Abstract 816: Biological evaluation of novel stearoyl gemcitabine nanoparticles in primary pancreatic cancer cells and PDX mice tumor models
Authors: Frimpong Esther K. , Inkoom Andriana , Ndemazie Nkafu B. , Bulusu Raviteja , Okoro Joy C. , Han Bo , Trevino Jose , Agyare Edward 
Published: April 2023

Purpose: This study aimed to improve the systemic stability and enhance the anticancer activity of gemcitabine (Gem) by modifying Gem with stearic acid to form 4-N-stearoylGem (4NSG). The 4NSG compound was formulated into solid lipid nanoparticles and tested against patient-derived pancreatic cancer (PCa) cell lines and patient-derived xenograft (PDX) mice bearing subcutaneous tumors.

Methods: Gem was modified by linking the 4-amino group of Gem and stearoyl acyl derivative to form 4-(N)-stearoyl-gemcitabine (4NSG). 4NSG was characterized using high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), and elemental analysis. 4NSG was developed into solid lipid nanoparticles (4NSG-SLN) and characterized using a particle size analyzer. Patient-derived primary PCa cells (PPCL-46 and PPCL-68) were treated with GemHCl and 4NSG-SLN. Cytotoxicity, cell migration, and cell-cycle studies were performed to determine the effectiveness of 4NSG-SLN against primary PCa cell lines. We performed antitumor efficacy testing using GemHCl and 4NSG-SLN in PDX mice bearing subcutaneous pancreatic tumors.

Results: Analysis of the H-NMR spectra displayed an amide bond at 10.88 ppm, confirming the conjugated bond between the 4-amino group of Gem and stearic acid. The purity of 4NSG was 99.8%. The hydrodynamic diameter (particle size) of 4NSG-SLN was 82±2.3nm, while the blank nanoparticle (SLN) was found to be 35 ± 4.3 nm. The half-maximal inhibitory concentration of 4NSG-SLN-treated PPCL-46 (IC50 =12 ± 2.1µM) and PPCL-68 cultures (IC50 =22 ± 2.6µM) showed higher cytotoxic activity compared with GemHCl-treated PPCL-46 and PPCL-68 cultures respectively (IC50 = 56 ± 2.4 µM, IC50 = 57 ± 1.5 µM, p-value: p&lt;0.001). Our migration study showed 4NSG-SLN treated PPCL-46 cells at 5μΜ concentrations significantly reduced cell mobility towards the wound area with (28 ± 3.5) number of cells migrated compared to GemHCl treatment which showed (120 ± 3.8). The cell-cycle analysis showed that 4NSG-SLN treated PPCL-46 cells at 5μΜ concentration had a higher G1 population (78.25%) than GemHCl (72.75%). 4NSG-SLN may have triggered apoptosis in PPCL-46 cells (2.45%) at 20μΜ in the S and G2/M phases compared to GemHCl treatments which showed a higher cell population of (9.54%).4NSG-SLN treated PDX mice exhibited a two-fold decrease in tumor growth compared to GemHCl-treated PDX mice bearing tumors.

Conclusion: This study reveals that 4NSG-SLNs may potentially prolong Gem's systemic circulation, increase its bioavailability, and, most importantly, enhance the therapeutic efficacy of Gem in the treatment of PCa.

Citation Format: Esther K. Frimpong, Andriana Inkoom, Nkafu B. Ndemazie, Raviteja Bulusu, Joy C. Okoro, Bo Han, Jose Trevino, Edward Agyare. Biological evaluation of novel stearoyl gemcitabine nanoparticles in primary pancreatic cancer cells and PDX mice tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 816.