Nanolipolee-007, a Novel Nanoparticle-Based Drug Containing Leelamine for the Treatment of Melanoma

Abstract

Malignant melanoma is a difficult cancer to treat due to the rapid development of resistance to drugs targeting single proteins. One response to this observation is to identify single pharmacological agents that due to a unique mechanism of action simultaneously target multiple key pathways involved in melanoma development. To develop a single nanoparticle-based agent targeting the PI3 kinase, STAT3 and MAP kinase signaling pathways, a natural product library was screened, identifying leelamine, as a potential inhibitor. To overcome the poor bioavailability of leelamine in animals and lethality when administered intravenously, a nanoliposomal-based delivery system has been developed called Nanolipolee-007, which stably loads 60% of the compound. The nanoparticle was as effective at killing melanoma cells as leelamine dissolved in DMSO and was 4.5-fold more effective at killing cultured melanoma cell survival compared to normal cells. Mechanistically, Nanolipolee-007 inhibited PI3K/Akt, STAT3 and MAPK signaling mediated through inhibition of cholesterol transport shutting down these key pathways. Nanolipolee-007 inhibited the growth of preexisting xenografted melanoma tumors by an average of 64% by decreasing cellular proliferation, reducing tumor vascularization, and increasing cellular apoptosis, with negligible toxicity. Thus, a unique clinical viable nanoparticle based drug has been developed containing leelamine for the treatment of melanoma that acts by inhibiting the activity of major signaling pathways regulating the development of this disease.

Nanoparticle-Based Celecoxib and Plumbagin for the Synergistic Treatment of Melanoma

“…To identify the optimal lipid formulation to enable loading of sufficient quantities of Celecoxib or Plumbagin into liposomes, several formulations were evaluated and results assessed for size, zeta potential, membrane fluidity and surface hydration (28). A PEGylated liposomal system made of 95:5 mol % for ePC: DPPE PEG-2000 was selected to form a stable liposome ~70 nm in size.…”

“…Solvent was removed and mixture dried under nitrogen gas followed by resuspension in sterile saline solution or water at 60°C with vortexing every 5 minutes over a 20-minute period followed by sonication and extrusion at 60°C through a 100-nm polycarbonate membrane using Avanti Mini Extruder (Avanti Polar Lipids). The particle size and zeta potential were measured using a Malvern Zetasizer (Malvern Instruments) (28). …”

“…During this period, no aggregation or precipitation of the liposomes was observed. Assessing stability involved comparing size and zeta potential using the Malvern Zetasizer as well as assessing efficacy for killing UACC 903 melanoma cells using the MTS assay (28). …”

“…Tumor kinetics were measured by subcutaneous injection of 1X10 6 UACC 903 or 1205 Lu cells were injected above both left and right rib cages of 4–6 week-old female Athymic-Foxn1 nu nude mice (Harlan Sprague Dawley) (28, 29). Six days later, when a fully vascularized tumor had formed, mice were randomly divided into 7 different groups and treated intravenously on alternate days for 3–4 weeks.…”

“…An oral formulation of these agents is not feasible due to drug incompatibility involving solubility, bioavailability and toxicity (26–28). In this study, a single nanoparticle has been developed called CelePlum-777, containing Celecoxib and Plumbagin.…”