Decontamination of Waste-water by Metal Phthalocyanines Encapsulated in Polymeric Microcapsules

Polymeric microcapsules encapsulating iron phthalocyanine (Fe-Pc) and zinc phthalocyanine (Zn-Pc) were successfully prepared in this study. Absorption spectra of polymeric microcapsules encapsulating metal phthalocyanines were measured in visible light range. It was expected from the results that the polymeric microcapsules encapsulating metal phthalocyanines showed high photocatalytic activity upon irradiation with visible light such as sunlight. The catalytic and phtocatalytic activities of encapsulated Fe-Pc and Zn-Pc were investigated in the decomposition of methylene blue in water. The encapsulatedd Fe-Pc with H(2)O(2) exhibited a high catalytic activity. Methlene blue was efficiently decomposed by interaction of Fe-Pc with H(2)O(2)

Emulsification Properties of Poly(lactide-block-ethylene glycol-block-lacticide) Block Polymers

Homo-and copolymers of poly(lactic acid) have gathered much attention because of their biodegradability and biocompatibility. They have numerous applications in the biomedical field due to their potential. In their polymers, we are interested in poly(lactic acid)-poly(ethylene glycol) block polymers. The amphiphilic triblock copolymers, poly(DL-lactic acid)-poly(ethylene glycol)-poly(DL-lactic acid)(PLEL), have known to be surface-active ability. Therefore, we have studied emulsification properties with the polymers. PLEL were prepared by ring-opening copolymerization of DL-lactide and poly(ethylene glycol) catalyzed by stannous 2-ethylhexanoate. We prepared ethyl acetate-water-PLEL emulsion and applied this emulsion to biodegradable polymer scaffolds. PLA scaffolds were prepared by an emulsion freeze-drying method. These scaffolds were made by varying water weight fraction. Their surface pore size became larger with increasing water weight fraction

Preparation of Biodegradable Polymer Microcapsules Enclosing Anti-mite Agent

Many kinds of mite was caused by allergy and sick house syndrome, so it has become one of the social problems. Farnesyl acetone is one of the most potent anti-mite agent. However the vapor pressure of farnesyl acetone is high even at room temperature. This indicates the anti-mite effect has not been sustained even though the agent has strong anti-mite effect. In this study, we attempted to prepare polylactide microcapsule with farnesyl acetone for the purpose of sustainable dosage form of anti-mite agent. Microcapsule was prepared by solvent evaporation, which was a method of microencapsulation. The effects of preparation conditions on the enclosing efficiency, the release of microcapsule and anti-mite effect of microcapsule were investigated

Formation of Crosslinked Polyurea Membrane by Phase Separation Method

This research was conducted to clarify the membrane formation mechanism of crosslinked polyurea microcapsules by phase separation method, specially the role of polymeric surfactant of poly(ethylene-alt-maleic anhydride),(poly(E-MA))at the interface of O/W emulsion. Because of its toxicity, alternative chemicals should be chosen. This understanding may make possible to find the alternative chemicals. It was found that poly(E-MA)was necessary for the formation of crosslinked polyurea membrane. The addition of sodium dodecyl sulfate (SDS) prohibited the membrane formation reaction at the interface, even in the care of poly(E-MA) concentration enough for polymeric microcapsule formation. From the results in this study, poly(E-MA) as polymeric surfactant was found to be adsorbed on the interface of O/W emulsion and provide the reaction site for the membrane formation of polymeric microcapsules

Synthesis of Novel Temperature-responsive Polymer Gel of Poly(aspartic acid)s

Recently, thermo-responsive polymer gels have been studied in various research fields such as drug delivery system. One of represetative thermo-responsive polymer gels is poly(N-isopropylacrylamide) gel (PNIPAAm) that has a rapid and reversible volume phase transition. However, PNIPAAm is not biodegradable, resulting in limitation of its use in medical fields. Novel thermo-responsive polymer gel was prepared by closslinking of isopropylamine modified poly(succinimide) (IPA-PSI) (Poly[α,β -(DL-aspartate isopropyl amide)-co-(succinimide)]) with hexamethylenediamine. Because of peptide bonds in backbone, therefore, it is expected to possess biodegradability and biocompatibility. These gels changed their volume in response to change of environment such as temperature, pH and concentration of salt in water. Crosslinkage density and substitution degree of IPA-PSI affected volume phase transition bahavior of the gel

