(M1030-01-01) Engineering of Layer-By-Layer “Smart” Acetate Coated Paclitaxel Loaded Polylactic-Co-Glycolic Acid Nanoparticles to Treat Prostate Cancer In Vitro

Purpose: A targeted (“Smart”) and layer-by-layer nano-delivery system improves chemotherapy’s effectiveness while reducing its side effects. It hypothesized that a layer-by-layer smart nanoparticle (NPs) with a core made of paclitaxel (PTX) -loaded Polylactic-co-glycolic acid (PLGA) NPs and the shell made of Prostate Specific Membrane Antigen (PSMA) ligand can be engineered to potentiate the cytotoxicity of PTX on LNCaP, a metastatic lymph node lesion of human prostate cancer cell line.

Methods: The layer-by-layer smart NPs were engineered using four steps: Step#1, Sodium Acetate (SA) anhydrous is dissolved in glacial acetic acid to make 36 mg/ml of SA/Glacial acetic acid solution for 30 minutes. Step#2, Polylactide-co-glycolide acid (PLGA) and Paclitaxel (PTX) were dissolved in the SA/Glacial acetic acid to make 2%w/v of PLGA solution, 3 mg/mL of PTX solution, respectively. Step#3, Poly(vinyl alcohol) (PVA) was dissolved in an aqueous solution of sodium acetate (36 mg/mL) to make 0.5 %w/v of PVA aqueous solution and subsequently centrifuge to collect the supernatant. The supernatant of PVA aqueous solution (0 .5%w/v, 4 mL) was added to 4 mL of PLGA/PTX solution, as explained in step#2. The nanoparticles spontaneously formed upon mixing the two solutions (i.e., nanoprecipitation) and were subsequently freeze-dried. This lyophilized nanoparticle is commonly known as a PTX-loaded PLGA nanoparticle. Finally, after freeze-drying, the nanoparticles were resuspended in 1%v/v of an aqueous ethyl phenyl phosphinate prostate-specific membrane antigen ligands and subsequently freeze-dried for the second time. This nanoparticle was the layer-by-layer Smart acetate-coated Paclitaxel-loaded polylactic-co-glycolic Acid Nanoparticles. The HPLC was used to assess the chemical stability of PTX. The particle mean diameter and morphology were analyzed using Nanosight NS300 and Transmission Electron Microscopy. Smart NPs cytotoxicity on LNCaP cells was assessed by MTS assay.

Results: The HPLC confirmed the chemical stability of PTX. The core-shell NPs are spherical. The particle’s mean diameters (PMD) are 89.4±2.3- to 114.4±7.6 nm. The TEM showed unique multilayer and spherical smart nanoparticles. The blank PLGA NPs and blank Smart acetate layer-by-layer NPs, which did not contain PTX, were not cytotoxic to the LNCaP cells. As expected, the Smart layer-by-layer PTX-loaded PLGA NPs were more cytotoxic to the cells than the PTX-loaded PLGA NPs by inhibiting cell growth by about 50% and 30% with 0.4 nM of PTX, respectively, after 48-hours exposure. The Smart NPs showed dose-dependent cytotoxicity on the LNCaP cells.

Conclusion: This unique process of Engineering Layer-By-Layer Smart acetate-coated Paclitaxel-loaded polylactic-co-glycolic Acid Nanoparticles is promising to potentiate the efficacy and reduce the side effects of Paclitaxel or other anti-cancer drugs targeting prostate cancers.

References: (1) Ngo AN, Ezoulin MJ, Murowchick JB, Gounev AD, Youan BB. Sodium Acetate Coated Tenofovir-Loaded Chitosan Nanoparticles for Improved Physico-Chemical Properties. Pharm Res. 2016;33(2):367-83. Epub 20151109. doi: 10.1007/s11095-015-1795-y. PubMed PMID: 26553351; PMCID: PMC5755613.
(2) Wu LY, Do JC, Kazak M, Page H, Toriyabe Y, Anderson MO, Berkman CE. Phosphoramidate derivatives of hydroxysteroids as inhibitors of prostate-specific membrane antigen. Bioorg Med Chem Lett. 2008;18(1):281-4. Epub 20071030. doi: 10.1016/j.bmcl.2007.10.096. PubMed PMID: 18023582; PMCID: PMC2254654.

Acknowledgements: The research reported was supported by the American Cancer Society Diversity in Institutional Development Grant under award number DICRDG-21-073-01-DICRDG. The authors declare no conflicts of interest.


Fig.1 Schematic representation of the engineering of the smart Nanoparticles


Fig.2 Transmission Electron Microscopic of Layer-By-Layer Smart Acetate Coated Paclitaxel Loaded Polylactic-Co-Glycolic Acid Nanoparticle. , Trypan blue(0.01%) is encapsulated in the upper layer to depict the different layers of the smart nanoparticle.


Fig.3 Percent LNCaP cell viability (%control) treated 48 hours with the different formulations *P <0.05 vs media; **P <0.01 vs media; *** P<0.001 vs media