Raman Spectroscopy detects changes in Bone Mineral Quality and Collagen Cross-linkage in Staphylococcus Infected Human Bone

Abstract

Diagnosis of osteomyelitis presents a formidable challenge. Lack of pathognomonic clinical sign(s) and diagnostic tests that can diagnose osteomyelitis at an early stage contribute to this difficulty. If the diagnosis is not made early, the disease becomes very difficult to eradicate and can lead to limb threatening and potentially life-threatening complications. Staphylococcus aureus is the most common organism causing osteomyelitis. Raman Spectroscopy provides information about molecular vibration that could potentially be harnessed as a spectral signature for cellular changes in specific pathologic conditions. In this study we describe a technique using Raman spectroscopy that could potentially be used to diagnose staphylococcal osteomyelitis. Human bone samples were co-cultured with Staphylococcus aureus (S. aureus) and the effects of bacterial growth on bone quality were then monitored using Raman spectroscopy. A major drop in the bone mineral quality and crystallinity was observed in the infected bones compared to the controls. S. aureus infection was also found to alter the collagen cross-linking. Our study shows that specific spectral signatures are present for the cause as well as the effect of staphylococcal osteomyelitis, opening the possibility of developing a useful diagnostic modality for early and rapid diagnosis of this condition.

Raman and Atr-Ftir Spectroscopy Towards Classification of Wet Blue Bovine Leather Using Ratiometric and Chemometric Analysis

“…The amide regions of proteins are overlapped by many underlying bands [27]. In vibrational spectroscopic methods, such as FTIR and Raman, resolution of underlying constituent peaks and calculation of their contributions offer a wealth of information, as these peaks are very sensitive to secondary structure [15,46]. Therefore, curve-fitting was carried out on both Raman and IR data to investigate the spectral changes in the secondary structures of collagen.…”

“…Therefore, changes in collagen's helical structure were investigated empirically by observing changes in the curve fitted area ratios, as identified by the curve-fitting analysis. Collagen crosslinking is measured as changes in the amide I envelope [39,46]. It was observed that the Raman band at~1669 cm − 1 was present in the fractions containing the trivalent collagen cross-links whereas IR observed a band at 1632 cm − 1 , but no band was evident at~1669 cm − 1 [17,27].…”

“…8b overlap with each other. PCA scores plots reveal the intra and intergroup variation between loose and tight wet blue samples [27,46].…”

Raman Spectroscopy as Noninvasive Method of Diagnosis of Pediatric Onset Inflammatory Bowel Disease

“…It is worth remarking, in this regard, that quantifying ratios of Raman bands is very advantageous, since they are least affected by background fluctuations and preprocessing methods [55]. In particular, as reported in [56], the parameter R is related to the nonreducible (trivalent)/reducible (divalent) crosslinking ratio. The obtained values for all the analyzed subjects are reported in Figure 4.…”

Quantitative and structural analysis of isotopically labelled natural crosslinks in type I skin collagen using LC-HRMS and SANS

“…Several methods have been developed to analyse collagen crosslinks, including isotopic labelling [11,12], chromatography [4,6,13,14] and spectroscopy [15][16][17][18]. Although there are a large number of methods for crosslink analysis, only one method has been successfully applied for the characterisation and quantitative analysis of all known natural crosslinks in collagen using liquidchromatography coupled with high-resolution accuratemass mass spectrometry (LC-HRMS).…”