Quality assessment for processed and sterilized bone using Raman spectroscopy

Abstract

To eliminate the potential for infection, many tissue banks routinely process and terminally sterilize allografts prior to transplantation. A number of techniques, including the use of scanning electron microscopy, bone graft models, and mechanical property tests, are used to evaluate the properties of allograft bone. However, as these methods are time consuming and often destroy the bone sample, the quality assessment of allograft bones are not routinely performed after processing and sterilization procedures. Raman spectroscopy is a non-destructive, rapid analysis technique that requires only small sample volumes and has recently been used to evaluate the mineral content, mineral crystallinity, acid phosphate and carbonate contents, and collagen maturity in human and animal bones. Here, to establish a quality assessment method of allograft bones using Raman spectroscopy, the effect of several common sterilization and preservation procedures on rat femoral bones were investigated. We found that freeze–thawing had no detectable effects on the composition of bone minerals or matrix, although heat treatment and gamma irradiation resulted in altered Raman spectra. Our findings suggest Raman spectroscopy may facilitate the quality control of allograft bone after processing and sterilization procedures.

Gamma Radiation Sterilization Reduces the High-cycle Fatigue Life of Allograft Bone

“…Methods of sterilization such as heat [31,41,42,45,63], hydrogen peroxide [15,24] and ethylene oxide [47,57,65] can negatively affect allograft mechanical and biological properties. Heat treatment greater than 60°C reduces the strength [41,42,45,71,72] and impairs osteoinductivity [44]. Chemical treatments such as ethylene oxide and hydrogen peroxide also are harmful to osteoinductivity [8,15,24,25,54,56].…”

Detailed Analysis of the Structural Changes of Bone Matrix During the Demineralization Process Using Raman Spectroscopy

“…2a) contains the Raman bands responsible for the mineral structure of bone matrix, such as 1 (PO 4 ) 3-vibrational mode in the molecule of hydroxyapatite at 956 cm -1 , 3 (PO 4 ) 3-at 1030 and 1045 cm -1 , 1 (CO 3 ) 2-(B type substitution where (PO 4 ) 3-a substituted (CO 3 ) 2-) at 1069 cm -1 and 1 (CO 3 ) 2-vibration mode (A type substitution where a substituted OH-(CO 3 ) 2-) at 1098 cm -1 [Yamamoto T. et al (2011), Crane N.J. et al (2013]. Band at 956 cm -1 is dominant by the intensity throughout all Raman spectrum of bone tissue, which determines the content of hydroxyapatite in bone matrix, and also possible to study the content of carbonate (CO 3 ) 2-in the process of demineralization.…”

“…Band at 956 cm -1 is dominant by the intensity throughout all Raman spectrum of bone tissue, which determines the content of hydroxyapatite in bone matrix, and also possible to study the content of carbonate (CO 3 ) 2-in the process of demineralization. Less intense bands at 816, 852, 920, 941 and 870 cm -1 corresponding to the stretching vibration of C-C in proline and hydroxyproline [Yamamoto T. et al (2011), Crane N.J. et al (2013], and the band at 1003 cm -1 responsible for C-C stretching vibration in phenylalanine [Crane N.J. et al (2013)] represent the organic component of bone matrix.…”

“…2b shows the spectral region responsible for structural integrity of bone collagen, where 1239, 1264, 1284, 1316, 1338 and 1381 cm -1 bands correspond to amide III (modes of (CN) and (NH)) [Yamamoto T. et al (2011), Crane N.J. et al (2013, Rehman I. et al (2012), Po omska M. et al (2010)] and 1396, 1418 and 1450 cm -1 correspond to mode of (CH2) and (CH3) [Rehman I. et al (2012), Po omska M. et al (2010)]. Spectral region of 1600-1700 cm -1 (Fig.…”

Radiation sterilization of tissue allografts: A review

“…Voggenreiter et al [62] studied the bone surface structure of cortical bone grafts using SEM and observed no deleterious effects of cryopreservation and irradiation. Yamamoto et al [68] reported that the gamma irradiation of femurs to a dose of 25 kGy increased the crystallinity, whereas, there was no change in the Raman spectrum. The authors concluded that increased crystallinity may be due to the adverse effects of gamma radiation on bone allografts.…”