Lipid bands of approx. 1740 cm-1 as spectral biomarkers and image of tissue oxidative stress

Studies with the use of FTIR and FTR methods to find spectroscopic biomarkers within the 1740 cm^-1 band of pathological tissues found that oxidative stress, including damage to epidermis and structural changes in pathological amnion and placenta tissue, are associated with the occurrence of products of lipid peroxidation and have impact on fluidity and transport function of membranes. In particular, the findings show that the absence of a marker lipid band of approx. 1743 cm^-1 and the occurrence of a minimum of 1764 cm^-1 (FTIR) and 1734 cm^-1 (FTR) testify to the integrity and absence of damage in the allogeneic dermis, while the presence the 1743 or 1747 cm^-1 bands indicates denaturation of the thermally or electrically burned epidermis. The absence of a marker lipid band of approx. 1736-1740 cm^-1 for a healthy placental and amniotic tissue and the presence of a band of 1740 cm^-1 indicate placental gestosis, while the presence of a band of 1742 cm^-1 indicates hypotrophy. The 1738 cm^-1 bands indicate amniotic macrosomia. Structural changes caused by tissue modification with antioxidants, which were observed on individual samples: the L-ascorbic acid (presence of a lipid band marker at a frequency of 1755 cm^-1), sodium ascorbate (disappearance of the marker band), orthosilicic acid (disappearance or decrease in the intensity of the marker band with a decrease in the concentration of the modifier), as well as graphene oxide (separation of the marker lipid band of 1755 cm^-1), inform us about the effect of modifiers on the tissue repair process. The studies also tracked spectral changes identified in serum. Withing the range of the lipid band and the amide I and II bands (α → β conversion), there are clear differences between normal and pathological serum lyophilisates and a sample analyzed from the solution.

Graphene Oxide as a Collagen Modifier of Amniotic Membrane and Burnt Skin

Introduction

The aim of this interdisciplinary study was to answer the question of whether active antioxidants as graphene oxide (GO), sodium ascorbate, and L-ascorbic acid modify at a molecular and supramolecular level the tissue of pathological amnion and the necrotic eschar degraded in thermal burn. We propose new solutions of modifiers based on GO that will become innovative ingredients to be used in transplants (amnion) and enhance regeneration of epidermis degraded in thermal burn.

Methods

A Nicolet 6700 spectrophotometer with Omnic software and the EasiDiff diffusion accessory were used in FTIR spectroscopic analysis. A Nicolet Magna-IR 860 spectrometer with an FT Raman accessory was used to record the Raman spectra of the samples. The surface of the samples was examined using a Phenom ProX scanning electron microscope with an energy-dispersive X-ray spectroscopy detector to diagnose and illustrate morphological effects on skin and amnion samples. SAXS measurements were carried out with a compact Kratky camera equipped with the SWAXS optical system.

Results

Characterisation of amide I-III regions, important for molecular structure, on both FTIR and FTR spectra revealed distinct shifts, testifying to organization of protein structure after GO modification. A wide lipid band associated with ester-group vibrations in phospholipids of cell membranes and vibrations of the carbonyl group of GO in the 1,790-1,720 cm^-1 band were observed in the spectra of thermally degraded and GO-modified epidermis and pathological amnion. SAXS studies revealed that GO caused a significant change in the structure of the burnt skin, but its influence on the structure of the amnion was weak.

Conclusion

Modification of burn-damaged epidermis and pathological amnion by means of GO results in stabilization and regeneration of tissue at the level of molecular (FTIR, FTR) and supramolecular (SAXS) interactions.

Graphene Oxide and Stabilized Ortho-Silicic Acid as Modifiers of Amnion and Burn Affected Skin: A Comparative Study

Introduction

Oxidative tissue damage caused by reactive oxygen species results in a significant decrease in the total antioxidant capacity of the biological system. The aim of this interdisciplinary study was to answer the question of whether active antioxidants modify, at a molecular and supramolecular level, the tissue of pathological amnion and the necrotic eschar degraded in thermal burn.

