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Iron fortification in food is considered as an important way to prevent and treat iron deficiency. However, adding iron in food can affect flavor, color, and oxidation of fat components. Encapsulation of iron can solve the drawbacks of taste, color, and reactivity of iron in oral iron consumption without adverse effect on food quality. The aim of this work was to nanoencapsulate iron into pectin (Pec) nanoparticles (NP) by ion gelation method to prevent undesirable sensorial changes in foods and improve bioavailability of iron. The effect of different parameters including pectin concentration (Pec Con), FeSO4 concentration (Fe Con), and volumetric ratio of Fe solution to Pec solution on iron loaded Pec nanoparticles (IP NP) size was investigated. Morphology, size, surface charge, and physicochemical features of the optimized particles were characterized. The iron released from IP NP was studied, and the mathematical model of release was extracted. Pec Con exhibited a direct effect on particle size. The optimized IP NP (Pec solution 0.1% (w/w), Fe solution 0.05% (w/w), and Pec/Fe: 2) had a hydrodynamic diameter of 417 nm with zeta potential of −11.7 mV and polydispersity index (PDI) of 0.13, with a nearly spherical morphology. Scanning electron microscopy (SEM) represented the mean size of 58 nm. Iron loading was about 7.5 ± 1.5%. FTIR results confirmed the interaction of iron ions with the hydroxyl and carboxyl groups of Pec. The results of differential scanning calorimetric (DSC) indicated the interaction of Pec with iron. The release profile of iron in all pH of 2, 6, and 7.4 showed a burst release at the beginning and then a sustained release occurred. In all three pH values, the mathematical model of release was Korsmeyer-Peppas with the highest R2 value. Therefore, encapsulation of iron using pectin have a high potential to make nanoparticles with appropriate properties, which can be helpful for iron fortification of food. [ABSTRACT FROM AUTHOR]

cysteamine (CysAm) nanostructure was generated to act as an intermediate layer between gold electrode and carbon nanotubes. A bare gold electrode was placed in a solution of CysAm to create a self-assembled monolayer on its surface. The modified electrode was then incubated with a solution of multi-walled carbon nanotubes. Cyclic voltammetry and atomic force microscopy were used to characterize the modified electrode. The results indicated that the number of functionalized MWCNTs on the surface of the electrodes increased by enhancing incubation time. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Inflammatory responses play a crucial role in the pathophysiology of spinal cord injury (SCI) and developing new approaches to establish an anti-inflammatory environment for the promotion of neuroregeneration holds promise as a potential approach. In this study, our aim was to investigate the potential of combining an acellular spinal cord scaffold (ASCS) with quercetin-loaded bovine serum albumin (Qu/BSA) nanoparticles (NPs) for the treatment of SCI. The ASCS was prepared using physical and chemical methods, while the Qu/BSA NPs were prepared through a desolvation technique. The NPs exhibited favorable characteristics, including a mean size of 203 nm, a zeta potential of –38, and an encapsulation efficiency of 96%. Microscopic evaluation confirmed the successful distribution of NPs on the walls of ASCS. Animal studies revealed that Qu/BSA NPs group exhibited a significant decrease in NLRP3, ASC, and Casp1 gene expression compared to the SCI group (p < 0.0001). The findings indicated a significant decrease in the NLRP3, ASC, and Casp1 protein level between the Qu/BSA/ASCS group and the SCI group (p < 0.0001). Moreover, treatment with ASCS containing either blank BSA (B/BSA) NPs or Qu/BSA NPs effectively promoted functional recovery via increasing the amount of nestin- and glial fibrillary acidic protein (GFAP)-positive cells in the site of injury. Notably, Qu/BSA/ASCS exhibited superior outcomes compared to B/BSA/ASCS. Overall, the combination of ASCS with the Qu delivery system presents a promising therapeutic approach for SCI by inhibiting inflammatory responses and promoting neuroregeneration, leading to the restoration of motor function in animals. This study demonstrates the potential of utilizing biomaterials and NPs to enhance the effectiveness of SCI treatment. Note: Graphic abstract was designed with Biorender (https://biorender.com/). [ABSTRACT FROM AUTHOR]

An electrochemical immunosensor based on carbon nanofibers (CNFs) and gold nanoparticles (AuNPs) was developed for detecting anti-Toxoplasma gondii antibodies (anti-T. gondii) IgG in human serum. CNFs were produced using electrospinning and carbonization processes. Screen-printed carbon electrode (SPCE) surface was modified with CNFs and AuNPs which were electrodeposited onto the CNFs. Then, T. gondii antigen was immobilized onto the AuNPs/CNFs/SPCE. Afterward, anti-T. gondii IgG positive serum samples were coated on the modified electrode and assessed via adding anti-human IgG labeled with horseradish peroxidase (HRP) enzyme. The morphology of SPCE, CNFs, and AuNPs/CNFs/SPCE surface was characterized using field emission scanning electron microscopy (FESEM) equipped with energy dispersive spectroscopy (EDS). Characterization of CNFs was evaluated by Raman spectroscopy and X-ray diffraction (XRD). Electrochemical characterization of the immunosensor was verified using cyclic voltammetry (CV), and electrochemical response of modified electrode for anti-T. gondii IgG was detected via differential pulse voltammetry (DPV). This immunosensor was detected in the range 0–200 U mL−1 with a low detection limit (9 × 10−3 U mL−1). In addition, the proposed immunosensor was exhibited with high selectivity, strong stability, and acceptable reproducibility and repeatability. Furthermore, there was a strong correlation between results obtained via the designed immunosensor and enzyme-linked immunosorbent assay (ELISA) as gold standard. In conclusion, the developed immunosensor is a promising route for rapid and accurate clinical diagnosis of toxoplasmosis. [ABSTRACT FROM AUTHOR]

