Breast cancer is a leading cause of cancer deaths among women in the US, with 40 % chance of relapse after treatment. Recent studies outline the role of cancer stem cells (CSCs) in tumor initiation, propagation, and regeneration of cancer. Moreover, it has been established that breast CSCs reside in a quiescent state that makes them more resistant to conventional cancer therapies than bulk cancer cells resulting in tumor relapse. In this study, we establish that CSCs are associated with the overexpression of vasoactive intestinal peptide (VIP) receptors which can be used to actively target these cells. We investigated the potential of using a novel curcumin nanomedicine (C-SSM) surface conjugated with VIP to target and hinder breast cancer with CSCs. Here, we formulated, characterized, and evaluated the feasibility of C-SSM nanomedicine in vitro. We investigated the cytotoxicity of C-SSM on breast cancer cells and CSCs by tumorsphere formation assay. Our results suggest that curcumin can be encapsulated in SSM up to 200 μg/ml with 1 mM lipid concentration. C-SSM nanomedicine is easy to prepare and maintains its original physicochemical properties after lyophilization, with an IC50 that is significantly improved from that of free curcumin (14.2±1.2 vs. 26.1±3.0 μM). Furthermore, C-SSM-VIP resulted in up to 20 % inhibition of tumorsphere formation at a dose of 5 μM. To this end, our findings demonstrate the feasibility of employing our actively targeted nanomedicine as a potential therapy for CSCs-enriched breast cancer.

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Since its discovery, small interfering RNA (siRNA) has been considered a potent tool for modulating gene expression. It has the ability to specifically target proteins via selective degradation of messenger RNA (mRNA) not easily accessed by conventional drugs. Hence, RNA interference (RNAi) therapeutics have great potential in the treatment of many diseases caused by faulty protein expression such as fibrosis and cancer. However, for clinical application siRNA faces a number of obstacles, such as poor in vivo stability, and off-target effects. Here we developed a unique targeted nanomedicine to tackle current siRNA delivery issues by formulating a biocompatible, biodegradable and relatively inexpensive nanocarrier of sterically stabilized phospholipid nanoparticles (SSLNPs). This nanocarrier is capable of incorporating siRNA in its core through self-association with a novel cationic lipid composed of naturally occuring phospholipids and amino acids. This overall assembly protects and delivers sufficient amounts of siRNA to knockdown over-expressed protein in target cells. The siRNA used in this study, targets connective tissue growth factor (CTGF), an important regulator of fibrosis in both hepatic and renal cells. Furthermore, asialoglycoprotein receptors are targeted by attaching the galactosamine ligand to the nanocarries which enhances the uptake of nanoparticles by hepatocytes and renal tubular epithelial cells, the major producers of CTGF in fibrosis. On animals this innovative nanoconstruct, small interfering RNA in sterically stabilized phospholipid nanoparticles (siRNA-SSLNP), showed favorable pharmacokinetic properties and accumulated mostly in hepatic and renal tissues making siRNA-SSLNP a suitable system for targeting liver and kidney fibrotic diseases.