title: A quantitative approach to scar analysis.
abstract: Analysis of collagen architecture is essential to wound healing research. However, to date no consistent methodologies exist for quantitatively assessing dermal collagen architecture in scars. In this study, we developed a standardized approach for quantitative analysis of scar collagen morphology by confocal microscopy using fractal dimension and lacunarity analysis. Full-thickness wounds were created on adult mice, closed by primary intention, and harvested at 14 days after wounding for morphometrics and standard Fourier transform-based scar analysis as well as fractal dimension and lacunarity analysis. In addition, transmission electron microscopy was used to evaluate collagen ultrastructure. We demonstrated that fractal dimension and lacunarity analysis were superior to Fourier transform analysis in discriminating scar versus unwounded tissue in a wild-type mouse model. To fully test the robustness of this scar analysis approach, a fibromodulin-null mouse model that heals with increased scar was also used. Fractal dimension and lacunarity analysis effectively discriminated unwounded fibromodulin-null versus wild-type skin as well as healing fibromodulin-null versus wild-type wounds, whereas Fourier transform analysis failed to do so. Furthermore, fractal dimension and lacunarity data also correlated well with transmission electron microscopy collagen ultrastructure analysis, adding to their validity. These results demonstrate that fractal dimension and lacunarity are more sensitive than Fourier transform analysis for quantification of scar morphology.
authors.affiliation: Division of Dermatologic & Cosmetic Surgery, The Mount Sinai Medical Center, New York, New York, USA.
authors.forename: Hooman
authors.initials: H
authors.lastname: Khorasani
authors.forename: Zhong
authors.initials: Z
authors.lastname: Zheng
authors.forename: Calvin
authors.initials: C
authors.lastname: Nguyen
authors.forename: Janette
authors.initials: J
authors.lastname: Zara
authors.forename: Xinli
authors.initials: X
authors.lastname: Zhang
authors.forename: Joyce
authors.initials: J
authors.lastname: Wang
authors.forename: Kang
authors.initials: K
authors.lastname: Ting
authors.forename: Chia
authors.initials: C
authors.lastname: Soo
mesh_terms: D000818:Animals; D002921:Cicatrix / Q000473:pathology*; D003094:Collagen / Q000378:metabolism; D020405:Dermis / Q000473:pathology / Q000648:ultrastructure; D016326:Extracellular Matrix Proteins / Q000172:deficiency / Q000378:metabolism; D005260:Female; D000071235:Fibromodulin; D005583:Fourier Analysis; D017709:Fractals; D005838:Genotype; D021621:Imaging, Three-Dimensional; D008297:Male; D051379:Mice; D018613:Microscopy, Confocal / Q000379:methods*; D011509:Proteoglycans / Q000172:deficiency / Q000378:metabolism
chemical_list: D016326:Extracellular Matrix Proteins; C000604332:Fmod protein, mouse; D011509:Proteoglycans; D000071235:Fibromodulin; D003094:Collagen