Chitosan/polyethylene oxide (PEO) solution makes electrospun nanofibers with decreased beads and diameters in comparison with lonely chitosan (CS). The aim of this work was to find an artificial neural network (ANN) model for predicting the chitosan/PEO blend electrospun nanofiber diameter. Chitosan/PEO concentration ratio, distance between nozzle tip and collector, applied voltage, and flow rate were considered as input variables, and chitosan/PEO blend electrospun nanofiber diameter was considered as output variable. Scanning electron microscopy images indicated that electrospun nanofiber diameter was approximately 50-185 nm. For increasing validity, k-fold cross validation method was applied to dataset. The ANN technique was used for training and testing via fivefold of dataset. The best results of prediction were obtained via network with three hidden layers including 10, 15, and 5 nodes in each layer, respectively. The mean square error (MSE) and correlation coefficient between the observed and predicted thickness of the nanofibers in the chosen model were about 0.0707 and 0.9630, respectively, indicating the ANN technique validity in the prediction procedure. For the analysis of interactions between the involved electrospinning parameters and nanofiber diameter, 3D graphs in various levels were plotted. In conclusion, the results indicated that using the prediction process via ANN could be relevant in the decision to produce nanofibers with desired shape and diameter via electrospinning. [ABSTRACT FROM AUTHOR]

An electrochemical aptamer-based sensor was designed to detect tetracycline (Tet) in chicken ham. First, polyacrylonitrile (PAN) polymer was used to prepare electrospun PAN nanofibers. PAN nanofibers were heat treated to form electrospun carbon nanofiber (CNF) mat. The electrospun CNF mat electrode was modified with Au and the aptamer of Tet was placed on the mat electrode. Raman spectroscopy and scanning electron microscopy equipped with energy-dispersive spectroscopy were used to identify the structure and morphology of electrospun CNFs, respectively. The behavior of CNF mat electrode was evaluated via cyclic voltammetry. The designed aptamer biosensor had a good repeatability, reproducibility, stability, and specific function for the detection of Tet in chicken ham. This biosensor was able to detect the Tet in the linear range of 1 × 10–9 M to 1 × 10–4 M with the detection limit of 1.2 × 10–10 M and preserve about 95% of its primary response after 20 days. In addition, the recoveries of Tet were achieved ranging from 96.92 to 104.31%. [ABSTRACT FROM AUTHOR]

The article titled "Investigating the effects of particle size and chemical structure on cytotoxicity and bacteriostatic potential of nano hydroxyapatite/chitosan/silica and nano hydroxyapatite/chitosan/silver; as antibacterial bone substitutes" has been retracted by the Editor-in-Chief of the Journal of Nanoparticle Research. The retraction was due to concerns raised about figure 3A, where panels a and b appear to overlap despite representing different materials. The authors did not respond to queries about this concern, leading to a loss of confidence in the results and conclusions of the article. The authors have also not responded to correspondence regarding this retraction. [Extracted from the article]

The purpose of this work was to fabricate an electrochemical DNA biosensor for detecting hepatitis B virus. Gold nanorods (GNRs), which are known for their conductivity, were used to increase surface area and consequently increase the immobilization of single-stranded DNA (ss-DNA) on the modified gold electrode. The GNRs were characterized via transmission electron microscopy. The morphology of the gold electrode before and after modification with GNRs was characterized by scanning electron microscopy. Atomic-force microscopy was used to evaluate the morphology of the GNR electrode surface before and after interaction with ss-DNA. Cyclic voltammetry was used to monitor DNA immobilization and hybridization, using [Co(phen)] as an electrochemical indicator. The target DNA sequences were quantified at a linear range from 1.0 × 10 to 10.0 × 10 mol L, with a detection limit of 2.0 × 10 mol L by 3 σ. The biosensor had good specificity for distinguishing complementary DNA in the presence of non-complementary and mismatched DNA sequences. [ABSTRACT FROM AUTHOR]

The restoration of defective bone tissue and complications related to surgery and fracture site infection are major concerns in orthopedic surgeries. However, it is crucial to develop osteoconductive and bacteriostatic composites. Chitosan/nano hydroxyapatite (CT/n-HAp) powder containing of Ag and Si were prepared by an in situ hybridization method. The aim of this work was to elucidate the effect of size, surface roughness, and chemical structure of mentioned nanocomposites on cytotoxicity and bacteriostatic activity via human osteoblast cells and Escherichia Coli, respectively. Particle size, surface roughness, reactive oxygen specious production, and bioactivity of nanocomposites were investigated by X ray diffraction, atomic force microscopy, DPPH assay, and SEM/UV–Visible spectrophotometer, respectively. Bacterial colony counting test, MTT assay and lactate dehydrogenase (LDH) release were performed as bacteriostatic and biocompatibility tests. The results showed that CT/n-HAp/Ag with smaller particle size in the range of 1–22.6 nm (10.00 ± 0.09 nm) than CT/n-HAp/Si in the range of 3–72.5 nm (18.00 ± 0.14 nm) exhibits higher cell viability and bacteriostatic activity, and less LDH release from cell plasma membrane. Integration of Ag into the nanocomposite hindered the release of Ag+ ions and restricts cytotoxic potential on cells. Higher cytotoxic effect of CT/n-HAp/Si might be related to proton concentration derived from nanocomposite and its chemical structure. In conclusion, the strong bone regeneration potential of CT/n-HAp and good biocompatibility and bacteriostatic activity of CT/n-HAp/Ag make it as potential bacteriostatic bone filler in site of infected bone fracture. [ABSTRACT FROM AUTHOR]