生物降解塑料已被普遍开发和应用,作为传统塑料的替代品,造成环境塑料污染。然而,生物降解塑料仍然存在局限性,如严格的降解条件和缓慢的降解速率,并可能对环境和生物造成伤害。因此,在这项研究中,斑马鱼被用来评估五种生物可降解微塑料(MPs)的效果,聚乙醇酸(PGA),聚乳酸(PLA),聚丁二酸丁二醇酯(PBS),聚羟基链烷酸酯(PHA)和聚己二酸丁二醇酯(PBAT)暴露于早期发展,视网膜形态学,视觉介导的行为,和浓度为1mg/L和100mg/L的甲状腺信号结果表明,所有MPs诱导的存活率降低,减少身体长度,小眼睛,和更小的头,影响斑马鱼幼虫的早期发育。此外,视网膜层的厚度,包括内丛状层(IPL),外核层(ONL),视网膜神经节层(RGL)减少,所有MPs暴露后,与眼睛和视网膜发育相关的关键基因的表达异常改变。暴露于PBS和PBAT导致异常的视觉介导行为,表明可能影响了视觉功能。所有国会议员也可能导致甲状腺系统疾病,其中甲状腺激素受体(TRs)基因的改变可能影响斑马鱼幼虫的视网膜发育。总之,可生物降解的MPs表现出眼睛发育毒性,并可能损害斑马鱼幼虫的视觉功能。这为揭示生物降解塑料对水生生物发育的影响以及对水生生态系统的环境风险提供了新的证据。
Biodegradable plastics have been commonly developed and applied as an alternative to traditional plastics, which cause environmental plastic pollution. However, biodegradable plastics still present limitations such as stringent degradation conditions and slow degradation rate, and may cause harm to the environment and organisms. Consequently, in this study, zebrafish was used to evaluate the effects of five biodegradable microplastics (MPs), polyglycolic acid (PGA), polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoate (PHA) and polybutylene adipate terephthalate (PBAT) exposure on the early development, retina morphology, visually-mediated behavior, and thyroid signaling at concentrations of 1 mg/L and 100 mg/L. The results indicated that all MPs induced decreased survival rate, reduced body length, smaller eyes, and smaller heads, affecting the early development of zebrafish larvae. Moreover, the thickness of retinal layers, including inner plexiform layer (IPL), outer nuclear layer (ONL), and retinal ganglion layer (RGL) was decreased, and the expression of key genes related to eye and retinal development was abnormally altered after all MPs exposure. Exposure to PBS and PBAT led to abnormal visually-mediated behavior, indicating likely affected the visual function. All MPs could also cause thyroid system disorders, among which alterations in the thyroid hormone receptors (TRs) genes could affect the retinal development of zebrafish larvae. In summary, biodegradable MPs exhibited eye developmental toxicity and likely impaired the visual function in zebrafish larvae. This provided new evidence for revealing the effects of biodegradable plastics on aquatic organism development and environmental risks to aquatic ecosystems.