Correlation Between Tensile Strength and Collagen Content in Cultured Skin Substitutes
Abstract (Summary)Cultured skin substitutes (CSS) have been extremely important in the treatment of full-thickness wounds; especially, when autograft is not available. CSS consist of collagen-glycosaminoglycan substrates inoculated with cultured keratinocytes and fibroblasts. CSS are incubated at an air-liquid interface to stimulate maturation. During this maturation process, the CSS develop epidermal barrier, and an increase in tensile strength. The hypothesis for this study was that the increase in tensile strength was due to the synthesis and deposition of collagen by fibroblasts. To test this hypothesis, the tensile strength of the CSS (n=6) was tested on an Instron 4442, and the collagen content of the CSS (n=6) was determined on 7,14,21, and 28 days of incubation by a colorimetric assay specific for hydroxyproline. A negative correlation was determined (r=0.77, t=-5.67, p<0.0001) as the tensile strength increased while the collagen content decreased. A decrease in collagen content can be interpreted as a degradation of the bovine skin collagen (BSC) at a faster rate than the human collagen is synthesized and deposited during the incubation of CSS in vitro. In a separate experiment, CSS with both cell types were incubated in culture medium with 0.0 or 0.1mM of L-ascorbic acid 2-phosphate, a vitamin C analog. Both conditions showed a similar decrease in collagen content; and because vitamin C stimulates collagen synthesis, these results also indicated faster degradation of the BSC than synthesis and deposition of human collagen. Future experiments may elucidate whether greater degradation than synthesis is responsible for the observed decrease in collagen content in CSS over time.
School:University of Cincinnati
School Location:USA - Ohio
Source Type:Master's Thesis
Date of Publication:01/01/2005