title: Injectable supramolecular hydrogel from insulin-loaded triblock PCL-PEG-PCL copolymer and γ-cyclodextrin with sustained-release property.
abstract: Supramolecular hydrogels formed by cyclodextrins and polymers have been widely investigated as a biocompatible, biodegradable and controllable drug delivery system. In this study, a supramolecular hydrogel based on biodegradable poly(caprolactone)-poly(ethylene glycol)-poly(caprolactone) (PCL-PEG-PCL) triblock copolymers and γ-cyclodextrin (γ-CD) was prepared through inclusion complexation as an injectable, sustained-release vehicle for insulin. The triblock copolymer PCL-PEG-PCL was synthesised by the ring-opening polymerisation method, using microwave irradiation. The polymerisation reaction and the copolymer structures were evaluated by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The supramolecular hydrogel was prepared in aqueous solution by blending an aqueous γ-CD solution with an aqueous solution of PCL-PEG-PCL triblock copolymer at room temperature. In vitro insulin release through the hydrogel system was studied. The relative surface hydrophobicity of standard and released insulin from the SMGel was estimated using 8-anilino-1-naphthalene sulfonic acid (ANS). Results of (1)HNMR and gel permeation chromatography revealed that microwave irradiation is a simple and reliable method for synthesis of PCL-PEG-PCL copolymer. Gelation occurred within a minute. The supramolecular hydrogel obtained by mixing 10.54% (w/v) γ-CD and 2.5% (w/v) copolymer had an excellent syringeability. Insulin was released up to 80% over a period of 20 days. Insulin kept its initial folding after formulating and releasing from SMGel. A supramolecular hydrogel based on complexation of triblock PCL-PEG-PCL copolymer with γ-cyclodextrin is a suitable system for providing sustained release of therapeutic proteins, with desirable flow behaviour.
authors.affiliation: Targeted Drug Delivery Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Elham
authors.initials: E
authors.lastname: Khodaverdi
authors.forename: Zinat
authors.initials: Z
authors.lastname: Heidari
authors.forename: Sayyed A Sajadi
authors.initials: SA
authors.lastname: Tabassi
authors.forename: Mohsen
authors.initials: M
authors.lastname: Tafaghodi
authors.forename: Mona
authors.initials: M
authors.lastname: Alibolandi
authors.forename: Farnaz Sadat Mirzazadeh
authors.initials: FS
authors.lastname: Tekie
authors.forename: Bahman
authors.initials: B
authors.lastname: Khameneh
authors.forename: Farzin
authors.initials: F
authors.lastname: Hadizadeh
mesh_terms: D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000138:chemical synthesis*; D004058:Diffusion; D004339:Drug Compounding / Q000379:methods; D004355:Drug Stability; D020100:Hydrogels / Q000737:chemistry*; D007267:Injections; D007328:Insulin / Q000008:administration & dosage* / Q000737:chemistry*; D046911:Macromolecular Substances / Q000138:chemical synthesis; D011091:Polyesters / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D047408:gamma-Cyclodextrins / Q000737:chemistry*
chemical_list: D003692:Delayed-Action Preparations; D020100:Hydrogels; D007328:Insulin; D046911:Macromolecular Substances; D011091:Polyesters; D047408:gamma-Cyclodextrins; C515340:poly(epsilon-caprolactone)-b-poly(ethyleneglycol)-b-poly(epsilon-caprolactone); D011092:Polyethylene Glycols; C023792:gamma-cyclodextrin