Size-Dependent Uptake and Distribution of AgNPs by Silkworms

Silk is an attractive natural fiber due to its excellent mechanical properties and biocompatibility. Xenobiotic modification of pristine silk is gaining significant attention to meet specific demands. The silk payload of xenobiotics is affected by their uptake efficiency, biodistribution, metabolism, and excretion. Herein, we systematically evaluated the effect of the nanoparticle size (20–100 nm) on the biodistribution and silk production by introducing silver nanoparticles (AgNPs) into the silkworm diet. Interestingly, the silk payload of AgNPs is highly dependent on their overall size, where 50 nm AgNPs are prone to accumulate in silk glands and reveal the highest content in the produced silk, qualifying silk antibacterial activity against both Gram-positive and Gram-negative bacteria. These findings provide new insights to understand how nanoparticle properties influence the incorporation of nanomaterials into silk and can help optimize the material design.