Methods

A Nicolet 6700 Fourier-transform spectrophotometer with OMNIC software and the EasiDiff diffusion accessory were used in the FTIR spectroscopic analysis. A NICOLET MAGNA-IR 860 spectrometer with FT-Raman accessory was used to record the Raman spectra of the samples. The samples were exposed to bacteria capable of causing nosocomial infections, ie Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli and Pseudomonas aeruginosa. Whereas samples of hypotrophic amnion interacted with Staphylococcus aureus, Escherichia coli and Enterococcus faecalis. The obtained flame retardant effect of placentas was evaluated using the method of the limiting oxygen index (LOI).

Results

The infrared spectroscopy analysis proved that after modification of the amniotic samples in graphene oxide and ortho-silicic acid, the amide II band is split into two components. Incubation of samples in modifier solutions: graphene oxide, sodium ascorbate and L-ascorbic acid results in shifts and changes of intensity within the broadly understood lipid band 1743–1745–1747 cm⁻¹. The oxidising changes observed within the lipid and amide bands are affected by the incubation effect of graphene oxide as a modifier, possibly adsorbing on the surface of the amniotic membrane. On the basis of microbiological studies, pathogenic bacteria commonly causing amniotic infections and growing in burn wounds were found to have particularly good resistance to stabilized ortho-silicic acid (E. coli) and lactoferrin (S.aureus).

Conclusion

This thermogravimetric study found the highest stability of the analysed tissues (hypotrophic amnion and burnt epidermis) after modification with graphene oxide and sodium ascorbate.

A Histologic Perspective on Electrical and Thermal Burn-Injured Human Skin

OBJECTIVE

To analyze specific spectroscopic (FT-Raman) and thermal (limiting oxygen index) aspects of skin samples exposed to electrical injury compared with thermal injury.

METHODS

An observational case-control study was conducted at the Dr Stanislaw Sakiel Center for Burns Treatment in Siemianowice, Silesia, Poland. A scanning electron microscope was used to diagnose and illustrate the topography of skin samples from electrical and thermal burns and the morphologic effects on damaged versus undamaged skin surfaces. In particular, researchers attempted to detect spectroscopic and thermal changes at the molecular level, namely, specific biomarkers of tissue degeneration and their regeneration under the influence of the applied modifiers (antioxidants and orthosilicic acid solutions).

RESULTS

Modification with L-ascorbic acid and hydrogel of orthosilicic acid caused an increase in the intensity of the amide I Raman peaks, whereas modification with sodium ascorbate and orthosilicic acid resulted in the separation of the band protein side chains (1,440-1,448 cm), which is a part of tissue regeneration. The best result was obtained when the skin was treated with 7% orthosilicic acid (limiting oxygen index, 26%).

CONCLUSIONS

Antioxidant treatment may be advantageous in minimizing injury in patients with thermal burns but not always in electrical burns.

Active antioxidants in ex-vivo examination of burn wound healing by means of IR and Raman spectroscopies-Preliminary comparative research

Being a complex traumatic event, burn injury also affects other organ systems apart from the skin. Wounds undergo various pathological changes which are accompanied by alterations in the molecular environment. Information about molecules may be obtained with the use of Raman spectroscopy and Fourier-transform infrared spectroscopy, and when combined, both methods are a powerful tool for providing material characterization. Alterations in the molecular environment may lead to identifying objective markers of acute wound healing. In general, incubation of samples in solutions of l-ascorbic acid and 5% and 7% orthosilicic acid organizes the collagen structure, whereas the increased intensity of the Raman bands in the region of 1500-800cm^-1 reveals regeneration of the burn tissue. Since oxidative damage is one of the mechanisms responsible for local and distant pathophysiological events after burn, antioxidant therapy can prove to be beneficial in minimizing burn wounds, which was examined on the basis of human skin samples and chicken skin samples, the latter being subject to modification when heated to a temperature sufficient for the simulation of a burn incident.