Silk Fibroin Scaffold Architecture Regulates Inflammatory Responses and Engraftment of Bone Marrow‐Mononuclear Cells. Issue 16 (7th May 2021)

• Record Type: Journal Article
• Authors: Yang, Nianji; Moore, Matthew J.; Michael, Praveesuda L.; Santos, Miguel; Lam, Yuen Ting; Bao, Shisan; Ng, Martin K. C.; Rnjak‐Kovacina, Jelena; Tan, Richard P.; Wise, Steven G.
• Is Part Of: Advanced healthcare materials. Volume 10:Issue 16(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-05-07
• Subjects: biophysical cues -- bone marrow mononuclear cells -- electrospinning -- inflammation -- silk fibroin; Biomedical materials -- Periodicals; 610.28
• DOI: 10.1002/adhm.202100615
• Languages: English
• ISSNs: 2192-2640

Abstract

Abstract: Despite being one of the most clinically trialed cell therapies, bone marrow‐mononuclear cell (BM‐MNC) infusion has largely failed to fulfill its clinical promise. Implanting biomimetic scaffolds at sites of injury prior to BM‐MNC infusion is a promising approach to enhance BM‐MNC engraftment and therapeutic function. Here, it is demonstrated that scaffold architecture can be leveraged to regulate the immune responses that drive BM‐MNC engraftment. Silk scaffolds with thin fibers and low porosity (LP) impairs immune activation in vitro compared with thicker fiber, high porosity (HP) scaffolds. Using the authors′ established in vivo bioluminescent BM‐MNC tracking model, they showed that BM‐MNCs home to and engraft in greater numbers in HP scaffolds over 14 days. Histological analysis reveals thicker fibrous capsule formation, with enhanced collagen deposition in HP compared to LP scaffolds consistent with substantially more native CD68 + macrophages and CD4 + T cells, driven by their elevated pro‐inflammatory M1 and Th1 phenotypes, respectively. These results suggest that implant architecture impacts local inflammation that drives differential engraftment and remodeling behavior of infused BM‐MNC. These findings inform the future design of biomimetic scaffolds that may better enhance the clinical effectiveness of BM‐MNC infusion therapy. Abstract : Tissue regenerative functions of bone marrow‐mononuclear cell (BM‐MNC) therapies heavily rely on their engraftment at sites of injury. Pre‐implantation of silk scaffolds can serve as support structures to improve engraftment. Architectures (fiber width and porosity) of electrospun silk scaffolds are manipulated to regulate distinct immune responses that drive and improve the engraftment of BM‐MNCs.