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The release of the water-soluble drug Captopril is controlled by tailoring the surface properties of mesoporous silica via stepwise silylation. The degree of silylation is manipulated by adjusting the initial concentration of silylanizing reagent (trimethylchlorosilane, TMCS). The silylanized and drug-loaded samples are characterized by powder X-ray diffraction, Fourier transform IR spectroscopy, N2 adsorption and desorption, 29Si cross-polarization magic angle spinning NMR spectroscopy, and transmission electron microscopy. The drug-loading amount is correlated to the Brunauer-Emmett-Teller surface area and surface hydrophilicity/hydrophobicity of the mesoporous silica material, while drug release profiles can be controlled by tailoring the surface properties and pore size.

A novel chitosan-based adsorbent (CCTE) was synthesized by the reaction between epichlorohydrin O-cross-linked chitosan and EDTA dianhydride under microwave irradiation (MW). The chemical structure of this new polymer was characterized by infrared spectra analysis, thermogravimetric analysis, and X-ray diffraction analysis. The results were in agreement with the expectations. The static adsorption properties of the polymer for Pb 2þ , Cu 2þ , Cd 2þ , Ni 2þ , and Co 2þ were investigated. Experimental results demonstrated that the CCTE had higher adsorption capacity for the same metal ion than the parent chitosan and cross-linked chitosan. In particular, the adsorption capacities for Pb 2þ and Cd 2þ were 1.28 mmol/g and 1.29 mmol/g, respectively, in contrast to only 0.372 mmol/g for Pb 2þ and 0.503 mmol/g for Cd 2þ on chitosan. Kinetic experiments indicated that the adsorption of CCTE for the above metal ions achieved the equilibrium within 4 h. The desorption efficiencies of the metal ions on CCTE were over 93%. Therefore, CCTE is an effective adsorbent for the removal and recovery of heavy metal ions from industrial waste solutions.

A novel chitosan-based adsorbent (CCTM) was prepared by the reaction of epichlorohydrin O-crosslinked chitosan with maleic anhydride under microwave irradiation. The chemical structure of this polymer was characterized by infrared spectroscopy and X-ray diffraction analyses. The effects of various variables such as degree of substitution, adsorption time, initial metal ion concentration, solution pH, and temperature, on the adsorption of Pb 2þ and Cu 2þ by CCTM were investigated. The results demonstrate that the microwave irradiation can remarkably enhance the reaction. CCTM has higher adsorption capacity than chitosan. The maximum adsorption capacities for Pb 2þ and Cu 2þ , with initial concentrations of 0.02 mol L À1 at pH 5, are 246.3 and 132.5 mg g À1 , respectively. The adsorbent can be recycled. These results have important implications for the design of effective chitosan-based adsorbents in the removal of heavy metal ions from wastewaters.

An enzyme and pH-responsive nanocomposite was constructed for sensitive intracellular drug release and photodynamic therapy (PDT). The novel nanoplatforms provide the potential application in cancer treatment.