R. F. (2020). Development and characterisation of novel poly (vinyl alcohol)/poly (vinyl pyrrolidone)-based hydrogel-forming microneedle arrays for enhanced and sustained transdermal delivery of methotrexate.

aThe preparation of Janus fibers using a new side-by-side electrospinning process is reported. By manipulating the angle between the two ports of the spinneret emitting the working fluids, Janus nanofibers with tunable structures in terms of width, interfacial area and also volume of each side can be easily fabricated.Among the different ''top-down'' processes for nanofabrication, electrohydrodynamic atomization processes (EHDA, including electrospinning, electrospraying and e-jetting printing) have the unique capability of simultaneous modulation of sizes, shapes and compartmentalization of their nanoproducts.1,2 This ability has been broadly exploited for the generation of core-shell nanostructures, both in the form of electrospun fibers, nanotubes 3-5 and electrosprayed particles or bubbles. [6][7][8] Most recently, even complex structures such as tri-axial nanofibers have also been investigated using multi-fluid electrospinning processes. [9][10][11][12] In sharp contrast, there are still very limited studies about the generation of sideby-side structures using these EHDA processes. [13][14][15][16][17][18][19][20][21] To create structures with double compartments, two types of relationships between components are feasible, one is the exterior and interior (i.e. a core-shell structure), and the other is side-by-side. The latter, being a heterojunction structure, can have an advantage for designing novel functional nanomaterials over the core-shell structures because it provides an opportunity for both components to interact with their surroundings. 22,23Side-by-side electrospinning involves a complex interplay between fluid dynamics, electrodynamics and rheology, and presents a challenge in controlling the movement in unison of two fluids in a side-by-side manner under an electrical field from spinneret to collector. To our knowledge, Gupta and Wilkes were the first to report the preparation of side-by-side polymer nanofibers, made of poly(vinyl chloride)/segmented polyurethane and poly(vinyl chloride)-poly(vinylidiene fluoride) using a spinneret consisting of two parallel Teflon capillaries.13 Lin et al. reported the preparation of self-crimping side-by-side nanofibers that spontaneously formed curled helical fibers, composed of polyacrylonitrile and polyurethane, using a homemade silicone microfluidic spinneret, which consisted of three capillary channels with two of them combined in another channel in parallel to form the side-by-side outlet. 14 Later, several publications describe the preparation of side-by-side nanofibers using spinnerets made from two syringes whose needle tips were confined in a side-byside geometry. [15][16][17][18] In all these studies it was possible to control the outlet of the double fluids in a parallel manner for successful preparation of Janus nanofibers. Using a different approach, we report here side-by-side electrospinning in which a series of spinnerets with varying port angles were exploited to create structure-tunable Janus fibers. Our initial purpose was to prepare high...

BackgroundExposure to aflatoxin, a mycotoxin produced by fungi that commonly contaminates cereal crops across sub-Saharan Africa, has been associated with impaired child growth. We investigated the impact of aflatoxin exposure on the growth of Gambian infants from birth to two years of age, and the impact on insulin-like growth factor (IGF)-axis proteins.MethodsA subsample (N = 374) of infants from the Early Nutrition and Immune Development (ENID) trial (ISRCTN49285450) were included in this study. Aflatoxin-albumin adducts (AF-alb) were measured in blood collected from infants at 6, 12 and 18 months of age. IGF-1 and IGFBP-3 were measured in blood collected at 12 and 18 months. Anthropometric measurements taken at 6, 12, 18 and 24 months of age were converted to z-scores against the WHO reference. The relationship between aflatoxin exposure and growth was analysed using multi-level modelling.ResultsInverse relationships were observed between lnAF-alb and length-for-age (LAZ), weight-for-age (WAZ), and weight-for-length (WLZ) z-scores from 6 to 18 months of age (β = − 0·04, P = 0·015; β = − 0·05, P = 0.003; β = − 0·06, P = 0·007; respectively). There was an inverse relationship between lnAF-alb at 6 months and change in WLZ between 6 and 12 months (β = − 0·01; P = 0·013). LnAF-alb at 12 months was associated with changes in LAZ and infant length between 12 and 18 months of age (β = − 0·01, P = 0·003; β = − 0·003, P = 0·02; respectively). LnAF-alb at 6 months was associated with IGFBP-3 at 12 months (r = − 0·12; P = 0·043).ConclusionsThis study found a small but significant effect of aflatoxin exposure on the growth of Gambian infants. This relationship is not apparently explained by aflatoxin induced changes in the IGF-axis.

# Yun Yun Gong is responsible for the statistical analysis. AbstractPurpose: To determine levels of urinary AFM1 in children and correlate the concentrations with previously reported aflatoxin albumin adduct (AF-alb) levels in these children.Materials and Methods: Matched urine and blood samples were collected from 84 Tanzanian children aged 6-14 months old. From 31 children in one village (Kigwa), samples were collected at three time points six months apart. Samples were collected from 31 and 22 children from two different regions at the second time point only. Urinary AFM1 was measured using a commercial ELISA kit with a modified protocol to improve sensitivity. AF-alb was measured using an established ELISA method.Results: The relative ranking of the three villages for exposure to aflatoxin based on either AFM1 or AF-alb biomarker measurements was the same. In Kigwa village, both AFM1 and AF-alb levels were higher at six months post-harvest compared to baseline. However, at the next visit the AFM1 levels dropped from a GM (interquartile range) of 71.0 (44.7, 112.6) at visit two to 49.3 (31.5, 77.3) pg/ml urine, whereas AF-alb levels increased from 47.3 (29.7, 75.2) to 52.7 (35.4, 78.3) pg/mg albumin between these two visits, reflecting the fact that AFM1 measures short term exposure whereas AF-alb measures longer term exposure. There was a correlation between AFB1 intake and AFM1 excretion (r = 0.442, p = < 0.001).Conclusions: Urinary AFM1 is a good biomarker for AFB1 exposure in Tanzanian children, reflecting geographical and temporal variations in exposure to this food borne toxin.3

Scope Aflatoxin exposure coincides with micronutrient deficiencies in developing countries. Animal feeding studies have postulated that aflatoxin exposure may be exacerbating micronutrient deficiencies. Evidence available in human subjects is limited and inconsistent. The aim of the study was to investigate the relationship between aflatoxin exposure and micronutrient status among young Guinean children. Method and results A total of 305 children (28.8 ± 8.4 months) were recruited at groundnut harvest (rainy season), of which 288 were followed up 6 months later post-harvest (dry season). Blood samples were collected at each visit. Aflatoxin-albumin adduct levels were measured by ELISA. Vitamin A, vitamin E and β-carotene concentrations were measured using HPLC methods. Zinc was measured by atomic absorption spectroscopy. Aflatoxin exposure and micronutrient deficiencies were prevalent in this population and were influenced by season, with levels increasing between harvest and post-harvest. At harvest, children in the highest aflatoxin exposure group, compared to the lowest, were 1.98 (95%CI: 1.00, 3.92) and 3.56 (95%CI: 1.13, 11.15) times more likely to be zinc and vitamin A deficient. Conclusion Although children with high aflatoxin exposure levels were more likely to be zinc and vitamin A deficient, further research is necessary to determine a cause and effect relationship.