compared the structural covariance networks between ASD and DCD in order to look for the signature of DCD independent of comorbid autism. Here, we aimed to address the question of whether abnormal connectivity in DCD overlaps that seen in autism or comorbid DCD-autism. Using graph theoretical analysis, we investigated differences in global and regional topological properties of structural brain networks in 53 children: 8 ASD children with DCD (DCD+ASD), 15 ASD children without DCD (ASD), 11 with DCD only, and 19 typically developing (TD) children. We constructed separate structural correlation networks based on cortical thickness derived from Freesurfer. The children were assessed on the Movement-ABC and the Beery Test of Visual Motor Integration. Behavioral results demonstrated that the DCD group and DCD+ASD group scored on average poorer than the TD and ASD groups on various motor measures. Furthermore, although the brain networks of all groups exhibited small-world properties, the topological architecture of the networks was significantly altered in children with ASD compared with DCD and TD. ASD children showed increased normalized path length and higher values of clustering coefficient. Also, paralimbic regions exhibited nodal clustering coefficient alterations in singular disorders. These changes were disorder-specific, and included alterations in clustering coefficient in the isthmus of the right cingulate gyrus and the pars orbitalis of the right inferior frontal gyrus in ASD children, and DCD-related increases in the lateral orbitofrontal cortex. Children meeting criteria for both DCD and ASD exhibited topological changes that were more widespread from those seen in children with only DCD, i.e. children with DCD+ASD showed alterations of clustering coefficient in (para)limbic regions, primary areas, and association areas. The DCD+ASD group showed changes in clustering coefficient in the left association cortex relative to the ASD group. Finally, the DCD+ASD group shared ASD-specific abnormalities in the pars orbitalis of right inferior frontal gyrus, which was hypothesized to reflect atypical emotional-cognitive processing. Our results provide evidence that DCD and ASD are neurodevelopmental disorders with a low degree of overlap in abnormalities in connectivity. The co-occurrence of DCD+ASD was also associated with a distinct topological pattern, highlighting the unique neural signature of comorbid neurodevelopmental disorders.

Experimental validation of finite element analysis of human vertebral collapse under large compressive strains.

Osteoporosis-related vertebral fractures represent a major health problem in elderly populations. Such fractures can often only be diagnosed after a substantial deformation history of the vertebral body. Therefore, it remains a challenge for clinicians to distinguish between stable and progressive potentially harmful fractures. Accordingly, novel criteria for selection of the appropriate conservative or surgical treatment are urgently needed. Computer tomography-based finite element analysis is an increasingly accepted method to predict the quasi-static vertebral strength and to follow up this small strain property longitudinally in time. A recent development in constitutive modeling allows us to simulate strain localization and densification in trabecular bone under large compressive strains without mesh dependence. The aim of this work was to validate this recently developed constitutive model of trabecular bone for the prediction of strain localization and densification in the human vertebral body subjected to large compressive deformation. A custom-made stepwise loading device mounted in a high resolution peripheral computer tomography system was used to describe the progressive collapse of 13 human vertebrae under axial compression. Continuum finite element analyses of the 13 compression tests were realized and the zones of high volumetric strain were compared with the experiments. A fair qualitative correspondence of the strain localization zone between the experiment and finite element analysis was achieved in 9 out of 13 tests and significant correlations of the volumetric strains were obtained throughout the range of applied axial compression. Interestingly, the stepwise propagating localization zones in trabecular bone converged to the buckling locations in the cortical shell. While the adopted continuum finite element approach still suffers from several limitations, these encouraging preliminary results towards the prediction of extended vertebral collapse may help in assessing fracture stability in future work.

3D-Printed Interfacially Jammed Emulsion Aerogels.

3D printing ultralightweight porous structures using direct ink writing (DIW) while maintaining their mechanical robustness is highly challenging. This difficulty is amplified when low ink concentrations are used to create complex geometries. Herein, this shortfall was addressed by interfacially jammed emulsion gels. The gel emerged from the electrostatic interaction among synergized nanomaterials (graphene oxide (GO) and cellulose nanocrystals (CNCs)) in the aqueous phase and a ligand in the oil phase. This interaction led to the jamming of the nanoparticles and the creation of stable emulsion gels. The formed interfacial assemblies were further treated by post-jamming ionic cross-linking with NaHCO3, which dictated the emulsion gels' rheological characteristics, enhancing the ink's viscoelastic properties for high-resolution 3D printing. The customizable emulsion system allows control over porosity from the macro- to the micro-scale and generates complex geometries with desired compositions. By manipulating post-annealing processes and varying concentrations, it is possible to achieve aerogels that feature a remarkably low density (∼2.63 mg/cm3) and adjustable mechanical robustness (elastic modulus of 0.45 MPa). Additionally, this method allows for producing aerogels with flexible or stiff characteristics as required, alongside the capability to tailor specific electromagnetic shielding effectiveness (ranging from 6791 to 19615 dB cm2/g), showcasing the technique's versatility and engineerability.

