Porous calcium phosphate glass microspheres for orthobiologic applications

Hossain, Kazi M. Zakir; Patel, Uresha; Kennedy, Andrew R.; Macri-Pellizzeri, Laura; Sottile, Virginie; Grant, David M.; Scammell, Brigitte E.; Ahmed, Ifty

Abstract

© 2018 Orthobiologics is a rapidly advancing field utilising cell-based therapies and biomaterials to enable the body to repair and regenerate musculoskeletal tissues. This paper reports on a cost-effective flame spheroidisation process for production of novel porous glass microspheres from calcium phosphate-based glasses to encapsulate and deliver stem cells. Careful selection of the glass and pore-forming agent, along with a manufacturing method with the required processing window enabled the production of porous glass microspheres via a single-stage manufacturing process. The morphological and physical characterisation revealed porous microspheres with tailored surface and interconnected porosity (up to 76 ± 5%) with average pore size of 55 ± 8 µm and surface areas ranging from 0.34 to 0.9 m 2 g −1 . Furthermore, simple alteration of the processing parameters produced microspheres with alternate unique morphologies, such as with solid cores and surface porosity only. The tuneable porosity enabled control over their surface area, degradation profiles and hence ion release rates. Furthermore, cytocompatibility of the microspheres was assessed using human mesenchymal stem cells via direct cell culture experiments and analysis confirmed that they had migrated to within the centre of the microspheres. The novel microspheres developed have huge potential for tissue engineering and regenerative medicine applications. Statement of Significance: This manuscript highlights a simple cost-effective one-step process for manufacturing porous calcium phosphate-based glass microspheres with varying control over surface pores and fully interconnected porosity via a flame spheroidisation process. Moreover, a simple alteration of the processing parameters can produce microspheres which have a solid core with surface pores only. The tuneable porosity enabled control over their surface area, degradation profiles and hence ion release rates. The paper also shows that stem cells not only attach and proliferate but more importantly migrate to within the core of the porous microspheres, highlighting applications for bone tissue engineering and regenerative medicine.

Citation

Hossain, K. M. Z., Patel, U., Kennedy, A. R., Macri-Pellizzeri, L., Sottile, V., Grant, D. M., Scammell, B. E., & Ahmed, I. (2018). Porous calcium phosphate glass microspheres for orthobiologic applications. Acta Biomaterialia, 72, 396-406. https://doi.org/10.1016/j.actbio.2018.03.040

• Journal Article Type: Article
• Acceptance Date: Mar 22, 2018
• Online Publication Date: Mar 29, 2018
• Publication Date: May 1, 2018
• Deposit Date: May 11, 2018
• Publicly Available Date: Mar 30, 2019
• Journal: Acta Biomaterialia
• Print ISSN: 1742-7061
• Electronic ISSN: 1878-7568
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 72
• Pages: 396-406
• DOI: https://doi.org/10.1016/j.actbio.2018.03.040
• Keywords: Calcium phosphate glass; Porous microspheres; Stem cells
• Public URL: https://nottingham-repository.worktribe.com/output/935824
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S1742706118301715
• Additional Information: This article is maintained by: Elsevier; Article Title: Porous calcium phosphate glass microspheres for orthobiologic applications; Journal Title: Acta Biomaterialia; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.actbio.2018.03.040; Content Type: article; Copyright: Crown Copyright © 2018 Published by Elsevier Ltd on behalf of Acta Materialia Inc. All rights reserved.