Solid Lipid Nanoparticles: Tuneable Anti-Cancer Gene/Drug Delivery Systems

With the advent of multifunctional nano delivery systems, simultaneous imaging and therapy aspires to detect and treat tumors at a very early stage with promising out‐ comes. In this context, numerous anti-cancer drug/gene delivery systems have been ex‐ plored with the primary aim to increase the treatment efficacy without compromising safety. Secondary goals include enhancing bioavailability, specific targeting, apart from the enhanced stability of the formulation [1]. The multifaceted applications of nanoparti‐ cles are the direct result of their ability to deliver high pay loads of drugs or biomarkers to the desired sites within the body. Design and development of tumor specific nanopar‐ ticles could significantly amplify the delivering capacity to a specific target of interest, without affecting healthy cells [2]. Technological advances in nanomaterials and nano‐ technology have paved the way for several carriers such as liposomes [3], dendrimers [4], and micelles [5], solid lipid nanoparticles (SLN) [6] and recently nanostructured lipid carriers [1, 7]. Polymeric micelles, or nanosized (~10–100 nm) supramolecular constructs composed of amphiphilic block-copolymers, are emerging as powerful drug delivery ve‐ hicles for hydrophobic drugs. Liposomes are currently the most popular nanosized drug delivery systems, with one or several lipid bilayers enclosing an aqueous core. Liposomeencapsulated formulations of doxorubicin earlier approved for the treatment of Kaposi’s sarcoma, are now used against breast cancer and refractory ovarian cancer. Breast cancer in particular has been the focus of many studies involving liposome-based chemothera‐ peutics, in part due to the clinical success of various drugs such as Doxil, which is a lip‐ osomal formulation currently used to treat recurrent breast cancer [7]. The anthracycline doxorubicin is the active cytotoxic agent and is contained within the internal aqueous core of the liposome. The encapsulation of doxorubicin within liposomes significantly re‐