聚电解质微胶囊磁力挤压形变控制释放的研究

Release of core material upon mechanical force is one of the most widely used methods in controlled release applications of microcapsules. However, the drawback is that the core content can only be delivered by rupturing the microcapsules shell, switching between "ON" and "OFF" two states makes the releasing speed cannot be precisely controlled. The aim of this study is to prepare elastic polyelectrolyte microcapsules incorporate with magnetic nanoparticles. When exposing the microcapsules to the external magnetic field, the embedded nanoparticles in the microcapsule shell are attracted, which causes the container wall to compress the microcapsules, subsequently deform the shell. Deformation of the shell will then induce the change of the osmotic pressure of the microcapsules, since the shell is permeable, the core material will be diffused through the shell. Therefore, by verifying the elasticity of the polyelectrolyte shell and the strength of the magnetic field, as so that the shell deformation is finely tunable, controlling the release speed of the core materials can be achieved. On the basis of the traditional slow diffusion and simple rupture of the microcapsules, our strategy combines the advantages of both above methods, offering a speed controllable and site specific release means for the microcapsules. Moreover, magnetic field is environmentally benign and biocompatible, which enables the applications in biomedical and drug delivery areas.

机械力控制微胶囊释放是被广泛采用的一种控制微胶囊释放的手段，但都是在闭合-破裂这两种形态间进行"0-1"的开关式控制，缺乏精细调控手段。本课题拟制备嵌入磁性纳米颗粒的弹性聚电解质微胶囊，利用磁场对囊壁中的磁性颗粒作用，当微胶囊附着在支撑平面上时，磁场对囊壁中磁性颗粒的吸引力可以作用于囊壁聚电解质膜，对微胶囊产生挤压作用，控制囊壁聚电解质材料和磁力大小，使微胶囊在相当范围内被挤压变形而不破裂，利用微胶囊形变所导致的内部压力改变来控制芯材物质从囊壁通道的释放速度。这种聚电解质微胶囊调控释放模式既不同于传统只改变释放通道的被动式扩散模式,也不同于简单的一次性破坏释放模式，而是一种新型的、调控性更强的主动式挤压释放。而且通过磁场调控对于在生物体内进行靶向药物传输和药物可控释放也更具有实际应用价值。

机械力控制微胶囊释放是被广泛采用的一种控制微胶囊释放的手段，但都是在闭合-破裂这两种形态间进行“0-1”的开关式控制，缺乏精细调控手段。本课题拟制备嵌入磁性纳米颗粒的弹性聚电解质微胶囊，利用磁场对囊壁中的磁性颗粒作用，当微胶囊附着在支撑平面上时，磁场对囊壁中磁性颗粒的吸引力可以作用于囊壁聚电解质膜，对微胶囊产生挤压作用，控制囊壁聚电解质材料和磁力大小，使微胶囊在相当范围内被挤压变形而不破裂，利用微胶囊形变所导致的内部压力改变来控制芯材物质从囊壁通道的释放速度。这种聚电解质微胶囊调控释放模式既不同于传统只改变释放通道的被动式扩散模式,也不同于简单的一次性破坏释放模式，而是一种新型的、调控性更强的主动式挤压释放。而且通过磁场调控对于在生物体内进行靶向药物传输和药物可控释放也更具有实际应用价值。