Tuesday, November 16, 2010

PEG/PLGA block copolymers thermogelation

The below article discusses the usage of PEG/PLGA thermosensitive polymers for drug delivery. Find these polymers at www.polyvivo.com, go to the link below or to the original source for full-text for the article. (note the below article did not not necessarily use an Akina product for this research). Abstract follows:

"The aqueous solutions of poly(ethylene glycol) grafted with poly(lactic acid-co-glycolic acid) flow freely at room temperature but form gels at higher temperature. The existence of micelles in water at low polymer concentration was confirmed by cryo-transmission electron microscopy and dye solubilization studies. The micellar diameter is about 9 nm, and the critical micelle concentration is in a range of 0.01-0.05 wt %. The critical gel concentration, above which a gel phase appears, was 16 wt %, and the sol-to-gel transition temperature was slightly affected by the concentration between 16 and 25 wt %. At sol-to-gel transition, viscosity and modulus increased abruptly, and 13C NMR showed molecular motion of hydrophilic poly(ethylene glycol) backbones decreased while that of hydrophobic poly(lactic acid-coglycolic acid) side chains increased. The hydrogel of PEG-g-PLGA with hydrophilic backbones was transparent during degradation and remained a gel for 1 week, suggesting a promising material for shortterm drug delivery."

B. Jeong, M.R. Kibbey, J.C. Birnbaum, Y.-Y. Won, A. Gutowska, Thermogelling Biodegradable Polymers with Hydrophilic Backbones: PEG-g-PLGA. Macromolecules 33(22) (2000) 8317-8322.

link to full-text
http://cobweb.ecn.purdue.edu/~yywon/publications/2000%20Macromolecules%2033(22)%208317-8322%20Thermogeling%20Biodegradable.pdf

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