Bone and Joint Research Group, Centre for Human Development, Stem Cells and Regeneration, Institute of Developmental Sciences, University of Southampton, Southampton, SO16 6YD, UK.
Adv Healthc Mater. 2018 Aug;7(15):e1800331. doi: 10.1002/adhm.201800331. Epub 2018 Jun 17.
Laponite nanoparticles have attracted attention in the tissue engineering field for their protein interactions, gel-forming properties, and, more recently, osteogenic bioactivity. Despite growing interest in the osteogenic properties of Laponite, the application of Laponite colloidal gels to host the osteogenic differentiation of responsive stem cell populations remains unexplored. Here, the potential to harness the gel-forming properties of Laponite to generate injectable bioactive microenvironments for osteogenesis is demonstrated. A diffusion/dialysis gelation method allows the rapid formation of stable transparent gels from injectable, thixotropic Laponite suspensions in physiological fluids. Upon contact with buffered saline or blood serum, nanoporous gel networks exhibiting, respectively, fivefold and tenfold increases in gel stiffness are formed due to the reorganization of nanoparticle interactions. Laponite diffusion gels are explored as osteogenic microenvironments for skeletal stem cell containing populations. Laponite films support cell adhesion, proliferation, and differentiation of human bone marrow stromal cells in 2D. Laponite gel encapsulation significantly enhances osteogenic protein expression compared with 3D pellet culture controls. In both 2D and 3D conditions, cell associated mineralization is strongly enhanced. This study demonstrates that Laponite diffusion gels offer considerable potential as biologically active and clinically relevant bone tissue engineering scaffolds.
拉蓬土纳米颗粒因其蛋白相互作用、凝胶形成特性，以及最近的成骨生物活性，在组织工程领域引起了关注。尽管人们对拉蓬土的成骨特性越来越感兴趣，但将拉蓬土胶体凝胶应用于宿主响应性干细胞群体的成骨分化仍未得到探索。本文展示了利用拉蓬土的凝胶形成特性来生成可注射的骨诱导微环境的潜力。扩散/透析凝胶化方法允许从可注射的、触变的拉蓬土悬浮液在生理流体中快速形成稳定的透明凝胶。与缓冲盐水或血清接触后，由于纳米颗粒相互作用的重新组织，分别形成了凝胶硬度增加五倍和十倍的纳米多孔凝胶网络。拉蓬土扩散凝胶被探索用作含有骨骼干细胞的群体的成骨微环境。拉蓬土薄膜在二维环境中支持人骨髓基质细胞的黏附、增殖和分化。与 3D 微球培养对照相比，拉蓬土凝胶包封显著增强了成骨蛋白的表达。在 2D 和 3D 条件下，细胞相关矿化都得到了强烈增强。本研究表明，拉蓬土扩散凝胶作为具有生物活性和临床相关性的骨组织工程支架具有很大的潜力。
