Multi-leveled Nanosilicate Implants Can Facilitate Near-Perfect Bone Healing

• Published in: ACS applied materials & interfaces 2023-05, Vol.15 (17), p.21476-21495
• Main Authors: Keshavarz, Mozhgan, Alizadeh, Parvin, Kadumudi, Firoz Babu, Orive, Gorka, Gaharwar, Akhilesh K., Castilho, Miguel, Golafshan, Nasim, Dolatshahi-Pirouz, Alireza
• Format: Article
• Language: English
• Subjects: Animals; Applications of Polymer, Composite, and Coating Materials; Bone and Bones; bone formation; bone marrow; Bone Regeneration; cell free system; hydrogels; immunohistochemistry; Mesenchymal Stem Cells; orthopedics; Osteogenesis; Rats; Tissue Scaffolds
• ISSN: 1944-8244; 1944-8252; 1944-8252
• DOI: 10.1021/acsami.3c01717

Several studies have shown that nanosilicate-reinforced scaffolds are suitable for bone regeneration. However, hydrogels are inherently too soft for load-bearing bone defects of critical sizes, and hard scaffolds typically do not provide a suitable three-dimensional (3D) microenvironment for cells to thrive, grow, and differentiate naturally. In this study, we bypass these long-standing challenges by fabricating a cell-free multi-level implant consisting of a porous and hard bone-like framework capable of providing load-bearing support and a softer native-like phase that has been reinforced with nanosilicates. The system was tested with rat bone marrow mesenchymal stem cells in vitro and as a cell-free system in a critical-sized rat bone defect. Overall, our combinatorial and multi-level implant design displayed remarkable osteoconductivity in vitro without differentiation factors, expressing significant levels of osteogenic markers compared to unmodified groups. Moreover, after 8 weeks of implantation, histological and immunohistochemical assays indicated that the cell-free scaffolds enhanced bone repair up to approximately 84% following a near-complete defect healing. Overall, our results suggest that the proposed nanosilicate bioceramic implant could herald a new age in the field of orthopedics.