Moisture adsorption by decellularized bovine pericardium collagen matrices studied by terahertz pulsed spectroscopy and solid immersion microscopy

Abstract

In this paper, terahertz (THz) pulsed spectroscopy and solid immersion microscopy were applied to study interactions between water vapor and tissue scaffolds–the decellularized bovine pericardium (DBP) collagen matrices, in intact form, cross-linked with the glutaraldehyde or treated by plasma. The water-absorbing properties of biomaterials are prognostic for future cell-mediated reactions of the recipient tissue with the scaffold. Complex dielectric permittivity of DBPs was measured in the 0.4–2.0 THz frequency range, while the samples were first dehydrated and then exposed to water vapor atmosphere with 80.0 ± 5.0% relative humidity. These THz dielectric measurements of DBPs and the results of their weighting allowed to estimate the adsorption time constants, an increase of tissue mass, as well as dispersion of these parameters. During the adsorption process, changes in the DBPs’ dielectric permittivity feature an exponential character, with the typical time constant of =8–10 min, the transient process saturation at =30 min, and the tissue mass improvement by =1–3%. No statistically-relevant differences between the measured properties of the intact and treated DBPs were observed. Then, contact angles of wettability were measured for the considered DBPs using a recumbent drop method, while the observed results showed that treatments of DBP somewhat affects their surface energies, polarity, and hydrophilicity. Thus, our studies revealed that glutaraldehyde and plasma treatment overall impact the DBP–water interactions, but the resultant effects appear to be quite complex and comparable to the natural variability of the tissue properties. Such a variability was attributed to the natural heterogeneity of tissues, which was confirmed by the THz microscopy data. Our findings are important for further optimization of the scaffolds’ preparation and treatment technologies. They pave the way for THz technology use as a non-invasive diagnosis tool in tissue engineering and regenerative medicine.

Crosslinking Improve Demineralized Dentin Performance and Synergistically Promote Biomimetic Mineralization by CaP_PILP

“…The calcium and phosphorus contents of the dentin collagen remained unchanged after treatment, unlike thermal crosslinking, which leads to negative changes in the collagen structure . GA crosslinking decreased the hydrophilicity because of coalescence of biological tissue fibers during crosslinking . The hydrophilicity of PA-treated demineralized dentin was greatly enhanced.…”

Sensitivity of Neuroblastoma and Induced Neural Progenitor Cells to High-Intensity THz Radiation

“…The recent advances in THz generation and detection techniques have led to widespread applications covering medical imaging, diagnostics, and therapy (see reviews [ 1 , 2 , 3 , 4 ]). These applications include the diagnosis of malignant and benign neoplasms [ 5 ], intraoperative neurodiagnostics [ 6 ], determination of the hydration level [ 7 ] and viability of tissue, as well as regulation of the expression of genes associated with systemic inflammatory diseases/cancer [ 8 ], and the application of Escherichia coli bacteria as biosensors for THz radiation [ 9 ]. Despite the low energy and non-ionizing nature of THz photons, one should be aware of the fundamental biological effects of THz radiation when developing THz-based diagnostic and therapeutic technologies.…”

PEG-fibrin conjugates: the PEG impact on the polymerization dynamics

“…The rapid progress in THz emitters, detectors and optical components promotes the THz technology as a perspective tool in the biomedicine. The advanced sensitivity of THz waves to the content and state (free or bound) of water 18,19 has allowed application of THz spectroscopy, imaging, and reflectometry in the diagnosis of tumors, 20 studies of the kinetics of different physical and chemical processes, [21][22][23] the diagnosis of traumatic 24 and thermal injuries, 25 monitoring of glycemic disorders, 26 control of drug administration, 27 etc. All these applications rely mostly on the tissue water as an endogenous label of a pathological process.…”