Lingyan Gao

Anti-tumor effects of bakuchiol, an analogue of resveratrol, on human lung adenocarcinoma A549 cell line

Anti-tumor activity of bakuchiol, an analogue of resveratrol, was investigated on human lung adenocarcinoma A549 cell line. MTT assay revealed that IC(50) of bakuchiol at 72h was 9.58+/-1.12 micromol/l, much lower than that of resveratrol (33.02+/-2.35 micromol/l). Bakuchiol but not resveratrol elevated intracellular reactive oxygen species. Bakuchiol reduced mitochondrial membrane potential (Psim) of cells in a concentration- and time-dependent manner, showing a more potent effect than that of resveratrol. More apoptotic cells were induced by bakuchiol, compared with resveratrol. Subsequently, S phase arrest, caspase 9/3 activaton, p53 and Bax up-regulation, as well as Bcl-2 down-regulation were observed in bakuchiol-treated A549 cells. The results point toward that S phase-related cell cycle regulation, more importantly reactive oxygen species-related apoptosis might contribute to the anticancer properties of bakuchiol, which will strongly support the further development of bakuchiol against non-small-cell lung cancer.

Construction of muscle-like metallo-supramolecular polymers from a pillar[5]arene-based [c2]daisy chain

A muscle-like metallo-supramolecular polymer based on a solvent-driven [c2]daisy chain has been prepared from an amino-modified pillar[5]arene. The integration of terpyridine moieties on both ends of the [c2]daisy chain and the stiff architecture of pillar[5]arene units facilitated the efficient formation of the metallo-supramolecular polymer. UV/vis absorption spectroscopy, dynamic light scattering, transmission electron microscopy and scanning electron microscopy were used to characterize the self-assembly behavior of the resulting polymer chains. From proton NMR studies, we confirmed that the pillar[5]arene-based [c2]daisy chain could change its length continuously in response to changes in the polarity of the solvent. Consequently, the metallo-supramolecular polymer could change its length continuously according to the solvent polarity based on the individual contraction or extension of each daisy chain repeating unit. The current system can serve as a platform to mimic the muscle movement.

Responsive reverse giant vesicles and gel from self-organization of a bolaamphiphilic pillar[5]arene

A novel bolaamphiphilic pillar[5]arene was prepared. It spontaneously forms responsive reverse multilamellar giant vesicles in chloroform and a gel in water–tetrahydrofuran (5:1, v/v). Dynamic light scattering, transmission electron microscopy, scanning electron microscopy, optical microscopy, and fluorescent microscopy were used to characterize its self-assembly in different solvents and aggregation behavior under external stimuli. These vesicles were not only stable for weeks, but also showed reversible thermal and dynamic properties under external physical stimuli. KPF6 and benzo-18-crown-6 can also be used as switches to turn-off and re-turn-on the assembly of vesicles. Moreover, the aggregation behaviour of this bolaamphiphilic pillar[5]arene can be changed by simply introducing host–guest chemistry. Besides, the gel formed from it showed reversible gel–sol phase transitions by heating and cooling, or adding and removing potassium cations.

A supramolecular polymer formed by the combination of crown ether-based and charge-transfer molecular recognition

Crown ether-based supramolecular polymers have been widely studied. The driving forces for their formation were usually focused on host–guest interactions and only very limited other supramolecular interactions are utilized to build crown ether-based supramolecular polymers. Here we report a supramolecular polymer constructed from two heteroditopic monomers driven by the combination of crown ether-based and charge-transfer molecular recognition. From our experiments, it is feasible and reasonable to introduce charge-transfer interactions into the field of supramolecular polymers constructed from crown ethers. In addition, we successfully demonstrated that this supramolecular polymer can be used in the preparation of nanofibers via electrospinning. The successful fabrication of nanofibers and supramolecular polymer films shows the versatility of this kind of low molecular weight supramolecular asymmetric AB-type monomers.

Anti-tumor effects of B-2, a novel 2,3-disubstituted 8-arylamino-3H-imidazo[4,5-g]quinazoline derivative, on the human lung adenocarcinoma A549 cell line in vitro and in vivo

This study evaluated the selective effects of 2-isopropyl-3-butyl-8-(4-fluorophenylamino)-3H-imidazo[4,5-g]quinazoline (B-2), a member of a series of quinazolines, on the cell survival and growth of the non-small cell lung cancer (NSCLC) cell line A549 in vitro and in vivo. Cytotoxicity assay, hollow fiber assay and cell xenograft model experiment revealed that B-2 showed selective effects on A549 cell survival or growth in a dose-dependent manner. At a dose of 100mg/kg, B-2 showed stronger efficacy on tumor growth inhibition in nude mice than Iressa. Exposure of A549 cells to B-2 caused inhibition of EGFR-dependent ERK-MAPK activation. In addition, inhibition of cell cycle progression and induction of mitochondria-dependent apoptosis might contribute to present the multitarget pathway of non-small cell lung cancer treatment of B-2.

Photo-responsive linear and cross-linked supramolecular polymers based on host-guest interactions

By incorporating a photochromophore, an azobenzene group, into a low molecular weight heteroditopic AB-type monomer, photo-responsive linear or cross-linked supramolecular polymers were prepared. After UV irradiation, both the linear and cross-linked supramolecular polymers showed obvious decrease in viscosity. More importantly, gels formed from the cross-linked supramolecular polymer could realize reversible photo-induced sol–gel transitions via UV or visible light irradiation. The work presented here provided an effective strategy to introduce photo-responsive properties into supramolecular polymers with different topological structures and to prepare complex and highly ordered supramolecular structures.

Formation of a Copillar[5]arene‐Based Supramolecular Polymer in Solution and in the Solid State

A linear supramolecular polymer based on the self-assembly of an easily available copillar[5]arene monomer is efficiently prepared, which is evidenced by the NMR spectroscopy, viscosity measurement, and DOSY experiment. The single-crystal X-ray analysis reveals that the polymerization of the AB-type monomer is driven by the quadruple CH•••π interactions and one CH•••O interaction.