Self-Targeting Fluorescent Carbon Dots for Diagnosis of Brain Cancer Cells

TLDR

The study aims to develop carbon dots that integrate diagnostic, targeting, and therapeutic functions for glioma imaging. The authors synthesized CD‑Asp carbon dots by pyrolyzing D‑glucose and L‑aspartic acid to confer glioma‑targeting capability. CD‑Asp exhibited excellent biocompatibility, tunable full‑color emission, and selective targeting of glioma cells, producing high‑contrast fluorescence in vivo and penetrating the blood‑brain barrier, whereas other CD variants lacked such selectivity.

Abstract

A new type of carbon dots (CD-Asp) with targeting function toward brain cancer glioma was synthesized via a straightforward pyrolysis route by using D-glucose and L-aspartic acid as starting materials. The as-prepared CD-Asp exhibits not only excellent biocompatibility and tunable full-color emission, but also significant capability of targeting C6 glioma cells without the aid of any extra targeting molecules. In vivo fluorescence images showed high-contrast biodistribution of CD-Asp 15 min after tail vein injection. A much stronger fluorescent signal was detected in the glioma site than that in normal brain, indicating their ability to freely penetrate the blood-brain barrier and precisely targeting glioma tissue. However, its counterparts, the CDs synthesized from D-glucose (CD-G), L-asparic acid (CD-A), or D-glucose and L-glutamic acid (CD-Glu) have no or low selectivity for glioma. Therefore, CD-Asp could act as a fluorescence imaging and targeting agent for noninvasive glioma diagnosis. This work highlights the potential application of CDs for constructing an intelligent nanomedicine with integration of diagnostic, targeting, and therapeutic functions.