Spatially-offset Raman spectroscopy for monitoring mineralization of bone tissue engineering scaffolds: feasibility study based on phantom samples

Dooley, Max; Prasopthum, Aruna; Liao, Zhiyu; Sinjab, Faris; Mclaren, Jane; Rose, Felicity R A J; Yang, Jing; Notingher, Ioan

Abstract

Using phantom samples, we investigated the feasibility of spatially-offset Raman spectroscopy (SORS) as a tool for monitoring non-invasively the mineralization of bone tissue engineering scaffold in-vivo. The phantom samples consisted of 3D-printed scaffolds of poly-caprolactone (PCL) and hydroxyapatite (HA) blends, with varying concentrations of HA, to mimic the mineralisation process. The scaffolds were covered by a 4 mm layer of skin to simulate the real in-vivo measurement conditions. At a concentration of HA approximately 1/3 that of bone (~0.6 g/cm 3), the characteristic Raman band of HA (960 cm-1) was detectable when the PCL:HA layer was located at 4 mm depth within the scaffold (i.e. 8 mm below the skin surface). For the layers of the PCL:HA immediately under the skin (i.e. top of the scaffold), the detection limit of HA was 0.18 g/cm 3 , which is approximately one order of magnitude lower than that of bone. Similar results were also found for the phantoms simulating uniform and inward gradual mineralisation of the scaffold, indicating the suitability of SORS to detect early stages of mineralisation. Nevertheless, the results also show that the contribution of the materials surrounding the scaffold can be significant and methods for subtraction need to be investigated in the future. In conclusion, these results indicate that spatially-offset Raman spectroscopy is a promising technique for in-vivo longitudinal monitor scaffold mineralization and bone re-growth.

Citation

Dooley, M., Prasopthum, A., Liao, Z., Sinjab, F., Mclaren, J., Rose, F. R. A. J., …Notingher, I. (2019). Spatially-offset Raman spectroscopy for monitoring mineralization of bone tissue engineering scaffolds: feasibility study based on phantom samples. Biomedical Optics Express, 10(4), 1678-1690. https://doi.org/10.1364/BOE.10.001678

• Journal Article Type: Article
• Acceptance Date: Feb 6, 2019
• Online Publication Date: Mar 6, 2019
• Publication Date: Apr 1, 2019
• Deposit Date: Feb 19, 2019
• Publicly Available Date: Feb 20, 2019
• Journal: Biomedical Optics Express
• Electronic ISSN: 2156-7085
• Publisher: Optical Society of America
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Issue: 4
• Pages: 1678-1690
• DOI: https://doi.org/10.1364/BOE.10.001678
• Keywords: Biotechnology; Atomic and Molecular Physics, and Optics
• Public URL: https://nottingham-repository.worktribe.com/output/1568404
• Publisher URL: https://www.osapublishing.org/boe/abstract.cfm?uri=boe-10-4-1678
• Additional Information: This article is maintained by: OSA - The Optical Society; Crossref DOI link to publisher maintained version: https://doi.org/10.1364/BOE.10.001678; Article type: research-article; Similarity check: Screened by Similarity Check; Peer reviewed: Yes; Review process: Single blind; Received: 21 November 2018; Accepted: 6 February 2019; Published: 6 March 2019; Copyright: Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.