Synthesis And Bio-application Of Fluorescent C-dots-based Theranostic Nano-materials

Synthesis of multifunctional theranostic nanomaterials with good biocompatibility though facile design and limited preparation / post-processing steps is essential for the development and further application in the field of biology and biomedicine.In the first part, Ribonuclease A(RNase A) surface modified Carbon dots(C-dots) with high fluorescence quantum yield(24.20%) have been successfully prepared by a one-step synthesis method. TEM, FTIR, XRD, UV Absorption Spectroscopy and Fluorescence Excitation-Emission Spectrometer have been utilized to characterized its structural and optical properties; Factors that influence the fluorescence character(pH, reaction time, etc.) of the as-prepared C-dots have been analyzed and discussed based on available data; Efforts have been made to figure out the underline mechanism responsible for the much enhanced fluorescence quantum yield; Results from MTT and Bio-imaging experiment seem to implement that the as-prepared C-dots could potentially be used as biocompatible theranostic nanomaterials with both in vitro/vivo imaging functionality and the ability to inhibit viability of cancer cells to some extent.In the second part, silk fibroin protein-coated C-dots have been synthesized through a well-designed one-step in situ method and the facile method has made it convenient for this kind of new nanomaterial to load drugs by simply adding the drugs during the reaction process. The final product SF@ C-dots-DOX combines the functionalities of imaging and drug-delivery-based cancer therapy. Results of in vitro drug-releasing study shows that: drug release profile of SF @ C-dots-DOX has a significant dependence of pH; acidic pH conditions could accelerate the drug-release rate. While results of MTT and confocal fluorescence imaging reveals that SF @ C-dots-DOX can efficiently enter into the cells by endocytosis and perform imaging-guided drug-release triggered by acid pH in the cancer cells which resulted in efficient inhibition of cancer cell viability.