Department of Chemical and Biological Engineering, ECCH 111, Campus Box 424, University of Colorado-Boulder, Boulder, CO 80309, USA.
Acta Biomater. 2011 Feb;7(2):492-504. doi: 10.1016/j.actbio.2010.08.021. Epub 2010 Sep 8.
While designing poly(ethylene glycol) hydrogels with high moduli suitable for in situ placement is attractive for cartilage regeneration, the impact of a tighter crosslinked structure on the organization and deposition of the matrix is not fully understood. The objectives of this study were to characterize the composition and spatial organization of new matrix as a function of gel crosslinking and study its impact on chondrocytes in terms of anabolic and catabolic gene expression and catabolic activity. Bovine articular chondrocytes were encapsulated in hydrogels with three crosslinking densities (compressive moduli 60, 320 and 590 kPa) and cultured for 25 days. Glycosaminoglycan production increased with culture time and was greatest in the gels with lowest crosslinking. Collagens II and VI, aggrecan, link protein and decorin were localized to pericellular regions in all gels, but their presence decreased with increasing gel crosslinking. Collagen II and aggrecan expression were initially up-regulated in gels with higher crosslinking, but increased similarly up to day 15. Matrix metalloproteinase (MMP)-1 and MMP-13 expression were elevated (∼25-fold) in gels with higher crosslinking throughout the study, while MMP-3 was unaffected by gel crosslinking. The presence of aggrecan and collagen degradation products confirmed MMP activity. These findings indicate that chondrocytes synthesized the major cartilage components within PEG hydrogels, however, gel structure had a significant impact on the composition and spatial organization of the new tissue and on how chondrocytes responded to their environment, particularly with respect to their catabolic expression.
虽然设计具有适合原位放置的高模量的聚乙二醇水凝胶对于软骨再生很有吸引力,但交联结构更紧密对基质的组织和沉积的影响还不完全清楚。本研究的目的是研究新基质的组成和空间组织随凝胶交联的变化,并研究其对软骨细胞的影响,包括合成代谢和分解代谢基因表达和分解代谢活性。牛关节软骨细胞被包裹在三种交联密度(压缩模量 60、320 和 590 kPa)的水凝胶中培养 25 天。糖胺聚糖的产生随培养时间的增加而增加,在交联度最低的凝胶中最高。在所有凝胶中,II 型胶原和 VI 型胶原、聚集蛋白、连接蛋白和饰胶蛋白都定位于细胞周围区域,但随着凝胶交联度的增加,它们的存在减少。在交联度较高的凝胶中,II 型胶原和聚集蛋白的表达最初上调,但在 15 天前增加相似。基质金属蛋白酶(MMP)-1 和 MMP-13 的表达在整个研究过程中在交联度较高的凝胶中升高(约 25 倍),而 MMP-3 不受凝胶交联度的影响。聚集蛋白和胶原降解产物的存在证实了 MMP 活性。这些发现表明软骨细胞在 PEG 水凝胶中合成了主要的软骨成分,然而,凝胶结构对新组织的组成和空间组织以及软骨细胞对其环境的反应有显著影响,特别是在它们的分解代谢表达方面。
Clin Orthop Relat Res. 2011-10
Osteoarthritis Cartilage. 2009-9-1
FEBS Lett. 2007-9-4
Macromol Biosci. 2023-9
Front Bioeng Biotechnol. 2023-3-7
Int J Mol Sci. 2022-5-27
Adv Funct Mater. 2020-10-28
Tissue Eng Part A. 2021-7
Osteoarthritis Cartilage. 2009-9-1
J Biomed Mater Res A. 2009-9-1
Tissue Eng Part B Rev. 2008-6
Osteoarthritis Cartilage. 2008-9
Osteoarthritis Cartilage. 2007-10