1 Orthopaedic Research Lab, Department of Orthopaedics, Radboud University Nijmegen Medical Centre , Nijmegen, The Netherlands .
Tissue Eng Part A. 2014 Feb;20(3-4):635-45. doi: 10.1089/ten.TEA.2013.0083. Epub 2013 Oct 19.
Lesions in knee joint articular cartilage (AC) have limited repair capacity. Many clinically available treatments induce a fibrous-like cartilage repair instead of hyaline cartilage. To induce hyaline cartilage repair, we hypothesized that type I collagen scaffolds with fibers aligned perpendicular to the AC surface would result in qualitatively better tissue repair due to a guided cellular influx from the subchondral bone. By specific freezing protocols, type I collagen scaffolds with isotropic and anisotropic fiber architectures were produced. Rabbits were operated on bilaterally and two full thickness defects were created in each knee joint. The defects were filled with (1) an isotropic scaffold, (2) an anisotropic scaffold with pores parallel to the cartilage surface, and (3) an anisotropic scaffold with pores perpendicular to the cartilage surface. Empty defects served as controls. After 4 (n=13) and 12 (n=13) weeks, regeneration was scored qualitatively and quantitatively using histological analysis and a modified O'Driscoll score. After 4 weeks, all defects were completely filled with partially differentiated hyaline cartilage tissue. No differences in O'Driscoll scores were measured between empty defects and scaffold types. After 12 weeks, all treatments led to hyaline cartilage repair visualized by increased glycosaminoglycan staining. Total scores were significantly increased for parallel anisotropic and empty defects over time (p<0.05). The results indicate that collagen scaffolds allow the formation of hyaline-like cartilage repair. Fiber architecture had no effect on cartilage repair.
膝关节关节软骨（AC）的损伤修复能力有限。许多临床可用的治疗方法会诱导形成纤维样软骨修复，而不是透明软骨修复。为了诱导透明软骨修复，我们假设纤维与 AC 表面垂直排列的 I 型胶原支架会导致更好的组织修复，因为这会引导来自软骨下骨的细胞流入。通过特定的冷冻方案，产生了各向同性和各向异性纤维结构的 I 型胶原支架。对兔子进行双侧手术，在每个膝关节中创建两个全层缺陷。用（1）各向同性支架、（2）与软骨表面平行的孔的各向异性支架和（3）与软骨表面垂直的孔的各向异性支架填充缺陷。空缺陷作为对照。4 周（n=13）和 12 周（n=13）后，使用组织学分析和改良 O'Driscoll 评分对再生进行定性和定量评分。4 周后，所有缺陷均完全被部分分化的透明软骨组织填充。O'Driscoll 评分在空缺陷和支架类型之间没有差异。12 周后，所有治疗方法均导致透明软骨修复，糖胺聚糖染色增加。随着时间的推移，平行各向异性和空缺陷的总评分显著增加（p<0.05）。结果表明，胶原支架允许形成透明样软骨修复。纤维结构对软骨修复没有影响。
