Departments of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Invest Ophthalmol Vis Sci. 2012 Dec 13;53(13):8192-9. doi: 10.1167/iovs.12-10561.
To investigate compositions of silica-collagen hybrid materials as potential artificial corneal substitutes, how these components affect the optical and biomechanical properties of the hybrids, and their biocompatibility in an organ culture model.
Hybrid materials were created from different proportions of collagen and silica precursors and manufactured to specific dimensions. The microstructure of the materials was determined by electron microscopy and mechanical strength was measured by using suture pullout tests. The refractive index and transmittance were measured by using an Abbe refractometer and a spectrophotometer. Materials were implanted into rabbit corneas to determine their epithelialization in organ culture.
Scanning electron microscopy demonstrated that the hybrid material consisted of silica-encapsulating collagen fibrils. The refractive index ranged from 1.332 to 1.403 depending upon the composition and manufacturing characteristics. The rupture strength of a 3:1 (silica:collagen ratio by weight) rehydrated xerogel was 0.161 ± 0.073 N/mm (n = 12), while the hydrogels and 9:1 xerogel were too fragile for suturing. Re-epithelialization of 5- to 6-mm-wide rabbit corneal epithelial defects was complete in 5.5 ± 2.4 days (n = 6), with evidence of epithelial stratification.
Silica-collagen hybrid materials can be manufactured to specific dimensions to serve as a possible artificial corneal substitute. In preliminary studies, the materials had favorable optical, biomechanical, and biocompatibility properties necessary for replacing the corneal stroma.
研究硅胶原杂化材料的组成作为潜在的人工角膜替代物，这些成分如何影响杂化材料的光学和生物力学性能，以及它们在器官培养模型中的生物相容性。
通过使用不同比例的胶原和硅前体来制备杂化材料，并将其制成特定的尺寸。通过电子显微镜确定材料的微观结构，通过缝线拔出试验测量机械强度。使用阿贝折射仪和分光光度计测量折射率和透光率。将材料植入兔角膜，以确定其在器官培养中的上皮化情况。
扫描电子显微镜显示，杂化材料由包裹胶原原纤维的二氧化硅组成。折射率取决于组成和制造特性，范围从 1.332 到 1.403。3:1（重量比的二氧化硅：胶原）复水的干凝胶的破裂强度为 0.161±0.073 N/mm（n=12），而水凝胶和 9:1 干凝胶太脆弱，无法缝合。兔角膜上皮缺损 5-6mm 宽的上皮再上皮化在 5.5±2.4 天内完成（n=6），有上皮分层的证据。
硅胶原杂化材料可以制成特定的尺寸，作为一种潜在的人工角膜替代物。在初步研究中，这些材料具有取代角膜基质所需的良好的光学、生物力学和生物相容性特性。
