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The purposes of this study were to develop and evaluate calcium pectinate/alginate microspheres (PAMs) and to exploit their pH-sensitive properties for colon-targeted delivery of encapsulated cisplatin. PAMs were prepared using an electrospraying method. The PAMs, as cores, were then coated with Eudragit S100 using a polyelectrolyte multilayer coating technique in aqueous solution. The morphology of the microspheres was observed under scanning electron microscopy. In vitro drug release studies were performed in simulated gastrointestinal fluid, and the results indicated that approximately 5 % of the cisplatin was released from the Eudragit S100-coated PAMs, and 51 % of the cisplatin was released from the uncoated PAMs at 1 h. The release of cisplatin from the Eudragit S100-coated PAMs was more sustained in simulated gastric fluid than in simulated intestinal fluid due to the increased solubility of the coating polymer in media with pH >7.0. Drug release from the Eudragit S100-coated PAMs was best described by the Higuchi's square root model. From these results, it was concluded that Eudragit S100-coated PAMs are a potential carrier for delivery of cisplatin to the colon.

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A sol-gel reaction was used to prepare core-shell nanoparticles of 5,10,15,20-tetrakis(pentafluorophenyl)-21H,23H-porphine (PF6) with titania (TiO 2 ) coating. PF6 molecules would self-assemble to form dispersed PF6 nanoparticles in water during dialysis. The resulting PF6-TiO 2 core-shell nanoparticle was characterized using several methods, revealing a thin TiO 2 layer coated on the surface of the PF6 nanoparticles and confirming the chemical composition of the coreshell structures. The absorption spectrum of the PF6-TiO 2 core-shell nanoparticle was extended to 300-500 nm, which greatly enhanced the photocatalytic efficiency in the visible light spectrum compared to that of bare TiO 2 .

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