Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, 19104, USA.
School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, 19104, USA.
Adv Sci (Weinh). 2023 Apr;10(10):e2206117. doi: 10.1002/advs.202206117. Epub 2023 Jan 30.
Granular hydrogels are an emerging class of biomaterials formed by jamming hydrogel microparticles (i.e., microgels). These materials have many advantageous properties that can be tailored through microgel design and extent of packing. To enhance the range of properties, granular composites can be formed with a hydrogel interstitial matrix between the packed microgels, allowing for material flow and then stabilization after crosslinking. This approach allows for distinct compartments (i.e., microgels and interstitial space) with varied properties to engineer complex material behaviors. However, a thorough investigation of how the compositions and ratios of microgels and interstitial matrices influence material properties has not been performed. Herein, granular hydrogel composites are fabricated by combining fragmented hyaluronic acid (HA) microgels with interstitial matrices consisting of photocrosslinkable HA. Microgels of varying compressive moduli (10-70 kPa) are combined with interstitial matrices (0-30 vol.%) with compressive moduli varying from 2-120 kPa. Granular composite structure (confocal imaging), mechanics (local and bulk), flow behavior (rheology), and printability are thoroughly assessed. Lastly, variations in the interstitial matrix chemistry (covalent vs guest-host) and microgel degradability are investigated. Overall, this study describes the influence of granular composite composition on structure and mechanical properties of granular hydrogels towards informed designs for future applications.
颗粒状水凝胶是通过凝胶化水凝胶微球（即微凝胶）形成的一类新兴生物材料。这些材料具有许多有利的特性，可以通过微凝胶设计和填充程度进行调整。为了增强性能范围，可以在填充的微凝胶之间形成具有水凝胶中间基质的颗粒状复合材料，允许材料流动，然后在交联后稳定。这种方法允许具有不同性质的不同隔室（即微凝胶和中间空间）来设计复杂的材料行为。然而，尚未对微凝胶和中间基质的组成和比例如何影响材料性能进行全面研究。本文通过将碎片化透明质酸（HA）微凝胶与由可光交联的 HA 组成的中间基质结合，制备了颗粒状水凝胶复合材料。具有不同压缩模量（10-70 kPa）的微凝胶与具有从 2-120 kPa 压缩模量的中间基质（0-30 体积%）组合。全面评估了颗粒状复合材料的结构（共聚焦成像）、力学性能（局部和整体）、流动行为（流变学）和可印刷性。最后，还研究了中间基质化学（共价与主体客体）和微凝胶降解性的变化。总体而言，本研究描述了颗粒状复合材料组成对颗粒状水凝胶结构和力学性能的影响，为未来应用的合理设计提供了信息。
