Department of Orthopaedic Surgery, National University of Singapore, 1E Kent Ridge Road, NUHS Tower Block 11, 119288, Singapore; Biosystem and Micromechanics Interdisciplinary Research Group, Singapore-MIT Alliance in Research and Technology, 1 Create Way, #04-13/14, 138602, Singapore.
Department of Orthopaedic Surgery, National University of Singapore, 1E Kent Ridge Road, NUHS Tower Block 11, 119288, Singapore; NUS Tissue Engineering Program, Life Sciences Institute, National University of Singapore, 27 Medical Drive, DSO (Kent Ridge) Building, Level 4, 117510, Singapore.
Biomaterials. 2019 Nov;220:119409. doi: 10.1016/j.biomaterials.2019.119409. Epub 2019 Aug 5.
The zonal property of articular cartilage endows the tissue with biphasic mechanical properties to withstand shearing force and compressional loading. Current treatments for articular cartilage damage are not able to efficiently restore the zonal organisation and functionality. Size-based sorting of freshly isolated chondrocytes from full thickness (FT) cartilage using a spiral microfluidic device was shown to efficiently separate and enrich zonal chondrocytes. The translational application of this sorting protocol is challenging in the clinical setting due to the limited number of autologous chondrocytes from a patient. It is thus essential to explore the practicability of this sorting protocol on expanded chondrocytes. In this study, we first show that size-sorted zonal chondrocytes expanded on microcarriers in dynamic condition (dMC) were able to support comparable proliferation, while maintaining cell morphology, and the zonal cell size-phenotype relation, in contrast to expansion on a tissue culture plate. We further show that post-expansion size-based sorting can be applied on dMC-expanded FT chondrocytes, generating enriched zonal subpopulations that form phenotypically distinct cartilage constructs in the 3D hydrogel. This study demonstrates a novel scale-up zonal chondrocyte production protocol, incorporating size-based zonal chondrocyte separation and dMC platform, to maintain zonal chondrocytes' phenotypes better to support zonal repair of articular cartilage.
关节软骨的分区特性赋予了组织双相机械特性，以承受剪切力和压缩载荷。目前针对关节软骨损伤的治疗方法无法有效地恢复分区组织和功能。使用螺旋微流控装置对全厚（FT）软骨中新鲜分离的软骨细胞进行基于大小的分选，已被证明可有效分离和富集分区软骨细胞。由于从患者获得的自体软骨细胞数量有限，该分选方案在临床环境中的转化应用具有挑战性。因此，有必要探索该分选方案在扩增软骨细胞上的实用性。在这项研究中，我们首先表明，在动态条件下（dMC）在微载体上扩增的经大小分选的分区软骨细胞能够支持可比的增殖，同时保持细胞形态和分区细胞大小表型关系，与在组织培养板上的扩增相比。我们进一步表明，扩增后的基于大小的分选可应用于 dMC 扩增的 FT 软骨细胞，产生富集的分区亚群，在 3D 水凝胶中形成表型上不同的软骨构建体。这项研究展示了一种新的规模化分区软骨细胞生产方案，该方案结合了基于大小的分区软骨细胞分离和 dMC 平台，以更好地维持分区软骨细胞的表型，从而支持关节软骨的分区修复。
