**Acknowledgements**

antibodies targeted against HER2 or estrogen or any other steroid hormone receptors that are overexpressed in breast cancer and cancer stem cells could be exploited to achieve better targeting, uptake and therapeutic outcomes both *in vivo* and *in vitro*. Multifunctional drug delivery carriers containing antibodies tend to show enhanced eradication of cancer and cancer stem cells, prospect targeting drug delivery systems depend on the discovery

Novel types of targeted cancer therapy like the multifunctional complexes-mediated photodynamic therapy are currently being considered along with other treatments including cancer vaccines, oncolytic virotherapy and immunotherapy [84–85]. The transcription factors that regulate cell mobility, invasion and migration during metastatic tumor stages of breast cancer are becoming attractive and constitute essential molecular targets for future treatment modalities [86, 87]. Hormone receptors remain the most currently used markers in clinical trials and the usage of breast cancer markers BRCA1 and BRCA2 is increasing as seen by numerous report studies [88, 89]. Most of the preclinical studies are performed with cell lines derived from breast cancers, and MCF-7, T-47D and MDA-MB-231 are among the

Cancer, an uncontrolled cell proliferation condition, has become a major health challenge and global killer. The incidence and related treatment facilities are unfortunately determined by the lifestyles and geographic locations of cancer patients. Breast cancer is a common carcinoma that affects the tear-shaped milk glands in women and its classification is been facilitated by the presence or not of certain receptors (HER-2 and HR), which are also to predict the prognosis. Photodynamic therapy is a promising cancer treatment and offers better specific targeting of cancer and limited side-effects, when compared to conventional therapy. Mitochondria, lysosomes and perinuclear areas are reported as the most frequent localization sites for third generations of photosensitizers. The treatment efficiency depends upon the successful light-activation and intersystem conversion into the excited triplet state, only then photosensitizers interact with molecular oxygen to produce reactive oxygen species, toxins responsible for cytodestruction and cell death. If required, Photodynamic can be repeated but the contribution of nanoparticles in combination therapy for cancer and particularly breast cancer, has permitted the successful delivery of therapeutic agents to the targeted tumor site and enhancement of therapeutic effects. When conjugated, they facilitate the delivery of hydrophobic drugs into biological environments, ensure the preservation of the pharmacologic properties of the drugs, and enhance selective targeting to cancer cells through their large surfaces, which can be functionalized with a various kind of components. The use of photodynamic therapy offers controlled conditions with high selectivity to cancer, hence reducing the undesired side-effects seen with conventional treatments. Whether used as main or adjuvant therapy, the aim of combination cancer therapy using photodynamic therapy is to selectively and completely eradicate cancer by targeting and killing both cancer

of cancer stem cell interacting mediators [81–83].

most commonly used [90].

**3. Conclusion**

190 Breast Cancer and Surgery

and cancer stem cells.

The work was conducted at the Laser Research Centre, Faculty of Health Sciences, University of Johannesburg, South Africa. The study was supported by the University Research Council of the University of Johannesburg. This work is based on the research supported by the South African Research Chairs Initiative of the Department of Science and Technology and National Research Foundation of South Africa (Grant No 98337), and the African Laser Centre.
