以恒定速率控制药物输送,按顺序,长期以来,人们一直在追求或响应环境条件,以增强治疗分子的功效并最大程度地减少高效药物的副作用。然而,实现药物分子的这种精细控制的递送是不平凡的并且仍然是挑战。我们建议使用微通道来控制速率,序列,和药物递送的pH响应性,以实现高精度和可预测性。在这项研究中,我们引入了基本的药物输送单元,由微储库和微通道组成,它们的长度有变化,宽度,数字,和直线度。释放研究表明,模型药物的释放速率可以通过微通道的设计来调节。药物释放的有限元建模以高精度预测药物递送单元的性能。在微通道中使用可生物降解的聚合物塞也证明了顺序药物递送的可能性。最后,还讨论了微流体单元中药物的pH响应性递送,并通过细胞活力测试进行了证明。
在这项工作中,我们开发了基于微通道的药物递送装置,其释放速率可以通过微通道几何形状的设计来精确计算和控制。尽管在微制造药物递送系统方面取得了许多进展,特别是,基于储层的系统,尚未对使用发布渠道进行系统的调查。在我们的工作中,将等效电路概念应用于微流体系统,以进行更详细的设计和分析。微流体通道被视为电阻器;它们的扩散/电通量可以通过诸如长度,宽度,多个通道/电阻器及其连接。此外,从使用通道几何结构的输送速率控制,证明了用于顺序和pH响应的多功能基于通道的释放系统。
Controlled delivery of drug at a constant rate, in a sequential order, or responsive to environment conditions has been pursued for a long time to enhance the efficacy of therapeutic molecules and to minimize side effects of highly potent drugs. However, achieving such delicately-controlled delivery of a drug molecule is non-trivial and still remains a challenge. We propose the use of microchannels to control the rate, sequence, and pH-responsiveness of drug delivery for high precision and predictability. In this study, we introduce elementary drug delivery units consisting of micro-reservoirs and microchannels that have variations in their lengths, widths, numbers, and straightness. The release study demonstrates that the release rates of model drugs can be modulated by the design of microchannels. Finite element modeling of drug release predicts the performance of the drug delivery units with high accuracy. The possibility of sequential drug delivery is also demonstrated using biodegradable polymer plug in microchannels. Finally, pH-responsive delivery of drugs in microfluidic units is also discussed and demonstrated via cell viability tests.
In this work, we developed microchannel-based drug delivery devices whose release rate could be accurately calculated and controlled by design of microchannel geometry. Although there have been many advances in microfabricated drug delivery systems, in particular, reservoir-based systems, no systematic investigation has been made to utilize the release channels. In our work, an equivalent electrical circuit concept was applied to the microfluidic systems for more detailed design and analysis. A microfluidic channel was regarded as an electrical resistor; their diffusion/electrical flux could be tuned with geometric factors such as length, width, a number of channel/resistor and their connections. Furthermore, from delivery rate control using channel geometry, multifunctional channel-based release systems for sequential and pH-responsive were demonstrated.