title: Peptide-functionalized thermo-sensitive hydrogels for sustained drug delivery.
abstract: In this study, a KRGDKK (Lys-Arg-Gly-Asp-Lys-Lys) peptide with a RGD sequence is utilized as a functional group to synthesize a novel thermo-sensitive hydrogel. The KRGDKK peptide prepared by a solid phase synthesis approach is coupled to the ends of a poly[(epsilon-caprolactone)-co-lactide]-poly(ethylene glycol)-poly[(epsilon-caprolactone)-co-lactide] (PCLA-PEG-PCLA) triblock copolymer to obtain peptide-PCLA-PEG-PCLA-peptide. The self-assembly behavior of both PCLA-PEG-PCLA and peptide-PCLA-PEG-PCLA-peptide copolymers in aqueous solution is investigated, and hydrogels prepared from PCLA-PEG-PCLA and peptide-PCLA-PEG-PCLA-peptide are also prepared. An in vitro cell viability study demonstrated that the peptide-PCLA-PEG-PCLA-peptide hydrogels do not exhibit an apparent cytotoxicity, which suggests that the hydrogels have promising potential as injectable drug-delivery systems. Furthermore, compared with the PCLA-PEG-PCLA hydrogels, the peptide-PCLA-PEG-PCLA-peptide hydrogels display improved mechanical properties because of hydrogen bonding between the amino groups of KRGDKK. An in vitro drug release study showed that the peptide-PCLA-PEG-PCLA-peptide hydrogels exhibit outstanding controlled release properties and the release of the drug could be sustained for more than a month without initial burst.
authors.affiliation: Key Laboratory of Biomedical Polymers of Ministry of Education & Department of Chemistry, Wuhan University, Wuhan 430072, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xun
authors.forename: De-Qun
authors.initials: DQ
authors.lastname: Wu
authors.forename: Ze-Yong
authors.initials: ZY
authors.lastname: Li
authors.forename: Hui-Yuan
authors.initials: HY
authors.lastname: Wang
authors.forename: Fu-Wei
authors.initials: FW
authors.lastname: Huang
authors.forename: Si-Xue
authors.initials: SX
authors.lastname: Cheng
authors.forename: Xian-Zheng
authors.initials: XZ
authors.lastname: Zhang
authors.forename: Ren-Xi
authors.initials: RX
authors.lastname: Zhuo
mesh_terms: D004317:Doxorubicin / Q000008:administration & dosage; D004337:Drug Carriers; D006367:HeLa Cells; D006801:Humans; D020100:Hydrogels; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D010455:Peptides / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*
chemical_list: D004337:Drug Carriers; D020100:Hydrogels; D008823:Micelles; D010455:Peptides; D011108:Polymers; D004317:Doxorubicin