Wanyun Liu

Polymerizable aggregation-induced emission dye-based fluorescent nanoparticles for cell imaging applications

A polymerizable aggregation-induced emission (AIE) dye (named PhE) was facilely incorporated into polymer nanoparticles through reversible addition fragmentation chain transfer polymerization. The thus obtained fluorescent organic nanoparticles showed uniform size, high water dispersibility, strong fluorescence and excellent biocompatibility, and are expected to show great potential for cell imaging applications.

Interaction of tannic acid with carbon nanotubes: enhancement of dispersibility and biocompatibility

The interaction of manufactured nanomaterials with environmental and biological systems has been a subject of great research interest for a long time. In the present study, adsorption of a universal environmental organic material (named tannic acid (TA)) on carbon nanotubes (CNTs) was investigated. The influence of CNT properties and pH values on the sorption capacity of CNTs for TA was also evaluated. Our results demonstrated that the sorption capacity of CNTs was positively correlated with their specific surface areas. Furthermore, TA could effectively enhance the water dispersibility of CNTs and reduce their cytotoxicity. Our results implied that TA could influence the environmental behavior and biological responses of the manufactured nanomaterials, reminding us that much more attention should be paid to the synergistic toxicity of nanomaterials when we evaluate their environmental impacts.

Fabrication of aggregation induced emission dye-based fluorescent organic nanoparticles via emulsion polymerization and their cell imaging applications

Aggregation induced emission (AIE) dye-based fluorescent organic nanoparticles (FONs) have recently emerged as novel fluorescent bioprobes due to their remarkable optical properties, water solubility and biocompatibility. In this work, a novel strategy for the fabrication of AIE-based FONs was developed via emulsion polymerization for the first time. During this procedure, a polymerizable AIE dye (named as PhE) with a double bond end functional group was facilely incorporated into the hydrophobic core of polymer nanoparticles. The obtained polymer nanoparticles (named as PhE–Pst NPs) exhibited strong fluorescence and high water dispersibility owing to the partial aggregation of PhE and the surface covered with a hydrophilic shell. More importantly, these FONs showed spherical morphology, uniform size (about 200 nm) and excellent biocompatibility, making them promising for bioimaging applications.

Facile fabrication and cell imaging applications of aggregation-induced emission dye-based fluorescent organic nanoparticles

Aggregation-induced emission (AIE) dye-based fluorescent organic nanoparticles (FONs) were prepared via Schiff base interactions between an AIE dye and a carbohydrate polymer (carboxymethyl chitosan). The obtained FONs with uniform size, high water dispersibility, strong fluorescence and high biocompatibility were explored for cell imaging applications.

PEGylation and cell imaging applications of AIE based fluorescent organic nanoparticles via ring-opening reaction

PEGylation of aggregation induced emission (AIE) based fluorescent organic nanoparticles (FONs) via one pot ring-opening polymerization and condensation reaction was developed for the first time. Thus PEGylated FONs exhibited high water dispersibility, strong fluorescence, uniform morphology and more important excellent biocompatibility, implying their high potential for various biomedical applications.

Fabrication of water-dispersible and biocompatible red fluorescent organic nanoparticles via PEGylation of aggregate induced emission enhancement dye and their cell imaging applications

PEGylated red fluorescent organic nanoparticles (FONs) with aggregate induced emission enhancement (AIEE) properties have been prepared via self assembly of a cyano-substituted diarylethene derivate dye (C18-R) and synthetic copolymers, which were obtained by reversible addition-fragmentation chain transfer (RAFT) polymerization using stearyl methacrylate and poly(ethylene glycol) methacrylate as monomers. Thus obtained FONs were characterized by a series of techniques including transmission electron microscopy, Fourier transform infrared spectroscopy and fluorescent spectroscopy. To explore their potential biomedical applications, biocompatibility and cell uptake behavior of these red FONs were subsequently investigated. We demonstrated that FONs showed uniform morphology, suitable particle size (70-90 nm), high water dispersibility, strong red fluorescence and excellent biocompatibility, making them promising for bioimaging applications.

