Anisotropic Hybrid Hydrogels with Superior Mechanical Properties Reminiscent of Tendons or Ligaments. (6th August 2019)

• Record Type: Journal Article
• Authors: Choi, Suji; Choi, Youngjin; Kim, Jaeyun
• Is Part Of: Advanced functional materials. Volume 29:Number 38(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-08-06
• Subjects: anisotropic hydrogels -- hybrid hydrogels -- ligament -- mesoporous silica -- tendon; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201904342
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Mimicking the hierarchically anisotropic structure and excellent mechanical properties of natural tissues, such as tendons and ligaments, using biomaterials is challenging. Despite recent achievements with anisotropic hydrogels, limitations remain because of difficulties in achieving both structural and mechanical characteristics simultaneously. A simple approach for fabricating hybrid hydrogels with a hierarchically anisotropic structure and superior mechanical properties that are reminiscent of tendons or ligaments is proposed. Alginate–polyacrylamide double‐network (DN) hydrogels incorporated with high aspect ratio mesoporous silica microparticles are stretched and fixed via subsequent drying and ionic crosslinking to achieve multiscale structures composed of an anisotropically aligned polymer network embedded with aligned microparticles. The mechanical properties of hydrogels can be further controlled by the degree of stretching, quantities, and functional groups of inorganic microparticles, and types of crosslinking cations. The subsequent reswelling results in a high water content (>80%) similar to that of natural tendons while high strength, modulus, and toughness are maintained. The optimized anisotropic hybrid hydrogel exhibits a tensile modulus of 7.2 MPa, strength of 1.3 MPa, and toughness of 1.4 MJ m −3 even in the swollen state, which is 451‐, 27‐, and 2.2 times higher than that observed in the non‐swollen tough DN hydrogel. This study suggests a new strategy for fabricating anisotropic hydrogels with superior mechanical properties to develop new biomaterials for artificial tendons or ligaments. Abstract : Anisotropic hybrid hydrogels are prepared by fixation of linearly stretched hydrogels consisting of double‐network hydrogel and inorganic microrod fillers. The resulting hydrogels show a hierarchically anisotropic internal structure and superior mechanical properties even after swelling, which is reminiscent of natural tendons or ligaments. This hybrid hydrogel has great potential for developing new biomaterials for artificial anisotropic tissues.