Surfactant-Mediated Highly Conductive Cellulosic Inks for High-Resolution 3D Printing of Robust and Structured Electromagnetic Interference Shielding Aerogels.

Technological fusion of emerging three-dimensional (3D) printing of aerogels with gel processing enables the fabrication of lightweight and functional materials for diverse applications. However, 3D-printed constructs via direct ink writing for fabricating electrically conductive structured biobased aerogels suffer several limitations, including poor electrical conductivity, inferior mechanical strength, and low printing resolution. This work addresses these limitations via molecular engineering of conductive hydrogels. The hydrogel inks, namely, CNC/PEDOT-DBSA, featured a unique formulation containing well-dispersed cellulose nanocrystal decorated by a poly(3,4-ethylene dioxythiophene) (PEDOT) domain combined with dodecylbenzene sulfonic acid (DBSA). The rheological properties were precisely engineered by manipulating the solid content and the intermolecular interactions among the constituents, resulting in 3D-printed structures with excellent resolution. More importantly, the resultant aerogels following freeze-drying exhibited a high electrical conductivity (110 ± 12 S m-1), outstanding mechanical properties (Young's modulus of 6.98 MPa), and fire-resistance properties. These robust aerogels were employed to address pressing global concerns about electromagnetic pollution with a specific shielding effectiveness of 4983.4 dB cm2 g-1. Importantly, it was shown that the shielding mechanism of the 3D printed aerogels could be manipulated by their geometrical features, unraveling the undeniable role of additive manufacturing in materials design.

Current opinions on the present and future use of functional near-infrared spectroscopy in psychiatry.

Functional near-infrared spectroscopy (fNIRS) is an optical imaging technique for assessing human brain activity by noninvasively measuring the fluctuation of cerebral oxygenated- and deoxygenated-hemoglobin concentrations associated with neuronal activity. Owing to its superior mobility, low cost, and good tolerance for motion, the past few decades have witnessed a rapid increase in the research and clinical use of fNIRS in a variety of psychiatric disorders. In this perspective article, we first briefly summarize the state-of-the-art concerning fNIRS research in psychiatry. In particular, we highlight the diverse applications of fNIRS in psychiatric research, the advanced development of fNIRS instruments, and novel fNIRS study designs for exploring brain activity associated with psychiatric disorders. We then discuss some of the open challenges and share our perspectives on the future of fNIRS in psychiatric research and clinical practice. We conclude that fNIRS holds promise for becoming a useful tool in clinical psychiatric settings with respect to developing closed-loop systems and improving individualized treatments and diagnostics.

Allometrically scaling tissue forces drive pathological foreign-body responses to implants via Rac2-activated myeloid cells.

Small animals do not replicate the severity of the human foreign-body response (FBR) to implants. Here we show that the FBR can be driven by forces generated at the implant surface that, owing to allometric scaling, increase exponentially with body size. We found that the human FBR is mediated by immune-cell-specific RAC2 mechanotransduction signalling, independently of the chemistry and mechanical properties of the implant, and that a pathological FBR that is human-like at the molecular, cellular and tissue levels can be induced in mice via the application of human-tissue-scale forces through a vibrating silicone implant. FBRs to such elevated extrinsic forces in the mice were also mediated by the activation of Rac2 signalling in a subpopulation of mechanoresponsive myeloid cells, which could be substantially reduced via the pharmacological or genetic inhibition of Rac2. Our findings provide an explanation for the stark differences in FBRs observed in small animals and humans, and have implications for the design and safety of implantable devices.

Hierarchical nickel hydroxide nanosheets grown on hollow nitrogen doped carbon nanoboxes as a high-performance surface substrate for alpha-fetoprotein cancer biomarkers electrochemical aptasensing.

During recent decades, we have witnessed a great improvement in the performance of aptamer-based sensors, specifically when aptamers are combined with new nanomaterials; as a platform for biosensors. The design of hollow carbon-based materials has also received a lot of attention due to its excellent properties in various applications. Herein, we aim at designing hierarchical porous Ni(OH)2 nanosheets on hollow N-doped carbon nanoboxes Ni(OH)2@N-C n-box). In this sense, we obtained the hollow N-C n-box skeletons from the Fe2O3 nanocubes template. The development of label-free electrochemical aptasensor was carried out using the covalently immobilizing NH2-functionalized aptamer on Ni(OH)2@N-C n-box as an efficient substrate. The Ni(OH)2@N-C n-box was characterized using scanning fourier transform infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Brunauer, Emmett and Teller (BET), transmission electron microscopes (TEM) and electron microscopy (FESEM). The electrochemical evaluations clarified the fact that a linear relationship exists between the alpha-fetoprotein (AFP) contents and the charge transfer resistance (Rct) (from 1 fg mL-1 to 100 ng mL-1) with a low detection limit of 0.3 fg mL-1. Moreover, regarding the aptasensor, the superior detection recoveries were experienced in real biological samples, illustrating its great detection performance and practical feasibility. Considering the aptasensor application, these studies showed that Ni(OH)2@N-C n-box possesses different enhanced electrochemical features, making it appropriate as an electrode material for aptasensor application.

