Runrun Wu

Fabrication and Evaluation of Magnetic/Hollow Double-Shelled Imprinted Sorbents Formed by Pickering Emulsion Polymerization

Magnetic/hollow double-shelled imprinted polymers (MH-MIPs) were synthesized by Pickering emulsion polymerization. In this method, attapulgite (ATP) particles were used as stabilizers to establish a stable oil-in-water emulsion, and a few hydrophilic Fe3O4 nanoparticles were allowed to be magnetic separation carriers. The imprinting system was fabricated by radical polymerization in the presence of the functional and polymeric monomers in the oil phase. The results of characterization indicated that MH-MIPs exhibited magnetic sensitivity (Ms = 4.76 emu g(-1)), thermal stability (especially below 200 °C), and hollow structure and were composed of exterior ATP shells and interior imprinted polymers shells. Then MH-MIPs were evaluated as sorbents for the selective binding of λ-cyhalothrin as a result of their magnetism, enhanced mechanical strength, hydrophilic surface, and recognition ability. The kinetic properties of MH-MIPs were well described by the pseudo-second-order equation, indicating that the chemical process could be the rate-limiting step in the adsorption process for λ-cyhalothrin. The equilibrium adsorption capacity of MH-MIPs was 60.06 μmol g(-1) at 25 °C, and the Langmuir isotherm model gave a better fit to the experimental data, indicating the monolayer molecular adsorption for λ-cyhalothrin. The selective recognition experiments also demonstrated the high affinity and selectivity of MH-MIIPs toward λ-cyhalothrin over fenvalerate and diethyl phthalate.

A Hierarchical Porous Bowl-like PLA@MSNs-COOH Composite for pH-Dominated Long-Term Controlled Release of Doxorubicin and Integrated Nanoparticle for Potential Second Treatment

We chemically integrated mesoporous silica nanoparticles (MSNs) and macroporous bowl-like polylactic acid (pBPLA) matrix, for noninvasive electrostatic loading and long-term controlled doxorubicin (DOX) release, to prepare a hierarchical porous bowl-like pBPLA@MSNs-COOH composite with a nonspherical and hierarchical porous structure. Strong electrostatic interaction with DOX rendered excellent encapsulation efficiency (up to 90.14%) to the composite. DOX release showed pH-dominated drug release kinetics; thus, maintaining a weak acidic pH (e.g., 5.0) triggered sustained release, suggesting the composites great potential for long-term therapeutic approaches. In-vitro cell viability assays further confirmed that the composite was biocompatible and that the loaded drugs were pharmacologically active, exhibiting dosage-dependent cytotoxicity. Additionally, a wound-healing assay revealed the composites intrinsic ability to inhibit cell migration. Moreover, pH- and time-dependent leaching of the integrated MSNs due to pBPLA matrix degradation allow us to infer that the leached (and drug loaded) MSNs may be engulfed by cancer cells contributing to a second wave of DOX-mediated cytotoxicity following pH-triggered DOX release.

Efficient capture, rapid killing and ultrasensitive detection of bacteria by a nano-decorated multi-functional electrode sensor

In this work, we demonstrated a nano-decorated porous impedance electrode sensor for efficient capture, rapid killing and ultrasensitive detection of bacteria. The multi-functional sensor was prepared by a facile sonochemical method via in situ deposition of antibacterial prickly Zn-CuO nanoparticles and graphene oxide (GO) nanosheets on a Ni porous electrode. Due to the surface burr-like nanostructures, the nano-decorated impedance sensor exhibited very good bacterial-capture efficiency (70 - 80% in 20min) even at a low concentration of 50 CFU mL-1, rapid antibacterial rate (100% killing in 30min) and high detection sensitivity (as low as 10 CFU mL-1). More importantly, the nano-decorated sensor has proven to be highly effective in quantitative detection of bacteria in a biological sample, for example, a rat blood sample spiked with E. coli. Despite the complexity of blood, the sensor still exhibited excellent detection precision within 30min at bacteria concentrations ranging from 10 - 105 CFU mL-1. The simplicity, rapidity, sensitivity, practicability and multifunctionality of this impedance sensor would greatly facilitate applications in portable medical devices for on-the-spot diagnosis and even the possibility for simultaneous therapy of diseases caused by bacterial infections.

A traceable porous bowl-like PLA@C-dots composite for in vitro drug delivery system: A case study of artemisinin.

Due to its excellent biocompatibility and biodegradability, poly(lactic acid) (PLA) has been extensively studied for controlled drug release [1]. Most of PLA-based drug delivery systems are spherical capsules or particles. However, recent studies have proven that non-spherical particles may be optimal for in vivo drug release [2]. Carbon dots (Cdots) as emerging bio-nontoxic luminescent materials have been extensively studied in target tracing. Artemisinin (ART) has special antitumor activity against melanoma, ovarian, breast, prostate, central nervous system, and renal cancer cell lines. However, it suffers many drawbacks such as low bio-availability, easy decomposition and high hydrophobicity. Herein, we have successfully produced a novel traceable porous bowl-like PLA@C-dots (TPBL-PLA@C-dots) composite, which can load ART through hydrogen bonding. The TPBL-PLA@C-dots composites were prepared by a modified emulsion-solvent evaporation method through electrostatic interaction of de-wetting process, a hydrolysis process and covalently bonding of C-dots afterwards (Fig. 1). The average size of TPBLPLA@C-dots and carbon dots were 8.0 μm and 4.0 nm, respectively, and they both exhibited strong luminescent under a 365 nm UV lamp. The loading efficiency of TPBL-PLA@C-dots was calculated to be as high as 169.26 μmol/g, and the ART was released in a sustained way. The as-prepared TPBL-PLA@C-dots composites with superior stability, reasonable drug loading and sustained release are promising for cancer chemotherapy.