We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
The toxicity of polylactic acid (PLA) nanoplastics and oligomers to Pseudomonas putida is driven by photoaged by-products
AI summary Read the abstract
Researchers broke down PLA bioplastic beads into tiny particles and exposed some to UV light to mimic sunlight aging, then tested both on bacteria called Pseudomonas putida. Light-aged particles caused more cell stress, lower metabolic activity, and membrane damage at moderate doses, suggesting sunlight exposure can turn biodegradable plastics into more harmful breakdown products.
In recent years, bioplastics, including biodegradable and bio-based polymeric materials, have been increasingly used in various industries such as packaging and agriculture. Despite their faster fragmentation in the environment, the occurrence and environmental toxicity of realistic nanoplastics (NP; <1000 nm) and oligomers (OL; <50 kDa) remain poorly understood, highlighting the need for further research before their widespread use. In this study, polylactic acid (PLA) microbeads, a biodegradable plastic widely applied in single-use products and agricultural mulching, were fragmented into nanoscale material. Part of the material was exposed to UV irradiation to simulate natural photoaging and to compare its physicochemical and toxicological behavior with the unirradiated counterpart. The chemical composition, colloidal stability, size distribution, morphology, and polymer chain structure of both irradiated (I) and non-irradiated (NI) secondary NP and OL were extensively characterized. The biological effects were evaluated using Pseudomonas putida at concentrations ranging from 0.1 to 50 mg/L. NP and OL induced ROS overproduction, metabolic alterations, and changes in membrane potential, likely linked to the toxicity of photoaged PLA by-products and the differential bioavailability of non-irradiated and irradiated materials. At moderate concentrations (≥10 mg/L), irradiated materials caused pronounced oxidative stress, reduced metabolic activity, and cytoplasmic membrane depolarization, indicating the formation of toxic photoaged species. MALDI TOF/TOF analysis confirmed the presence of degradation by-products primarily generated during photoaging. Overall, the results demonstrate that abiotic transformations of biodegradable plastics can produce persistent toxic compounds that pose potential environmental risks.
More Papers Like This
Photoaging of biodegradable nanoplastics regulates their toxicity to aquatic insects (Chironomus kiinensis) by impairing gut and disrupting intestinal microbiota
AI summary Read the abstract
This study found that biodegradable PLA nanoplastics become more toxic after aging in sunlight, causing worse gut damage, oxidative stress, and disruption of gut bacteria in aquatic insects than fresh particles. The aging process made the particles smaller and more chemically reactive, enhancing their harmful effects. This challenges the assumption that biodegradable plastics are inherently safer -- once they break down into nanoplastics in the environment, they may actually pose greater health risks.
Photo-Aging of Biodegradable Polylactic Acid Microplastics
AI summary Read the abstract
Researchers investigated the photo-aging of polylactic acid (PLA) microplastics, finding that UV exposure caused fragmentation that increased total particle numbers while decreasing average particle size. The study provides quantitative data on how biodegradable PLA plastics generate secondary microplastics through photoaging, a previously poorly characterized degradation pathway for this widely used industrial bioplastic.
Photolytic degradation elevated the toxicity of polylactic acid microplastics to developing zebrafish by triggering mitochondrial dysfunction and apoptosis
AI summary Read the abstract
Researchers found that biodegradable polylactic acid (PLA) microplastics become more toxic to zebrafish after being broken down by sunlight over 90 days. UV exposure shrank the particles and generated nanoplastics, which were harder for the fish to expel from their bodies compared to the original material. The degraded PLA triggered oxidative stress and mitochondrial damage in developing zebrafish, suggesting that the environmental breakdown of biodegradable plastics may actually increase their harmful effects.
Aging behavior of biodegradable polylactic acid microplastics accelerated by UV/H2O2 processes
AI summary Read the abstract
Researchers used UV and hydrogen peroxide to simulate environmental aging of biodegradable polylactic acid (PLA) microplastics, finding that PLA microplastics undergo significant surface and structural changes during weathering that alter their environmental behavior and persistence.
Photoaging Promotes Toxic Micro/Nanoplastics Release from PLA/PBAT Biodegradable Plastic in Gastrointestinal Condition
AI summary Read the abstract
Researchers found that when biodegradable plastics made from PLA/PBAT are aged by sunlight and then exposed to digestive conditions, they release significantly more micro- and nanoplastic particles than non-aged versions. These released particles showed toxicity to intestinal cells, raising important questions about the safety of biodegradable food packaging as it weathers before disposal.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.