中国组织工程研究 ›› 2016, Vol. 20 ›› Issue (47): 7090-7096.doi: 10.3969/j.issn.2095-4344.2016.47.014

• 纳米生物材料 nanobiomaterials • 上一篇    下一篇

MnFe2O4纳米胶束合成及其应用于磁共振分子影像的可行性

杨  华1,龚明福2,邹利光2,张  松2,舒通胜2,周培华1
  

  1. 1重庆市中医院放射科,重庆市  400021;2解放军第三军医大学新桥医院放射科,重庆市  400037
  • 收稿日期:2016-08-21 出版日期:2016-11-18 发布日期:2016-11-18
  • 通讯作者: 周培华,主任医师,重庆市中医院放射科,重庆市 400021
  • 作者简介:杨华,男,1978年生,重庆市人,博士,副主任医师,主要从事磁共振分子影像研究。
  • 基金资助:

    国家自然科学基金(81071197,81501521);重庆市前沿与应用基础研究一般项目(cstc2015jcyjA1338)

Synthesis of MnFe2O4 nanomicelles and its application in magnetic resonance molecular imaging

Yang Hua1, Gong Ming-fu2, Zou Li-guang2, Zhang Song2, Shu Tong-sheng2, Zhou Pei-hua1
  

  1. 1Department of Radiology, Chongqing Traditional Chinese Medicine Hospital, Chongqing 400021, China; 2Department of Radiology, Xinqiao Hospital, Third Military Medical University of PLA, Chongqing 400037, China
  • Received:2016-08-21 Online:2016-11-18 Published:2016-11-18
  • Contact: Zhou Pei-hua, Chief physician, Department of Radiology, Chongqing Traditional Chinese Medicine Hospital, Chongqing 400021, China
  • About author:Yang Hua, M.D., Associate chief physician, Department of Radiology, Chongqing Traditional Chinese Medicine Hospital, Chongqing 400021, China
  • Supported by:

    the National Natural Science Foundation of China, No. 81071197, 81501521; Frontier and Applied Basic Research Projects in Chongqing, No. cstc2015jcyjA1338

摘要:

文章快速阅读:

 

文题释义:
MnFe2O4纳米胶束
:铁酸盐(MnFe2O4)纳米粒在结构上为金属粒子(M 2+)和铁粒子(Fe 3+)构成的内部支架,氧原子形成外围包被。通过分子工程改变M 2+可获得不同弛豫活性的MFe2O4纳米微粒,其中MnFe2O4由于具有易于反磁化的特性,相对其他铁酸盐纳米粒具有更高的饱和磁化强度,被广泛应用在包括药物释放、生物传感及磁共振分子成像等生物医学领域。同时,锰/铁纳米粒中Mn 2+具有顺磁性,可明显缩短T1时间,因而可将锰/铁纳米粒用于磁共振双对比成像。
高温热解法合成铁氧化物纳米粒:第一步,金属盐与配体(如油胺、油酸等)结合形成能溶于非极性溶剂金属配合物;第二步,金属配合物在还原剂存在的条件下逐级升温、分解、还原形成纳米粒的核心,这个步骤决定纳米粒的分散性;第三步,金属离子在纳米粒核心的表面吸附最终形成纳米粒,这个过程决定纳米粒的粒径。

背景:研究已证明,多个纳米粒簇样聚集或增大纳米粒的粒径可增加纳米粒的饱和磁化强度,但粒径的增大会降低纳米粒在体内的有效循环时间。
目的:合成MnFe2O4纳米胶束,检测其应用于磁共振分子影像的可行性。
方法:采用高温热解法合成MnFe2O4纳米粒,以聚乙二醇-聚已内酯两亲嵌段聚合物自组装包裹MnFe2O44纳米粒,形成聚乙二醇-聚已内酯-MnFe2O4纳米胶束。对MnFe2O4纳米粒及聚乙二醇-聚已内酯-MnFe2O4纳米胶束的粒径、形态、包被物、铁/锰构成比、分散性等参数进行表征。将不同铁浓度(0,0.01,0.02,0.03,0.04,0.06,0.08,0.1,0.2,0.4,0.6,0.8 mmol/L)的聚乙二醇-聚已内酯-MnFe2O4纳米胶束或聚乙二醇-聚已内酯-Fe3O4溶液放于EP管中,利用磁共振测量弛豫率。
结果与结论:①MnFe2O4纳米粒呈单分散性,粒径约11 nm,Zeta粒径为(11.18±1.72) nm,铁/锰摩尔构成比为2.13∶1;聚乙二醇-聚已内酯-MnFe2O4纳米胶束由十几个到数十个纳米粒聚集呈团状或簇状,粒径为52-86 nm,zeta粒径为(78.8±12.4) nm;②聚乙二醇-聚已内酯-MnFe2O4纳米胶束或聚乙二醇-聚已内酯-Fe3O4的信号变化趋势相似,随着铁浓度的增加,T1WI信号强度先升高后降低;T2WI信号强度逐渐降低,且在T2*WI信号强度降低更明显;③结果表明,聚乙二醇-聚已内酯-MnFe2O4纳米胶束粒径适中,单分散性好,T2弛豫效能强,有望作为敏感的T2WI对比剂应用于磁共振分子影像。

关键词: 生物材料, 纳米材料, 纳米胶束, MnFe2O4, 磁共振成像, 分子影像, 国家自然科学基金

Abstract:

BACKGROUND: Studies have shown that the saturation magnetization of nanoparticles can be increased by increasing of particle size of nanoparticles or cluster-like aggregation of multiple nanoparticles. But the increased particle size can reduce the cycle time of nanoparticles in the body.
OBJECTIVE: To synthesize MnFe2O4  nanomicelles and explore the feasibility of its application in magnetic resonance molecular imaging.
METHODS: MnFe2O4  nanoparticles were synthesized using thermal decomposition method and self-assembled with polyethylene glycol-polycaprolactone amphiphilic diblock copolymers (PEG-PCL) to construct PEG-PCL-MnFe2O4  nanomicelles. The characteristics of the MnFe2O4 nanoparticles and nanomicelles were tested. Then, MnFe2O4  nanoparticles and nanomicelles at different iron concentrations (0, 0.01, 0.02, 0.03, 0.04, 0.06, 0.08, 0.1, 0.2, 0.4, 0.6, 0.8 mmol/L) were placed into EP tubes. Relaxation rate of the nanomicelles were measured using magnetic resonance scanner.
RESULTS AND CONCLUSION: (1) MnFe2O4  nanoparticles appeared as round under transmission electron microscopy. The size of nanoparticles was 11 nm with good monodispersion. The Zeta-particle size was (11.18±1.72) nm. The molar ratio of Fe/Mn was 2.13:1. The size of PEG-PCL-MnFe2O4  nanomicelles ranged from 52 to 86 nm, with a mean Zeta-particle size of (78.8±12.4) nm. (2) The signal intensity (SI) change of PEG-PCL-MnFe2O4  nanomicelles and PEG-PCL-Fe3O4 nanomicelles shared similar trend according to iron concentration. With the increasing of iron concentration, SI first increased and then decreased in T1WI, and it gradually decreased in T2WI and T2*WI. The SI changes in T2*WI were significantly stronger than that in T2WI and T1WI. Taken together, our results show that PEG-PCL-MnFe2O4 nanomicelles are expected to perform as a sensitive contrast agent used in T2WI as their moderate particle size, good monodisperse and strong T2 relaxation.

Key words: Nanostructures, Magnetic Resonance Imaging, Tissue Engineering

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