1 Experimental Rheumatology Unit, Department of Orthopedics, Jena University Hospital, Waldkrankenhaus "Rudolf Elle", Eisenberg, Germany.
2 Department of Orthopedics, Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang, China.
Cartilage. 2019 Jul;10(3):346-363. doi: 10.1177/1947603518756985. Epub 2018 Feb 20.
Limitations of matrix-assisted autologous chondrocyte implantation to regenerate functional hyaline cartilage demand a better understanding of the underlying cellular/molecular processes. Thus, the regenerative capacity of a clinically approved hydrogel collagen type I implant was tested in a standardized bovine cartilage punch model.
Cartilage rings (outer diameter 6 mm; inner defect diameter 2 mm) were prepared from the bovine trochlear groove. Collagen implants (± bovine chondrocytes) were placed inside the cartilage rings and cultured up to 12 weeks. Cartilage-implant constructs were analyzed by histology (hematoxylin/eosin; safranin O), immunohistology (aggrecan, collagens 1 and 2), and for protein content, RNA expression, and implant push-out force.
Cartilage-implant constructs revealed vital morphology, preserved matrix integrity throughout culture, progressive, but slight proteoglycan loss from the "host" cartilage or its surface and decreasing proteoglycan release into the culture supernatant. In contrast, collagen 2 and 1 content of cartilage and cartilage-implant interface was approximately constant over time. Cell-free and cell-loaded implants showed (1) cell migration onto/into the implant, (2) progressive deposition of aggrecan and constant levels of collagens 1 and 2, (3) progressively increased mRNA levels for aggrecan and collagen 2, and (4) significantly augmented push-out forces over time. Cell-loaded implants displayed a significantly earlier and more long-lasting deposition of aggrecan, as well as tendentially higher push-out forces.
Preserved tissue integrity and progressively increasing cartilage differentiation and push-out forces for up to 12 weeks of cultivation suggest initial cartilage regeneration and lateral bonding of the implant in this model for cartilage replacement materials.
基质辅助自体软骨细胞移植在再生功能透明软骨方面的局限性，要求我们更好地了解其潜在的细胞/分子过程。因此，本研究采用标准化的牛软骨打孔模型，对一种临床认可的水凝胶型 I 型胶原植入物的再生能力进行了测试。
从牛滑车沟制备软骨环（外径 6mm；内缺损直径 2mm）。将胶原植入物（含/不含牛软骨细胞）置于软骨环内，并培养至 12 周。通过组织学（苏木精/伊红；番红 O）、免疫组织化学（聚集蛋白聚糖、胶原 1 和 2）以及蛋白质含量、RNA 表达和植入物推出力分析评估软骨-植入物构建体。
软骨-植入物构建体呈现出有活力的形态，在整个培养过程中保持基质完整性，“宿主”软骨或其表面的蛋白聚糖逐渐但轻微丢失，并且蛋白聚糖向培养上清液中的释放逐渐减少。相比之下，软骨和软骨-植入物界面的胶原 2 和 1 含量随时间的推移而大致保持不变。无细胞和细胞负载的植入物表现出（1）细胞迁移到/进入植入物，（2）聚集蛋白聚糖的逐渐沉积和胶原 1 和 2 的恒定水平，（3）聚集蛋白聚糖和胶原 2 的 mRNA 水平逐渐增加，（4）推出力随时间逐渐增加。负载细胞的植入物表现出更早和更持久的聚集蛋白聚糖沉积，以及更高的推出力趋势。
在 12 周的培养过程中，组织完整性得以保留，软骨分化逐渐增加，推出力逐渐增大，这表明该模型中软骨替代材料存在初始软骨再生和植入物的侧向结合。
