Delivering therapeutic agents into the brain via convection-enhanced delivery (CED), a mechanically controlled infusion method, provides an efficient approach to bypass the blood–brain barrier and deliver drugs directly to the targeted focus in the brain. Mathematical methods based on Darcy’s law have been widely adopted to predict drug distribution in the brain to improve the accuracy and reduce the side effects of this technique. However, most of the current studies assume that the hydraulic permeability and porosity of brain tissue are homogeneous and constant during the infusion process, which is less accurate due to the deformability of the axonal structures and the extracellular matrix in brain white matter. To solve this problem, a multiscale model was established in this study, which takes into account the pressure-driven deformation of brain microstructure to quantify the change of local permeability and porosity. The simulation results were corroborated using experiments measuring hydraulic permeability in ovine brain samples. Results show that both hydraulic pressure and drug concentration in the brain would be significantly underestimated by classical Darcy’s law, thus highlighting the great importance of the present multiscale model in providing a better understanding of how drugs transport inside the brain and how brain tissue responds to the infusion pressure. This new method can assist the development of both new drugs for brain diseases and preoperative evaluation techniques for CED surgery, thus helping to improve the efficiency and precision of treatments for brain diseases.
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No. 688279. Daniele Dini would like to acknowledge the support received from the EPSRC under the Established Career Fellowship Grant No. EP/N025954/1. Tian Yuan would also like to acknowledge financial support from CSC Imperial Scholarship. Wenbo Zhan would like to acknowledge the support received from the Children with Cancer UK under the project Children's Brain Tumour Drug Delivery Consortium Grant No. 16-224
- Heterogeneous response
- Brain tissue
- Convection-enhanced delivery
- Multiscale modelling