Fertilizer Microencapsulated with Biodegradable Polymer

Many fertilizers are soluble in water, therefore their effect does not last for long time after fertilizing in soils. The nitrogenous fertilizers such as urea transported to groundwater cause serious agricultural contamination and health problems. To solve these problems, sustained release of fertilizer has attracted much attention. In this study, we attempted to prepare polylactide microcapsules with fertilizer by phase separation technique, which was a method of microencapsulation. Polylactide (PLA) was used as a biodegradable polymer bacause the biodegradable polymer has no influence on the soil and the ecosystem. The effect of preparation conditions such as stirring time and fertilizer concentration on morphology of microcapsule and on cumulative percentage released of enclosed urea was also investigated

Preparation of a Nanoscaled Poly(vinyl alcohol)/Hydroxyapatite/DNA Complex Using High Hydrostatic Pressure Technology for In Vitro and In Vivo Gene Delivery

Our previous research showed that poly(vinyl alcohol) (PVA) nanoparticles incorporating DNA with hydrogen bonds obtained by high hydrostatic pressurization are able to deliver DNA without any significant cytotoxicity. To enhance transfection efficiency of PVA/DNA nanoparticles, we describe a novel method to prepare PVA/DNA nanoparticles encapsulating nanoscaled hydroxyapatites (HAps) prepared by high hydrostatic pressurization (980 MPa), which is designed to facilitate endosomal escape induced by dissolving HAps in an endosome. Scanning electron microscopic observation and dynamic light scattering measurement revealed that HAps were significantly encapsulated in PVA/HAp/DNA nanoparticles. The cytotoxicity, cellular uptake, and transgene expression of PVA/HAp/DNA nanoparticles were investigated using COS-7 cells. It was found that, in contrast to PVA/DNA nanoparticles, their internalization and transgene expression increased without cytotoxicity occurring. Furthermore, a similar level of transgene expression between plasmid DNA and PVA/HAp/DNA nanoparticles was achieved using in vivo hydrodynamic injection. Our results show a novel method of preparing PVA/DNA nanoparticles encapsulating HAp nano-crystals by using high hydrostatic pressure technology and the potential use of HAps as an enhancer of the transfection efficiency of PVA/DNA nanoparticles without significant cytotoxicity

Preparation and In Vitro Release Property of PLA Microspheres Enclosing Antitumor Agent

Recently, many antitumor agents developed. Irinotecan hycrochloride (CPT) has a great side effect even though it is well effective against the cancer. Drug delivery system (DDS) medicine indicates that the release rate of medicine is constant for a long time. Therefore, in order to materialize the general idea of DDS, we applied microencapsulation technique to prepare biodegradable polymer microspheres (MS) enclosing antitumor drug having no side effect. Polylactide microparticles enclosing antitumor agent were prepared by solvent evaporation method under various operation conditions. The effects of operation parameter on release rate of drug and morphology of microparticles were studied

Preparation of Monodispersed Hydrophilic Polymer Microspheres in Gel Permeation Chromatography

Monodispersed porous polymer microspheres having diameter of ca. 50 μm were successfully prepared by suspension polymerization of styrene, polyoxyethylene methacrylate and ethylenegycol dimethacrylate. Monodispersed O/W emulsion was firstly made by SPG membrane emulsification technique, following droplets-swelling method of monodispersed seed emulsion by the addition of secondary emulsion. The effect of solvent used in suspension polymerization on porous structure of prepared polymer microspheres was investigated in this paper by identification with scanning electron microscopy, porosimeter and the performance in gel permeation chromatography. It was found that benzene, 1-butanol and butyl acetate worked as poor solvent for polymer prepared in this study and that polymer microspheres prepared with these solvents had larger pores. Gel permeation chromatography measurements indicates that polystyrene having molecular weight smaller than 50,000-100,000 can be clearly separated by using gel columns packed with polymer microspheres prepared with poor solvents