Differences in infrared spectroscopic data of connective tissues in transflectance and transmittance modes

Hanifi, Amir Reza; McGoverin, Cushla; Ou, Ya-Ting; Safadi, Fayez F.; Spencer, Richard G.; Pleshko, Nancy

doi:10.1016/j.aca.2013.03.053

Cited by 14 publications

(9 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A contributor to this is likely the effect of radiation going through a “double pass” through the sample in transflectance mode [40]. In contrast, the peak areas and peak heights from MIR data of samples imaged on silicon wafers in transmittance exhibit increased absorbance with increasing thickness for the full range of thickness investigated through 100 μm (Fig.…”

Section: Resultsmentioning

confidence: 99%

Near infrared spectroscopic imaging assessment of cartilage composition: Validation with mid infrared imaging spectroscopy

Palukuru

Hanifi

McGoverin

et al. 2016

Analytica Chimica Acta

Self Cite

View full text Add to dashboard Cite

Disease or injury to articular cartilage results in loss of extracellular matrix components which can lead to the development of osteoarthritis (OA). To better understand the process of disease development, there is a need for evaluation of changes in cartilage composition without the requirement of extensive sample preparation. Near infrared (NIR) spectroscopy is a chemical investigative technique based on molecular vibrations that is increasingly used as an assessment tool for studying cartilage composition. However, the assignment of specific molecular vibrations to absorbance bands in the NIR spectrum of cartilage, which arise from overtones and combinations of primary absorbances in the mid infrared (MIR) spectral region, has been challenging. In contrast, MIR spectroscopic assessment of cartilage is well-established, with many studies validating the assignment of specific bands present in MIR spectra to specific molecular vibrations. In the current study, NIR imaging spectroscopic data were obtained for compositional analysis of tissues that served as an in vitro model of OA. MIR spectroscopic data obtained from the identical tissue regions were used as the gold-standard for collagen and proteoglycan (PG) content. MIR spectroscopy in transmittance mode typically requires a much shorter pathlength through the sample (≤10 microns thick) compared to NIR spectroscopy (millimeters). Thus, this study first addressed the linearity of small absorbance bands in the MIR region with increasing tissue thickness, suitable for obtaining a signal in both the MIR and NIR regions. It was found that the linearity of specific, small MIR absorbance bands attributable to the collagen and PG components of cartilage (at 1336 and 856 cm−1, respectively) are maintained through a thickness of 60 μm, which was also suitable for NIR data collection. MIR and NIR spectral data were then collected from 60 μm thick samples of cartilage degraded with chondroitinase ABC as a model of OA. Partial least squares (PLS) regression using NIR spectra as input predicted the MIR-determined compositional parameters of PG/collagen within 6% of actual values. These results indicate that NIR spectral data can be used to assess molecular changes that occur with cartilage degradation, and further, the data provide a foundation for future clinical studies where NIR fiber optic probes can be used to assess the progression of cartilage degradation.

show abstract

Section: Resultsmentioning

confidence: 99%

Near infrared spectroscopic imaging assessment of cartilage composition: Validation with mid infrared imaging spectroscopy

Palukuru

Hanifi

McGoverin

et al. 2016

Analytica Chimica Acta

Self Cite

View full text Add to dashboard Cite

show abstract

“…FTIR was performed and analyzed according to standard protocols (Hanifi et al, ) using PerkinElmer FTIR Spectrometer Frontier/Spotlight 400. Human tendon surgical samples were fixed in 10% neutral buffered formalin and embedded in paraffin.…”

Section: Methodsmentioning

confidence: 99%

Tendinosis develops from age‐ and oxygen tension‐dependent modulation of Rac1 activity

et al. 2019

View full text Add to dashboard Cite

Age‐related tendon degeneration (tendinosis) is characterized by a phenotypic change in which tenocytes display characteristics of fibrochondrocytes and mineralized fibrochondrocytes. As tendon degeneration has been noted in vivo in areas of decreased tendon vascularity, we hypothesized that hypoxia is responsible for the development of the tendinosis phenotype, and that these effects are more pronounced in aged tenocytes. Hypoxic (1% O2) culture of aged, tendinotic, and young human tenocytes resulted in a mineralized fibrochondrocyte phenotype in aged tenocytes, and a fibrochondrocyte phenotype in young and tendinotic tenocytes. Investigation of the molecular mechanism responsible for this phenotype change revealed that the fibrochondrocyte phenotype in aged tenocytes occurs with decreased Rac1 activity in response to hypoxia. In young hypoxic tenocytes, however, the fibrochondrocyte phenotype occurs with concomitant decreased Rac1 activity coupled with increased RhoA activity. Using pharmacologic and adenoviral manipulation, we confirmed that these hypoxic effects on the tenocyte phenotype are linked directly to the activity of RhoA/Rac1 GTPase in in vitro human cell culture and tendon explants. These results demonstrate that hypoxia drives tenocyte phenotypic changes, and provide a molecular insight into the development of human tendinosis that occurs with aging.

show abstract

“…Low-e slides are used in transflection mode, i.e., the signal passes through the section twice as it is reflected back from the slide. A comparison between transflectance and transmittance modes in bone, tendon, and cartilage showed differences in peak shapes, positions, and intensities (12). These differences are likely due to distortions caused by the electric-field standing wave observed in transflectance measurements (13).…”

mentioning

confidence: 98%

Vibrational spectroscopy of articular cartilage

Rieppo

Töyräs

Saarakkala

2016

Applied Spectroscopy Reviews

View full text Add to dashboard Cite

Articular cartilage is a connective tissue that is located at the ends of long bones. Type II collagen, proteoglycans, water, and chondrocytes are the main constituents of articular cartilage. Osteoarthritis, the most common joint disease in the world, causes degenerative changes in articular cartilage tissue. Fourier transform infrared, Raman, and near infrared spectroscopic techniques offer versatile tools to assess biochemical composition and quality of articular cartilage. These vibrational spectroscopic techniques can be used to broaden our understanding about the compositional changes during osteoarthritis, and they also hold promise in disease diagnostics. In this article, the current literature of articular cartilage spectroscopic studies is reviewed.

show abstract

Differences in infrared spectroscopic data of connective tissues in transflectance and transmittance modes

Cited by 14 publications

References 35 publications

Near infrared spectroscopic imaging assessment of cartilage composition: Validation with mid infrared imaging spectroscopy

Near infrared spectroscopic imaging assessment of cartilage composition: Validation with mid infrared imaging spectroscopy

Tendinosis develops from age‐ and oxygen tension‐dependent modulation of Rac1 activity

Vibrational spectroscopy of articular cartilage

Contact Info

Product

Resources

About