School of Chemical and Biomedical Engineering, Nanyang Technological University, 637459, Singapore.
J Control Release. 2010 Jun 1;144(2):203-12. doi: 10.1016/j.jconrel.2010.02.003. Epub 2010 Feb 6.
SiRNA delivery has found useful applications particularly as therapeutic agents against genetic diseases. Currently, the delivery of siRNA typically takes the form of nanoparticles. In order to expand the applications of these potent but labile molecules for long-term use required by tissue engineering and regenerative medicine, alternative delivery vehicles are required. This work presents a scaffold-mediated approach to siRNA delivery. By encapsulating siRNA within polycaprolactone (PCL) nanofibers (300-400nm in diameter) controlled release of intact siRNA could be achieved for at least 28days under physiological conditions. The successful transfection of HEK 293 cells with GAPDH siRNA released from fibrous scaffolds at day 5, 15 and 30 demonstrated that the encapsulated molecules remained bioactive throughout the period of sustained release, providing silencing efficiency of 61-81% that was comparable to conventional siRNA transfection. Direct seeding of cells on these biofunctional scaffolds, with and without transfection reagent, demonstrated enhanced cellular uptake and efficient GAPDH gene-silencing. This work demonstrates the potential of nanofibrous scaffold-mediated siRNA delivery for long-term gene-silencing applications. The combination of topographical features provided by nanofibrous scaffolds may provide synergistic contact guidance and biochemical signals to mediate and support cellular development in regenerative medicine.
siRNA 递送在治疗遗传疾病方面的应用已经得到了广泛的关注。目前，siRNA 的递送通常采用纳米颗粒的形式。为了将这些有效的但不稳定的分子应用于组织工程和再生医学所需的长期使用，需要替代的递送载体。本研究提出了一种基于支架的 siRNA 递送方法。通过将 siRNA 包裹在聚己内酯（PCL）纳米纤维（直径 300-400nm）中，可以在生理条件下至少 28 天内实现完整 siRNA 的控制释放。从纤维支架中释放的 GAPDH siRNA 在第 5、15 和 30 天成功转染 HEK 293 细胞，表明包裹的分子在整个持续释放期间保持生物活性，提供了 61-81%的沉默效率，与传统的 siRNA 转染相当。直接在这些生物功能支架上种植细胞，无论是否转染试剂，都显示出增强的细胞摄取和有效的 GAPDH 基因沉默。本研究证明了纳米纤维支架介导的 siRNA 递送在长期基因沉默应用中的潜力。纳米纤维支架提供的形貌特征的组合可能提供协同的接触引导和生化信号，以介导和支持再生医学中的细胞发育。
