Strobel Hannah A, Dikina Anna D, Levi Karen, Solorio Loran D, Alsberg Eben, Rolle Marsha W
1 Department of Biomedical Engineering, Worcester Polytechnic Institute , Worcester, Massachusetts.
2 Department of Biomedical Engineering, Case Western Reserve University , Cleveland, Ohio.
Tissue Eng Part A. 2017 Feb;23(3-4):143-155. doi: 10.1089/ten.TEA.2016.0260. Epub 2016 Dec 6.
Cellular self-assembly has been used to generate living tissue constructs as an alternative to seeding cells on or within exogenous scaffold materials. However, high cell and extracellular matrix density in self-assembled constructs may impede diffusion of growth factors during engineered tissue culture. In the present study, we assessed the feasibility of incorporating gelatin microspheres within vascular tissue rings during cellular self-assembly to achieve growth factor delivery. To assess microsphere incorporation and distribution within vascular tissue rings, gelatin microspheres were mixed with a suspension of human smooth muscle cells (SMCs) at 0, 0.2, or 0.6 mg per million cells and seeded into agarose wells to form self-assembled cell rings. Microspheres were distributed throughout the rings and were mostly degraded within 14 days in culture. Rings with microspheres were cultured in both SMC growth medium and differentiation medium, with no adverse effects on ring structure or mechanical properties. Incorporated gelatin microspheres loaded with transforming growth factor beta 1 stimulated smooth muscle contractile protein expression in tissue rings. These findings demonstrate that microsphere incorporation can be used as a delivery vehicle for growth factors within self-assembled vascular tissues.
细胞自组装已被用于生成活组织构建体，作为在外源支架材料上或内部接种细胞的替代方法。然而，自组装构建体中高细胞和细胞外基质密度可能会在工程组织培养过程中阻碍生长因子的扩散。在本研究中，我们评估了在细胞自组装过程中将明胶微球掺入血管组织环以实现生长因子递送的可行性。为了评估微球在血管组织环中的掺入和分布情况，将明胶微球与每百万细胞0、0.2或0.6毫克的人平滑肌细胞（SMC）悬浮液混合，并接种到琼脂糖孔中以形成自组装细胞环。微球分布在整个环中，并且在培养14天内大部分被降解。含有微球的环在SMC生长培养基和分化培养基中培养，对环结构或机械性能没有不利影响。掺入载有转化生长因子β1的明胶微球可刺激组织环中平滑肌收缩蛋白的表达。这些发现表明，微球掺入可作为自组装血管组织中生长因子的递送载体。
