Search

Abstract Background Although plastic pollution is increasing worldwide, very little is known about the microbial processes that take place once plastic debris is incorporated into the soil matrix. In this study, we conducted the first metatranscriptome analysis of polyethylene (PE)-associated biofilm communities in highly polluted landfill soil and compared their gene expression to that of a forest soil community within a 53-day period. Results Our findings indicate that the microbial population present in soil contaminated with plastic debris is predisposed to both inhabit and degrade plastic surfaces. Surprisingly, the microbial community from undisturbed forest soil contained a diverse array of plastic-associated genes (PETase, alkB, etc.), indicating the presence of an enzymatic machinery capable of plastic degradation. Plastic-degrading taxa were upregulated in the early stages of biofilm formation. During the maturation of the biofilm, the alkB1/alkM transcripts, which encode PE-degrading enzymes, and transporters such as fadL, livG, livF, livH, and livM were upregulated, along with transcripts associated with the fatty acid β-oxidation pathway. Conclusions In this study, we address the underlying patterns of gene expression during biofilm development in a PE-associated plastisphere in soil and address the pressing question of whether natural microbial communities have the potential to biodegrade petrochemical-based plastic in the soil environment.

Processing parameters of melt mixing (one of the most conventional techniques in polymer processing) play a significant role in the quality and properties of the resulting material, especially when nanoreinforcements are involved. The current study investigates varying processing temperature, rotation speed and elements of the screw extruder, aiming to enhance mechanical properties of polyethylene (PE) nanocomposites by improving dispersion of nanoparticles from a commercial masterbatch in two grades of PE. The study investigates the effect of a common compatibilizer (MAPE) and shearing forces at varying amounts of graphene nanoplatelets (GNPs) in polyethylene. A comparison is made on mechanical properties, morphology, and changes in the microstructure. Results show that increasing amounts of GNPs lead to expected continuous increase of mechanical properties with reference to the base polymer. Addition of MAPE did not result in significant improvement in the performance of the studied systems. Use of stronger shear forces resulted in mostly negative impact on the properties.

The potential of recycling carbon fiber reinforced polymers (CFRP) as a sustainable solution for waste management is yet to be fully understood. This study reports on the evolution of mechanical, and chemical properties of reclaimed carbon fibers when recycled multiple times via pyrolysis and partial oxidation. The performed work aims at filling the knowledge gap related to repetitive recycling when moving towards a circular flow of resources. A recycling process existing at industrial scale is used to ensure the relevance and usefulness of the results in the current industry scene. Two sets of three identical model composites are recycled using distinct recycling parameters, and their properties are characterized at the end of each recycling cycle. Results show that recycling can lead to an increase in stiffness but can have a negative impact on strength of recovered fibers. Mechanical behaviour shows recovered fibers suitable for secondary applications with medium performance requirements after two recycling cycles. The findings highlight the importance of understanding the material properties evolution during recycling processes. This research contributes to the development of sustainable waste management strategies and a more environmentally friendly future.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer characterised by poor survival rates and an increasing global incidence. Advances in the staging and categorization of pancreatic tumours, along with the discovery of functional mutations, have made precision treatments possible, which may lead to better clinical results. To further improve customized treatment approaches, in vitro models that can be used for functional drug sensitivity testing and precisely mimic the disease at the organ level are required. In this study, we present a workflow for creating a personalized PDAC chip utilising primary tumour-derived human pancreatic organoids (hPOs) and Human Umbilical Vein Endothelial Cells (HUVECs) to simulate the vascular barrier and tumour interactions within a PDMS-free organ-on-a-chip system. The patient PDAC tissue, expanded as tumour hPOs, could be cultured as adherent cells on the chip for more than 50 days, allowing continuous monitoring of cell viability through outflows from tumour and endothelial channels. Our findings demonstrate a gradual increase in cell density and cell turnover in the pancreatic tumor channel. Tumour-specific biomarkers, including CA-19.9, TIMP-1, Osteopontin, MIC-1, ICAM-1 and sAXL were consistently detected in the PDAC chip outflows. Comparative analyses between tissue culture plates and microfluidic conditions revealed significant differences in biomarker secretion patterns, highlighting the advantages of the microfluidics approach. This PDAC chip provides a stable, reproducible tumour model system with a functional endothelial cell barrier, suitable for drug sensitivity and secretory biomarker studies, thus serving as a platform for functional precision medicine application and multi-organ chip development.