title: Injectable and sustained delivery of human growth hormone using chemically modified Pluronic copolymer hydrogels.
abstract: A new injectable biodegradable hydrogel system with thermosensitive sol-gel transition behavior was developed. A series of A-B-A triblock copolymers consisting of Pluronic copolymer end-capped with D- or L-lactic acid oligomers (PL-LA(n)) with various chain lengths (n = 5,12) was synthesized. It was assumed that a pair of two triblock copolymers with enantiomeric oligolactide chains, when blended in an equimolar mixture, would form more stable, self-assembled, and stereocomplexed (ST) hydrogels. A series of blend hydrogels encapsulating human growth hormone (hGH) was prepared by varying blend ratios between PL and stereocomplexed PL copolymers. They showed sustained release of hGH via an erosion-dependent mechanism. The hydrogel with a 5% blending ratio exhibited the most delayed mass erosion as well as sustained protein release patterns in vitro possibly due to the formation of a fish-net like 3-D mesh structure. The effect of incubation condition on hGH release and degradation behaviors was also assessed.
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.
authors.forename: Sung Young
authors.initials: SY
authors.lastname: Park
authors.forename: Hyun Jung
authors.initials: HJ
authors.lastname: Chung
authors.forename: Yuhan
authors.initials: Y
authors.lastname: Lee
authors.forename: Tae Gwan
authors.initials: TG
authors.lastname: Park
mesh_terms: D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000737:chemistry*; D004058:Diffusion; D004353:Drug Evaluation, Preclinical; D019382:Human Growth Hormone / Q000008:administration & dosage* / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D007267:Injections; D008422:Materials Testing; D020442:Poloxamer / Q000737:chemistry*
chemical_list: D003692:Delayed-Action Preparations; D020100:Hydrogels; D020442:Poloxamer; D019382:Human Growth Hormone