Mengge Xia

NIR‐Laser‐Switched In Vivo Smart Nanocapsules for Synergic Photothermal and Chemotherapy of Tumors

In vivo MEO2 MA@MEO2 MA-co-OEGMA-CuS-DOX (G-CuS-DOX) nanocapsules increase the temperature of tumors from room temperature to 57 °C due to the photothermal effect under irradiation from a 915-nm laser. When the temperature exceeds 42 °C, photothermal therapy of G-CuS-DOX is switched on. Simultaneously, higher temperatures (>LCST, 42 °C) induce volume shrinkage of G-CuS-DOX in vivo, leading to the controllable release of the anticancer drug DOX. If the NIR laser is switched off, both therapy effects are interrupted immediately.

A Novel Nanocomposite Hydrogel with Precisely Tunable UCST and LCST

Novel thermosensitive nanocomposite (NC) hydrogels consisting of organic/inorganic networks are prepared via in situ free radical polymerization of 2-(2-methoxyethoxy) ethyl methacrylate (MEO2 MA) and oligo(ethylene glycol) methacrylate (OEGMA) in the presence of inorganic cross-linker clay in aqueous solution. The obtained clay/P(MEO2 MA-co-OEGMA) hydrogels exhibit double volume phase transition temperatures, an upper critical solution temperature (UCST), and a lower critical solution temperature (LCST), which can be controlled between 5 and 85 °C by varying the fraction of OEGMA units and the weight percentage of cross-linker clay. These new types of NC hydrogels with excellent reversible thermosensitivity are promising for temperature-sensitive applications such as smart optical switches.

Optimization of photothermal performance of hydrophilic W18O49 nanowires for the ablation of cancer cells in vivo

Near-infrared (NIR) laser-induced photothermal ablation (PTA) therapy has great potential to revolutionize conventional therapeutic approaches for cancers, and a prerequisite is to obtain biocompatible and efficient photothermal agents. Herein, we have developed hydrophilic W18O49 nanowires with average lengths of about 800 nm (abbreviated as W18O49-800 NWs) as an efficient photothermal agent, which are prepared by the solvothermal synthesis-simultaneous PEGylation/exfoliation/breaking two-step route. These W18O49-800 NWs exhibit stronger NIR photoabsorption than short nanowires with average lengths of about 50 nm (abbreviated as W18O49-50 NWs) that are prepared via a solvothermal one-step route. Under irradiation of 980 nm with a safe intensity of 0.72 W cm-2, the aqueous dispersion of W18O49-800 NWs (1.0 mg mL-1) exhibits the temperature elevation by 35.2 °C in 5 min; which is a 37.5% increase compared to that (by 25.6 °C) from W18O49-50 NWs (1.0 mg mL-1). More importantly, under 980 nm laser irradiation (0.72 W cm-2) for 10 min, in vivo cancer cells can be efficiently ablated by the photothermal effects of W18O49-800 NWs. Therefore, these W18O49-800 NWs can be used as a more efficient and promising photothermal nanoagent for the ablation of cancer cells in vivo.

Mechanical properties of biocompatible clay/P(MEO2MA-co-OEGMA) nanocomposite hydrogels

The effects of crosslinking density, polymer concentration and monomer ratio on the mechanical properties (tensile and compressive properties) of biocompatible clay/P(MEO2MA-co-OEGMA) nanocomposite (NC) hydrogels were investigated. These novel NC hydrogels, composed of inorganic/organic networks, were prepared via in-situ free radical polymerization. The results showed that with increasing inorganic crosslinking agent, i.e. clay concentration, an increase in the tensile strength, elongation at break and compressive strength was observed. Similarly, with increasing polymer concentration, the tensile strength and compressive strength of the NC hydrogels increased while the elongation at break decreased. Increasing the molar concentration of OEGMA in the comonomer led to an increase in the tensile strength of the NC hydrogels but a reduction in the compressive strength. Moreover, clay/P(MEO2MA-co-OEGMA) NC hydrogels presented good biocompatibility bolstering their application as tissue engineering scaffolds.

A Facile Approach to Fabrication of Novel Magnetic Hydrogels Crosslinked by Multi-Functional Pomegranate-Like Nanospheres

A facile approach was explored to fabricate a novel magnetic hydrogel using pomegranate-like functional magnetic nanospheres (FMNs) as photoactive crosslinker and polyacrylamide as polymer matrix by photoinitiated free radical polymerization. These novel pomegranate-like FMNs were prepared by embedding Fe3O4 nanoparticles into polystyrene by miniemulsion polymerization. The effect of FMN concentration, acrylamide monomer molar concentration, polymerization time on the magnetic properties, morphology, swelling behaviour, and dynamic mechanical properties of magnetic hydrogels were systematically investigated. Our synthetic route expands the application of these materials in the fields of smart magnetic switches, targeted drug release, biomimetic sensors, and chemical devices.

Tumor Therapy: NIR‐Laser‐Switched In Vivo Smart Nanocapsules for Synergic Photothermal and Chemotherapy of Tumors (Adv. Mater. 2/2016)

Under the irradiation of a 915 nm laser, MEO2 MA@MEO2 MA-co-OEGMA-CuS-DOX (G-CuS-DOX) nanocapsules increase the temperature of tumors (T). As described by Z. G. Chen, H. P. Wang, M. F. Zhu, and co-workers on page 245, when T exceeds 42 °C, synergic photothermal-/chemotherapy can be controllably switched on, resulting in efficient destruction of cancer cells in vivo.

Design and fabrication of novel organic/inorganic thermoresponsive hydrogels with excellent mechanical properties

Abstract A novel hybrid hydrogels were synthesised by using inorganic clay as physical cross-linker and 2-(2-methoxyethoxy) ethyl methacrylate (MEO2MA) and oligo(ethylene glycol) methacrylate (OEGMA) as comonomer via in situ free radical polymerisation. These hydrogels were characterised by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). In addition, this new kind of organic/inorganic hybrid hydrogels exhibit remarkably thermoresponsiveness. The effect of clay content on the morphology, swelling/deswelling behaviours, temperature responsiveness, and mechanical properties of hybrid hydrogels were systematically investigated. The development of hybrid hydrogels will provide a new avenue for stimuli-responsive and biocompatible hydrogels, this novel kind of thermosensitive nanocomposite hydrogels promise to be interesting for the use in various applications.

Surface modification of quartz fibre and its reinforced bis-GMA/MMA composites for dental post

Abstract A kind of bis-phenol-A-glycidyl dimethacrylate (bis-GMA)/methyl methacrylate (MMA) composite based dental post reinforced by quartz fibres (QFs) was prepared in this paper. Different factors were investigated to observe their influences on the mechanical properties of quartz fibre reinforced composite (QFRC) dental post, including the surface etching, silanisation grafting to QFs and the volume fraction of QFs. 3-methacryloxypropyl trimethoxysilane (γ-MPS) and 3-aminopropyl triethoxysilane (APTES) were used to graft to QFs to enhance compatibility of fibres and resins, and they were grafted to QFs successfully with different grafting ratios, which were confirmed by results of Fourier transform infrared spectroscopy (FTIR), Thermal gravimetric analysis (TGA) and contact angle measurements. The sorption and solubility in artificial saliva (AS) of QFRC post was also studied by soaking in AS for 4 weeks to compare weight changes and mechanical properties. Mechanical testing results suggested that QFRC posts with QFs grafted by APTES presented better properties and the optimal flexural strength and modulus were up to 620·3 MPa and 21·6 GPa respectively, which is outstanding in similar materials and suitable for the clinical application.