کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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9024 | 615 | 2009 | 8 صفحه PDF | دانلود رایگان |
Hydrogels are an important class of biomaterials for cell encapsulation and delivery, providing a physical barrier or “immuno-isolation” between the host tissue and encapsulated cells. The semi-permeable gel protects the encapsulated cells from host immune cells and/or antibody recognition while allowing facile diffusion of nutrients. However, a previously un-addressed problem is that highly permissive hydrogels cannot exclude the infiltration of soluble immune-mediators, such as pro-inflammatory cytokines that are highly expressed in wounded environments in vivo. When encountered with pro-inflammatory cytokines, encapsulated cells fail to perform their desired functions. Here, we report the synthesis, characterization, and application of peptide-functionalized, cytokine-antagonizing poly(ethylene glycol) (PEG) hydrogels capable of sequestering the pro-inflammatory cytokine, tumor necrosis factor α (TNFα). Results demonstrate that the survival, function, and differentiation of encapsulated cells (e.g., rat adrenal pheochromocytoma cells – PC12s, mouse pancreatic islets, and human mesenchymal stem cells or hMSCs) are significantly hindered in un-modified PEG hydrogels under in vitro TNFα treatments. In contrast, cells encapsulated in TNFα-antagonizing hydrogels are un-affected by the infiltrated TNFα. This study demonstrates the importance of controlling the availability of pro-inflammatory cytokines in highly permissive hydrogels.
Journal: Biomaterials - Volume 30, Issue 28, October 2009, Pages 4907–4914