Controlled pulsatile drug release from a ferrogel by a high-frequency magnetic field
Controlled pulsatile drug release from a ferrogel by a high-frequency magnetic field
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DOI：
10.1021/ma0707584
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发表时间：
2007-09-18
期刊：
影响因子：
5.5
通讯作者：
Chen, San-Yuan
中科院分区：
文献类型：
--
作者：
Hu, Shang-Hsiu;Liu, Ting-Yu;Chen, San-Yuan
聚合物刺激响应型控释药物由于具有比传统给药途径更好的给药效率和靶向性治疗等优点而受到人们的极大关注。利用这些优势，人们已经成功地提出了将活性药物分子与宿主材料相结合，进行理想的药物释放控制的研究。以前的许多研究报道了对特定刺激的反应，如温度、1-3pH、4、5电场、6、7机械信号、8和超声波。9 Ehrick等人报道了一种含有蛋白质的水凝胶的最新成果，10解决了由于嵌入的钙调蛋白与生物活性物质相互作用的构象变化而触发的刺激敏感水凝胶。这种从感知驱动到机械作用的转变是新颖的，但作为一种突发控制的药物输送系统，它可能很难在治疗剂量中达到高精度和高灵敏度。使用磁场来调节药物从聚合物骨架中的释放是先前开发的。11-13萨斯拉夫斯基等人。报道了利用振荡磁场脉冲释放胰岛素的海藻酸化微球。14海藻酸锶铁氧体微球在无磁场的情况下，胰岛素的释放速率有所提高。最近，一种嵌入Co/Au的聚电解质微胶囊利用100-300赫兹和1200Oe的外加磁场来增加其对大分子的渗透率。15在以前的研究中，已经表征了具有直流(DC)磁敏特性的铁凝胶，并且在施加外部直流磁场时，铁凝胶的药物释放量被有效地限制。16、17到目前为止，关于高频磁场(HFMF)下药物控制释放的研究很少。药物的实时突释需要一个快速反应的药物释放系统，在身体需要时“注射”精确剂量的药物，并在注射后立即“停止”或“减缓”释放；然而，使用传统的刺激反应水凝胶很难轻易做到这一点。一种可控制的脉冲式给药装置，具有可重复给药的能力和治疗效果的精确度，在临床上是理想的。因此，本文报道了一种由明胶和直径为10-250 nm的磁性纳米颗粒(纳米磁铁)组成的具有机械可靠性和柔性的杂化结构的高频磁场触发的脉动给药铁凝胶。此外，在高频磁刺激的循环暴露下，实现了从铁氧体以期望的精度进行高度可控和可重复的猝发释放。
Stimuli-responsive controlled release drug from polymeric devices has been received great attention, as it provides advantages such as better delivery efficiency and site-specific therapy over the conventional routes of drug delivery. By making use of these advantages, a number of studies have been successfully proposed to integrate active drug molecules and host materials, to manipulate drug release desirably. Many previous studies have been reported in response to specific stimuli, such as temperature, 1-3 pH, 4, 5 electric field, 6, 7 mechanical signal, 8 and ultrasound. 9 A very recent achievement of a protein-containing hydrogel, reported by Ehrick et al., 10 addressed the stimuli-sensitive hydrogel that can be triggered as a result of the conformational change of the embedded calmodulin protein interacting to bioactive agents. Such a transfer from sensing actuation to mechanical action is novel, but it may be hard for it to reach high accuracy and sensitivity in therapeutic dosing as a burst-controlled drug delivery system. The use of a magnetic field to modulate drug release from polymeric matrices was previously developed. 11-13 Saslawski et al. reported the alginated microspheres for pulsed release of insulin by an oscillating magnetic field. 14 The release rate of insulin from alginate-strontium ferrite microspheres was enhanced in the absence of a magnetic field. Recently, a polyelectrolyte microcapsule embedded with Co/Au used external magnetic fields of 100-300 Hz and 1200 Oe to increase its permeability to macromolecules. 15 In previous studies, a ferrogel with direct current (dc) magnetic-sensitive properties has been characterized and the amount of drug released from the ferrogel was effectively restricted while applying an external dc magnetic field. 16, 17 So far, little investigation has been addressed on the controlled drug release under high-frequency magnetic fields (HFMF). A real-time burst release of drug needs a fast-responsive drug release system to “inject” a precise dose of drug when the body needs it and to “stop” or “slow” the release right after the injection; however, it is hard to easily achieve this with traditional stimuli-responsive hydrogels. A controllable pulsatile-type drug delivery device with repeatable dosing ability in therapeutically effective precision is clinically desirable. Therefore, in this communication, a high-frequency magnetic field (HFMF) triggered pulsatile drug delivery ferrogel with a mechanically reliable and flexible hybrid structure composed of gelatin and magnetic nanoparticles (nanomagnets) of 10-250 nm in diameter is reported. Furthermore, under cyclic exposures to the high-frequency magnetic stimuli, a highly controllable and repeatable burst release with desirable precision from the ferrogels is achieved.