Endosomal Confinement of Gold Nanospheres, Nanorods, and Nanoraspberries Governs Their Photothermal Identity and Is Beneficial for Cancer Cell Therapy

Abstract

Gold nanoparticles can act as photothermal agents to generate local tumor heating and subsequent depletion upon laser exposure. Herein, photothermal heating of four gold nanoparticles and the resulting induced cancer cell death are systematically assessed, within extra‐ or intracellular localizations. Two state‐of‐the‐art gold nanorods are compared with small nanospheres (single‐core) and nanoraspberries (multicore). Heat generation is measured in water dispersion and in cancer cells, using lasers at wavelengths of 680, 808, and 1064 nm, covering the entire range used in photothermal therapy, defined as near infrared first (NIR‐I) and second (NIR‐II) windows, with NIR‐II offering more tissue penetration. When dispersed in water, gold nanospheres provide no significant heating, gold nanorods are efficient in NIR‐I, and only gold nanoraspberries are still heating in NIR‐II. However, in cells, due to endosomal confinement, all nanoparticles present an absorption red‐shift translating visible and NIR‐I absorbing nanoparticles into effective NIR‐I and NIR‐II nanoheaters, respectively. The gold nanorods then become competitive with the multicore nanoparticles (nanoraspberries) in NIR‐II. Similarly, once in cells, gold nanospheres can be envisaged for NIR‐I heating. Remarkably, nanoraspberries are efficient nanoheaters, whatever the laser applied, and the extra‐ versus intra‐cellular localization demonstrates treatment versatility.

Gold/Polyoxometalate Core/Shell Nanoparticles for Combined Chemotherapy–Photothermal Cancer Therapy

“…16,17 However, as zoledronate is known to produce time dependent inhibition of cell proliferation, it is particularly important to underline that the increase in activity from zoledronate to Mo 4 Zol 2 Mn is observed herein even after a short period of incubation (24 h) compared to these previous works. 29 Furthermore, the dose-response curves of free internalized in cells and already noticed in a recent work for other gold nanosystems 30 (Figure S8). Also, after irradiation in presence of the nanohybrid, the IC 50 value is divided by 5 compared to the value determined for a non-irradiated AuNP@Mo 4 Zol 2 Mn colloidal suspension ( 2a).…”

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

“…However, only a few reports have addressed the impact that tumor cell internalization can have on the photo-thermal outcome in the complex environment of the tumors. 57,59 Here, we have seen that intracellular clustering of NIR-transparent AuNPs could trigger efficient photothermal heating in three cellular components of the tumor microenvironment. It is worth noting that this complexity of gold nanoparticles and biological tissue interaction has been also addressed by developing an adaptive hyperspectral image algorithm.…”

Ever-Evolving Identity of Magnetic Nanoparticles within Human Cells: The Interplay of Endosomal Confinement, Degradation, Storage, and Neocrystallization

“…The latter mostly relies on the use of plasmonic gold nanoparticles, and an opposite effect could be observed, with an increased heat generation in the intracellular environment. 49,50 In a similar way, the intracellular confinement of magnetic nanoparticles, which are T2-agents (negative contrast agents) due to their high r2 values (transverse relaxivity), is beneficial for magnetic resonance imaging (MRI). When confined in cells, the magnetic nanoparticles r1 value (longitudinal relaxivity) decreases massively (100-fold or more), while r2 only falls by a factor of 2.5, resulting in a remarkable increase in the r2/r1 ratio (almost 10-fold), governing the MRI negative contrast (Figure 1h).…”