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The continuous use of nonsteroidal anti-inflammatory drugs such as ibuprofen frequently leads to some serious side-effects including stomach ulcers and bleeding. In this paper, two kinds of new biocompatible polyesters (PIGB, PIGH) and polyester-amide (PIGA) comprising biodegradable components (L-glutamic acid, 1,4-butanediol, and 1,6-hexanediol and 6-amino hexanol) and ibuprofen as pendant group have been prepared by the melting polycondensation. The chemical structures of the monomer and polymers are characterized by FTIR, 1H NMR spectrum, GPC, and contact angle measurements. The drug loading of ibuprofen reaches very high level (35–37%) for PIGB, PIGH, and PIGA carriers. The free ibuprofen molecules are released in vitro from polymer carriers in a controlled manner without a burst release, different from the release pattern observed in the other drug-encapsulated systems. It is also found that the different hydrophilicity among PIGB, PIGH, and PIGA plays a key role in the time-controlled release of ibuprofen. In addition, the viability of HeLa cells after 48 h of incubation reaches more than 100%, indicating no cytotoxicity for PIGB, PIGH, and PIGA carriers.

The cage-ladder-structure phosphorus-containing amino-functionalized polyhedral oligomeric silsesquinoxanes (CLNH2-POSS) have been synthesized through a facile catalyst-free hydrolytic condensation of 9,10-dihydro-9-oxa10-phosphaphenanthrene-10-oxide-vinyltrimethoxysilane (DOPO-VTMS) with 3-aminopropyl trimethoxysilane (KH540). The successful preparation of CLNH2-POSS has been proven by the characterization of Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy (1 H-NMR, 29Si-NMR), matrix-assisted laser desorption ionization time of flight (MALDITOF), and X-ray diffraction (XRD). Then flame retardant (FR) epoxy resins (EPs) were prepared by the addition of different content of CLNH2-POSS into EPs with thermal curing technology. The CLNH2-POSS showed good solubility in EP matrix. The well-dispersed CLNH2-POSS contributed to thermal, mechanical, and FR properties of EP. Dynamic scanning calorimetry nonisothermal curing scans showed that CLNH2-POSS had accelerating effect on the curing of EP. With the addition of only 3 wt% CLNH2-POSS (0.30% phosphorus loading), the limiting oxygen index value of the EP composite increased from 25.5 of pure EP to 31.8, and vertical burning (UL-94) V-0 ratings was achieved. In addition, the EP composites showed improved thermal and mechanical properties. The investigations on char residue and pyrolysis volatiles of cured EP further revealed that CLNH2-POSS exerted FR effects in condensed and gas phase simultaneously. [ABSTRACT FROM AUTHOR]

A pH/temperature and degradable-responsive hydrogel (PSMEA) was prepared from chitosan (CS), N-acryloylglycine methyl ester (NAGME), N-acryloylglycine ethyl ester (NAGEE), acrylic acid (AA), and N-methylenebisacrylamide (NMBA). The swelling properties of PSMEA were systematically investigated at different temperatures, pH, and CS contents. It was found that the PSMEA demonstrated obvious pH and temperature-responsive natures. The caffeine-release behaviors showed that only 42.9% caffeine was released from PSEMA in pH 2.1 phosphate buffer solution (PBS) after 360 min, whereas more than 71.5% caffeine was gradually diffused into pH 7.4 PBS over the same time interval. In addition, the caffeine release was much higher at 37.0°C than that at 14.0°C in PBS medium. The apparent degradability of PSMEA was also observed in the pH 7.4 PBS at 37.0°C through the chemical cleavage of CS. As seen from the results, PSEMA seems to be a potential application in the drug-delivery system controlled by the external pH value and temperature. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]