Appel Eric A, Tibbitt Mark W, Greer Jessica M, Fenton Owen S, Kreuels Klaus, Anderson Daniel G, Langer Robert
David H. Koch Institute for Integrative Cancer Research, Department of Chemical Engineering, and Division of Health Science and Technology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
ACS Macro Lett. 2015 Aug 18;4(8):848-852. doi: 10.1021/acsmacrolett.5b00416. Epub 2015 Jul 27.
Shear-thinning injectable hydrogels exploit dynamic noncovalent cross-links to flow upon applied stress and rapidly self-heal once the stress is relaxed. These materials continue to gather interest as they afford minimally invasive deployment in the body for a variety of biomedical applications. Here, we present rationally engineered polymer-nanoparticle (PNP) interactions based on electrostatic forces for the fabrication of self-assembled hydrogels with shear-thinning and self-healing properties. The selective adsorption of negatively charged biopolymers, including hyaluronic acid (HA) and carboxymethylcellulose (CBMC), to biodegradable nanoparticles comprising poly(ethylene glycol)--poly(lactic acid) (PEG--PLA) is enhanced with a positively charged surfactant, cetyltrimethylammonium bromide (CTAB). We demonstrate that, in this manner, electrostatic interactions can be leveraged to fabricate PNP hydrogels and characterize the viscoelastic properties of the gels imparted by CBMC and HA. This work introduces PNP hydrogels that use common biopolymers without the need for chemical modification, yielding extremely facile preparation and processing, which when coupled with the tunability of their properties are distinguishing features for many important biomedical and industrial applications.
剪切变稀可注射水凝胶利用动态非共价交联在施加应力时流动，并在应力松弛后迅速自愈。这些材料因其能够在体内以微创方式用于多种生物医学应用而持续受到关注。在此，我们基于静电力提出了合理设计的聚合物 - 纳米颗粒（PNP）相互作用，用于制备具有剪切变稀和自愈特性的自组装水凝胶。带正电的表面活性剂十六烷基三甲基溴化铵（CTAB）增强了包括透明质酸（HA）和羧甲基纤维素（CBMC）在内的带负电生物聚合物对由聚（乙二醇） - 聚（乳酸）（PEG - PLA）组成的可生物降解纳米颗粒的选择性吸附。我们证明，通过这种方式，可以利用静电相互作用来制备PNP水凝胶，并表征由CBMC和HA赋予凝胶的粘弹性特性。这项工作引入了使用常见生物聚合物且无需化学修饰的PNP水凝胶，其制备和加工极为简便，再加上其性能的可调性，使其成为许多重要生物医学和工业应用的显著特征。
