Wenshan Li

Self-Assembled Supramolecular Nanoprobes for Ratiometric Fluorescence Measurement of Intracellular pH Values

Self-assembly of small building blocks into functional supramolecular nanostructure has opened prospects for the design of novel materials. With this molecular engineering strategy, we have developed self-assembled supramolecular nanoprobes (SSNPs) for ratiometric fluorescence measurement of pH values in cells. The nanoprobes with a diameter of ∼30 nm could be formulated just by mixing pH-sensitive adamantane-fluorescein (Ad-F) and pH-insensitive adamantane-Rhodamine B (Ad-R) with β-cyclodextrin polymer (poly-β-CD) at one time. The nanoprobes with good biocompatibility have been successfully applied to measure intracellular pH in the pH range of 4-8 and estimate pH fluctuations associated with different stimuli in cells. Moreover, we expect that this self-assembled approach is applicable to the construction of nanoprobes for other targets in cells just by replacing the respective indicator dyes with relevant indicators.

A simple label-free aptamer-based method for C-reactive protein detection

We developed a simple label-free aptamer-based method for C-reactive protein (CRP) detection. In our previous work, we obtained a G-rich aptamer named 6th-62-40, which exhibited good affinity and specificity toward CRP. Herein, we demonstrated that 6th-62-40 could enhance the fluorescence of thioflavin T (ThT). In the absence of CRP, ThT bound to the G-rich aptamer and formed an aptamer/ThT complex, which showed high fluorescence. However, the fluorescence decreased due to the formation of an aptamer/CRP complex in the presence of CRP. The proposed method was a rapid strategy for CRP detection with a detection limit of 380 pM.

Self‐Assembled Supramolecular Nanoparticles for Targeted Delivery and Combination Chemotherapy

It is challenging but imperative to merge imaging agents and small molecule therapeutics into one nanoentity for diagnosis and treatment. Herein, we constructed polymeric nanoparticles for targeted delivery and combination chemotherapy, which formed through host–guest interactions among three elements: 1) β‐cyclodextrin polymer (poly‐β‐CD), as the backbone of nanoparticles; 2) two antitumor drugs—doxorubicin (DOX) and docetaxel (DTX); and 3) aptamers labeled with adamantane and fluorescein (Ad‐aptamer‐FAM), as recognition elements. First, polymeric nanoparticles, termed self‐assembled supramolecular nanoparticles (SSNPs), were formulated by combining hydrophobic DTX and DOX with poly‐β‐CD via host–guest interactions. Then, the surface of SSNPs modified the aptamer to acquire targeting ability; such nanoparticles were termed targeted self‐assembled supramolecular nanoparticles (T‐SSNPs). As evidenced by MTS assay data, T‐SSNPs exhibited significant selective cytotoxicity toward target cells. The results also indicated that combination drugs achieved a good synergistic effect with a combination index of 0.43. Thus, an effective and simple drug delivery system was constructed for targeted delivery and combination chemotherapy.