A New System Of Carbon Dots-hyaluronan / Doxorubicin For Targeted Cancer Cell Imaging And Drug Delivery

Carbon dots(CDs)represent a new class of fluorescent carbon nanomaterial recent years.The unique properties of CDs,such as water solubility,good light stability,low biological toxicity and tunable optical properties make them to be the fluorescent nanoprobe for tumor targeted imaging and drug delivery.The paper developed an approach for targeting and detecting HA receptor over expressed cancer cells through non-covalent conjugation of Hyaluronan-Doxorubicin(HA-Dox)on polyethyleneimine(PEI)modified CDs(PEI-CDs).The PEI-CDs/ HA-Dox can be used as a turn-on fluorescent nanoprobe for targeting CD44 over expression cancer cells in vivo.The main contents are as follows:1.The preparation and characterization of CDs?PEI-CDs and PEI-CDs/ HA-Dox: First,CDs are modified with a cationic polymer polyelectrolyte,PEI via electrostatic interaction,and then functionalized PEI-CDs with HA-Dox by non-covalent conjugation.The as prepared complex was characterize by TEM?Zeta potential?AFM?UV/vis and FL to study their particle morphology?surface potential?dispersibility?UV absorption and fluorescence spectra.The results verified that PEI and HA-Dox were wrapped on the surface of CDs through electrostatic interaction.In addition,the fluorescence of PEI-CDs from quenching to recovery was preliminary studied.2.The effect of HA-Dox and HAase on the fluorescence properties of PEI-CDs and PEI-CDs/HA-Dox,respectively: This section validated the impact of HA-Dox and HAase on the fluorescence of PEI-CDs.The experimental conditions of p H,salt concentration and fluorescence stability were optimized,and the reason of fluorescence quenching of PEI-CDs was studied.These findings indicated that PEI-CDs had strong emission and futher quenched by HA-Dox.In the presence of HAase,HA was degrade by HAase and Dox became far away from the surface of PEI-CDs,leading to the recovery of PEI-CDs fluorescence intensity.3.The distinguished,targeted imaging and drug delivery of PEI-CDs/HA-Dox in CD44 over expressed cancer cells: To examine the cancer-targetable ability,human cervical cancer Hela cells(CD44 high expression)and normal mice fibroblast NIH-3T3 cells(CD44 low expression)were employed as model cells by laser confocal imaging.All these results demostrated that the prepared PEI-CDs/HA-Dox could enter into cancer cells by CD44-mediated endocytosis and be used as a turn-on nanoprobe for targeted imaging and drug delivery.The results of this study provide a more effective method for cancer cell targeted imaging analysis and drug delivery,and may offer a promising approach for early tumor diagnosis and therapy.