Novel Carbon Dots-Derived from Radix Puerariae Carbonisata Significantly Improve the Solubility and Bioavailability of Baicalin

: Baicalin (BA) has gained considerable attention in recent years for its multiple pharmacological activities. However, its optimum pharmaceutical potential has been limited by its poor solubility in water. In this study, for the first time, we discovered that novel water-soluble carbon dots (CDs, named RPC-CDs) from aqueous extracts of Radix Puerariae Carbonisata (RPC). The chemical composition and morphological features of the RPC-CDs we obtained were characterized using various spectroscopies and transmission electron microscopy and the CDs have a low toxicity against RAW 264.7 cells by the CCK-8 assay. Most importantly, the RPC-CDs were able to greatly increase the solubility of baicalin in water, which could be related to the glucuronide structure of baicalin. Moreover, the result of indirect competitive enzyme-linked immunosorbent assays (icELISA) indicated that the area under the baicalin concentration-time curve value of baicalin-RPC-CDs (BA-CDs) was 1.7-fold greater than those of a baicalin suspension liquid (BA control) after oral administration at a dose of 72 mg/kg. This study not only provides evidence to support further investigation of the considerable potential of carbon dots, but also offers support for the future clinical application of baicalin.