title: Tuning the non-equilibrium state of a drug-encapsulated poly(ethylene glycol) hydrogel for stem and progenitor cell mobilization.
abstract: Injectable and biodegradable hydrogels have been increasingly studied for sustained drug delivery in various molecular therapies. However, it remains a challenge to attain desired delivery rate at injection sites due to local tissue pressures exerted on the soft hydrogels. Furthermore, there is often limited controllability of stiffness and degradation rates, which are key factors required for achieving desired drug release rate and therapeutic efficacy. This study presents a stiff and metastable poly(ethylene glycol) diacrylate (PEGDA)-poly(ethylene imine) (PEI) hydrogel which exhibits an elastic modulus equivalent to bulk plastic materials, and controllable degradation rate independent of its initial elastic modulus. Such unique stiffness was attained from the highly branched architecture of PEI, and the decoupled controllability of degradation rate was achieved by tuning the non-equilibrium swelling of the hydrogel. Furthermore, a single intramuscular administration of granulocyte colony stimulating factor (GCSF)-encapsulated PEGDA-PEI hydrogel extended the mobilization of mononuclear cells to four days. A larger yield of expanded CD34+ and CD31+ endothelial progenitor cells (EPCs) was also obtained as compared to the daily bolus administration. Overall, the hydrogel created in this study will be useful for the controlled and sustained delivery of a wide array of drug molecules.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Youyun
authors.initials: Y
authors.lastname: Liang
authors.forename: Tor W
authors.initials: TW
authors.lastname: Jensen
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Roy
authors.forename: Chaenyung
authors.initials: C
authors.lastname: Cha
authors.forename: Ross J
authors.initials: RJ
authors.lastname: Devolder
authors.forename: Richie E
authors.initials: RE
authors.lastname: Kohman
authors.forename: Bao Zhong
authors.initials: BZ
authors.lastname: Zhang
authors.forename: Kyle B
authors.initials: KB
authors.lastname: Textor
authors.forename: Lauretta A
authors.initials: LA
authors.lastname: Rund
authors.forename: Lawrence B
authors.initials: LB
authors.lastname: Schook
authors.forename: Yen Wah
authors.initials: YW
authors.lastname: Tong
authors.forename: Hyunjoon
authors.initials: H
authors.lastname: Kong
mesh_terms: D000818:Animals; D002642:Chick Embryo; D002645:Chickens; D016503:Drug Delivery Systems / Q000379:methods; D005260:Female; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D008810:Mice, Inbred C57BL; D011092:Polyethylene Glycols / Q000737:chemistry*; D016188:Receptors, Granulocyte Colony-Stimulating Factor / Q000008:administration & dosage / Q000737:chemistry; D013234:Stem Cells
chemical_list: D016188:Receptors, Granulocyte Colony-Stimulating Factor; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols