Abstract

The toxic effects of various substances on Daphnia magna (D. magna) observed through traditional waterborne uptake may involve alterations to the nutritional quality of the contaminated algae and culture media. It is essential to find an alternative delivery method that will not affect the nutritional quality of D. magna’s diet in order to elucidate the mechanisms of dietary metal toxicity. Therefore, this study examined the application of liposome encapsulation on the dietary toxicity of D. magna. Ag⁺-laden liposomes were prepared and the Ag encapsulation efficiency and inhibition effect on algae growth were examined. Then, acute and 14-day subchronic studies were performed to examine the effect of Ag⁺-laden liposomes on D. magna. The EC₅₀ for the 24 h immobilization test was 10.59 µg/L for Ag⁺-laden liposomes and 3.07 µg/L for Ag⁺. In terms of subchronic effects, the estimated ECx values under the Ag⁺-laden liposome condition were always higher than the direct exposure condition. Furthermore, the bioaccumulation of Ag⁺-laden liposomes was about 1.68 times lower than direct exposure. Generally, Ag⁺-laden liposomes produced less efficient toxicity than direct exposure, e.g., lower D. magna mortality, production of more neonates, higher intrinsic rate of natural increase (r_m), earlier time to first brood, and higher enzyme activities.

摘要

对各种物质的毒性作用水蚤（D.蚤通过传统水性摄取观察到的）可以涉及改变到被污染的藻类和培养基的营养质量。为了阐明饮食中金属毒性的机理，找到一种不影响大麦D的饮食营养质量的替代递送方法至关重要。因此，本研究考察了脂质体包封对大麦蛾的饮食毒性的应用。制备载有Ag ^+的脂质体，并研究了Ag的包封效率和对藻类生长的抑制作用。然后，进行了急性和14天亚慢性研究，以检查银的作用D. magna上的⁺ -脂质体。的EC ₅₀为24小时的固定化试验10.59微克/升的Ag ⁺ -laden脂质体和3.07微克/升的Ag ⁺。就亚慢性影响而言，在载有​​Ag ^+的脂质体条件下的估计ECx值始终高于直接暴露条件。此外，载有Ag ^+的脂质体的生物蓄积比直接暴露低约1.68倍。通常，载有Ag ^+的脂质体产生的毒性比直接暴露产生的毒性要低，例如，低D. magna死亡率，产生更多的新生儿，更高的自然增长率（r _m），最早孵化的时间和更高的酶活性。