许多海洋动物经常摄取从纳米级到微米级的塑料。这些颗粒表现出生物毒性,并且另外充当在生物体内输送和聚集吸附的化学物质的载体。同时,二苯甲酮-3和环丙沙星的检测频率可以吸附在塑料颗粒上,然后在双壳类动物中积累,导致生物毒性.为了了解它们在体内未知的累积动力学受不同塑料尺寸和共同暴露的毒性作用的影响,建立了几种方案,其中模式生物暴露于0.6mg/L的三种尺寸的携带二苯甲酮-3和环丙沙星的聚苯乙烯(300nm,38μm,和0.6毫米)。选择活的亚洲绿贻贝作为暴露实验的模式生物,在这些环境中,他们暴露于不同尺寸的塑料中,含有二苯甲酮-3和环丙沙星,然后净化了7天。在暴露和净化一周后,使用HPLC-MS/MS测量了二苯甲酮-3和环丙沙星的生物累积和净化动力学。同时,通过测量六种生物标志物(条件指数,活性氧,过氧化氢酶,谷胱甘肽,脂质过氧化,细胞色素P450和DNA损伤)。不同暴露条件下贻贝中的生物富集因子二苯甲酮-3为41.48-111.75,环丙沙星为6.45-12.35。结果表明,微塑料和纳米塑料可以作为载体,以大小依赖的方式增加贻贝中吸附物的生物积累和毒性。由微塑料和纳米塑料引起的活性氧的过度产生导致DNA损伤增加,脂质过氧化,以及暴露过程中抗氧化酶和非酶抗氧化剂的变化。去净化过程中贻贝中抗氧化防御和遗传毒性作用的明显破坏表明恢复受损。与尺寸超过一百微米的微米级塑料相比,对双壳类动物的生物累积和毒性几乎没有影响,纳米塑料大大增强了生物毒性效应。
Plastics ranging from nano-scale to micron-scale are frequently ingested by many marine animals. These particles exhibit biotoxicity and additionally perform as vectors that convey and amass adsorbed chemicals within organisms. Meanwhile, the frequency of detection of the benzophenone-3 and ciprofloxacin can be adsorbed on plastic particles, then accumulated in bivalves, causing biotoxicity. To understand their unknown accumulative kinetics in vivo affected by different plastic sizes and toxic effect from co-exposure, several scenarios were set up in which the mode organism were exposed to 0.6 mg/L of polystyrene carrying benzophenone-3 and ciprofloxacin in three sizes (300 nm, 38 μm, and 0.6 mm). The live Asian green
mussels were chosen as mode organism for exposure experiments, in which they were exposed to environments with plastics of different sizes laden with benzophenone-3 and ciprofloxacin, then depurated for 7 days. The bioaccumulation and depuration kinetics of benzophenone-3 and ciprofloxacin were measured using HPLC-MS/MS after one week of exposure and depuration. Meanwhile, their toxic effect were investigated by measuring the changes in six biomarkers (condition index, reactive oxygen species, catalase, glutathione, lipid peroxidation, cytochrome P450 and DNA damage). The bioconcentration factors in
mussels under different exposure conditions were 41.48-111.75 for benzophenone-3 and 6.45 to 12.35 for ciprofloxacin. The results suggested that microplastics and nanoplastics can act as carriers to increase bioaccumulation and toxicity of adsorbates in
mussels in a size-dependent manner. Overproduction of reactive oxygen species caused by microplastics and nanoplastics led to increased DNA damage, lipid peroxidation, and changes in antioxidant enzymes and non-enzymatic antioxidants during exposure. Marked disruption of antioxidant defenses and genotoxic effects in
mussels during depuration indicated impaired recovery. Compared to micron-scale plastic with sizes over a hundred micrometers that had little effect on bivalve bioaccumulation and toxicity, nano-scale plastic greatly enhanced the biotoxicity effect.