Department of Chemistry, University of Toronto , 80 Saint George Street, Toronto, M5S 3H6 Ontario, Canada.
Institute of Biomaterials and Biomedical Engineering, University of Toronto , 4 Taddle Creek Road, Toronto, Ontario M5S 3G9, Canada.
Langmuir. 2017 Oct 31;33(43):12344-12350. doi: 10.1021/acs.langmuir.7b02906. Epub 2017 Oct 10.
In the search for new building blocks of nanofibrillar hydrogels, cellulose nanocrystals (CNCs) have attracted great interest because of their sustainability, biocompatibility, ease of surface functionalization, and mechanical strength. Making these hydrogels fluorescent extends the range of their applications in tissue engineering, bioimaging, and biosensing. We report the preparation and properties of a multifunctional hydrogel formed by CNCs and graphene quantum dots (GQDs). We show that although CNCs and GQDs are both negatively charged, hydrogen bonding and hydrophobic interactions overcome the electrostatic repulsion between these nanoparticles and yield a physically cross-linked hydrogel with tunable mechanical properties. Owing to their shear-thinning behavior, the CNC-GQD hydrogels were used as an injectable material in 3D printing. The hydrogels were fluorescent and had an anisotropic nanofibrillar structure. The combination of these advantageous properties makes this hybrid hydrogel a promising material and fosters the development of new manufacturing methods such as 3D printing.
在寻找纳米纤维水凝胶的新构建块的过程中，由于其可持续性、生物相容性、易于表面功能化和机械强度，纤维素纳米晶体 (CNC) 引起了极大的兴趣。使这些水凝胶具有荧光性扩展了它们在组织工程、生物成像和生物传感中的应用范围。我们报告了由 CNC 和石墨烯量子点 (GQD) 形成的多功能水凝胶的制备和性质。我们表明，尽管 CNC 和 GQD 均带负电荷，但氢键和疏水相互作用克服了这些纳米粒子之间的静电排斥，从而产生了具有可调节机械性能的物理交联水凝胶。由于其剪切稀化行为，CNC-GQD 水凝胶可用作 3D 打印中的可注射材料。水凝胶具有荧光性和各向异性的纳米纤维结构。这些有利性质的结合使这种混合水凝胶成为一种有前途的材料，并促进了新的制造方法（如 3D 打印）的发展。
