Shun Yang

Visible-light degradable polymer coated hollow mesoporous silica nanoparticles for controlled drug release and cell imaging

A core-shell nanocomposite based on photo-degradable polymer coated hollow mesoporous silica nanoparticles (HMS) was successfully prepared for targeted drug delivery and visible-light triggered release, as well as fluorescence cell imaging. The HMS nanoparticles were first modified by the long-chain hydrocarbon octadecyltrimethoxysilane (C18) and fluorescent agent Rhodamine B isothiocyanate (RITC), and then encapsulated by a photodegradable amphiphilic copolymer via a self-assembly process. The obtained nanocarrier showed a high drug loading content due to the hollow core and mesopores of the HMS and could target folic acid receptor over-expressed tumor cells efficiently for conjugating folic acid (FA) in the amphiphilic polymer. The drug release could be triggered by the irradiation of green light (500-540 nm) due to the photodegradation of amphiphilic copolymer coated on the HMS. Furthermore, the targeted drug delivery and controlled release processes could be tracked by fluorescence imaging for the doping of RITC on the HMS. The In vitro results suggested that a smart visible light responsive drug delivery system was successfully prepared for the potential applications of cancer diagnosis and therapy.

A facile preparation of targetable pH-sensitive polymeric nanocarriers with encapsulated magnetic nanoparticles for controlled drug release

Novel multifunctional nanocomposites were successfully prepared for the controlled release of anti-cancer drug and magnetic resonance imaging (MRI) via a simple self-assembly process. In this strategy, superparamagnetic iron oxide nanoparticles (SPIONPs) were “fixed” between the hydrophobic segment of the pH-sensitive amphiphilic polymer (HAMAFA-b-DBAM) and the surface of hollow mesoporous silica nanoparticles (HMS) which were modified by the long-chain hydrocarbon octadecyltrimethoxysilane (C18). Since the amphiphilic polymer was conjugated with a folic acid (FA) group, the nanocomposites could target the folic acid receptor (FR) of over-expressed tumor cells efficiently. Moreover, high drug loading content was obtained simultaneously due to the hollow core of HMS. The loaded drug could release from the HMS core triggered by the mildly acidic pH environment in the cancer cells due to the hydrolysis of the pH-sensitive polymer shell. The targeting process of the nanocomposites could be easily tracked by MRI due to the magnetism of the SPIONPs. Therefore, a nanocarrier with high drug-loading capacity and controlled drug release property for tumor diagnosis and therapy was obtained via the self-assembly of HMS core, magnetic Fe3O4 nanoparticles and targetable pH-sensitive polymer shell.

A new magnetic nanocomposite for selective detection and removal of trace copper ions from water

A core–shell structured, magnetic nanocomposite (SDMA) modified by a new organic fluorescent probe and selective chelating groups was prepared for simultaneous detection and removal of low Cu2+ concentrations. A series of experiments was designed to detect and adsorb copper ions in aqueous solution via SDMA. Results showed that SDMA could detect Cu2+ from copper ion solution qualitatively and quantifiably with a certain degree of selectivity, and remove Cu2+ with a respectable removal efficiency of about 80%. In comparative adsorption experiments, the adsorption capacity of SDMA was significantly higher than that of another two common magnetic nanoadsorbents (Fe3O4@mSiO2–SH and Fe3O4@mSiO2–NH2). The adsorption behavior of SDMA was studied through equilibrium and kinetic experiments. The adsorption isotherm was perfectly fitted via the Freundlich model and the pseudo-second-order model could fit the kinetic adsorption. Moreover, the SDMA could reach the adsorption equilibrium in only 20 min, which showed a fast kinetic adsorption to Cu2+. Prepared SDMA can be an effective and potential nanoadsorbent for detecting and removing copper ions from wastewater.

Surface‐Nanoengineered Bacteria for Efficient Local Enrichment and Biodegradation of Aqueous Organic Wastes: Using Phenol as a Model Compound

Bacteria armed with thermally responsive silica nanoparticles are prepared for efficient biodegradation of phenol in water. The adsorption and release properties of thermally responsive silica nanoparticles under different temperatures can lead to a higher local concentration of phenol, which accelerates the biodegradation process.

A versatile and cost-effective reduced graphene oxide-crosslinked polyurethane sponge for highly effective wastewater treatment

Gradually deteriorating water quality caused by oil or chemical leakage and heavy metal wastewater discharge is becoming a global problem. To address this issue, a versatile absorbent material was designed and fabricated by coating reduced graphene oxide (rGO) on porous polyurethane (PU) sponges. Firstly, calcium carbonate nanoparticles (nano-CaCO3) and graphene oxide (GO) were added during the preparation of the PU sponge. A PU sponge with nanosized porous framework was obtained after etching the nano-CaCO3. After the reducing process, rGO was precisely coated on the prepared porous PU via crosslinking to obtain porous rGO-based PU sponge (porous PU@rGO). The physicochemical properties of the as-fabricated porous PU@rGO indicated that it was recyclable, hydrophobic and conductive. Batch experiments were carried out, and results suggested that porous PU@rGO has a widespread potential for applications in oil–water separation, the break-up of oil-in-water emulsions, as well as hazardous ion adsorption.