Department of Biomedical Engineering, University of California Davis, Davis, CA, USA.
Department of Biomedical Engineering, University of California Davis, Davis, CA, USA; Department of Biochemistry, University of Sao Paulo, Sao Paulo, Brazil.
Biomaterials. 2018 Oct;179:109-121. doi: 10.1016/j.biomaterials.2018.06.038. Epub 2018 Jun 27.
The objective of this study was to design an injectable biomaterial system that becomes porous in situ to deliver and control vascular progenitor cell release. Alginate hydrogels were loaded with outgrowth endothelial cells (OECs) and alginate lyase, an enzyme which cleaves alginate polymer chains. We postulated and confirmed that higher alginate lyase concentrations mediated loss of hydrogel mechanical properties. Hydrogels incorporating 5 and 50 mU/mL of alginate lyase experienced approximately 28% and 57% loss of mass as well as 81% and 91% reduction in storage modulus respectively after a week. Additionally, computational methods and mechanical analysis revealed that hydrogels with alginate lyase significantly increased in mesh size over time. Furthermore, alginate lyase was not found to inhibit OEC proliferation, viability or sprouting potential. Finally, alginate hydrogels incorporating OECs and alginate lyase promoted up to nearly a 10 fold increase in OEC migration in vitro than nondegradable hydrogels over the course of a week and increased functional vasculature in vivo via a chick chorioallantoic membrane (CAM) assay. Overall, these findings demonstrate that alginate lyase incorporated hydrogels can provide a simple and robust system to promote controlled outward cell migration into native tissue for potential therapeutic revascularization applications.
本研究的目的是设计一种可注射的生物材料系统，使其在体内形成多孔结构，从而输送和控制血管祖细胞的释放。海藻酸钠水凝胶中负载有出芽内皮细胞（OEC）和海藻酸钠裂解酶，后者可以裂解海藻酸钠聚合物链。我们假设并证实，较高的海藻酸钠裂解酶浓度会导致水凝胶力学性能丧失。水凝胶中加入 5 和 50 mU/mL 的海藻酸钠裂解酶，在一周后分别经历了约 28%和 57%的质量损失，以及 81%和 91%的储能模量降低。此外，计算方法和力学分析表明，含有海藻酸钠裂解酶的水凝胶的网格尺寸随时间显著增加。此外，海藻酸钠裂解酶并没有抑制 OEC 的增殖、活力或发芽潜力。最后，与不可降解水凝胶相比，含有 OEC 和海藻酸钠裂解酶的海藻酸钠水凝胶在体外促进 OEC 迁移的能力增加了近 10 倍，并且通过鸡胚尿囊膜（CAM）试验在体内增加了功能性血管生成。总的来说，这些发现表明，含有海藻酸钠裂解酶的水凝胶可以提供一种简单而强大的系统，以促进控制细胞向天然组织的外向迁移，从而为潜在的治疗性血管再生应用提供可能。
