Evaluation of Anticancer Activity of Zhubech, a New 5-FU Analog Liposomal Formulation, against Pancreatic Cancer.

Pancreatic cancer is projected to be the second leading cause of cancer-related death by 2030 in the US. The benefits of the most common systemic therapy for various pancreatic cancers have been masked by high drug toxicities, adverse reactions, and resistance. The use of nanocarriers such as liposomes to overcome these unwanted effects has become very popular. This study aims to formulate 1,3-bistertrahydrofuran-2yl-5FU (MFU)-loaded liposomal nanoparticles (Zhubech) and to evaluate itsstability, release kinetics, in vitro and in vivo anticancer activities, and biodistribution in different tissues. Particle size and zeta potential were determined using a particle size analyzer, while cellular uptake of rhodamine-entrapped liposomal nanoparticles (Rho-LnPs) was determined by confocal microscopy. Gadolinium hexanoate (Gd-Hex) was synthesized and entrapped into the liposomal nanoparticle (LnP) (Gd-Hex-LnP), as a model contrast agent, to evaluate gadolinium biodistribution and accumulation by LnPs in vivo using inductively coupled plasma mass spectrometry (ICP-MS). The mean hydrodynamic diameters of blank LnPs and Zhubech were 90.0 ± 0.65 nm and 124.9 ± 3.2 nm, respectively. The hydrodynamic diameter of Zhubech was found to be highly stable at 4 °C and 25 °C for 30 days in solution. In vitro drug release of MFU from Zhubech formulation exhibited the Higuchi model (R2 value = 0.95). Both Miapaca-2 and Panc-1 treated with Zhubech showed reduced viability, two- or four-fold lower than that of MFU-treated cells in 3D spheroid (IC50Zhubech = 3.4 ± 1.0 µM vs. IC50MFU = 6.8 ± 1.1 µM) and organoid (IC50Zhubech = 9.8 ± 1.4 µM vs. IC50MFU = 42.3 ± 1.0 µM) culture models. Confocal imaging confirmed a high uptake of rhodamine-entrapped LnP by Panc-1 cells in a time-dependent manner. Tumor-efficacy studies in a PDX bearing mouse model revealed a more than 9-fold decrease in mean tumor volumes in Zhubech-treated (108 ± 13.5 mm3) compared to 5-FU-treated (1107 ± 116.2 mm3) animals, respectively. This study demonstrates that Zhubech may be a potential candidate for delivering drugs for pancreatic cancer treatment.

Application of smart solid lipid nanoparticles to enhance the efficacy of 5-fluorouracil in the treatment of colorectal cancer.

5-Fluorouracil (5-FU) is a standard treatment option for colorectal cancer (CRC) but its rapid metabolism and systemic instability (short half-life) has hindered its therapeutic efficacy. The objective of this study was to develop a novel drug delivery system, solid lipid nanoparticle (SLN), capable of delivering high payload of 5-FU to treat CRC. The rational was to improve 5FU-nanocarrier compatibility and therapeutic efficacy. The SLN-loaded 5-FU was developed by utilizing a Strategic and unique Method to Advance and Refine the Treatment (SMART) of CRC through hot and cold homogenization approach. The SLN was made of unique PEGylated lipids and combination of the surfactants. Cytotoxicity studies, clonogenic assay, flow cytometry and confocal imaging were conducted to evaluate the effectiveness and cellular uptake of 5FU-SLN4 in HCT-116 cancer cells. Pharmacokinetic (PK) parameters and receptor expressions were determined while tumor efficacy studies were conducted on mouse bearing subcutaneous HCT-116 cancer. Among the all the formulations, 5FU-SLN4 was the most effective with particle size of was 263 ± 3 nm, zeta potential was 0.1 ± 0.02 and entrapment efficiency of 81 ± 10%. The IC50 value of 5FU-SLN4 (7.4 ± 0.02 µM) was 2.3 fold low compared with 5-FU (17.7 ± 0.03 µM). For tumor efficacy studies, 5FU-SLN4 significantly inhibited tumor growth in comparison to 5-FU while area-under plasma concentration-time curve (AUC) of 5FU-SLN4 was 3.6 fold high compared with 5-FU. HER2 receptors expression were markedly reduced in 5-FU-SLN4 treated mice compared with 5FU and liver and kidney tissues showed no toxicity at dose of 20 mg/kg. 5FU-SLN4 was highly cytotoxic against HCT-116 cells and significantly inhibited subcutaneous tumor growth in mice compared with 5-FU. This emphasizes the significance of developing a smart nano-delivery system to optimize the delivery efficiency of anticancer drugs to tumors.

Smart thermosensitive liposomes for effective solid tumor therapy and in vivo imaging.

In numerous studies, liposomes have been used to deliver anticancer drugs such as doxorubicin to local heat-triggered tumor. Here, we investigate: (i) the ability of thermosensitive liposomal nanoparticle (TSLnp) as a delivery system to deliver poorly membrane-permeable anticancer drug, gemcitabine (Gem) to solid pancreatic tumor with the aid of local mild hyperthermia and, (ii) the possibility of using gadolinium (Magnevist®) loaded-TSLnps (Gd-TSLnps) to increase magnetic resonance imaging (MRI) contrast in solid tumor. In this study, we developed and tested gemcitabine-loaded thermosensitive liposomal nanoparticles (Gem-TSLnps) and gadolinium-loaded thermosensitive liposomal nanoparticles (Gd-TSLnps) both in in-vitro and in-vivo. The TSLnps exhibited temperature-dependent release of Gem, at 40-42°C, 65% of Gem was released within 10 min, whereas < 23% Gem leakage occurred at 37°C after a period of 2 h. The pharmacokinetic parameters and tissue distribution of both Gem-TSLnps and Gd-TSLnps were significantly greater compared with free Gem and Gd, while Gem-TSLnps plasma clearance was reduced by 17-fold and that of Gd-TSLpns was decreased by 2-fold. Area under the plasma concentration time curve (AUC) of Gem-TSLnps (35.17± 0.04 µghr/mL) was significantly higher than that of free Gem (2.09 ± 0.01 µghr/mL) whereas, AUC of Gd-TSLnps was higher than free Gd by 3.9 fold high. TSLnps showed significant Gem accumulation in heated tumor relative to free Gem. Similar trend of increased Gd-TSLnps accumulation was observed in non-heated tumor compared to that of free Gd; however, no significant difference in MRI contrast enhancement between free Gd and Gd-TSLnps ex-vivo tumor images was observed. Despite Gem-TSLnps dose being half of free Gem dose, antitumor efficacy of Gem-TSLnps was comparable to that of free Gem(Gem-TSLnps 10 mg Gem/kg compared with free Gem 20 mg/kg). Overall, the findings suggest that TSLnps may be used to improve Gem delivery and enhance its antitumor activity. However, the formulation of Gd-TSLnp needs to be fully optimized to significantly enhance MRI contrast in tumor.