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Abstract One of the most fundamental characteristics of a biomaterial tailored for bone repair and regeneration is its ability to promote bone regeneration and healing of large defects. This work reports producing a functionalized and hieratically porous bone scaffold that significantly supports cell adhesion and proliferation by providing bone mimicry structure and controlled release of protein. The Slit Guidance Ligand 3 (SLIT3) protein was previously tested to promote bone formation and control the resorption process in natural bone healing. In this study, our goal was to design a nanocomposite bone scaffold to be functionalized with SLIT3 protein and then evaluate the uptake and release profile from surface into culture media to support bone marrow-derived mesenchymal stem cells (MSC) 3D culture. Indirect 3D printing of a polylactic-co-glycolic acid (PLGA), hydroxyapatite nanoparticles, and polydopamine coated (PLGA-HANPs-PDA) was utilized to obtain a hierarchically porous and SLIT3 protein-releasing scaffold. The produced scaffold was evaluated and optimized using chemical, architectural, mechanical, and biological characterization techniques. Optimal physicochemical properties resulted in a unique microstructure with an average pore size of 178.06 ± 45 µm, 63% porosity, and stable and homogenous chemical composition. Mechanical testing demonstrated a compression strength up to 1.5 MPa at 75% strain, with a compression modulus of 0.58 ± 0.05 MPa. Preliminary biological experiments showed that the scaffold exhibited gradual SLIT3 protein release, biodegradability, and reliable biocompatibility for MSC cell culture. Finally, we showed for first time the bioactivity of SLIT3 protein within PLGA-HANPs-PDA scaffold to promote attachment and growth of mesenchymal stem cell (MSCs) seeded in bone mimicry scaffold matrix. The collected findings will serve as a bedrock for thorough and targeted in vitro studies to evaluate anticipated osteogenesis the MSCs.
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Nanomechanical Characterization of Bone Quality Depending on Tissue Age via Bimodal Atomic Force Microscopy
Abstract Characterization of bone quality during the healing process is crucial for successful implantation procedures and patient comfort. In this study, a bone implant specimen that underwent a 4-week healing period was investigated. Bimodal atomic force microscopy (AFM) was employed to simultaneously obtain the morphology and elastic modulus maps of the newly formed and pre-existing bone regions within the sample. Results indicate that the new bone matrix possessed lower mineralization levels and presented larger, uneven mineral grains, exhibiting the attributes of a woven bone. On the other hand, the old bone matrix exhibited a more uniform and mineralized structure, which is characteristic of lamellar bones. The new bone had a lower overall elastic modulus than the old bone. Bimodal AFM further confirmed that the new bone displayed three regions comprising unmineralized, partially mineralized, and fully matured sections, which indicate a turbulent change in its composition. Meanwhile, the old bone exhibited two sections comprising partially mineralized and matured bone parts, which denote the final phase of mineralization. This study provides valuable insights into the morphological and nanomechanical differences between the old and new bone matrixes and presents a novel approach to investigate bone quality at different phases of the bone-healing process.
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- Award ID(s):
- 2227527
- PAR ID:
- 10440604
- Publisher / Repository:
- Springer Science + Business Media
- Date Published:
- Journal Name:
- Nanomanufacturing and Metrology
- Volume:
- 6
- Issue:
- 1
- ISSN:
- 2520-811X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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