Kim Minwook, Garrity Sean T, Steinberg David R, Dodge George R, Mauck Robert L
McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, 36th Street and Hamilton Walk, Philadelphia, Pennsylvania, 19104.
Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania, 19104.
J Orthop Res. 2018 Jun;36(6):1717-1727. doi: 10.1002/jor.23815. Epub 2017 Dec 29.
The purpose of study was to investigate the maturation of mesenchymal stem cells (MSC) laden in HA constructs with various combinations of chemically defined medium (CM) components and determine the impact of dexamethasone and serum on construct properties. Constructs were cultured in CM with the addition or withdrawal of media components or were transferred to serum containing media that partially represents an in vivo-like condition where pro-inflammatory signals are present. Constructs cultured in CM+ (CM with TGF-β3) and DEX- (CM+ without dexamethasone) conditions produced robust matrix, while those in ITS/BSA/LA- (CM+ without ITS/BSA/LA) and Serum+ (10% FBS with TGF-β3) produced little matrix. While construct properties in DEX- were greater than those in CM+ at 4 weeks, properties in CM+ and DEX- reversed by 8 weeks. While construct properties in DEX- were greater than those in CM+ at 4 weeks, the continued absence or removal of dexamethasone resulted in marked GAG loss by 8 weeks. Conversely, the continued presence or new addition of dexamethasone at 4 weeks further improved or maintained construct properties through 8 weeks. Finally, when constructs were converted to Serum (in the continued presence of TGF-β3 with or without dexamethasone) after pre-culture in CM+ for 4 weeks, GAG loss was attenuated with addition of dexamethasone. Interestingly, however, collagen content and type was not impacted. In conclusion, dexamethasone influences the functional maturation of MSC-laden HA constructs, and may help to maintain properties during long-term culture or with in vivo translation by repressing pro-inflammatory signals. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1717-1727, 2018.
本研究的目的是研究负载间充质干细胞（MSC）的HA构建体在含有化学定义培养基（CM）成分的各种组合中的成熟情况，并确定地塞米松和血清对构建体特性的影响。构建体在添加或去除培养基成分的CM中培养，或转移到含有血清的培养基中，后者部分代表存在促炎信号的类似体内的条件。在CM+（含TGF-β3的CM）和DEX-（不含地塞米松的CM+）条件下培养的构建体产生了大量基质，而在ITS/BSA/LA-（不含ITS/BSA/LA的CM+）和Serum+（含TGF-β3的10%胎牛血清）条件下培养的构建体产生的基质很少。虽然在4周时DEX-条件下的构建体特性优于CM+条件下的构建体，但在8周时CM+和DEX-条件下的特性发生了逆转。虽然在4周时DEX-条件下的构建体特性优于CM+条件下的构建体，但持续缺乏或去除地塞米松会导致在8周时明显的糖胺聚糖损失。相反，在4周时持续存在或重新添加地塞米松可在8周内进一步改善或维持构建体特性。最后，当构建体在CM+中预培养4周后转换为Serum（在持续存在或不存在地塞米松的情况下含有TGF-β3）时，添加地塞米松可减轻糖胺聚糖损失。然而，有趣的是，胶原蛋白含量和类型并未受到影响。总之，地塞米松影响负载MSC的HA构建体的功能成熟，并可能通过抑制促炎信号在长期培养或体内转化过程中有助于维持其特性。©2017骨科学研究协会。由威利期刊公司出版。《矫形外科学研究》36:1717 - 1727，2018年。
