Development of photo-crosslinkable collagen hydrogel building blocks for vascular tissue engineering applications: A superior alternative to methacrylated gelatin?

The present work targets the development of collagen-based hydrogel precursors, functionalized with photo-crosslinkable methacrylamide moieties (COL-MA), for vascular tissue engineering (vTE) applications. The developed materials were physico-chemically characterized in terms of crosslinking kinetics, degree of modification/conversion, swelling behavior, mechanical properties and in vitro cytocompatibility. The collagen derivatives were benchmarked to methacrylamide-modified gelatin (GEL-MA), due to its proven track record in the field of tissue engineering. To the best of our knowledge, this is the first paper in its kind comparing these two methacrylated biopolymers for vTE applications. For both gelatin and collagen, two derivatives with varying degrees of substitutions (DS) were developed by altering the added amount of methacrylic anhydride (MeAnH). This led to photo-crosslinkable derivatives with a DS of 74 and 96% for collagen, and a DS of 73 and 99% for gelatin. The developed derivatives showed high gel fractions (i.e. 74% and 84%, for the gelatin derivatives; 87 and 83%, for the collagen derivatives) and an excellent crosslinking efficiency. Furthermore, the results indicated that the functionalization of collagen led to hydrogels with tunable mechanical properties (i.e. storage moduli of [4.8-9.4 kPa] for the developed COL-MAs versus [3.9-8.4 kPa] for the developed GEL-MAs) along with superior cell-biomaterial interactions when compared to GEL-MA. Moreover, the developed photo-crosslinkable collagens showed superior mechanical properties compared to extracted native collagen. Therefore, the developed photo-crosslinkable collagens demonstrate great potential as biomaterials for vTE applications.

Method for beta-carotene extraction from processed baby foods as a model for plant-based fatty food products

Reliable quantitative determination of carotenoids in complex food matrices such as processed baby food products is challenging because of their incorporation in rigid cellular structures, their sensitivity to oxidation and their lipophilic character. A one-pot liquid-liquid β-carotene extraction procedure is described for solid baby foods, in the presence of enzymes (Clara-Diastase and Rapidase) facilitating matrix disintegration. The combined extraction and enzymatic dissolution not only protected β-carotene from oxidation compared to the sequential approach, but also reduced the use of solvents and amount of filtrations steps, favouring a higher recovery. The addition of phenolic antioxidants (BHT, TBHQ and BHA) to calibration solutions and during the procedure at 25 mg/mL resulted in an up to 2.5-fold higher absorbance of β-carotene solutions which was not observed for trans-β-apo-8'-carotenal (used as internal standard) solutions. When applying the full procedure on β-carotene spiked sunflower oil, an apparent recovery of 80% for β-carotene was obtained. Finally, this protocol was applied to 50 vegetable-based and 22 fruit-based processed baby foods (range 0 to 1179 and 504 µg/100 g, respectively), and it was concluded that this extraction procedure may be used for similar processed foods products. The procedure proved to be sensitive (LOD = 0.12 µg/mL) and reproducible (CV for baby foods: 4-10%).

Do Current Fortification and Supplementation Programs Assure Adequate Intake of Fat-Soluble Vitamins in Belgian Infants, Toddlers, Pregnant Women, and Lactating Women?

Abstracts: Adequate intakes of fat-soluble vitamins are essential to support the growth and development of the foetus, the neonate, and the young child. By means of an online self-administered frequency questionnaire, this study aimed to evaluate the intake of vitamins A, D, E, and K in Belgian infants (n = 455), toddlers (n = 265), pregnant women (n = 161), and lactating women (n = 165). The contribution of foods, fortified foods, and supplements on the total intake was quantified. 5% of toddlers, 16% of pregnant women, and 35% of lactating women had an inadequate vitamin A intake. Conversely, excessive vitamin A intakes were associated with consumption of liver (products). Furthermore, 22% of infants were at risk for inadequate vitamin D intake due to the lack of prophylaxis, while consumption of highly dosed supplements posed a risk for excessive intakes in 6%-26% of infants. Vitamin D intake in pregnant women and lactating women was inadequate (median of 51%, respectively, 60% of the adequate intake). In all groups, the risk for inadequate intake of vitamin E and K was low. Contribution of fortified foods to vitamin A, D, E, and K intake was minor, except in toddlers. National fortification strategies should be investigated as an alternative or additional strategy to prevent vitamin D and A deficiency. There is a need to revise and set uniform supplement recommendations. Finally, non-users of vitamin D prophylaxis need to be identified for targeted treatment.