Endocytosis-driven gold nanoparticle fractal rearrangement in cells and its influence on photothermal conversion

Autor: Vladimir Mulens-Arias, Florent Carn, Alice Balfourier, Florence Gazeau, Alba Nicolas-Boluda
Přispěvatelé: European Commission, Association de la Recherche Contre le Cancer (France), Agence Nationale de la Recherche (France), Instituts Thématiques Multi-organismes (France), Matière et Systèmes Complexes (MSC (UMR_7057)), Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Rok vydání: 2020
Předmět:
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
instname
Nanoscale
Nanoscale, Royal Society of Chemistry, 2020, 12 (42), pp.21832-21849. ⟨10.1039/D0NR05886F⟩
ISSN: 2040-3364
2040-3372
Popis: Cellular endocytosis and intracellular trafficking of nanoparticles induce dynamic rearrangements that profoundly modify the physical properties of nanoparticle and govern their biological outcomes when activated by external fields. The precise structure, organization, distribution, and density of gold nanoparticles (AuNPs) confined within intracellular compartments such as lysosomes have not been studied comprehensively, hampering the derivation of predictive models of their therapeutic activity within the cells of interest. By using transmission electron microscopy and small-angle X-ray scattering, we have determined that canonical spherical citrate-coated AuNPs in the 3–30 nm size range form fractal clusters in endolysosomes of macrophages, endothelial cells, and colon cancer cells. Statistical analysis revealed that the cluster size and endolysosome size are correlated but do not depend on the size of AuNPs unless larger preformed aggregates of AuNPs are internalized. Smaller AuNPs are confined in greater numbers in loose aggregates covering a higher fraction of the endolysosomes compared to the largest AuNPs. The fractal dimensions of intracellular clusters increased with the particle size, regardless of the cell type. We thus analyzed how these intracellular structure parameters of AuNPs affect their optical absorption and photothermal properties. We observed that a 2nd plasmon resonance band was shifted to the near-infrared region when the nanoparticle size and fractal dimensions of the intracellular cluster increased. This phenomenon of intracellular plasmon coupling is not directly correlated to the size of the intralysosomal cluster or the number of AuNPs per cluster but rather to the compacity of the cluster and the size of the individual AuNPs. The intracellular plasmon-coupling phenomenon translates to an efficient heating efficiency with the excitation of the three cell types at 808 nm, transforming the NIR-transparent canonical AuNPs with sizes below 30 nm into NIR-absorbing clusters in the tumor microenvironment. Harnessing the spontaneous clustering of spherical AuNPs by cells might be a more valuable strategy for theranostic purposes than deploying complex engineering to derive NIR-absorbent nanostructures out of their environment. Our paper sheds light on AuNP intracellular reorganization and proposes a general method to link their intracellular fates to their in situ physical properties exploited in medical applications.
This work has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 685795 and 801305. The authors thank the ANR CarGold-16-CE09-026, ANR Coligomere-18-CE06-0006 and ANR CycLys-18-CE09-0015-01. VMA received a Post-doc fellowship from Association pour le Recherche contre le Cancer (ARC, Aides Individuelles, post-doctorant, dossier 20150603405). ANB received a PhD fellowship by the Institute thematique multi-organismes (ITMO) Cancer and the doctoral school Frontières du Vivant (FdV) – Programme Bettencourt. AB received a PhD fellowship by the doctoral school Physique en Ile de France (EDPIF). This work was supported by the ITMO-Inserm Plan Cancer 2014-2019.
Databáze: OpenAIRE
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