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Thermosensitive Poly (thermosensitive + poly)
Selected AbstractsThermosensitive Poly[(2-(diethylamino)ethyl methacrylate)- co -(N,N -dimethylacrylamide)] Cryogels Prepared by a Two-Step Polymerization MethodMACROMOLECULAR MATERIALS & ENGINEERING, Issue 10 2006Tuncer Caykara Abstract Summary: Temperature-sensitive P(DEAEMA- co -DMAAm) cryogels with five different DMAAm contents were synthesized via a two-step polymerization method, the initial polymerization being conducted for various times at 22,°C, followed by polymerization at ,26,°C for 24 h. The influence of the first-step time and the content of DMAAm on the swelling ratio and network parameters such as the polymer/solvent interaction parameter, the average molecular mass between crosslinks, and the mesh size of the cryogels were reported and discussed. The swelling studies indicated that the swelling increased in the following order: 22C45,>,22C30,>,22C15,>,22C0. The cryogels exhibited swelling/deswelling transitions (reentrant phenomena) in water depending on temperature. These properties were attributed to the macroporous and regularly arranged network of the cryogels. Scanning electron microscope graphs reveal that the macroporous network structure of the cryogels can be adjusted by applying a two-step polymerization. Chemical structure of the P(DEAEMA- co -DMAAm) cryogels. [source] Injectable and thermosensitive poly(organophosphazene) hydrogels for a 5-fluorouracil deliveryJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2009Sun Mi Lee Abstract The drug solubility and its release profiles of an anticancer drug from an injectable thermosensitive poly(organophosphazene) hydrogel bearing hydrophobic L -isoleucine ethyl ester and hydrophilic ,-amino-,-methoxy-poly(ethylene glycol) with and without hydrolysis-sensitive glycyl lactate ethyl ester or functional glycyl glycine have been investigated. 5-Fluorouracil (5-FU) was used as a model anticancer drug. The aqueous solutions of 5-FU incorporated poly(organophosphazenes) were an injectable fluid state at room temperature and formed a transparent gel at body temperature. The poly(organophosphazene) solution could enhance the solubility of 5-FU and its solubility (34.26 mg/mL) was increased up to 10-fold compared to that in phosphate-buffered saline (3.39 mg/mL, pH 7.4, 4°C). The in vitro drug release profiles from poly(organophosphazene) hydrogels were established in phosphate-buffered saline at pH 7.4 at 37°C and the release of 5-FU was significantly affected by the diffusion-controlled stage. The results suggest that the injectable and thermosensitive poly(organophosphazene) hydrogel is a potential carrier for 5-FU to increase its solubility, control a relatively sustained and localized release at target sites and thus decrease systemic side effects. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Synthesis of poly(vinyl ether) polyols with pendant oxyethylene chains and properties of hydrophilic, thermo-responsive polyurethanes prepared therefromJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 7 2010Tamotsu Hashimoto Abstract Hydroxy-terminated telechelic poly(vinyl ether)s with pendant oxyethylene chains were synthesized by the reaction of the CH3CH(OCOCH3)O[CH2]4OCH(OCOCH3)CH3/Et1.5AlCl1.5/THF-based bifunctional living cationic polymers of 2-methoxyethyl vinyl ether (MOVE), 2-ethoxyethyl vinyl ether (EOVE), and 2-(2-methoxyethoxy)ethyl vinyl ether (MOEOVE) with water and the subsequent reduction of the aldehyde polymer terminals with NaBH4. The obtained poly(vinyl ether) polyols were reacted with an equimolar amount of toluene diisocyanates [a mixture of 2,4- (80%) and 2,6- (20%) isomers] to give water-soluble polyurethanes. The aqueous solutions of these polyurethanes caused thermally induced precipitation at a particular temperature depending on the sort of the thermosensitive poly(vinyl ether) segments containing oxyethylene side chains. These polyurethanes also function as polymeric surfactants, lowered the surface tension of their aqueous solutions. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1641,1648, 2010 [source] Synthesis and characterization of radio-opaque thermosensitive poly[N -isopropylacrylamide-2,2,-(ethylenedioxy)bis(ethylamine)-2,3,5-triiodobenzamide]POLYMER INTERNATIONAL, Issue 8 2009Christine M Leon Abstract BACKGROUND:In situ gelling polymers, like poly(N -isopropylacrylamide) (poly(NIPAAm)), have many potential medical applications due to their biocompatibility and thermosensitivity. RESULTS: Radio-opaque thermosensitive poly(NIPAAm) grafted with 10.7 wt% 2,2,-(ethylenedioxy)bis(ethylamine)-2,3,5-triiodobenzamide was successfully synthesized and characterized. The conjugated polymer showed good visibility with X-ray fluoroscopy. The polymer had a lower critical solution temperature of 30 °C after conjugation with triiodobenzamide as determined by cloud point determination and a transition peak temperature of 33.3 ± 0.57 °C as determined by differential scanning calorimetry. CONCLUSION: The polymer synthesized was highly visible under X-rays, based upon the percentage incorporation of triiodobenzamide. After conjugation of the NIPAAm to the triiodobenzamide through a bis(ethylamine) linkage, the resultant polymer retained lower critical solution temperature characteristics in a temperature region that makes it physiologically useful. Copyright © 2009 Society of Chemical Industry [source] | ||||||||||