Natural antibacterial silk produced by feeding silkworms with human hair derived carbon dots

Abstract

Mulberry silk has exceptional mechanical properties and biocompatible nature, but suffers from its poor antibacterial capacity as protein fiber, a nutrient‐rich environment for bacterial growth. Endowing the natural silk with antibacterial properties while preserving its inherent advantages remains a longstanding challenge. In this study, blue fluorescence carbon dots (B‐CDs) are prepared from Crinis carbonisatus , which is derived from calcination of human hair and has been used as the traditional Chinese medicine for about 1800 years. Such B‐CDs exhibit robust Staphylococcus aureus ‐inhibiting activity, and thus they are employed as feed additives for silkworms. The experimental silkworms show blue fluorescence in their bodies, cocoons, and even as moths, while the dissection of silkworms confirms the transport of B‐CDs from the digestive tract to the silk gland. The degummed silk possesses visible blue fluorescence and anti‐ S. aureus properties, while retaining its inherent mechanical properties. Notably, B‐CDs also regulate the secondary structure of silk proteins and upregulate the antibacterial protein contents, resulting in a synergistic antibacterial effect. As a result, the B‐CDs@silk can accelerate wound healing, which outperforms the conventional gauze. In addition, B‐CDs show no observable adverse effects on silkworm or rat health, indicating their biocompatibility and biosafety preliminarily.