We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Photolytic degradation elevated the toxicity of polylactic acid microplastics to developing zebrafish by triggering mitochondrial dysfunction and apoptosis
Summary
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.
Biodegradable plastics (BPs), as alternatives to conventional plastics, are increasingly consumed, but pose potential threats to aquatic ecosystems. In addition, the impact of natural aging on the toxicity of BPs is poorly understood. In this study, the photodegradation of polylactic acid (PLA, a typical BP) microplastics (MPs) under ultraviolet irradiation in water for 90 days was investigated, and the toxicities of virgin and degraded PLA to infantile zebrafish were compared. The results revealed that the size of MPs was reduced from ~25.56 to ~11.22 µm after degradation and nanoparticles were generated with a maximum yield of 7.13%. The formation of abundant oxygen-containing groups (i.e. C˭O and C-O-C) improved the hydrophilia and stability of MPs. Compared with pristine PLA, the efflux and detoxification of degraded PLA mediated by ABC transporters and P450 enzymes were slower, leading to higher bioaccumulation and skeletal development inhibition of zebrafish. Further, oxidative stress-triggered mitochondrial structural damage, depolarization, fission inhibition, and apoptosis were identified as crucial mechanisms underlying the elevated toxicity of PLA after degradation. These findings highlight the importance and necessity of considering natural degradation of BPs and related toxicity, which poses great implications for risk assessment and management of BPs.
Sign in to start a discussion.
More Papers Like This
Enhanced reproductive toxicity of photodegraded polylactic acid microplastics in zebrafish
Researchers found that polylactic acid (PLA) microplastics, often marketed as biodegradable, became more toxic after being broken down by sunlight. The sun-degraded PLA caused worse reproductive damage in zebrafish than the original material, disrupting hormone levels and egg development. This is concerning because PLA is widely used as an eco-friendly plastic alternative, but its breakdown products may actually pose greater risks to organisms and ecosystems.
Photoaging enhanced the adverse effects of polyamide microplastics on the growth, intestinal health, and lipid absorption in developing zebrafish
Researchers found that polyamide microplastics became significantly more harmful to developing zebrafish after being aged by simulated sunlight, shrinking in size and generating nanoplastic fragments. The aged particles caused greater damage to intestinal health, impaired lipid absorption, and stunted growth compared to unaged microplastics. The study demonstrates that environmental weathering can substantially increase the biological risks posed by microplastics in aquatic ecosystems.
Photo-Oxidative Degradation Mitigated the Developmental Toxicity of Polyamide Microplastics to Zebrafish Larvae by Modulating Macrophage-Triggered Proinflammatory Responses and Apoptosis
Visible light photo-oxidation of polyamide microplastics for 90 days reduced particle size, generated nanoparticles, and significantly mitigated developmental toxicity in zebrafish larvae by modulating macrophage-triggered inflammatory responses and apoptosis — suggesting weathering can reduce but not eliminate MP toxicity.
Assessment on intestinal health from polylactic acid microplastics degradation on rare minnow (Gobiocypris rarus): Inflammation regulation by mitochondrial dysfunction
Researchers exposed rare minnow fish to photodegraded polylactic acid microplastics to assess intestinal health effects. The study found that these biodegradable plastic particles induced visible intestinal damage, triggered inflammation through mitochondrial dysfunction, and caused oxidative stress, suggesting that even biodegradable plastics may pose ecological risks after environmental degradation.
Photoaged microplastics induce neurotoxicity via oxidative stress and abnormal neurotransmission in zebrafish larvae (Danio rerio)
This study found that microplastics aged by sunlight were more toxic to zebrafish larvae than fresh microplastics, causing brain damage and abnormal behavior. The sun-aged particles triggered greater oxidative stress and disrupted neurotransmitter systems in the developing fish. This is concerning because most microplastics in the environment have been weathered by sunlight, meaning the real-world health risks may be greater than lab studies using fresh plastics suggest.