Kosuke Uehara1, Chunfeng Zhao1, Anne Gingery1, Andrew R Thoreson1, Kai-Nan An1, Peter C Amadio1. 1. Orthopedic Biomechanics and Tendon and Soft Tissue Biology Laboratories, Division of Orthopedic Research, and Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First Street S.W., Rochester, MN 55905. E-mail address for P.C. Amadio: pamadio@mayo.edu.
Abstract
BACKGROUND: Cell-based tissue engineering techniques have been introduced to improve tendon repair outcomes. The purpose of this study was to determine optimal concentrations of fibrinogen and thrombin for use as a scaffold to deliver stromal cells to the tendon repair site. METHODS: Lacerated flexor digitorum profundus tendons from forty canine forepaws underwent simulated repair with fibrin gel interposition. The tendons were divided into five groups with different ratios of fibrinogen (mg/mL) to thrombin (NIH units/mL) used to form the gels. These ratios, which ranged from those found in normal hemostasis to those used clinically as adhesives, were 5:25 (the physiological ratio, used as a control), 40:250 (a low adhesive concentration of fibrinogen and a low adhesive concentration of thrombin [low-low group]), 80:250 (high-low group), 40:500 (low-high group), and 80:500 (high-high group). The failure load and tensile stiffness at time zero, compressive stiffness of the fibrin gel, and cell viability and migration were evaluated. RESULTS: The failure loads of the high-low and high-high groups were significantly higher than that of the control group. The tensile stiffness of the high-high group was significantly higher than that of the control group. The high-low and high-high groups had significantly higher compressive stiffness than the other groups. While there was no significant difference among the groups regarding cell viability, the cells in the control, low-low, and low-high gels were spindle-shaped whereas those in the high-low and high-high groups were rounded. Cells migrated across scratch gaps within twenty-four hours in the control, low-low, and low-high groups, but not in the high-low and high-high groups. CONCLUSIONS: Higher concentrations of fibrinogen resulted in stronger and stiffer gels, but the strength was far less than that of a tendon suture and these gels were associated with a more rounded cell morphology and reduced cell migration. Therefore, lower concentrations of fibrinogen should be used if a fibrin gel is employed to deliver cells for tendon repair. CLINICAL RELEVANCE: Concentrations of fibrinogen lower than those used in fibrin glue may be more appropriate if fibrin is employed to create a cell delivery matrix for tendon repair.
BACKGROUND: Cell-based tissue engineering techniques have been introduced to improve tendon repair outcomes. The purpose of this study was to determine optimal concentrations of fibrinogen and thrombin for use as a scaffold to deliver stromal cells to the tendon repair site. METHODS: Lacerated flexor digitorum profundus tendons from forty canine forepaws underwent simulated repair with fibrin gel interposition. The tendons were divided into five groups with different ratios of fibrinogen (mg/mL) to thrombin (NIH units/mL) used to form the gels. These ratios, which ranged from those found in normal hemostasis to those used clinically as adhesives, were 5:25 (the physiological ratio, used as a control), 40:250 (a low adhesive concentration of fibrinogen and a low adhesive concentration of thrombin [low-low group]), 80:250 (high-low group), 40:500 (low-high group), and 80:500 (high-high group). The failure load and tensile stiffness at time zero, compressive stiffness of the fibrin gel, and cell viability and migration were evaluated. RESULTS: The failure loads of the high-low and high-high groups were significantly higher than that of the control group. The tensile stiffness of the high-high group was significantly higher than that of the control group. The high-low and high-high groups had significantly higher compressive stiffness than the other groups. While there was no significant difference among the groups regarding cell viability, the cells in the control, low-low, and low-high gels were spindle-shaped whereas those in the high-low and high-high groups were rounded. Cells migrated across scratch gaps within twenty-four hours in the control, low-low, and low-high groups, but not in the high-low and high-high groups. CONCLUSIONS: Higher concentrations of fibrinogen resulted in stronger and stiffer gels, but the strength was far less than that of a tendon suture and these gels were associated with a more rounded cell morphology and reduced cell migration. Therefore, lower concentrations of fibrinogen should be used if a fibrin gel is employed to deliver cells for tendon repair. CLINICAL RELEVANCE: Concentrations of fibrinogen lower than those used in fibrin glue may be more appropriate if fibrin is employed to create a cell delivery matrix for tendon repair.
Authors: Brian Miller; Seth D Dodds; Adam deMars; Niko Zagoreas; Thanapong Waitayawinyu; Thomas E Trumble Journal: J Hand Surg Am Date: 2007 May-Jun Impact factor: 2.230
Authors: Chunfeng Zhao; Hsiao-Feng Chieh; Karim Bakri; Jun Ikeda; Yu-Long Sun; Steven L Moran; Kai-Nan An; Peter C Amadio Journal: Med Eng Phys Date: 2009-09-06 Impact factor: 2.242
Authors: Thomas E Trumble; Nicholas B Vedder; John G Seiler; Douglas P Hanel; Edward Diao; Sarah Pettrone Journal: J Bone Joint Surg Am Date: 2010-06 Impact factor: 5.284
Authors: Stefan Hankemeier; Martijn van Griensven; Marco Ezechieli; Tanja Barkhausen; Matthew Austin; Michael Jagodzinski; Rupert Meller; Ulrich Bosch; Christian Krettek; Johannes Zeichen Journal: Arch Orthop Trauma Surg Date: 2007-06-14 Impact factor: 3.067
Authors: Kosuke Uehara; Chunfeng Zhao; Anne Gingery; Andrew R Thoreson; Kai-Nan An; Peter C Amadio Journal: J Orthop Sci Date: 2020-08-16 Impact factor: 1.805
Authors: Guidong Shi; Yicun Wang; Zhanwen Wang; Andrew R Thoreson; Daniel S Jacobson; Peter C Amadio; Atta Behfar; Steven L Moran; Chunfeng Zhao Journal: J Orthop Res Date: 2020-10-14 Impact factor: 3.102