title: Sustained Delivery of Chemokine CXCL12 from Chemically Modified Silk Hydrogels.
abstract: A delivery platform was developed using silk-based hydrogels, and sustained delivery of the cationic chemokine CXCL12 at therapeutically relevant doses is demonstrated. Hydrogels were prepared from plain silk and silk that had been chemically modified with sulfonic acid groups. CXCL12 was mixed with the silk solution prior to gelation, resulting in 100% encapsulation efficiency, and both hydrated and lyophilized gels were compared. By attaching a fluorescein tag to CXCL12 using a site-specific sortase-mediated enzymatic ligation, release was easily quantified in a high-throughput manner using fluorescence spectroscopy. CXCL12 continually eluted from both plain and acid-modified silk hydrogels for more than 5 weeks at concentrations ranging from 10 to 160 ng per day, depending on the gel preparation method. Notably, acid-modified silk hydrogels displayed minimal burst release yet had higher long-term release rates compared to those of plain silk hydrogels. Similar release profiles were observed over a range of loading capacities, allowing dosage to be easily varied.
authors.affiliation: Department of Chemistry, Western Washington University, Bellingham, Washington 98225, United States.
authors.forename: Paige N
authors.initials: PN
authors.lastname: Atterberry
authors.affiliation: Department of Chemistry, Western Washington University, Bellingham, Washington 98225, United States.
authors.forename: Travis J
authors.initials: TJ
authors.lastname: Roark
authors.affiliation: Department of Chemistry, Western Washington University, Bellingham, Washington 98225, United States.
authors.forename: Sean Y
authors.initials: SY
authors.lastname: Severt
authors.affiliation: Department of Chemistry, Western Washington University, Bellingham, Washington 98225, United States.
authors.forename: Morgan L
authors.initials: ML
authors.lastname: Schiller
authors.affiliation: Department of Chemistry, Western Washington University, Bellingham, Washington 98225, United States.
authors.forename: John M
authors.initials: JM
authors.lastname: Antos
authors.affiliation: Department of Chemistry, Western Washington University, Bellingham, Washington 98225, United States.
authors.forename: Amanda R
authors.initials: AR
authors.lastname: Murphy
mesh_terms: D054377:Chemokine CXCL12 / Q000138:chemical synthesis / Q000737:chemistry*; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry*; D047011:Silk / Q000138:chemical synthesis / Q000737:chemistry*; D013451:Sulfonic Acids / Q000737:chemistry
chemical_list: C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D020100:Hydrogels; D047011:Silk; D013451:Sulfonic Acids