Remote Activation of Mechanotransduction via Integrin Alpha-5 via Aptamer-Conjugated Magnetic Nanoparticles Promotes Osteogenesis

Bone regeneration and repair are complex processes in the adult skeleton, and current research has focused on understanding and controlling these processes. Magnetic nanoparticle (MNP)-based platforms have shown potential in tissue engineering and regenerative medicine through the use of magnetic nanomaterials combined with remotely applied dynamic fields. Previous studies have demonstrated the ability of MNP-induced mechanoactivation to trigger downstream signaling and promote new bone formation. In this study, we aimed to compare the osteogenic induction achieved using the mechanoreceptor targets, Piezo1, Fzd1, Fzd2, and integrin alpha-5. We compared the binding efficacy of different types of agonists (antibodies vs. aptamers) to these receptors. Moreover, we optimized the aptamer concentration (2.5, 5, and 10 μg/mg) for the selected receptor to determine the optimum concentration for promoting bone formation. Our data demonstrated that the mechanoactivation of integrins (CD49e) significantly upregulated the RUNX2 and LEF1 genes compared to other selected receptors. Furthermore, comparing the mechanoactivation of cells using MNPs conjugated with CD49e antibodies and aptamers revealed that MNP–aptamers significantly enhanced the upregulation of LEF1 genes. This suggests that aptamer-mediated mechanoactivation is a promising alternative to antibody-mediated activation. Finally, our results showed that the concentration of the aptamer loaded onto the MNPs strongly influenced the mechanoactivation of the cells. These findings provide valuable insights into the use of MNP platforms for bone regeneration and highlight the potential of aptamers in promoting signaling pathways related to bone formation. The novelty of our study lies in elucidating the unique advantages of aptamers in mediating mechanoactivation, presenting a promising avenue for advancing bone regenerative strategies

Electrospun PGA/gelatin nanofibrous scaffolds and their potential application in vascular tissue engineering

Hadi Hajiali1, Shapour Shahgasempour1, M Reza Naimi-Jamal2, Habibullah Peirovi11Nanomedicine and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences; 2Department of Chemistry, Iran University of Science and Technology, Tehran, IranBackground and methods: In this study, gelatin was blended with polyglycolic acid (PGA) at different ratios (0, 10, 30, and 50 wt%) and electrospun. The morphology and structure of the scaffolds were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and differential scanning calorimetry. The mechanical properties were also measured by the tensile test. Furthermore, for biocompatibility assessment, human umbilical vein endothelial cells and human umbilical artery smooth muscle cells were cultured on these scaffolds, and cell attachment and viability were evaluated.Results: PGA with 10 wt% gelatin enhanced the endothelial cells whilst PGA with 30 wt% gelatin increased smooth muscle cell adhesion, penetration, and viability compared with the other scaffold blends. Additionally, with the increase in gelatin content, the mechanical properties of the scaffolds were improved due to interaction between PGA and gelatin, as revealed by Fourier transform infrared spectroscopy and differential scanning calorimetry.Conclusion: Incorporation of gelatin improves the biological and mechanical properties of PGA, making promising scaffolds for vascular tissue engineering.Keywords: polyglycolic acid, gelatin, nanofiber, vascular tissue engineering, biocompatible scaffold&nbsp

Influence of topography of nanofibrous scaffolds on functionality of engineered neural tissue

Properly engineered scaffolds combined with functional neurons can be instrumental for the effective repair of the neural tissue. In particular, it is essential to investigate how three-dimensional (3D) systems and topographical features can impact on neuronal activity to obtain engineered functional neural tissues. In this study, polyphenylene sulfone (PPSu) scaffolds constituted by randomly distributed or aligned electrospun nanofibers were fabricated to evaluate the neural activity in 3D culture environments for the first time. The obtained results demonstrated that the nanofibers can successfully support the adhesion and growth of neural stem cells (NSCs) and enhance neuronal differentiation compared to 2D substrates. In addition, NSCs could spread and migrate along the aligned fibers. The percentage of active NSC-derived neurons and the overall network activity in the fibrous substrates were also remarkably enhanced. Finally, the data of neuronal activity showed not only that the neurons cultured on the nanofibers are part of a functional network, but also that their activity increases, and the direction of neural signals can be controlled in the aligned 3D scaffolds

Spatially controlled proliferation, migration and differentiation of neural stem cells on novel 3D conductive scaffolds [Abstract]

Spatially controlled proliferation, migration and differentiation of neural stem cells on novel 3D conductive scaffolds [Abstract

Alginate nanofibers with tunable biodegradability for regenerative medicine [Abstract]

Alginate nanofibers with tunable biodegradability for regenerative medicine [Abstract

Enhanced chondrogenic potential in GelMA-based 3D cartilage model via Wnt3a surface immobilization

Cartilage tissue engineering aims to develop functional substitutes for treating cartilage defects and osteoarthritis. Traditional two-dimensional (2D) cell culture systems lack the complexity of native cartilage, leading to the development of 3D regenerative cartilage models. In this study, we developed a 3D model using Gelatin Methacryloyl (GelMA)-based hydrogels seeded with Y201 cells, a bone marrow mesenchymal stem cell line. The model investigated chondrogenic differentiation potential in response to Wnt3a stimulation within the GelMA scaffold and validated using known chondrogenic agonists. Y201 cells demonstrated suitability for the model, with increased proteoglycan content and upregulated chondrogenic marker expression under chondrogenic conditions. Wnt3a enhanced cell proliferation, indicating activation of the Wnt/β-catenin pathway, which plays a role in cartilage development. GelMA hydrogels provided an optimal scaffold, supporting cell viability and proliferation. The 3D model exhibited consistent responses to chondrogenic agonists, with TGF-β3 enhancing cartilage-specific extracellular matrix (ECM) production and chondrogenic differentiation. The combination of Wnt3a and TGF-β3 showed synergistic effects, promoting chondrogenic differentiation and ECM production. This study presents a 3D regenerative cartilage model with potential for investigating cartilage biology, disease mechanisms, and drug screening. The model provides insights into complex cartilage regeneration mechanisms and offers a platform for developing therapeutic approaches for cartilage repair and osteoarthritis treatment

