title: Thermogelling aqueous solutions of alternating multiblock copolymers of poly(L-lactic acid) and poly(ethylene glycol).
abstract: We are reporting alternating multiblock copolymers of poly(L-lactic acid)/poly(ethylene glycol) aqueous solution (> 15 wt %) undergoing sol-gel-sol transition as the temperature increases from 20 to 60 degrees C. Micelles of the multiblock copolymers (in water) are about 20 nm in radius at low temperature. They are aggregated to a larger size as the temperature increases, which should play a critical role in the sol-to-gel transition. The transition temperature and gel window were affected by the molecular weight and composition of the multiblock copolymer. In particular, the aqueous solution of an alternating multiblock copolymer (Mn approximately 6700 daltons) prepared from poly(ethylene glycol) (Mn approximately 600 daltons) and poly(L-lactic acid) (Mn approximately 1300 daltons) showed a maximum modulus at body temperature (37 degrees C). The in situ gel forming ability of the polymer aqueous solution in vivo as well as in vitro indicates that it can be a promising injectable biomaterial.
authors.affiliation: Department of Chemistry, Division of Nano Sciences, Ewha Womans University, Daehyun-Dong, Seodaemun-Ku, Seoul, 120-750, Korea.
authors.forename: Jisun
authors.initials: J
authors.lastname: Lee
authors.forename: You Han
authors.initials: YH
authors.lastname: Bae
authors.forename: Youn Soo
authors.initials: YS
authors.lastname: Sohn
authors.forename: Byeongmoon
authors.initials: B
authors.lastname: Jeong
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000008:administration & dosage / Q000138:chemical synthesis / Q000737:chemistry*; D004353:Drug Evaluation, Preclinical; D005782:Gels / Q000008:administration & dosage / Q000737:chemistry; D019344:Lactic Acid / Q000138:chemical synthesis / Q000737:chemistry*; D008823:Micelles; D015394:Molecular Structure; D008970:Molecular Weight; D044367:Phase Transition; D011091:Polyesters; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D051381:Rats; D012680:Sensitivity and Specificity; D012996:Solutions / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D005782:Gels; D008823:Micelles; D011091:Polyesters; D011108:Polymers; D012996:Solutions; D014867:Water; D019344:Lactic Acid; D011092:Polyethylene Glycols; C033616:poly(lactide)