Aerosol Delivery of Functionalized Gold Nanoparticles Target and Activate Dendritic Cells in a 3D Lung Cellular Model

Abstract

Nanocarrier design combined with pulmonary drug delivery holds great promise for the treatment of respiratory tract disorders. In particular, targeting of dendritic cells that are key immune cells to enhance or suppress an immune response in the lung is a promising approach for the treatment of allergic diseases. Fluorescently encoded poly(vinyl alcohol) (PVA)-coated gold nanoparticles, functionalized with either negative (−COO − ) or positive (−NH 3 + ) surface charges, were functionalized with a DC-SIGN antibody on the particle surface, enabling binding to a dendritic cell surface receptor. A 3D coculture model consisting of epithelial and immune cells (macrophages and dendritic cells) mimicking the human lung epithelial tissue barrier was employed to assess the effects of aerosolized AuNPs. PVA-NH 2 AuNPs showed higher uptake compared to that of their −COOH counterparts, with the highest uptake recorded in macrophages, as shown by flow cytometry. None of the AuNPs induced cytotoxicity or necrosis or increased cytokine secretion, whereas only PVA-NH 2 AuNPs induced higher apoptosis levels. DC-SIGN AuNPs showed significantly increased uptake by monocyte-derived dendritic cells (MDDCs) with subsequent activation compared to non-antibody-conjugated control AuNPs, independent of surface charge. Our results show that DC-SIGN conjugation to the AuNPs enhanced MDDC targeting and activation in a complex 3D lung cell model. These findings highlight the potential of immunoengineering approaches to the targeting and activation of immune cells in the lung by nanocarriers.

Effects of engineered nanoparticles on the innate immune system

“…Positively charged NPs enhance the electrostatic attraction between NPs and negatively charged cell membrane, leading to the increased surface endocytosis (or phagocytosis) [56]. Hence, cationic NPs showed higher uptake in macrophage and DCs [57,58]. Hu et al demonstrated that positively charged Fe 2 O 3 NPs enhanced the cross-presentation ability of DCs, while negatively charged Fe 2 O 3 NPs were associated with rapid autophagy [59].…”

Assessing the Stability of Fluorescently Encoded Nanoparticles in Lysosomes by Using Complementary Methods

“…It has been previously reported that surface-exposed dye molecules, such as non-shielded ATTO590,i nterfere with cellular uptake.T his makes shielded NPs favorable candidates,s ince the polymer used provides protection from the dye while the fluorescence remains uncompromised. [7] AuNPs were selected as model NPs not only for their well-established synthetic procedure but also because they did not show any adverse effects in previous in vitro [10] or in vivo [11] studies. Moreover,t he fluorescent dye allows the detection and quantification by flow cytometry,f luorescence spectroscopy, and imaging techniques,hence allowing the direct tracking of the fate of NPs.…”

Design of Gold Nanoparticles in Dendritic Cell‐Based Vaccines

“…To study this specifically in DCs, Fytianos et al coated AuNPs with PVA and functionalized them with either COO − or NH 3 + . The results showed that AuNP‐PVA and NH 3 + induced better uptake (5% vs 30%) efficiency than COO − . Interestingly, uptake of the AuNP‐PVA and using DC‐SIGN as the targeting molecule to DCs was independent of charge .…”