口服纳米银对大鼠的生物有效性及其体内分布的研究

由于独特的抗菌特性,纳米银(AgNP)在诸多领域得到广泛应用,但是其生物有效性、动物组织分布及排出尚不清楚。将聚乙烯吡咯烷酮包被的AgNP溶液按照10 mg·kg~(-1)给雌性SD大鼠灌胃,采用ICP-MS检测SD大鼠组织、粪便及尿液中总银浓度。结果表明,AgNP通过小肠吸收后,可以通过血液循环快速分布在肝、肾、脾、肺、脑等靶器官。灌胃后1 h,大鼠各组织中总银浓度达到最大值(肝、肾、脾、肺、脑中银浓度分别为(0.29±0.13)mg·kg~(-1)、(0.23±0.04)mg·kg~(-1)、(0.17±0.05)mg·kg~(-1)、(0.11±0.01)mg·kg~(-1)、(0.06±0.02)mg·kg~(-1)),之后银浓度随时间而降低,直至和对照组无显著性差异。在灌胃途径下,AgNP对SD大鼠的有效性为8.5%,且73%的AgNP是通过粪便的途径排出体外。

Bioavailability and Distribution of Nanosilver after Oral Administration in Rats

Due to the unique antimicrobial properties,nanosilver (AgNP) are widely applied in many fields.However,its bioavailability,tissue distribution and excretion in rats are less known.Female Sprague-Dawley rats were treated by a single intragastic administration of 10 mg·kg-1 polyvinylpyrrolidone-AgNPs,and rat tissues,feces and urine were collected periodically to analyze total Ag concentrations by ICP-MS.The results showed that after uptake by gastrointestine,AgNP was transported via the blood circulation and distributed to tissues such as liver,kidney,spleen,lung,and brain.At 1 h after AgNP exposure,total silver accumulation in those tissues peaked (i.e.0.29 ± 0.13 mg·kg-1,0.23 ± 0.04 mg·kg-1,0.17 ± 0.05 mg·kg-1,0.11 ± 0.01 mg·kg-1 and 0.06 ± 0.02 mg·kg-1 for liv er,kidney,spleen,lung and brain,respectively),and declined to background levels over time.Our calculation showed that the bioavailability of AgNP to Sprague-Dawley rats via intragastric administration was 8.5％.Especially,73％ of the dosed AgNP was excreted via feces.