|Start date:||August 10, 2018 at 11:30|
Nanomedicine and ultrasound for treatment of cancer and brain disease
Chemotherapy is limited by inadequate delivery to the tumor and severe side-effects due to accumulation in healthy tissues. Encapsulation of drugs in nanoparticles can enable a more targeted delivery, improved efficacy and reduced toxicity. However, delivery of nanoparticles is often insufficient due to various biological barriers in the tumor. Drug delivery to the brain is also severely restricted due to the blood-brain barrier, limiting treatment of a range of brain diseases. Ultrasound in combination with microbubbles has emerged as a promising method to enhance delivery of nanomedicines. The biomechanical effects from the oscillating microbubbles enhance permeability of the vascular wall and improve extravasation and distribution of the nanoparticles in the tumor, resulting in enhanced therapeutic efficacy. We investigated two novel microbubble-platforms; a multifunctional drug delivery system consisting of microbubbles stabilized by nanoparticles, and another highly interesting system based on clusters of microbubbles and microdroplets which phase shift and turn into large microbubbles that temporarily block the capillaries. We demonstrated increased uptake and distribution of nanomedicines in tumors in mice, leading to increased survival. The same technique can also be used to open the blood-brain barrier in a non-invasive, localized and reversible manner, and we have shown that the two microbubble-platforms can also be used to deliver drugs to the brain. We are now investigating the underlying mechanisms, which will enable us to further optimize the treatment, and to move ultrasound-mediated delivery of drugs closer to clinical practice.