Ultrasound for accurate drug delivery
Conventional chemotherapy uses toxic chemical substances that damage rapidly dividing cells, a characteristic of cancer cells. These substances can permeate the whole body and can also damage healthy. The EU-funded 'Ultrasound activated nano-encapsulated targeted drug delivery and tumour cell poration' (NANOPORATION) project focused on new methods of directed drug delivery exclusively to tumours. Objectives included the development of a new treatment, whereby reduced dosage of existing anti-cancer drugs is achieved with more effective tumour cell uptake. Researchers optimised nano-drug carriers to improve specific encapsulation properties for different anti-cancer drugs: Doxorubicin, Taxol, Camptothecin and Mitoxantrone. The results of optimisation were verified thorough in vitro release under hyperthermia and sonication conditions. The final kinetics study in vivo was performed by ultrasound under magnetic resonance (MR) imaging guidance. In vitro experiments have carried out for researching the kinetics of uptake of the drugs by human carcinoma cell lines (MCF7, A375M, PANC-1, PC-3 and KB). Cytotoxicity was measured using standard techniques and the separation of thermal and mechanical (bubble-mediated) effects were investigated.protocols were explored using in vivo mouse models. The scientists monitored immune-compromised mice with human xenograft tumours (colon carcinoma HCT116) to measure tumour growth rate. MR imaging in vivo verified the best MRI parameters. To encourage and strengthen the transfer of knowledge, two summer schools were organised during the project. Five publications presented project results and NANOPORATION has been widely recognised in the international community. The project has proved that using the developed technique, anti-cancer substances in nano-capsules could be delivered only when focused ultrasound is applied. This reduces the potential harmful side effects of chemotherapy and increases its efficacy which may lead to higher survival rates and enhanced quality of life for patients.
Keywords
Drug delivery, nano-drug carrier, ultrasound, cell poration, tumour, nano-capsule