3种磁性氧化铁的理化性质和动物体内分布测定

Primary Study of Organic Silane Attached MagneticIron as an Oral Contrast Agent for MR Imaging

测定有机硅烷化、聚丙烯酰胺和聚苯乙烯３ 种包埋体磁性氧化铁在水中溶解度分别为＜ ０ ．１ ％ 、５ ．６ ％ ±０ ．４ ％ 和３ ．９ ％ ±０ ．５ ％ ；模拟胃酸条件下浸泡２４ｈ 的溶解度分别为１３ ．４ ％ ±０ ．４ ％ ，１２ ．４ ％ ±０ ．８ ％ 和１０ ．５ ％ ±０ ．２ ％ ；用０ ．０１ ～１０ｍｍｏｌ／ Ｌ不同浓度的有机硅烷化磁性氧化铁溶液在磁共振仪上测定不同铁浓度下 Ｔ２信号强度显示， Ｔ２ 信号强度随铁浓度增加而下降；小鼠口服溶液后１ｈ 和４ｈ ，铁主要集中于胃和肠；家兔和小鼠喂药后分别饲养４ 周和２ 周，活动如常，未见不良反应。结果表明，有机硅烷化氧化铁颗粒有可能用作口服磁共振造影剂。

Purpose To determine physical and chemical properties and distribution of magnetic iron oxide coated with organic silane polyavrylamide and polystyrene in vivo in animal for observing the possibility as an oral contrast agent in magnetic resonance imaging(MRI). Method ① Iron solubility of the three kinds of coated iron oxide was determined after immersing in medium HC1 of pH 1.2 and in distilled water for 24h. ② The MRI signal intensityies (SI) T 2 of the iron oxide solution with various concentrations from 0.01 to 10 mmol Fe/L was measured. ③ In vivo distribution in mice 1h and 4h after taking orally 0.1 mg Fe/kg body weight was measured. Result ① Iron solubilities of the three kinds of coated iron oxide in medium HC1 of pH 1.2 were 13.4±0.4%,12.4±0.8% and 10.5±0.2%, respectively;their water solubillties were less than 0.1%, 5.6±0.4% and 3.9±0.5%, respectively. ② The T 2 SI of iron oxide was obviously decreased with the increased iron concentration. ③ The distribution of magnetic iron in mice indicated that iron mainly accumulated in stomach and intestine 1h and 4h after taking orally 0.1 mg Fe/kg body weight. There was no adverse reaction observed in mice and rabbits. The animals, behaviour was as usual 2～4 weeks after taking magnetic iron oxide. Conclusion The study showed the possibility of using coated iron oxide as oral contrast agent for abdomen MRI.