Enhanced chondrogenic potential in GelMA-based 3D cartilage model via Wnt3a surface immobilization

Cartilage tissue engineering aims to develop functional substitutes for treating cartilage defects and osteoarthritis. Traditional two-dimensional (2D) cell culture systems lack the complexity of native cartilage, leading to the development of 3D regenerative cartilage models. In this study, we developed a 3D model using Gelatin Methacryloyl (GelMA)-based hydrogels seeded with Y201 cells, a bone marrow mesenchymal stem cell line. The model investigated chondrogenic differentiation potential in response to Wnt3a stimulation within the GelMA scaffold and validated using known chondrogenic agonists. Y201 cells demonstrated suitability for the model, with increased proteoglycan content and upregulated chondrogenic marker expression under chondrogenic conditions. Wnt3a enhanced cell proliferation, indicating activation of the Wnt/β-catenin pathway, which plays a role in cartilage development. GelMA hydrogels provided an optimal scaffold, supporting cell viability and proliferation. The 3D model exhibited consistent responses to chondrogenic agonists, with TGF-β3 enhancing cartilage-specific extracellular matrix (ECM) production and chondrogenic differentiation. The combination of Wnt3a and TGF-β3 showed synergistic effects, promoting chondrogenic differentiation and ECM production. This study presents a 3D regenerative cartilage model with potential for investigating cartilage biology, disease mechanisms, and drug screening. The model provides insights into complex cartilage regeneration mechanisms and offers a platform for developing therapeutic approaches for cartilage repair and osteoarthritis treatment

Sustained adenosine release:Revealing its impact on osteogenic signalling pathways of human mesenchymal stromal cells

Non-healing fractures, a global health concern arising from trauma, osteoporosis, and tumours, can lead to severe disabilities. Adenosine, integral to cellular energy metabolism, gains prominence in bone regeneration via adenosine A2B receptor activation. This study introduces a controlled-release system for localized adenosine delivery, fostering human mesenchymal stromal cell (hMSC) differentiation into functional bone cells. The study investigates how the ratio of lactic acid to glycolic acid in microparticles can influence adenosine release and explores the downstream effects on gene expression and metabolic profiles of osteogenic differentiation in hMSCs cultured in growth and osteoinductive media. Insights into adenosine-modulated signalling pathways during MSC differentiation, with osteogenic factors, provide a comprehensive understanding of the pathways involved. Analysing gene expression and metabolic profiles unravels adenosine's regulatory mechanisms in MSC differentiation. Sustained adenosine release from microparticles induces mineralization, synergizing with osteogenic media supplements, showcasing the potential of adenosine for treating critical bone defects and metabolic disorders. This study highlights the efficacy of a polymeric microparticle-based delivery system, offering novel strategies for bone repair. Unveiling adenosine's roles and associated signalling pathways advances our comprehension of molecular mechanisms steering bone regeneration, propelling innovative biomaterial, combined with metabolites, approaches for clinical use

Sustained adenosine release:Revealing its impact on osteogenic signalling pathways of human mesenchymal stromal cells

Non-healing fractures, a global health concern arising from trauma, osteoporosis, and tumours, can lead to severe disabilities. Adenosine, integral to cellular energy metabolism, gains prominence in bone regeneration via adenosine A2B receptor activation. This study introduces a controlled-release system for localized adenosine delivery, fostering human mesenchymal stromal cell (hMSC) differentiation into functional bone cells. The study investigates how the ratio of lactic acid to glycolic acid in microparticles can influence adenosine release and explores the downstream effects on gene expression and metabolic profiles of osteogenic differentiation in hMSCs cultured in growth and osteoinductive media. Insights into adenosine-modulated signalling pathways during MSC differentiation, with osteogenic factors, provide a comprehensive understanding of the pathways involved. Analysing gene expression and metabolic profiles unravels adenosine's regulatory mechanisms in MSC differentiation. Sustained adenosine release from microparticles induces mineralization, synergizing with osteogenic media supplements, showcasing the potential of adenosine for treating critical bone defects and metabolic disorders. This study highlights the efficacy of a polymeric microparticle-based delivery system, offering novel strategies for bone repair. Unveiling adenosine's roles and associated signalling pathways advances our comprehension of molecular mechanisms steering bone regeneration, propelling innovative biomaterial, combined with metabolites, approaches for clinical use

Review of emerging nanotechnology in bone regeneration: progress, challenges, and perspectives

The application of nanotechnology to regenerative medicine has increased over recent decades. The development of materials that can influence biology at the nanoscale has gained interest as our understanding of the interactions between cells and biomaterials at the nanoscale has grown. Materials that are either nanostructured or influence the nanostructure of the cellular microenvironment have been developed and shown to have advantages over their microscale counterparts. There are several reviews which have been published that discuss how nanomaterials have been used in regenerative medicine, particularly in bone regeneration. Most of these studies have explored this concept in specific areas, such as the application of glass-based nanocomposites, nanotechnology for targeted drug delivery to stimulate bone repair, and the progress in nanotechnology for the treatment of osteoporosis. In this review paper, the impact of nanotechnology in biomaterials development for bone regeneration will be discussed highlighting specifically, nanostructured materials that influence mechanical properties, biocompatibility, and osteoinductivity