Enhanced delivery of polymer beads into cells through arrayed metal nanotubes by the Soret effect

Abstract

Intracellular delivery is crucial for drug delivery, genetic manipulation, and regenerative medicine. Traditional methods such as electroporation are limited by low efficiency and high cell toxicity caused by lipid barriers and endosomal degradation. This can be addressed by developing a gold nanotube (AuNT) stamping system for the direct delivery of beads into adherent cells. The delivery of 200 nm beads through metallic hollow nanotubes occurs within 10 min, which is significantly faster than the 24 h required for endocytosis. Furthermore, controlled temperature gradients based on the Soret effect enhanced the delivery efficiency by up to 152%. Our results demonstrate a significant advancement over conventional techniques while maintaining cell viability above 90% across HeLa, NIH3T3, Hs27, and HCE-T cells. These findings suggest that the AuNT-based stamping system provides a rapid and efficient alternative for intracellular delivery, maintaining high cell viability, while offering precise control over the delivery quantity through temperature gradients.