Soft Active Materials Laboratory, Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 27708, USA.
Proc Natl Acad Sci U S A. 2011 Jan 4;108(1):67-72. doi: 10.1073/pnas.1007862108. Epub 2010 Dec 13.
Porous biomaterials have been widely used as scaffolds in tissue engineering and cell-based therapies. The release of biological agents from conventional porous scaffolds is typically governed by molecular diffusion, material degradation, and cell migration, which do not allow for dynamic external regulation. We present a new active porous scaffold that can be remotely controlled by a magnetic field to deliver various biological agents on demand. The active porous scaffold, in the form of a macroporous ferrogel, gives a large deformation and volume change of over 70% under a moderate magnetic field. The deformation and volume variation allows a new mechanism to trigger and enhance the release of various drugs including mitoxantrone, plasmid DNA, and a chemokine from the scaffold. The porous scaffold can also act as a depot of various cells, whose release can be controlled by external magnetic fields.
多孔生物材料已被广泛用作组织工程和基于细胞的治疗中的支架。传统多孔支架中生物制剂的释放通常受分子扩散、材料降解和细胞迁移的控制，这些控制方式不允许进行动态的外部调节。我们提出了一种新的主动多孔支架，它可以通过磁场远程控制，按需释放各种生物制剂。主动多孔支架采用大孔铁凝胶的形式，在适度的磁场下可产生超过 70%的大变形和体积变化。这种变形和体积变化提供了一种新的机制来触发和增强包括米托蒽醌、质粒 DNA 和趋化因子在内的各种药物从支架中的释放。多孔支架还可以作为各种细胞的储存库，其释放可以通过外部磁场来控制。
