Ultrasound targeted microbubble destruction using docetaxel and Rose Bengal loaded Microbubbles for targeted Chemo-Sonodynamic therapy treatment of prostate cancer.

Docetaxel (DTX) chemotherapy is commonly used in the treatment of patients with advanced prostate cancer demonstrating modest improvements in survival. As these patients are often elderly and the chemotherapy treatment is not targeted, it is often poorly tolerated. More targeted approaches that increase therapeutic efficacy yet reduce the amount of toxic chemotherapy administered are needed. In this manuscript, we investigate the potential of ultrasound targeted microbubble destruction (UTMD) to deliver a combination of docetaxel chemotherapy and Rose Bengal mediated sonodynamic therapy (SDT) in pre-clinical prostate cancer models. A Rose Bengal modified phospholipid was synthesized and used as a component lipid to prepare a microbubble (MB) formulation that was also loaded with DTX. The DTX-MB-RB formulation was used in the UTMD mediated treatment of androgen sensitive and androgen resistant 3D spheroid and murine models of prostate cancer. Results from the 3D spheroid experiments showed UTMD mediated DTX-MB-RB chemo-sonodynamic therapy to be significantly more effective at reducing cell viability than UTMD mediated DTX or SDT treatment alone. In an androgen sensitive murine model of prostate cancer, UTMD mediated DTX-MB-RB chemo-sonodynamic therapy was as effective as androgen deprivation therapy (ADT) at controlling tumour growth. However, when both treatments were combined, a significant improvement in tumour growth delay was observed. In an androgen resistant murine model, UTMD mediated DTX-MB-RB chemo-sonodynamic therapy was significantly more effective than standard DTX monotherapy. Indeed, the DTX dose administered using the DTX-MB-RB formulation was 91% less than standard DTX monotherapy. As a result, UTMD mediated DTX-MB-RB treatment was well tolerated while animals treated with DTX monotherapy displayed significant weight loss which was attributed to acute toxic effects. These results highlight the potential of UTMD mediated DTX-MB-RB chemo-sonodynamic therapy as a targeted, well tolerated alternative treatment for advanced prostate cancer.

Rose Bengal-Amphiphilic Peptide Conjugate for Enhanced Photodynamic Therapy of Malignant Melanoma.

Malignant melanoma is an aggressive skin cancer with poor survival outcomes for patients diagnosed at an advanced stage. While targeted serine/threonine-protein kinase B-Raf (BRAF) and immune checkpoint inhibitors have improved survival outcomes for a proportion of these patients, response rates remain variable. There is a need, therefore, for more effective treatments to bolster the options available for melanoma patients. In this manuscript, we covalently attached Rose Bengal (RB) to the amphipathic peptide (AMP) C(KLAKLAK)2 and determined the effectiveness of the resulting RB-C(KLAKLAK)2 conjugate as a photodynamic therapy (PDT) sensitizer. RB-C(KLAKLAK)2-mediated PDT treatment of subcutaneous B16-F10-Luc2 tumors in C57 mice resulted in lesions that were 479% smaller at the end of the study than animals treated with RB-mediated PDT. The synergistic effect between RB and C(KLAKLAK)2 has been attributed to the AMP sensitizing cells to reactive oxygen species (ROS), making them more susceptible to ROS-induced oxidative stress.

Targeted chemo-sonodynamic therapy treatment of breast tumours using ultrasound responsive microbubbles loaded with paclitaxel, doxorubicin and Rose Bengal.

Mastectomy is a common surgical treatment used in the management of breast cancer but has associated physical and psychological consequences for the patient. Breast conservation surgery (BCS) is an alternative to mastectomy but is only possible when the tumour is of an appropriate size. Neo-adjuvant chemotherapy has been successfully used to downstage tumours and increase the number of patients eligible for BCS. However, the chemotherapies used in this approach are non-targeted and often result in significant side effects to the patient. In this manuscript, we evaluate the potential of ultrasound targeted microbubble destruction (UTMD) to deliver Rose Bengal-mediated sonodynamic therapy (SDT) in combination with paclitaxel (PTX) and doxorubicin (Dox) chemotherapy as a potential treatment for breast cancer. Efficacy of the combined treatment was determined in a three-dimensional (3D) spheroid model of human breast cancer and in a murine model of the disease bearing subcutaneous MCF-7 tumours. The results demonstrated a significant reduction in both the cell viability of spheroids and tumour volume following treatment with the drug loaded microbubbles and ultrasound compared to targets treated with the drug loaded microbubbles alone or a Cremophor EL suspension of PTX and Dox. In addition, the weight of animals that received the microbubble treatment was unchanged throughout the study while a reduction of 12.1% was observed for animals treated with a Cremophor suspension of PTX/Dox. These results suggest that UTMD-mediated chemo-sonodynamic therapy is an efficacious and well tolerated approach for the treatment of breast cancer.