title: A Small Chimeric Fibronectin Fragment Accelerates Dermal Wound Repair in Diabetic Mice.
abstract: Objective:During wound repair, soluble fibronectin is converted into biologically active, insoluble fibrils via a cell-mediated process. This fibrillar, extracellular matrix (ECM) form of fibronectin stimulates cell processes critical to tissue repair. Nonhealing wounds show reduced levels of ECM fibronectin fibrils. The objective of this study was to produce a small, recombinant wound supplement with the biological activity of insoluble fibronectin fibrils.Approach:A chimeric fibronectin fragment was produced by inserting the integrin-binding Arg-Gly-Asp (RGD) loop from the tenth type III repeat of fibronectin (FNIII10) into the analogous site within the heparin-binding, bioactive fragment of the first type III repeat (FNIII1H). FNIII1HRGDwas tested for its ability to support cell functions necessary for wound healing, and then evaluated for its capacity to accelerate healing of full-thickness dermal wounds in diabetic mice.Results:In vitro, FNIII1HRGDsupported cell adhesion, proliferation, and ECM fibronectin deposition. Application of FNIII1HRGDto dermal wounds of diabetic mice significantly enhanced wound closure compared with controls (73.9% ±4.1% vs. 58.1% ±4.7% closure on day 9, respectively), and significantly increased granulation tissue thickness (2.88 ± 0.75-fold increase over controls on day 14).Innovation:Recombinant proteins designed to functionally mimic the ECM form of fibronectin provide a novel therapeutic approach to circumvent diminished fibronectin fibril formation by delivering ECM fibronectin signals in a soluble form to chronic wounds.Conclusion:A small, chimeric fibronectin protein was developed. FNIII1HRGDdemonstrated enhanced bioactivityin vitroand stimulated wound repair in a murine model of chronic wounds.
authors.affiliation: Department of Biomedical Engineering, University of Rochester, Rochester, New York.; Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester, Rochester, New York.
authors.forename: Denise C
authors.initials: DC
authors.lastname: Hocking
authors.affiliation: Department of Biomedical Engineering, University of Rochester , Rochester, New York.
authors.forename: James R
authors.initials: JR
authors.lastname: Brennan
authors.affiliation: Department of Biomedical Engineering, University of Rochester , Rochester, New York.
authors.forename: Carol H
authors.initials: CH
authors.lastname: Raeman
keywords: diabetes; extracellular matrix; fibronectin; wound healing