Department of Chemical and Biomolecular Engineering, University of California Los Angeles, Los Angeles, CA, United States.
Department of Biomedical Engineering, Duke University, Durham, NC, United States.
Acta Biomater. 2019 Aug;94:160-172. doi: 10.1016/j.actbio.2019.02.054. Epub 2019 May 30.
Designing scaffolds for polyplex-mediated therapeutic gene delivery has a number of applications in regenerative medicine, such as for tissue repair after wounding or disease. Microporous annealed particle (MAP) hydrogels are an emerging class of porous biomaterials, formed by annealing microgel particles to one another in situ to form a porous bulk scaffold. MAP gels have previously been shown to support and enhance proliferative and regenerative behaviors both in vitro and in vivo. Therefore, coupling gene delivery with MAP hydrogels presents a promising approach for therapy development. To optimize MAP hydrogels for gene delivery, we studied the effects of particle size and stiffness as well as adhesion potential on cell surface area and proliferation and then correlated this information with the ability of cells to become transfected while seeded in these scaffolds. We find that the void space size as well as the presentation of integrin ligands influence transfection efficiency. This work demonstrates the importance of considering MAP material properties for guiding cell spreading, proliferation, and gene transfer. STATEMENT OF SIGNIFICANCE: Microporous annealed particle (MAP) hydrogels are an emerging class of porous biomaterials, formed by annealing spherical microgels together in situ, creating a porous scaffold from voids between the packed beads. Here we investigated the effects of MAP physical and adhesion properties on cell spreading, proliferation, and gene transfer in fibroblasts. Particle size and void space influenced spreading and proliferation, with larger particles improving transfection. MAP stiffness was also important, with stiffer scaffolds increasing proliferation, spreading, and transfection, contrasting studies in nonporous hydrogels that showed an inverse response. Last, RGD ligand concentration and presentation modulated spreading similar to non-MAP hydrogels. These findings reveal relationships between MAP properties and cell processes, suggesting how MAP can be tuned to improve future design approaches.
设计用于多聚物介导的治疗性基因传递的支架在再生医学中有许多应用，例如在创伤或疾病后进行组织修复。微孔退火颗粒 (MAP) 水凝胶是一类新兴的多孔生物材料，通过将微凝胶颗粒彼此退火原位形成多孔块状支架。MAP 凝胶以前已被证明在体外和体内都能支持和增强增殖和再生行为。因此，将基因传递与 MAP 水凝胶结合是一种有前途的治疗开发方法。为了优化 MAP 水凝胶用于基因传递，我们研究了粒径和刚度以及粘附潜力对细胞表面积和增殖的影响，然后将这些信息与细胞在这些支架中接种时转染的能力相关联。我们发现，空隙大小以及整联蛋白配体的呈现影响转染效率。这项工作证明了考虑 MAP 材料特性对指导细胞铺展、增殖和基因转移的重要性。
微孔退火颗粒 (MAP) 水凝胶是一类新兴的多孔生物材料，由球形微凝胶在原位退火形成，由颗粒之间的空隙形成多孔支架。在这里，我们研究了 MAP 的物理和粘附特性对成纤维细胞的细胞铺展、增殖和基因转移的影响。颗粒大小和空隙空间影响铺展和增殖，较大的颗粒可提高转染效率。MAP 刚度也很重要，较硬的支架可增加增殖、铺展和转染，与非多孔水凝胶的研究结果相反，后者显示出相反的反应。最后，RGD 配体浓度和呈现方式类似于非 MAP 水凝胶一样调节铺展。这些发现揭示了 MAP 特性与细胞过程之间的关系，表明如何调整 MAP 以改善未来的设计方法。
