Tumor-targeted polymeric nanostructured lipid carriers with precise ratiometric control over dual-drug loading for combination therapy in non-small-cell lung cancer

Abstract

Gemcitabine (GEM) and paclitaxel (PTX) are effective combination anticancer agents against non-small-cell lung cancer (NSCLC). At the present time, a main challenge of combination treatment is the precision of control that will maximize the combined effects. Here, we report a novel method to load GEM (hydrophilic) and PTX (hydrophobic) into simplex tumor-targeted nanostructured lipid carriers (NLCs) for accurate control of the ratio of the two drugs. We covalently preconjugated the dual drugs through a hydrolyzable ester linker to form drug conjugates. N -acetyl- d -glucosamine (NAG) is a glucose receptor-targeting ligand. We added NAG to the formation of NAG-NLCs. In general, synthesis of poly(6- O -methacryloyl- d -galactopyranose)–GEM/PTX (PMAGP-GEM/PTX) conjugates was demonstrated, and NAG-NLCs were prepared using emulsification and solvent evaporation. NAG-NLCs displayed sphericity with an average diameter of 120.3±1.3 nm, a low polydispersity index of 0.233±0.04, and accurate ratiometric control over the two drugs. A cytotoxicity assay showed that the NAG-NLCs had better antitumor activity on NSCLC cells than normal cells. There was an optimal ratio of the two drugs, exhibiting the best cytotoxicity and combinatorial effects among all the formulations we tested. In comparison with both the free-drug combinations and separately nanopackaged drug conjugates, PMAGP-GEM/PTX NAG-NLCs (3:1) exhibited superior synergism. Flow cytometry and confocal laser scanning microscopy showed that NAG-NLCs exhibited higher uptake efficiency in A549 cells via glucose receptor-mediated endocytosis. This combinatorial delivery system settles problems with ratiometric coloading of hydrophilic and hydrophobic drugs for tumor-targeted combination therapy to achieve maximal anticancer efficacy in NSCLC.

<p>A NAG-Guided Nano-Delivery System for Redox- and pH-Triggered Intracellularly Sequential Drug Release in Cancer Cells</p>

“…Finally, the product was dialyzed with deionized water (MWCO = 4,000 Da), and PTXL-ss-PMAGP-GEM conjugates were obtained after freeze-dried. An optimal molar ratio of GEM and PTXL 3:1 was chosen 28 for the PTXLss-PMAGP-GEM conjugates, and was confirmed by doublewavelength ultraviolet spectrophotometry, following the principle reported in the literature. 30,31 The 1 H-NMR spectra were recorded using deuterated DMSO-d 6 as the solvent.…”

“…The copolymer poly(6-O-methacryloyl-1,2;3,4-di-O-isopropylidene-D-galactopyranose) (PMaIPG) was synthesized via reversible addition-fragmentation chaintransfer (RAFT) polymerization according to our previous report. 28 Briefly, PMaIPG (200 mg) was dissolved in 80% methanoic acid (20 mL) and stirred for 48 h. Distilled water (3 mL) was then added and stirred. The pure PMAGP was obtained by dialyzing followed by freeze-drying (FDU-2110; Rikakikai, Tokyo, Japan).…”

“…As controls, non-disulfide functionalized PTXL-PMAGP -GEM conjugates were also synthesized according to our previous report. 28…”

“…26,27 We have previously found that 3:1 was the optimal molar ratio of GEM and PTXL in treating NSCLC mouse models. 28 In this study, we aimed to investigate the feasibility and effectiveness of a dual-drug-polymer conjugate incorporated in an NLCs system for sequential release of PTXL and GEM within cancer cells using pH in and intracellular GSH as stimuli for treatment NSCLC. Specifically, drug-polymer conjugate PTXL-ss-poly(6-O-methacryloyld-galactopyranose)-GEM (PTXL-ss-PMAGP-GEM) was synthesized.…”

Neochamaejasmin A Induces Mitochondrial-Mediated Apoptosis in Human Hepatoma Cells via ROS-Dependent Activation of the ERK1/2/JNK Signaling Pathway

“…The viabilities of HepG2/BEL-7402 cells were determined with the MTT assay [12][13][14]. The HepG2/BEL-7402 cell suspensions were inoculated into a 96-well plate with 100 μL per well.…”