Due to the large surface area and excellent mechanical flexibility, Photoluminescent (PL) graphene quantum dots (GQDs) with fascinating optical and electronic properties have promising applications in biomedical engineering. In order to enhance the therapeutic efficiency, the research team proposed a multifunctional nanocomposite of poly(l-lactide) (PLA) and polyethylene glycol (PEG)-grafted GQDs (f-GQDs) used for the analysis of intracellular microRNAs (miRNAs) imaging and combined gene delivery. The functionalization of GQDs with PEG and PLA endows the nanocomposite with physiological stability and stable photoluminescence over a broad pH range, which is important to cell imaging.
Cell experiments suggest that the f-GQDs have excellent biocompatibility, lower cytotoxicity and protective properties. The researchers also found that using the HeLa cell as a model, the f-GQDs delivered a miRNA probe for the analysis and regulation of intracellular miRNA imaging effectively. It is worth noting that the large surface of GQDs can adsorb agents targeting miRNA-21 and survivin simultaneously.
The combined conjugation of miRNA-21-targeting and survivin-targeting agents have good inhibition effects on the growth of cancer cells and induce more apoptosis of cancer cells. To sum up, the highly versatile multifunctional nanocomposite has a good prospect in biomedical application, such as the analysis of intracellular molecules and clinical gene therapy.