Rajagopal Karthikeyan, Ramesh Sowmya, Walter Noel Malcolm, Arora Aditya, Katti Dhirendra S, Madhuri Vrisha
Department of Paediatric Orthopaedics, Christian Medical College, Vellore, India.
Centre for Stem Cell Research (A Unit of inStem, Bengaluru), Christian Medical College, Vellore, India.
Bone Joint Res. 2020 Sep 23;9(9):601-612. doi: 10.1302/2046-3758.99.BJR-2019-0210.R2. eCollection 2020 Sep.
Extracellular matrix (ECM) and its architecture have a vital role in articular cartilage (AC) structure and function. We hypothesized that a multi-layered chitosan-gelatin (CG) scaffold that resembles ECM, as well as native collagen architecture of AC, will achieve superior chondrogenesis and AC regeneration. We also compared its in vitro and in vivo outcomes with randomly aligned CG scaffold.
Rabbit bone marrow mesenchymal stem cells (MSCs) were differentiated into the chondrogenic lineage on scaffolds. Quality of in vitro regenerated cartilage was assessed by cell viability, growth, matrix synthesis, and differentiation. Bilateral osteochondral defects were created in 15 four-month-old male New Zealand white rabbits and segregated into three treatment groups with five in each. The groups were: 1) untreated and allogeneic chondrocytes; 2) multi-layered scaffold with and without cells; and 3) randomly aligned scaffold with and without cells. After four months of follow-up, the outcome was assessed using histology and immunostaining.
In vitro testing showed that the secreted ECM oriented itself along the fibre in multi-layered scaffolds. Both types of CG scaffolds supported cell viability, growth, and matrix synthesis. In vitro chondrogenesis on scaffold showed an around 400-fold increase in collagen type 2 ) expression in both CG scaffolds, but the total glycosaminoglycan (GAG)/DNA deposition was 1.39-fold higher in the multi-layered scaffold than the randomly aligned scaffold. In vivo cartilage formation occurred in both multi-layered and randomly aligned scaffolds treated with and without cells, and was shown to be of hyaline phenotype on immunostaining. The defects treated with multi-layered + cells, however, showed significantly thicker cartilage formation than the randomly aligned scaffold.
We demonstrated that MSCs loaded CG scaffold with multi-layered zonal architecture promoted superior hyaline AC regeneration.Cite this article: 2020;9(9):601-612.
细胞外基质（ECM）及其结构在关节软骨（AC）的结构和功能中起着至关重要的作用。我们假设，一种类似于ECM以及AC天然胶原结构的多层壳聚糖 - 明胶（CG）支架，将实现卓越的软骨形成和AC再生。我们还将其体外和体内结果与随机排列的CG支架进行了比较。
兔骨髓间充质干细胞（MSCs）在支架上分化为软骨细胞系。通过细胞活力、生长、基质合成和分化来评估体外再生软骨的质量。在15只4个月大的雄性新西兰白兔中制造双侧骨软骨缺损，并将其分为三个治疗组，每组5只。分组如下：1）未处理的同种异体软骨细胞；2）有细胞和无细胞的多层支架；3）有细胞和无细胞的随机排列支架。随访4个月后，使用组织学和免疫染色评估结果。
体外测试表明，分泌的ECM在多层支架中沿纤维方向排列。两种类型的CG支架均支持细胞活力、生长和基质合成。支架上的体外软骨形成显示，两种CG支架中Ⅱ型胶原表达均增加约400倍，但多层支架中的总糖胺聚糖（GAG）/DNA沉积比随机排列支架高1.39倍。在有细胞和无细胞处理的多层和随机排列支架中均发生了体内软骨形成，免疫染色显示为透明软骨表型。然而，多层 + 细胞处理的缺损显示出比随机排列支架明显更厚的软骨形成。
我们证明，加载有多层区域结构的CG支架的MSCs促进了卓越的透明软骨AC再生。引用本文：2020；9（9）：601 - 612。
