Bioinspired multifunctional biomaterials with hierarchical microstructure for wound dressing

Developing multifunctional wound dressing with desired mechanical strength is of great significance for the treatment of different types of skin wounds. Inspired by the close relationship between strength and hierarchical structure of nacre, hierarchical and porous graphene oxide-chitosan-calcium silicate (GO-CTS-CS) film biomaterials are fabricated by a combination of vacuum filtration-assisted assembly and freeze-drying methods. The bioinspired hierarchical materials emulate an orderly porous lamellar micron-scale structure and the brick-and-mortar-layered nanostructure. The hierarchical microstructure endows the GO-CTS-CS biomaterials with good tensile strength, compatible breathability, and water absorption. Furthermore, the hierarchical GO-CTS-CS biomaterials exhibit ideal photothermal performance, leading to significant photothermal antibacterial and antitumor efficacy. Further, the hierarchical GO-CTS-CS biomaterials show stimulatory effect on in vivo chronic wound healing. Therefore, such a high performance and multifunctional biomaterial is believed to offer a promising alternative to traditional wound dressing in future. Statement of Significance Although it is an effective strategy to prepare high-performance materials by mimicking the hierarchical microstructure of nacre, the preparation of nacre-inspired materials in tissue engineering fields still needs to be investigated. In this work, we prepared a nacre-inspired multifunctional graphene oxide-chitosancalcium silicate (GO-CTS-CS) biomaterial with a hierarchical microstructure. The hierarchical microstructure endows the biomaterials with desired properties of strength, breathability, and water absorption. Further, the hierarchical GO-CTS-CS biomaterial showed good photothermal antibacterial/antitumor and wound healing effects. This work may provide an approach to combine the preparation of multifunctional biomaterials with bioinspired engineering by constructing a hierarchical microstructure, indicating that the assembling hierarchical microstructure in biomaterials is of great importance for tissue engineering and regenerative medicine. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.