Label-free electrochemical aptasensor for rapid detection of SARS-CoV-2 spike glycoprotein based on the composite of Cu(OH)2 nanorods arrays as a high-performance surface substrate.

The development of advanced electrode materials and the combination of aptamer with them have improved dramatically the performance of aptasensors. Herein, a new architecture based on copper hydroxide nanorods (Cu(OH)2 NRs) are directly grown on the surface of screen printed carbon electrode (SPCE) using a two-step in situ, very simple and fast strategy and was used as a high-performance substrate for immobilization of aptamer strings, as well as an electrochemical probe to development a label-free electrochemical aptasensor for SARS-CoV-2 spike glycoprotein measurement. The Cu(OH)2 NRs was characterized using X-ray Diffraction (XRD) and electron microscopy (FESEM). In the presence of SARS-CoV-2 spike glycoprotein, a decrease in Cu(OH)2 NRs-associated peak current was observed that can be owing to the target-aptamer complexes formation and thus blocking the electron transfer of Cu(OH)2 NRs on the surface of electrode. This strategy exhibited wide dynamic range in of 0.1 fg mL-1 to 1.2 µg mL-1 and with a high sensitivity of 1974.43 µA mM-1 cm-2 and low detection limit of 0.03 ± 0.01 fg mL-1 of SARS-CoV-2 spike glycoprotein deprived of any cross-reactivity in the presence of possible interference species. In addition, the good reproducibility, repeatability, high stability and excellent feasibility in real samples of saliva and viral transport medium (VTM) were found from the provided aptasensor. Also, the aptasensor efficiency was evaluated by real samples of sick and healthy individuals and compared with the standard polymerase chain reaction (PCR) method and acceptable results were observed.

Removal of methylene blue from wastewater using ternary nanocomposite aerogel systems: Carboxymethyl cellulose grafted by polyacrylic acid and decorated with graphene oxide.

In this study, environmentally-friendly nanocomposite hydrogels were fabricated. These hydrogels consisted of semi-interpenetrating networks of carboxymethyl cellulose (CMC) molecules grafted to polyacrylic acid (PAA), as an eco-friendly and non-toxic polymer with numerous carboxyl and hydroxyl functional groups, which were reinforced with different levels of graphene oxide particles (0.5, 1.5 or 3% wt). Field-emission electron scanning microscopy (FESEM) images indicated that the pore size of the nanocomposites decreased with increasing graphic oxide concentration. The presence of the graphic oxide increased the storage modulus and thermal stability of the nanocomposite hydrogels. The hydrogels had an adsorption capacity of 138 mg/g of a model cationic dye pollutant (methylene blue) after 250 min. Moreover, a reusability test showed that the adsorption capacity remained at around 90% after 9 cycles. Density functional theory (DFT) simulations suggested that the adsorption of methylene blue was mainly a result of π-π bonds, hydrogen bonds, and electrostatic interactions with graphene oxide. Our results indicated that the nanocomposite hydrogels fabricated in this study may be eco-friendly, stable, efficient, and reusable adsorbents for ionic pollutants in wastewater treatment.

Introducing a flexible drug delivery system based on poly(glycerol sebacate)-urethane and its nanocomposite: potential application in the prevention and treatment of oral diseases.

In this study, a novel biopolymer based on poly(glycerol sebacic)-urethane (PGS-U) and its nanocomposites containing Cloisite@30B were synthesized by facile approach in which the crosslinking was created by aliphatic hexamethylene diisocyanate (HDI) at room temperature and 80 °C. Moreover, metronidazole and tetracycline drugs were selected as target drugs and loaded into PGSU based nanocomposites. A uniform and continuous microstructure with smooth surface is observed in the case of pristine PGS-U sample. The continuity of microstructure is observed in the case of all bionanocomposites. XRD result confirmed an intercalated morphology for PGSU containing 5 wt% of clay nanoparticles with a d-spacing 3.4 nm. The increment of nanoclay content up to 5%, the ultimate tensile stress and elastic modulus were obtained nearly 0.32 and 0.83 MPa, which the latter was more than eight-fold than that of pristine PGS-U. A sustained release for both dugs was observed by 200 h. The slowest and controlled drug release rate was determined in the case of PGSU containing 5 wt% clay and cured at 80 °C. A non-Fickian diffusion can be concluded in the case of tetracycline release via PGS-U/nanoclay bionanocomposites, while a Fickian process was detected in the case of metronidazole release by PGS-U/nanoclay bionanocomposites. As a result, the designed scaffold showed high flexibility, which makes it an appropriate option for utilization in the treatment of periodontal disease.

