Salivary Excretion of Renal-Clearable Silver Nanoparticles.

Salivary elimination is an important pathway for the body to excrete small molecules with digestive enzymes. However, very few engineered nanoparticles can be excreted through salivary glands, which often host bacteria or viruses during infection and involve in disease transmission. Herein, we report that renal clearable glutathione coated AgNPs (GS-AgNPs) can selectively accumulate in the submandibular salivary gland, followed by being excreted in its excretory duct. By conducting head-to-head comparison on in vivo transport and interactions of both GS-AgNPs and glutathione coated gold nanoparticles (GS-AuNPs) with the same sizes, we found that low-density GS-AgNPs showed much higher vascular permeability than GS-AuNPs and can rapidly penetrate into submandibular salivary glands, be efficiently taken up by striated and excretory duct cells, and eventually secreted into saliva.