title: Nondestructive method to evaluate the collagen content of fibrin-based tissue engineered structures via ultrasound.
abstract: In the field of tissue engineering, there is a growing need for quantitative methods to analyze in situ and in real time the tissue development in three-dimensional scaffolds. To evaluate the performance of cell-gel constructs in terms of extracellular matrix synthesis, we are still restricted to time-consuming histological and biochemical assays that are not able, as a destructive method, to monitor the tissue formation online. Ultrasound is a well-known noninvasive and nondestructive imaging method. Therefore, the potential of ultrasound for the quantitative in vitro evaluation of tissue development in fibrin-based tissue-engineered structures was evaluated in this study. As simplified parameter, the gray-scale values of ultrasound scans of cell-embedded fibrin gels were correlated with the hydroxyproline content and the histological and immunohistological images of the same gels at different culturing time points. The gray-scale value of the ultrasound demonstrated a good correlation with the hydroxyproline content (Pearson correlation coefficient of 0.98) as marker of collagen formation and with the histological findings. In conclusion, the described simple ultrasound method is a good tool to evaluate the collagen formation of fibrin-based tissue-engineered constructs and facilitates the broad use to monitor tissue development and remodeling in bioreactor systems.
authors.affiliation: Department of Tissue Engineering and Biomaterials, Institute of Applied Medical Engineering, Helmholtz Institute of the RWTH Aachen University, Aachen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kreitz
authors.forename: Guido
authors.initials: G
authors.lastname: Dohmen
authors.forename: Stefan
authors.initials: S
authors.lastname: Hasken
authors.forename: Thomas
authors.initials: T
authors.lastname: Schmitz-Rode
authors.forename: Petra
authors.initials: P
authors.lastname: Mela
authors.forename: Stefan
authors.initials: S
authors.lastname: Jockenhoevel
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003094:Collagen / Q000032:analysis*; D005109:Extracellular Matrix / Q000378:metabolism; D005337:Fibrin / Q000737:chemistry*; D005782:Gels; D006801:Humans; D006909:Hydroxyproline / Q000378:metabolism; D007150:Immunohistochemistry; D012756:Sheep; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*; D014465:Ultrasonics / Q000379:methods*
chemical_list: D005782:Gels; D005337:Fibrin; D003094:Collagen; D006909:Hydroxyproline