정병문 교수

Aqueous solutions of new biodegradable triblock copolymers, poly(ethylene glycol-b-(dl-lactic acid-co-glycolic acid)-b-ethylene glycol) (PEG−PLGA−PEG), have shown to have sol-to-gel (lower transition) and gel-to-sol (upper transition) transitions as temperature monotonically increases. The lower transition is important for drug delivery application because the solution flows freely at room temperature and becomes a gel at body temperature. In this paper, the mechanism of gelation was proposed, a

Aqueous solutions that undergo sol-to-gel transition as the temperature increases have been extensively studied during the last decade. The material can be designed by controlling the hydrophilic and hydrophobic balance of the material. Basically, the molecular weight of the hydrophilic block and hydrophobic block of a compound should be fine-tuned from the synthetic point of view. In addition, stereochemistry, microsequence, topology, and nanostructures of the compound also affect the transitio

Aqueous solutions of poly(ethylene glycol-b-[DL-lactic acid-co-glycolic acid]-b-ethylene glycol) (PEG-PLGA-PEG) triblock copolymers form a free-flowing sol at room temperature and become a gel at body temperature. In this study, in situ gel formation was investigated in rats. Upon subcutaneous injection of 33 wt % aqueous solutions of PEG-PLGA-PEG triblock copolymer into rats, transparent gels were observed. The gel showed good mechanical strength and the integrity of gels persisted longer than

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 %

This paper reports on the thermogelling, biodegradable polymer formulations based on poly(DL-lactic acid-co-glycolic acid)/(poly(ethylene glycol) graft copolymers for in vivo biomedical applications using animal models. The description includes diabetic control by sustained insulin delivery and cartilage repair by chondrocyte cell delivery. With one injection of the poly(DL-lactic acid-co-glycolic acid)/(poly(ethylene glycol) graft copolymers insulin formulation, the blood glucose level could be

The gel to sol transition of aqueous solutions of di- and triblock copolymers consisting of poly(ethylene oxide) and biodegradable polyesters was studied as a function of temperature. The molecular weight and the chemical composition of the biodegradable blocks, (poly(l-lactic acid), poly(dl-lactic acid), poly(dl-lactic acid-co-caprolactone), and poly(dl-lactic acid-co-glycolic acid)) were varied to investigate the effects of chain packing and relative hydrophobicity on the gel to sol transition