Introducing a bio sorbent for removal of methylene blue dye based on flexible poly(glycerol sebacate)/chitosan/graphene oxide ecofriendly nanocomposites.

As a consequence of industrial activities, one of the most prevalent components in wastewater is Water-soluble dyes needed to be removed. In this research, eco-friendly adsorbents based on poly(glycerol sebacate) (PGS), including PGS-graphene oxide nanoparticles (GO), PGS-graft-chitosan(CS), and PGS-CS-GO nanocomposites, have been proposed as efficient dye adsorbents for the wastewater treatment procedure. FESEM images showed that a smooth and uniform structure was created over incorporating CS into PGS. Besides, the presence of CS within PGS/GO nanocomposites had a positive impact on the exfoliation of GO. Moreover, it was found that the incorporation of both CS and GO into PGS reduced the glass transition of PGS. Besides, their coexistence can probably increase the chain regularity in the polymer matrix and cause a relatively larger crystal size of PGS. In this regard, the ternary nanocomposite saw a Tg value of -29.4 °C. A high adsorption capacity of 178 mg g-1, as well as 99 removal% efficiency, were observed in the case of the PGS-CS-GO sample after 300 min at a dye concentration of 100 mg L-1 and pH 7. Additionally, the adsorption capacity value of the adsorbent was preserved around 129 mg g-1 after 7 cycles of adsorption-desorption. The findings revealed that innovatively synthesized PGS-g-CS/GO nanocomposites could efficiently remove methylene blue from water solutions. Hence, they can be used as a powerful and influential dye adsorbent to purify water solutions.

A novel environmentally friendly nanocomposite aerogel based on the semi-interpenetrating network of polyacrylic acid into Xanthan gum containing hydroxyapatite for efficient removal of methylene blue from wastewater.

Eco-friendly nanocomposite aerogels were prepared as adsorbents for the removal of a model pollutant (methylene blue, MB) from water. These aerogels were comprised of hydroxyapatite (HA) nanoparticles embedded within a polymer matrix consisting of a semi-interpenetrating network of xanthan gum (XG) and polyacrylic acid (PAA). Microscopy and BET analysis showed that the aerogels formed had a nanofibrous porous microstructure with a surface area of 89 m2/g. Rheological analysis showed that the aerogels were viscoelastic materials whose elasticity increased with increasing HA concentration (up to 5 w/w%). The aerogels were effective at removing MB from water, exhibiting an adsorption capacity of 130 mg/g after 200 min. The binding of the MB to the aerogels was mainly attributed to hydrogen bonding and electrostatic attraction. A reusability test showed that the MB removal efficiency of over 86% was preserved after 10 cycles of adsorption-desorption. These results suggest that our nanocomposite aerogels may be useful for the efficient removal of anionic pollutants from wastewater and water supplies due to their ease of synthesis, cost-effectiveness, good mechanical properties, high thermal stability, and good adsorption performance.

Hollow carbon nanocapsules-based nitrogen-doped carbon nanofibers with rosary-like structure as a high surface substrate for impedimetric detection of Pseudomonas aeruginosa.

The design of hollow mesoporous carbon-based materials has attracted tremendous attention, due to their sizeable intrinsic cavity to load specific chemical and unique physical/chemical properties in various applications. Herein, we have established an effective strategy for the preparation of novel hollow carbon nanocapsules-based nitrogen-doped carbon nanofibers (CNCNF) with rosary-like structure. By embedding ultrafine hollow carbon nanocapsules into electrospun polyacrylonitrile (PAN) skeleton, the as-designed composite CNFs were carbonized into hierarchical porous CNFs, consisted of interconnected nitrogen-doped hollow carbon nanocapsules. Due to its individual structural properties and unique chemical composition, the performance of CNCNF was evaluated in aptasensor application via the detection of Pseudomonas aeruginosa (PA). Under optimized conditions, the aptasensor based on CNCNF has a detection limit of 1 CFU⋅mL-1 and a linear range from 101 CFU ⋅mL-1 to 107 CFU ⋅mL-1 (n = 3). Moreover, the designed aptasensor possesses high sensivity, high selectivity, low detection limit, and high reproducibility. These studies showed that the CNCNF material offers a wide variety of enhanced electrochemical features as an electrode material for aptasensor application.