Ultrastructural Features of Gold Nanoparticle Interactions with T47D Spheroids

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Cancer Research

Background:

• Breast cancer remains a leading cause of mortality worldwide.
• Tumor spheroids are advanced 3D models mimicking in vivo tumor microenvironments.
• Gold nanoparticles (AuNPs) are explored for their potential in cancer therapy due to their unique properties.

Purpose of the Study:

• To investigate the effects of 45 nm gold nanoparticles (AuNPs) on T47D breast cancer spheroids.
• To analyze ultrastructural alterations and AuNP interactions within the spheroid model.
• To assess AuNP delivery, diffusion, uptake, and accumulation in a 3D cancer cell model.

Main Methods:

• Characterization of T47D spheroids using Transmission Electron Microscopy (TEM) at various culture ages.
• Imaging analysis to observe structural changes post-AuNP treatment.
• Evaluation of AuNP interactions, including delivery, diffusion, uptake, and accumulation.

Main Results:

• Spheroids exhibited significant heterogeneity in cell morphology and signs of necrosis, particularly in inner cells by Day 20.
• AuNPs were primarily taken up by the outermost, peripheral cells of the spheroids.
• AuNP treatment led to observable cellular damage, including cell shrinkage, membrane disruption, widened intercellular spaces, and nuclear fragmentation.

Conclusions:

• Gold nanoparticles demonstrate preferential uptake in the outer layers of T47D breast cancer spheroids.
• AuNP exposure induces significant ultrastructural damage and necrosis, suggesting potential for targeted cancer therapy.
• The study highlights the utility of 3D spheroids for evaluating nanoparticle-cell interactions and therapeutic potential in breast cancer models.