Caruso Andrea B, Dunn Michael G
Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, New Brunswick, NJ 08903, USA.
J Biomed Mater Res A. 2005 Jun 15;73(4):388-97. doi: 10.1002/jbm.a.30233.
Resorbable scaffolds for anterior cruciate ligament (ACL) reconstruction should provide temporary mechanical function then gradually breakdown while promoting matrix synthesis by local cells. Crosslinking influences collagen's mechanical properties, degradation rate, and interactions with cells. Our objective was to compare the effects of different crosslinkers on cellularity and mechanical properties during long-term (8 week) culture of collagen fiber scaffolds. Fibers were fabricated from an acid-insoluble dispersion of bovine dermal collagen and crosslinked with either ultraviolet irradiation (UV; a physical crosslinker) or 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC; a chemical crosslinker). Scaffolds consisted of 50 fibers bundled in parallel. Initial attachment of fibroblasts was similar on both scaffolds; however, from 1 to 8 weeks in culture, UV-crosslinked scaffolds had significantly more cells attached than EDC-crosslinked scaffolds. The initial breaking load (3.50 N) and stiffness (2.23 N/mm) of EDC-crosslinked scaffolds were significantly greater than those of UV-crosslinked scaffolds (2.32 N; 1.21 N/mm) and were unaffected by long-term fibroblast culture. In contrast, the load-bearing capacity of fibroblast-seeded UV-crosslinked scaffolds decreased 60% to 0.91 N after 8 weeks in culture. EDC-crosslinked scaffolds maintained strength and moderate cellularity; UV-crosslinked scaffolds, in contrast, were highly cellular, but had poor mechanical properties that decreased during culture. These in vitro results suggest that collagen fiber scaffolds crosslinked with EDC may be more suitable for ACL reconstruction than those crosslinked with UV.
用于前交叉韧带（ACL）重建的可吸收支架应提供临时机械功能，然后逐渐分解，同时促进局部细胞的基质合成。交联会影响胶原蛋白的机械性能、降解速率以及与细胞的相互作用。我们的目标是比较不同交联剂对胶原纤维支架长期（8周）培养过程中的细胞数量和机械性能的影响。纤维由牛真皮胶原蛋白的酸不溶性分散体制备而成，并用紫外线照射（UV；一种物理交联剂）或1-乙基-3-（3-二甲基氨基丙基）碳二亚胺（EDC；一种化学交联剂）进行交联。支架由50根平行排列的纤维组成。两种支架上成纤维细胞的初始附着情况相似；然而，在培养1至8周期间，UV交联的支架上附着的细胞明显多于EDC交联的支架。EDC交联支架的初始断裂载荷（3.50 N）和刚度（2.23 N/mm）明显大于UV交联支架（2.32 N；1.21 N/mm），并且不受长期成纤维细胞培养的影响。相比之下，接种有成纤维细胞的UV交联支架在培养8周后的承载能力下降了60%，至0.91 N。EDC交联的支架保持了强度和适度的细胞数量；相比之下，UV交联的支架细胞数量很多，但机械性能较差，在培养过程中会下降。这些体外实验结果表明，与UV交联的胶原纤维支架相比，EDC交联的胶原纤维支架可能更适合用于ACL重建。
