| Authors: | Nguyen, Tan D.; Liang, Rui; Woo, Savio L-Y.; Burton, Shawn D.; Wu, Changfu; Almarza, Alejandro; Sacks, Michael S.; Abramowitch, Steven. |
| Abstract: | The porcine small intestine submucosa, an extracellular matrix-derived bioscaffold (ECM-SIS), has been successfully used to enhance the healing of ligaments and tendons. Since the collagen fibers of ECM-SIS have an orientation of +- 30 Deg, its application in improving the healing of the parallel-fibered ligament and tendon may not be optimal. Therefore, the objective was to improve the collagen fiber alignment of ECM-SIS in vitro with fibroblast seeding and cyclic stretch. The hypothesis was that with the synergistic effects of cell seeding and mech. stimuli, the collagen fibers in the ECM-SIS can be remodeled and aligned, making it an improved bioscaffold with enhanced conductive properties. Three exptl. groups were established: group I (n = 14), ECM-SIS was seeded with fibroblasts and cyclically stretched; group II (n = 13), ECM-SIS was seeded with fibroblasts but not cyclically stretched; and group III (n = 8), ECM-SIS was not seeded with fibroblasts but cyclically stretched. After 5 days' expts., the scaffolds from all the three groups (n = 9 for group I; n = 8 for groups II and III) were processed for quantification of the collagen fiber orientation with a small-angle light scattering (SALS) system. For groups I and II, in which the scaffolds were seeded with fibroblasts, the cell morphol. and orientation and newly produced collagen fibrils were examd. with confocal fluorescent microscopy (n = 3/group) and transmission electronic microscopy (n = 2/group). The results revealed that the collagen fiber orientation in group I was more aligned closer to the stretching direction when compared to the other two groups. The mean angle decreased from 25.3 Deg to 7.1 Deg (p < 0.05), and the assocd. angular dispersion was also reduced (37.4 Deg vs. 18.5 Deg, p < 0.05). In contrast, groups II and III demonstrated minimal changes. The cells in group I were more aligned in the stretching direction than those in group II. Newly produced collagen fibrils could be obsd. along the cells in both groups I and II. This study demonstrated that a combination of fibroblast seeding and cyclic stretch could remodel and align the collagen fiber orientation in ECM-SIS bioscaffolds. The better-aligned ECM-SIS has the prospect of eliciting improved effects on enhancing the healing of ligaments and tendons. [on SciFinder (R)] |
