Lipid-based nanoparticles: Enhanced cellular uptake via surface thiolation

Patrick Knoll; Giuseppe Francesco Racaniello; Valentino Laquintana; Florina Veider; Ahmad Saleh; Anna Seybold; Nunzio Denora; Andreas Bernkop-Schnürch

doi:10.1016/j.ijpharm.2023.122753

Lipid-based nanoparticles: Enhanced cellular uptake via surface thiolation

Int J Pharm. 2023 Mar 25:635:122753. doi: 10.1016/j.ijpharm.2023.122753. Epub 2023 Mar 1.

Authors

Patrick Knoll¹, Giuseppe Francesco Racaniello², Valentino Laquintana², Florina Veider¹, Ahmad Saleh³, Anna Seybold⁴, Nunzio Denora², Andreas Bernkop-Schnürch⁵

Affiliations

¹ Center for Chemistry and Biomedicine, Department of Pharmaceutical Technology, Institute of Pharmacy, Leopold-Franzens-University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria.
² Department of Pharmacy - Pharmaceutical Sciences, University of Bari "Aldo Moro", Italy.
³ Center for Chemistry and Biomedicine, Department of Pharmaceutical Technology, Institute of Pharmacy, Leopold-Franzens-University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria; Department of Pharmacy, Universitas Mandala Waluya, A.H.Nasution, Kendari 93231, Southeast Sulawesi, Republic of Indonesia.
⁴ Department of Zoology, University of Innsbruck, 6020 Innsbruck, Austria.
⁵ Center for Chemistry and Biomedicine, Department of Pharmaceutical Technology, Institute of Pharmacy, Leopold-Franzens-University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria. Electronic address: Andreas.Bernkop@uibk.ac.at.

PMID: 36863545
DOI: 10.1016/j.ijpharm.2023.122753

Abstract

The aim of this study was to evaluate the uptake mechanism of thiolated nanostructured lipid carriers (NLCs). NLCs were decorated with a short-chain polyoxyethylene(10)stearyl ether with a terminal thiol group (NLCs-PEG₁₀-SH) or without (NLCs-PEG₁₀-OH) as well as with a long-chain polyoxyethylene(100)stearyl ether with thiolation (NLCs-PEG₁₀₀-SH) or without (NLCs-PEG₁₀₀-OH). NLCs were evaluated for size, polydispersity index (PDI), surface morphology, zeta potential and storage stability over six months. Cytotoxicity, adhesion to the cell surface and internalization of these NLCs in increasing concentrations were evaluated on Caco-2 cells. The influence of NLCs on the paracellular permeability of lucifer yellow was determined. Furthermore, cellular uptake was examined with and without various endocytosis inhibitors as well as reducing and oxidizing agents. NLCs were obtained in a size ranging from 164 to 190 nm, a PDI of 0.2, a negative zeta potential < -33 mV and stability over six months. Cytotoxicity was shown to be concentration dependent and to be lower for NLCs with shorter PEG chains. Permeation of lucifer yellow was 2-fold increased by NLCs-PEG₁₀-SH. All NLCs displayed concentration dependent adhesion to the cell surface and internalization, which was in particular 9.5-fold higher for NLCs-PEG₁₀-SH compared to NLCs-PEG₁₀-OH. Short PEG chain NLCs and especially thiolated short PEG chain NLCs showed higher cellular uptake than NLCs with longer PEG chain. Cellular uptake of all NLCs was mainly clathrin-mediated endocytosis. Thiolated NLCs showed also caveolae-dependent and clathrin- and caveolae-independent uptake. Macropinocytosis was involved in NLCs with long PEG chains. NLCs-PEG₁₀-SH indicated thiol-dependent uptake, which was influenced by reducing and oxidizing agents. Due to thiol groups on the surface of NLCs their cellular uptake and paracellular permeation enhancing properties can be substantially improved.

Keywords: Cellular uptake; Endocytosis; Nanostructured lipid carriers; Permeation; Thiolation; Uptake mechanism.

MeSH terms

Caco-2 Cells
Drug Carriers / pharmacology
Humans
Lipids / pharmacology
Nanoparticles*
Nanostructures*
Particle Size
Polyethylene Glycols

Substances

Drug Carriers
Lipids
Polyethylene Glycols