Zinc nanoparticles from oral supplements accumulate in renal tumours and stimulate antitumour immune responses.

Summary

The study shows that oral zinc gluconate can self-assemble with plasma proteins into ZnO nanoparticles in vivo, which preferentially accumulate in papillary Caki-2 renal tumors. This accumulation enhances antitumor immunity by recruiting dendritic cells and cytotoxic CD8+ T cells, suggesting an accessible oral route for nanomedicine-based immunotherapy.

Key Findings

• Oral zinc gluconate assembles with plasma proteins to form ZnO nanoparticles in vivo.
• ZnO nanoparticles preferentially accumulate in papillary Caki-2 renal tumors.
• Accumulation promotes recruitment of dendritic cells and cytotoxic CD8+ T cells, enhancing antitumor immunity.

Clinical Implications

While preclinical, the findings suggest potential development of oral adjuvants to enhance intratumoral delivery and antitumor immunity. Caution is warranted before translation; dosing, safety, and tumor-type specificity must be evaluated.

Limitations

• Preclinical model; human safety, pharmacokinetics, and long-term toxicity are not established
• Tumor-type generalizability and dosing windows require further definition

Future Directions

Assess biodistribution, safety, and efficacy across tumor types in larger animal models; explore combination with checkpoint inhibitors; define pharmacology for human translation.