SCC-131

QbD-Assisted Synthesis and Exploration of Plasmonic Laser Activatable Nanogold Seeds for Photothermal and Photodynamic Therapy of Cancer Cells

NanoGold seeds are promising for photothermal therapy due to their surface plasmon resonance properties. Gadeval et al. synthesized these seeds using a quality-by-design approach, targeting a 30-40 nm size range. To evaluate the anticancer potential of nanoGold seeds, cellular studies were conducted on both 2D monolayer and 3D spheroids models in SCC-131 cells. Solid tumor spheroids closely resemble the tumor environment in vivo as they are composed of proliferating cells at the outermost layer of tumor spheroid, quiescent cells at middle and necrotic cells at centre with gradient supply of nutrients and gases.

Cellular uptake studies compared nanoGold seeds-NR with plain Nile red solution. Results showed that Nile red alone did not enter cells significantly over 12 hours. NanoGold seeds-NR without NIR laser irradiation also showed minimal cellular uptake (Fig. 1e, f). However, nanoGold seeds-NR with NIR laser irradiation, especially dual-pulse irradiation (Fig. 1i, j), significantly enhanced cellular uptake compared to single-pulse irradiation (Fig. 1g, h). This suggests that NIR laser irradiation enhances the uptake of nanoGold seeds. The study also found that the cellular uptake of nanoGold seeds-NR improved over time, with significant red fluorescence intensity increases up to 6 hours, indicating that nanoGold seeds can enter and remain inside cells within 3-6 hours. This aligns with reports that NIR laser irradiation enhances the uptake of photothermally active nanocarriers, likely due to increased cell membrane mobility at elevated temperatures (42-45 °C).