Storage Stability of an Antioxidant Active Packaging Coated with Citrus Extract Following a Plasma Jet Pretreatment

yesAntioxidant active packaging was prepared by coating a citrus extract on the surface of polyethylene terephthalate (PET) trays which had been either treated with an atmospheric pressure plasma jet or left untreated. The surface characteristics of the packaging were examined, as were its stability and antioxidant efficacy following storage for up to 24 weeks under the following three storage conditions: room temperature, 0 % relative humidity (RH) or 50 °C. Plasma pretreatment increased coating density, thickness and roughness, and oxygenated functional groups at the polymer surface, whereas water contact angle decreased. Trays stored at room temperature did not lose their antioxidant efficacy over 24 weeks and plasma pretreatment enhanced the efficacy from week 8 onwards. Gravimetric analysis of the coating revealed a loss of antioxidant compounds only after 16 weeks. Trays stored at 0 % RH lost coating from week 1 onwards, with lower loss in plasma pretreated trays, while loss of coating was highest at 50 °C, with lower loss in plasma pretreated trays only after 24 weeks. Overall, the surface characteristics of the antioxidant active packaging were modified by plasma pretreatment of the PET surface, with some improvement in antioxidant efficacy, and the efficacy of the packaging in delaying oxidative deterioration in cooked meats was retained during storage at ambient temperature

Design and Validation of an Open-Hardware Print-Head for Bioprinting Application

In the last decades drop-on-demand inkjet technology played an increasing role in industrial and medical applications. This is due to the ability to deposit a small amount of material in precisely defined position. In the field of Biofabrication, inkjet printers are used to build 2D and 3D scaffolds and gels with biological molecules, including living cells. Several works, including seminal papers on inkjet bioprinting, were carried out with modified office printers. These printers have fixed structural characteristics and operating size, especially on the print-head, limiting the range of materials that can be dispensed. The aim of the present work is the design and fabrication of an open-source piezoelectric inkjet print-head, optimized for the bioprinting field. This low-cost, reproducible, reliable, versatile and biocompatible device will enable various research laboratories to work with a shared device; the open source allowing for parts to be modified to suit specific needs. The design was carried out by Finite Element (FE) modelling of the piezoelectric, mechanical, fluid dynamics and their coupling. The design was optimized for shear rate, which we minimized in order to be able to print cells. The mechanical frame of the printer was designed and built using a low-cost 3D printer. The nozzle plate was fabricated from a polycarbonate disc coated with biocompatible silicone, to increase the hydrophobicity of the outer surface of the disc, preventing ink adhesion on the edge of the nozzle; the refilling system, and the electronic control were also part of the project and will be freely available to download. The FE models were validated with ad-hoc experiments, printing water, gelatin solution, and cell culture media, by modulating the wave power in amplitude, frequency and duty cycle. The tests showed a large working window both respect to viscosity and to surface tension. Finally Human Skin Fibroblasts (ATCC-CRL- 2522, Teddington UK), suspended in culture media, were printed. Cell viability, assessed by CellTiter-Blue and LIVE / DEAD tests, resulted comparable with the control, demonstrating the validity of the first open source piezoelectric inkjet print-head for biofabrication

Different mechanisms are involved in apoptosis induced by melanoma gangliosides on human monocyte-derived dendritic cells

Tumor escape is linked to multiple mechanisms, notably the liberation, by tumor cells, of soluble factors that inhibit the function of dendritic cells (DC). We have shown that melanoma gangliosides impair DC differentiation and induce their apoptosis. The present study was aimed to give insight into the mechanisms involved. DC apoptosis was independent of the catabolism of gangliosides since lactosylceramide did not induce cell death. Apoptosis induced by GM3 and GD3 gangliosides was not blocked by inhibitors of de novo ceramide biosynthesis, whereas the acid sphingomyelinase inhibitor desipramine only prevented apoptosis induced by GM3. Furthermore, our results suggest that DC apoptosis was triggered via caspase activation, and it was ROS dependent with GD3 ganglioside, suggesting that GM3 and GD3 induced apoptosis through different mechanisms

A high degree of LINE-1 hypomethylation is a unique feature of early-onset colorectal cancer

Objective Early-onset colorectal cancer (CRC) represents a clinically distinct form of CRC that is often associated with a poor prognosis. Methylation levels of genomic repeats such as LINE-1 elements have been recognized as independent factors for increased cancer-related mortality. The methylation status of LINE-1 elements in early-onset CRC has not been analyzed previously. Design We analyzed 343 CRC tissues and 32 normal colonic mucosa samples, including 2 independent cohorts of CRC diagnosed ≤50 years old (n = 188), a group of sporadic CRC >50 years (MSS n = 89; MSI n = 46), and a group of Lynch syndrome CRCs (n = 20). Tumor mismatch repair protein expression, microsatellite instability status, LINE-1 and MLH1 methylation, somatic BRAF V600E mutation, and germline MUTYH mutations were evaluated. Results Mean LINE-1 methylation levels (±SD) in the five study groups were early-onset CRC, 56.6% (8.6); sporadic MSI, 67.1% (5.5); sporadic MSS, 65.1% (6.3); Lynch syndrome, 66.3% (4.5) and normal mucosa, 76.5% (1.5). Early-onset CRC had significantly lower LINE-1 methylation than any other group (p<0.0001). Compared to patients with <65% LINE-1 methylation in tumors, those with ≥65% LINE-1 methylation had significantly better overall survival (p = 0.026, log rank test). Conclusions LINE-1 hypomethylation constitutes a potentially important feature of early-onset CRC, and suggests a distinct molecular subtype. Further studies are needed to assess the potential of LINE-1 methylation status as a prognostic biomarker for young people with CRC