Preparation and characterization of electrospun PLGA/gelatin nanofibers as a drug delivery system by emulsion electrospinning

Novel biocompatible poly(lactide-co-glycolide) (PLGA) nanofiber mats with favorable biocompatibility and good mechanical strength were prepared, which could serve as an innovative type of tissue engineering scaffold or an ideal controllable drug delivery system. Both hydrophobic and hydrophilic drugs, Cefradine and 5-fluorouracil were successfully loaded into PLGA nanofiber mats by emulsion electrospinning. The natural bioactive protein gelatin (GE) was incorporated into the nanofiber mats to improve the surface properties of the materials for cell adhesion. Nanofibrous scaffolds were characterized by scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, contact angle and tensile measurements. Emulsion electrospun fibers with GE had perfect hydrophilic and good mechanical property. The in vitro release test showed thedrugs released from emulsion electrospun fibers, which achieved lower burst release. The cells cytotoxicity experiment indicated that emulsion electrospun fibers were less toxic and tended to promote fibroblasts cells attachment and proliferation, which implied that the electrospun fibers had promising potential application in tissue engineering or drug delivery.

Electrospinning of Poly(L-lactide) Nanofibers Encapsulated with Water-Soluble Fullerenes for Bioimaging Application

Photoluminescent fullerene nanoparticles/nanofibers have potential applications in bioimaging. A novel fluorescent nanofibrous material, consisting of fullerene nanoparticles and poly(L-lactide) (PLLA), was fabricated via a simple electrospinning method, and the composite nanofibers were characterized by various techniques such as scanning electron microscopy (SEM), laser scanning confocal microscopy (LSCM), and transmission electron microscopy (TEM). The nanofibers were uniform, and their surfaces were reasonably smooth, with the average diameters of fibers ranging from 300 to 600 nm. The fullerene nanoparticles were encapsulated within the composite nanofibers, forming a core-shell structure. The nanofiber scaffolds showed excellent hydrophilic surface due to the addition of water-soluble fullerene nanoparticles. The composite nanofibers used as substrates for bioimaging in vitro were evaluated with human liver carcinoma HepG2 cells, the fullerene nanoparticles signal almost displayed in every cell, implying the potential of fluorescent fullerene nanoparticles/PLLA nanofibers to be used as scaffolds for bioimaging application.

Substituent effects and activation mechanism of norbornene polymerization catalyzed by three-dimensional geometry α-diimine palladium complexes

A series of three-dimensional geometry 9,10-dihydro-9,10-ethanoanthracene-11,12-diimine methyl palladium chloride complexes were synthesized and characterized. These three-dimensional geometry α-diimine palladium complexes exhibited high activities toward the homopolymerization of norbornene and copolymerization of norbornene with 5-norbornene-2-carboxylic acid methyl ester in the presence of B(C6F5)3. It was observed that the palladium–halogen bond of the complexes could be effectively activated by B(C6F5)3. The activation mechanism was clarified by the end group analysis of the polymer, which provided a new pathway for the activation of palladium complexes. Meanwhile, the palladium catalysts with a three-dimensional geometry on the backbone were found to show a good thermal stability and afford a high incorporation of the polar monomer in norbornene polymerization. Moreover, the α-diimine palladium complexes with a large steric hindrance or strongly electron-donating group on the aryl ring of ligands could achieve a higher reactivity.

Electrospun poly(L-lactide) nanofibers loaded with paclitaxel and water-soluble fullerenes for drug delivery and bioimaging

Multifunctional electrospun composite nanofibrous scaffolds have attracted much interest as drug delivery vehicles and in bioimaging application for real-time tracing the whole process of postoperative therapy. Novel poly(L-lactide) (PLLA) composite nanofibers loaded with water-soluble fullerene C70 nanoparticles and paclitaxel were successfully fabricated. The nanofibers with the average diameter of fibers ranging from 350 to 750 nm were uniform and their surfaces were reasonably smooth. The nanofibers showed an excellent hydrophilic surface and good mechanical properties. The in vitro release results demonstrated that the release rate of paclitaxel could be controlled by the content of C70 nanoparticles. With the increase of the content of C70 nanoparticles, the drug release rate became faster with increased total release amount. The composite nanofibers used as substrates for cytotoxicity and bioimaging in vitro were evaluated with human liver carcinoma HepG-2 cells. Paclitaxel was released from the composite nanofibers without losing cytotoxicity, the drug-loaded composite nanofibers inhibited the proliferation of HepG-2 cells effectively. Meanwhile, the fluorescent signal of C70 nanoparticles could be detected in HepG-2 cells, which reflected the growth state of cells clearly. These results strongly suggested that these PLLA composite nanofibers could be used in the fields of tissue engineering, drug delivery and bioimaging.