Elder Benjamin D, Eleswarapu Sriram V, Athanasiou Kyriacos A
Department of Bioengineering, Rice University, Houston, TX 77251-1892, USA.
Biomaterials. 2009 Aug;30(22):3749-56. doi: 10.1016/j.biomaterials.2009.03.050. Epub 2009 Apr 23.
Several prior studies have been performed to determine the feasibility of tissue decellularization to create a non-immunogenic xenogenic tissue replacement for bladder, vasculature, heart valves, knee meniscus, temporomandibular joint disc, ligament, and tendon. However, limited work has been performed with articular cartilage, and no studies have examined the decellularization of tissue engineered constructs. The objective of this study was to assess the effects of different decellularization treatments on articular cartilage constructs, engineered using a scaffoldless approach, after 4wks of culture, using a two-phased approach. In the first phase, five different treatments were examined: 1) 1% SDS, 2) 2% SDS, 3) 2% Tributyl Phosphate, 4) 2% Triton X-100, and 5) Hypotonic followed by hypertonic solution. These treatments were applied for either 1h or 8h, followed by a 2h wash in PBS. Following this wash, the constructs were assessed histologically, biochemically for cellularity, GAG, and collagen content, and biomechanically for compressive and tensile properties. In phase II, the best treatment from phase I was applied for 1, 2, 4, 6, or 8h in order to optimize the application time. Treatment with 2% SDS for 1h or 2h significantly reduced the DNA content of the tissue, while maintaining the biochemical and biomechanical properties. On the other hand, 2% SDS for 6h or 8h resulted in complete histological decellularization, with complete elimination of cell nuclei on histological staining, although GAG content and compressive properties were significantly decreased. Overall, 2% SDS, for 1 or 2h, appeared to be the most effective agent for cartilage decellularization, as it resulted in decellularization while maintaining the functional properties. The results of this study are exciting as they indicate the feasibility of creating engineered cartilage that may be non-immunogenic as a replacement tissue.
此前已有多项研究来确定组织脱细胞化以创建用于膀胱、血管、心脏瓣膜、膝关节半月板、颞下颌关节盘、韧带和肌腱的非免疫原性异种组织替代物的可行性。然而,关于关节软骨的相关研究较少,且尚无研究考察组织工程构建体的脱细胞化情况。本研究的目的是采用两阶段方法,评估不同脱细胞化处理对无支架方法构建的关节软骨构建体培养4周后的影响。在第一阶段,考察了五种不同处理:1)1%十二烷基硫酸钠(SDS),2)2% SDS,3)2%磷酸三丁酯,4)2% Triton X - 100,以及5)低渗溶液后接高渗溶液。这些处理分别进行1小时或8小时,随后在磷酸盐缓冲液(PBS)中洗涤2小时。洗涤后,对构建体进行组织学评估、生化评估以检测细胞数量、糖胺聚糖(GAG)和胶原蛋白含量,以及生物力学评估以检测压缩和拉伸性能。在第二阶段,应用第一阶段中最佳的处理方法1、2、4、6或8小时,以优化处理时间。用2% SDS处理1小时或2小时可显著降低组织中的DNA含量,同时保持生化和生物力学性能。另一方面,2% SDS处理6小时或8小时可导致完全的组织学脱细胞化,组织学染色时细胞核完全消失,尽管GAG含量和压缩性能显著降低。总体而言,2% SDS处理1或2小时似乎是软骨脱细胞化最有效的试剂,因为它能实现脱细胞化同时保持功能特性。本研究结果令人振奋,因为它们表明了创建可能作为替代组织的非免疫原性工程软骨的可行性。