Feasibility of low field MRI and proteomics for the analysis of Tissue Engineered bone

Abstract

There is a need for the replacement of bone tissue that has been lost due to trauma. On average, there are an estimated 10 million cases of fracture-related injuries in the US every year [Amini et al 2012 Crit. Rev. Biomed. Eng. 40, 363–408]. A potential solution is offered by tissue engineering which aims to create biological substitutes for natural tissues. Magnetic resonance imaging (MRI) has been proposed to assess engineering outcomes, however one challenge is the use of high field, which is costly and with regulatory effect on the cells not well understood. This study aims to illustrate the capability of a table top, low field MRI system in monitoring the development of Tissue Engineered bone, supported through proteome analysis. MR images, spin-spin (T2) relaxation, and proteomics were acquired for samples assessed at three in vitro developmental time points: week 0, week 2, and week 4. A ∼45% decrease in the T2 relaxation time was observed from weeks 0 to 4. During cellular differentiation, proteomics revealed the appearance of proteins [alkaline phosphatase (ALP), collagen I and III, fibronectin, transforming growth factor beta (TGF-β), and latent transforming growth factor beta binding protein-1 (LTBP1)] consistent with osteogenesis. The data demonstrated that low field MRI can offer a cost-effective alternative to study the development of Tissue Engineered bone, in addition to proteomics analysis of the developing tissue.