Microwave-assisted sol-gel synthesis of hydroxyapatite nanoparticles

A rapid sol-gel method for preparing hydroxyapatite nanoparticles(nHAP) has been developed. Three different sets of experimental conditions, in terms of solvents(water and ethanol), synthesis temperatures(25, 40 and 60℃), and microwave irradiation(on and off) were explored. Crystal phase composition, functional groups and morphology of the products were characterized by thermogravimetric analysis(TGA), X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FT-IR), scanning electron microscopy(SEM) and transmission electron microscopy(TEM). The solvent and temperature were optimized based on product properties. Most importantly, the microwave-assisted method(with little to no ageing necessary) was much faster than the conventional methods(with slow ageing processes needing from hours to days), while affording pure nHAP with virtually identical morphological and structural properties. This study represents a practical application of the powerful microwave technique in synthesis of nHAP, offering guidance on the selection of optimum experiment conditions.

Paclitaxel Prodrug Nanomedicine for Potential CT-imaging Guided Breast Cancer Therapy

Nanotheranostics,which combine the therapeutic and diagnostic functions in one integrated system,have received extensive attentions in cancer treatments because they enable non-invasive diagnosis,tumor-targeted drug delivery,and real-time monitoring of therapeutic response.However,due to the high systemic toxicity of commonly used chemotherapeutics,current treatment still has limitations.Herein,to simultaneously achieve safe cancer therapy and therapeutic response monitoring,an iodinated prodrug strategy was proposed.2,3,5-Triiodobenzoic acid(TIBA)was used to modify both paclitaxel(PTX)and the polymeric vehicle,so that the encapsulation efficiency of PTX could be increased and the systemic toxicity could be reduced.As-prepared prodrug nanoparticles could accumulate passively in the tumor site and promptly release loaded drugs in response to the overexpressed GSH in cancer cells,which then caused efficient cell cycle arrest and apoptosis like that of the parent PTX.With this rational design,safe and efficient antitumor therapy and real-time computer tomography(CT)imaging could be simultaneously realized,facilitating potential CT imaging-guided therapy of metastatic breast cancer.

Folic Acid Modified Polymeric Micelles for Intravesical Instilled Chemotherapy

In this study, a targeting micellar drug delivery system was developed for intravesical instilled chemotherapy of bladder cancer. The amphiphilic diblock copolymer poly（？-caprolactone）-block-poly（ethylene glycol）（PCL-b-PEO） with functional amino group（NH2） at the end of PEO block was synthesized. Then the copolymer was conjugated with folic acid（FA） and fluorescein isothiocyannate（FITC） via the PEO-NH2 terminus, and then assembled into micelles with the target moiety and fluorescence labeling. In addition, drug loaded micelles were also fabricated with anticancer drug doxorubicin（DOX） encapsulated in the hydrophobic core. The micelles were characterized in terms of size, drug loaded efficiency and critical micellization concentration（CMC） by means of DLS, UV and fluorescence spectra. In vitro cellular uptake and cytotoxicity studies showed that FA modified PCL-b-PEO-FA micelles have a greater targeting efficiency to human bladder cancer cell（T-24 cell） compared to PCL-b-PEO-NH2 micelles due to the conjugation of FA on the surface, while no targeting effect to normal tissue originated human embryonic kidney 293（HEK-293） cells was observed, enabling the micelles a promising drug carrier for intravesical instilled chemotherapy of bladder cancer.

Naphthalene diimide based near-infrared luminogens with aggregation-induced emission characteristics for biological imaging and high mobility ambipolar transistors

Organic conjugated materials combining high conductivity with strong solid-state emission are highly desired for organic electronic applications,yet still rather rare.Herein,a novel luminogen(TEN)comprised by linking naphthalene diimides and triphenyl ethylene with vinyl bridges is reported.TEN exhibits aggregation-induced emission(AIE)behavior of a strong nearinfrared fluorescence over 700 nm and the efficiency above 60.5%in the solid state,while also shows promising application in vivo bio-imaging with good permeability and extremely low background.Single crystal of TEN reveals intra-and intermolecular C–H…O hydrogen bonds,contributing to an inclined molecular stacking along the a-axis of the cell,creating a 1 D charge carrier transporting channel under a shortπ-πinteraction distance of 3.42?,which might benefit the solid emission and charge transport ability simultaneously.Solution processed bottom contact,top gate organic field effect transistors based on TEN reveal a high ambipolar charge transport ability with the hole mobility up to 0.13 cm2 V-1 s-1 and electron mobility up to0.010 cm2 V-1 s-1.Further atomic force microscopy and X-ray diffraction analysis on TEN thin film confirm the existence of the1 Dπ-πstacking channel,suggesting the stacking geometry revealed in crystal crucial for facilitating high charge carrier mobility while preserving the strong solid emission at the same time.

Effect of Microwave Irradiation on Dipeptides and Proteins Derived from Silk During Solvation

Silkworm silk and spider silk have been attracting numerous interests.Rapid solvation of silkworm silk protein and spider silk protein without hydrolysis of peptide bonds is highly desirable.Microwave irradiation has been proposed for facile extraction of water-soluble silk protein by various liquid media.However,microwave exposure can cause hydrolysis of peptide bonds,leading to irreversible degradation of silk protein.In this study,a series of representative dipeptides and a rationally designed recombinant protein derived from silk protein is employed to investigate the efect of microwave on the stability of the peptide bonds during a long time dissolution process,i.e.,heating at 60℃in a CaCl_(2):CH_(3)CH_(2)OH:H_(2)O(1:2:8)solution.Results demonstrate that microwave irradiation imposes a minor damage and a negligible cleavage of the peptide bonds,compared with the conventional heating method.The microwave irradiation treatment suggested in this is suitable for dissolution of silk protein.It is anticipated that this approach can be developed to a commercial level commercially.